Đánh giá thực trạng và đề xuất giải pháp nhằm tăng cường sự ổn định các vùng tái định cư ở mai sơn thuộc nhà máy thủy điện sơn la

DANH MUC CAC BANG TRONG BAO CAO Du bao tang dan so' va lao dong tu nhien Tang truang kinh te toan tinh giai doan 1995-2005 Hien trang sir dung dat tinh San La Dien tfch cac loai dat cua

DAI HOC QUOC GIA HA NOI TRITCJNG DAI HOC KHOA HOC TlT NHIEN

Hc^^^:!^^^^^:

DANH GIA THUC TRANG VA DE XUAT GIAI PHAP NHAM

TANG CUdNG SU ON DINH CAC VUNG TAI DINH CU d

MAI SON THUOC NHA MAY THUY DIEN SON LA

^^

MA SO: QG-05-47

CHU TRI DE TAI: PGS.TS NGUYEN XUAN CU

U A , MOC Q U O C GiA - M N O ' FRurgG TAM THONG T I N TMU V I E N

f r (^

f C

HA NOI - 2007

DAI HOC QUOC GIA HA NOI TRirClNG DAI HOC KHOA HOC TlT NHIEN

TANG CUdNG SUON DINH CAC VUNG TAI DINH CUd MAI SON THUOC NHA MAY THUY DIEN SON LA

MA SO: QG-05-47

CHU TRI D£ TAI: PCS TS Nguyen Xuan Cu

CAC CAN BO THAM GIA:

PGS.TS Le Diic ThS Tran Thi Tuyet Thu

ThS Nguyin Quoc Viet CN Vu Quang Giang

CN Nguyen Xuan Huan CN Cam Chfnh Nghia

CN Ngo Van Gidi ThS Nguyin Trong Dac

HA NOI - 2007

A BAO CAO TOM TAT

l.Tendetai:

Ddnh gid thuc trang vd de xudt gidi phdp nhdm tdng cu&ng su on dinh cdc viing tdi dinh cua Mai San thuoc nhd mdy thuy dien San La

Ma so: QG-05-47

2 Chu tri de tai: PGS.TS Nguyin Xuan Cir

3 Cac can bo tham gia:

PGS.TS Le Dii-c ThS Tran Thi Tuyet Thu

ThS Nguyen Quoc Viet CN Vu Quang Giang

CN Nguyen Xuan Huan CN Cam Chfnh NghTa

CN Ngo Van Gidi ThS Nguydn Trong DSc

4 Miic tieu va noi dung nghien ciiu:

- Muc tieu nghien ciJu:

Phan tfch thirc trang va tim cac nguyen nhan gay mat 6n dinh cac khu tai dinh

eu d Mai San, San La

Xay dung ca sd khoa hoc va de xuat giai phap gdp phan on dinh san xuat va

tang cudng sir ben vung cac viing tai dinh c\x nghien cuu

- Noi dung nghien ciiu:

Phan tfch cac dieu kien tu nhien, kinh te xa hoi va van 6t su dung ngudn tai

nguyen thien nhien tren dia ban huyen Mai Son, tap trung vao cac xa diem nghien cuu

Phan tfch cac he thdng su dung dat va hieu qua cac md hinh canh tac hien cd

Xac dinh tfnh ben virng va nhirng nguyen nhan gay mat dn dinh d cac khu tai dinh cu

De xua't cac giai phap nham tang cudng su dn dinh cac viing tai dinh cu tren ca

sd sir dung hap ly tai nguyen thien nhien d dia phuang

5 Cac ket qua dat duac :

d nude ta tai dinh cu la mot trong nhirng cdng tac ldn dugc Dang va Nha nuac rat quan tam, tuy nhien viec thue hien cong tac nay vao nhirng thai ki khac nhau van con nhieu ba't cap Trong giai doan dau, vai each quan ly cua nen kinh te trong thai kl bao cap viec giai phong mat bang eon mang tfnh menh lenh hoac chu yeu dua vao tuyen truyen, van dong Den thai ki doi mdi, mot mat do van de so hiru dat dai, mat khac de phii hgp vai yeu cau ciia nen kinh te ma, cong tac di dan tai dinh cu da co nhirng thay d6i lan, tham chi duge dua len hang cac dieu kien tien quyel cho nhirng quyet dinh cap von Tuy vay, nhung diem tai dinh cu dat yeu cau con rat ft Nguyen nhan chfnh ciia tinh trang nay la con thieu sir quan tam den cong tac quy hoach, danh gia diing thuc trang tai nguyen khu vuc TDC va chua xay dung dugc mo hinh di dan tai dinh cu thfch hgp

Mai San la mgt huyen mien mii phia Tay Bac co tai nguyen dat phong phii va

da dang vai tdng dien tich dat tu nhien la 142.821 ha, trong do dien tich dat nong nghiep 35.972,21 ha (25,19%), dien tfch dat lam nghiep 55.202,11 ha (38,65%) va dat chua sir dung co kha nang lam nghiep co dien tfch 43.076,55 ha (30,16%) Ben canh

do Mai San co nguon nhan lire doi dao, khf hau thai tiet phii hgp cho viec phat trien n6ng lam nghiep da dang, dac biet la cay an qua co gia tri cao nhu nhan, xoai man

ma va cac cay cong nghiep nhu ca phe, che, mia Tuy nhien cac loai hinh sir dung sir dung dat doc a Mai San hien nay van mang tfnh quang canh dgc canh la chfnh; tinh trang xoi mon dat van liep dien; thu hoach trong do co ky thuat bao quan du tiu che bien thieu, thi truang khong on dinh nen chua thiic day qua trinh san xuat han" hoa

Qua trinh chuyen doi cac loai hinh sir dung dat doc trong nhimg nam qua da dien ra manh me a Mai Son Da hinh thanh he thong canh tac nong - lam ket hgp gan li^n viec phat trien rirng, cay nong nghiep vai trong cay cong nghiep va chan nuoi dai gia siic Cac nuang rSy du canh truyen thong da chuyen sang du canh theo chu ky ngan va nuang rSy dinh canh Tren khu vuc canh tac nuang rSy da thuc hien tang vu dua da't nuong ray dinh canh dgc eanh 1 vu liia nuang, ngo nuong len 2 vu/nam, he so sir dung da't nuong ray da tang len tir 0,7 lan len 1,3 lan Su chuyen ddi mgt bg phan da't ddc sang phat trien vucm doi, trang trai, hinh thanh cac viing chuyen canh ca phe, mia, che va cay an qua da dem lai hieu qua kinh te, hieu qua xa hgi va moi truang ro net Gia tri san xua't tren 1 ha da't ddc da tang tir 10 trieu dong/nam len 20 - 30 trieu ddng/nam, giai quyel mgt bg phan ngudi lao dgng co viec lam, tang thu nhap, xoa dugc doi, giam dugc ngheo, dat trdng ddi mii trgc tung budc thu hep, tlnh trang xoi mon, thoai hoa dat giam di dang ke

Hien nay, Mai Son dugc chgn la viing trgng diem ciia cong tac tai dinh cu tir du

an xay dung Nha may thuy dien Son La, vdi hon mgt nghin hg dan Thuc trang cac khu tai dinh cu d Mai Son ndi rieng va Son La ndi chung la rat khac nhau nhung nhin chung cdn gap rat nhieu khd khan va chua nhieu nguy co gay anh hudng xau den ddi sdng cua ngudi dan Vdi mdi khu tai dinh cu nghien curu cd nhirng dac thii rieng ve hinh thurc va thdi gian tai dinh khac nhau Vdi cgng ddng ngudi dan di cu lam kinh te mdi (Ban Na Cang), hay tir cong trinh thuy dien Hda Binh (Ban Tien Son) mac dii chfnh sach hd trg cua Nha nudc khong nhieu nhung tai thdi diem nghien cuu ddi sdng Clia cac cgng ddng nay da kha dn dinh va dang timg budc xay dung cgng ddng theo hudng ben virng Cac dieu kien ve co sd ha tang ciia cac cgng ddng nay da tuong ddi hoan thien Nong nghiep phat trien manh dac biet la chan nuoi d Na Cang va cac ban deu trdng mia nguyen lieu cho nha may, day la ngudn thu nhap chfnh cho cac cgng ddng nay

Ngugc lai, vdi cac khu mdi tai djnh cu tir du an thuy dien Son La nhu Pu Nhudng thi ddi sdng ciia cgng ddng van chua dn dinh va da xuat hien nhieu van de birc xuc Cac nhu cau tdi thieu cho ngudi dan cdn thieu tram irgng nhu nudc sinh hoat dat

canh tac, co sd ha tSng Tien den bu tai dinh cu dugc trg cap tir du an khong dugc sir dung diing muc dfch Dia diem tai dinh cu mdi chua dap ung nhimg nhu cau co ban de dam bao mgt ddi sdng dn dinh, da cd nhieu hg da tu y bd ve ndi d cu

Miic ben vung hien thdi ciia 3 ban tai dinh cu nghien cuu dugc xep theo thii' tu giam dSn tir Na Cang den Tien Son va Na Nhung Na Cang dang d muc ben virng tiem nang, hai ban Tien Son va Na Nhung cd miic ben virng trung binh

Nhirng nguyen nhan cd nguy co gay mat dn dinh cho cac khu TDC d Son La la thieu CO sd tai nguyen nhu da't ndng nghiep, nudc sinh hoat va san xuat, dien tfch rirng

bi suy giam Mat khac do phai thay ddi tap quan sinh hoat va san xuat trong khi ngudi dan khd chuyen ddi nghe san xuat do thdi quen lau ngay Da sd cgng ddng tai dinh cu

cd trinh do van hda tha'p, sd ngudi biet tieng kinh khdng nhieu Day la mgt trd ngai ldn khi tiep thu nhirng chu chuang, chfnh sach va cac qua trinh chuyen giao cdng nghe ciia Dang va Nha nudc Dai bg phan ngudi dan cdn thieu kinh nghiem trong canh tac nuong ray cung nhu chuyen ddi san xuat theo cac dac diem ciia noi d mdi

De nang cao tmh ben virng cho cac cgng ddng nghien curu can thuc hien ddng thdi cac giai phap ve luat phap, ehfnh sach va the che; cac giai phap ve kinh te; cac giai phap giao due truyen thdng va cac giai phap khoa hgc ky thuat Cu the can dac biet quan tam tdi cdng tac chuan bi, bd trf cac noi d mdi cd kha nang dap irng dieu kien sdng va san xuat cho cgng ddng; viec xay dung cgng ddng doan ket, phai huy van hda dan tgc; cdng tac td churc dao tao lap huan hudng dan chuyen ddi san xuat: hd trg nang cao y thirc ciia cgng ddng ve bao ve mdi trudng va DDSH

6 Tinh hinh kinh phi ciia de tai:

Tdng kinh phf ciia de tai: 60.000.000 d (Sau muoi trieu ddng chan)

Kinh phi da su dung: 60.000.000 d

KHOA QUAN LY

(Ky va ghi r5 ho ten)

CHU TRI DE TAI (Ky va ghi ro ho ten

Mumi

TS Nguyen Thi Ha PGS.TS Nguyen Xuan Cir

TRUONG DAI HOC KHOA HOC TU NHIEN

OHO HIEU

TRIONG-GS.lS.^^^yi^ ^/^A*'

Assoc.Prof.Dr Le Due MSc Tran Thi Tuyet Thu

MSc Nguyen Quoc Viet BSc Vu Quang Giang

BSc Nguyen Xuan Huan BSc Cam Chinh Nghia

BSc Ngo Van Gioi MSc Nguyen Trong Dac

4 Aims and Objectives:

- The research contents:

Analyze natural and socio-economic conditions, and natural resource use in Mai Son; focus on the researched villages

Economic analysise of main land use systems in the region

Determine the sustainabihty and the reasons that cause unstable of the research villages

Propose solution to improve the sustability based on proper natural use in the local

5 The results:

In Vietnam, resettlement is considered as one of the main issues of the Nation However, it is still problem up to present In the pass, the resettlement processes are presses from government or local authorities But now, it is also considered with the willing of the peoples There are lots of problems of the resettlement, e.g policies, resources and construction of resettlement models

Son La is a province with large projects of resettlement for Hydropower plans construction In fact, the resettlement projects usually have problems because of limited resources So that il is sometime not successful The project pays attention to evaluate the present status and sustainability of some resettlement areas, and identify the main reasons of instability of resettlement areas in Mai Son, Son La Scientific basses and solutions for improving sustainability of the resettlement areas are also proposed

Mai Son is a mountain district in the North-West The natural area of Mai Son

is 142.821 ha Among these, there are 35.972,21 ha (25.19%) of agriculture land; 55,202.11 ha (38.65%) of forestry land, 43,076.55 ha (30.16%) of open land with potential for forestry Mai Son also has the suitable climate conditions for agriculture development with diversity of crops, fruit and forest trees In general, the agriculture production in Mai Son, now, is characterized by extensive and monoculture techniques and lacking food processing after harvest The main problems of land use is soil erosion and soil degradation that cause low crop yields and low standard of people lives

In the pass decades, the purpose of land use change quickly in Mai Son The development of agro-forestry systems are researched and improved Forest plantation, intensive agriculture and husbandry are applied The techniques of shifting agriculture are replaced by fixed milpas Sloping land are used for house-gardens, hill-gardens and farming systems Some crops are grown popular with large areas, i.e sugar cane, tea plant, coffee and fruit trees The economic value increased 10 mills VND/ha.year

to 20 - 30 mills VND/ha.year In additional, it creates jobs, poverty elimination and decrease open land with bare hill

At present, Mai Son district is selected as an important resettlement area for Son La Hydro power plant with more than one thousand households The situation of each resettlement in Mai Son in particular, and in Son La in general, now are quite different and generally not meet the people demand Na Cang village (resettlement caused by new economic program) and Tien Son (resettlement caused by construction

of Hoa Binh hydro power plant) are more or less considered as sustainability These villages are establishing for long time So that the infrastructure is available and contribute to economic growth The agriculture, including crop production and husbandry are improvement It might be supply enough food and stuff for local people and economic growth in the region

In the cases of resettlements of Son La hydropower plant, e.g Pu Nhuong village, the hfehood of famers are very difficant The main supply for people is not meet the demand, e.g shortage of water supply, limitation of rarable land, poor in infrastructure The financial support from government are misuse fos many requirement The resettled areas are un suitable So that there are many ouseholds has returned to their homeland

The sustaibility of three researched villages are decreased from Na Cang to Tien Son and Na Nhung Na Cang is at the potential stability, while both two rest villages, i.e Tien Son and Na Nhung are at the medium level of sustability The sustainability of Tien Son is little higher than that in Na Nhung because of more

abundant natural resources, i.e land, water and forests However, Na Nhung will be

less sustainable in near future when financial subsidy of the Government will be ended

The main reason of low sustainability of these villages may be caused by limited natual resources, i.e land, water and forests On the social side, it may belong

to backward of production methods, gender inequality and low income of farmers The local knowledge is at low level so they Vietnam language They speak local language that cause a big problems for them to learn and understand scientific works, even new techniques of production

To improve sustainability of these resettlement villages, it should have suitable policies to subsidy production systems, natural resources management to increase farmer's income In financial support, it should more concerning with production and extension systems, infrastructure for community, but less pay in cash

to farmers Scientists should organize training for farmers as well as local government people Improving people knowledge on natural resources management and agriculture production in combination with environmental protection

B PHAN CHINH BAO CAO

MUC LUC 1

l M d d a u 3

2 Ddi tugng va phuong phap nghien cihi 6

2.1 Ddi tugng nghien cun 6

2.2 Phirong phap nghien ciJu 8

2.2.1 Phuong phap dieu tra thuc dia 8

2.2.2 Phuong phap danh gia mii'c ben virng ciia cgng ddng 8

2.2.3 Phuang phap thdng ke toan hgc va danh gia kinh te sir dung dat 10

2.2.4 Phuong phap phan tich da't trong phdng thf nghiem 10

3 Dieu kien tu nhien, kinh te xa hgi cua Son La 11

3.1 Dieu kien tu nhien ciia Son La 11

3.1.1 Vitridjaly, djahinh 11

3.1.2 Khf hau 12

3.1.3 Thuy van 17

3.1.4 Thien tai va sued mdi trudng 19

3.2 Dac diem kinh te, xa hgi dSon La 21

3.2.1 Dansd 21

3.2.2 Dien bien dd thi hda 22

3.2.3 Hien trang phat trien ndng nghiep va ndng thdn 23

3.2.4 Phat trien kinh te 23

3.2.5 Ket qua thuc hien cac muc tieu phat trien van hoa - xa hgi 24

3.3 Thuc trang tai nguyen ciia Son La 25

3.3.1 Tai nguyen nudc mat 25

3.3.2 Tai nguyen dat 26

3.3.3 Tai nguyen sinh vat va rirng 28

4 Tdng quan ve cong tac tai dinh c u d n u d e ta 31

4.1 Tinh hinh chung ve cdng tacdi dan tai dinh cu d Viet Nam 31

4.1.1 Dac diem chung ve di dan tai dinh cu d Viet Nam 31

4.1.2 Cac hinh thirc di dan tai dinh cu 32

4.1.3 Cac van ban phap luat va chfnh sach lien quan den di dan tai dinh cu

ciia Viet Nam 33

4.2 Nhu'ng ldn tai chii yeu trong cdng tac di dan tai dinh c u d nudc ta 34

4.2.1 Cdng trinh thuy dien Hoa Binh 34

4.2.2 Cdng trinh thuy dien Yali 36

4.2.3 Cdng trinh thuy dien Na Hang 37

4.2.4 Cdng tac di dan TDC trong cac diriin khdng phai thuy dien 37

4.3 Cdng tac di dan tai dinh cu ciia thuy dien Son La 37

4.3.1 Quan didm chi dao cua nha nudc 37

4.3.2 Muc tieu cua cong tac di dan tai dinh cud Son La 38

5 Dieu kien tu nhien, kinh te xahgi va sir dung dat oMai Son 39

5.1 Dieu kien tu nhien vakinh te xa hgi cua Mai Son 39

5.1.1 Dieu kien tu nhien 39

5.1.2 Dac diem kinh t e - x a hgi 41

5.2 Hien trang su dung dat oMai Son 43

5.2.1 Khai quat ve sir dung tai nguyen da't d huyen Mai Son 43

5.2.2 Du canh va va'n de sir dung dat 45

5.2.3 Cac loai hinh sir dung da't ddc oMai Son 51

5.2.4 Nhirng nhan td anh hudng den qua trinh chuyen ddi sir dung dat d Mai

Son 60 5.2.5 Cac xu hudng chuydn ddi sir dung da't ddc oMai Son 65

6 Thuc trang cac khu tai dinh cunghidn cu'u 71

6.1 Dac diem mgt sd'khu tai dinh cu nghien ciin 71

6.1.1 Khu tai dinh cuPii Nhudng 71

6.1.2 Khu tai dinh cu Na Nhung 72

6.1.3 Khu tai dinh cu Tien Son 74

6.1.4 Khu tai dinh cuNa Cang v 77

6.2 Danh gia miic dn dinh cua khu tai dinh cu nghien ciiru 80

6.2.1 Danh gia mu'c dn dinh cua cgng ddng theo cac chi thi don 80

6.2.2 Danh gia tdng hgp muc ben virng cac khu tai dinh cu 85

6.3 Nguyen nhan gay mat dn dinh va nhirng giai phap nang cao tfnh ben virng

cho cac khu tai dinh cu nghien ciru 87

6.3.1 Nguyen nhan gay mat dn dinh dcac khu tai dinh cu nghien ciru 87

6.3.2 Nhirng giai phap nham nang cao tfnh ben vu'ng cho cac khu tai dinh cu

DANH MUC CAC BANG TRONG BAO CAO

Du bao tang dan so' va lao dong tu nhien Tang truang kinh te toan tinh giai doan 1995-2005 Hien trang sir dung dat tinh San La

Dien tfch cac loai dat cua tinh San La Di6n bien rimg tren dia ban tinh San La

Da dang thuc vat a tinh San La

Da dang dong vat a San La Dac diem dan so va cac dan toc a San La Tmh hinh sii dung dat a Mai San nam 2006 Mot so tfnh chat 1 hoa hoc ciia dat a Mai San Bieu di6n he thdng cay trong tren dat nuang ray Tfnh chat dat nuang ray d Mai San

Dien tfch, nang suat va san lugng mot sd cay trdng chfnh tren dat nuang ray huyen Mai Son

Dien tfch va san lugng mdt sd cay trdng chfnh Hieu qua kinh te mdt sd cay trdng chfnh tren dat vudn ddi d Mai San

Hieu qua kinh te ciia loai hinh su dung da't canh tac hd gia dinh

Cau tnic dan sd ciia ban Na Nhung 73 Can dd'i muc thu nhap binh quan nam 2005 ciia ban Na Nhung Thanh phan dan tdc ban Tie'n San

Ty le gidi va thanh phan ludi d ban Tien San

Can ddi mu'c thu nhap binh quan ciia ban Tien San nam 2005

Can ddi mirc thu nhap binh quan cua ban Na Cang nam 2005

Chi'nh sach ciia Nha nudc vdi cac ban TDC nghien cuu

Cac chl thi dan trong danh gia miic ben viing cho cdng ddng

Ty le da't dugc ca'p theo thoa thuan

Ty le thang du nudc trong nam cho cac ban TDC nghien ciiu

Ty le tre em dudi 5 tudi khdng bi viem phdi cap nam 2005

Ty le thang khdng sir dung nhien lieu tir san pham phu ndng nghiep

Ty le da't dugc su dung hgp ly

Ty le tre sa sinh khdng bi tir vong trong nam 2005

Ty le thu nhap ngoai phan chi cho luang thuc thuc phaim ciia gia dinh

Ty le cac hd gia dinh chap hanh td't chfnh sach

Ty le nir gidi so vdi nam gidi trong cac budi hgp ban Ket qua tdng hgp die'm ssos theo danh gia ciia phuang phap

Vi trf cac khu tai dinh cu nghien ciiu

Ca cau dien tfch dat d huyen Mai Son

Chu ky luan canh nuang ray d Mai San trude nam 1985

Chu ky luan canh nuang ray d Mai San sau nam 1985

Su thay doi dien tfch cay trdng tren dat nuang ray d Mai San

Su thay ddi dien tfch canh tac tren dat vudn ddi d Mai San

Miic ben vQng ciia cac cdng ddng nghien ciiu theo BS

1 MO DAU

6 nudc ta su phat trien nhanh chdng cua kinh te xa hgi, sir gia tang dan sd nhanh lam tang nhu c^u ve nang lugng, luong thuc va chd d dan den phai di dan de phuc vu cac nhu c^u ve kinh te xa hgi va chinh tri, dac biet la di dan cho cac cdng trinh ldn nhu thuy dien Son La hien nay Sd dan phai di chuyen la 12.479 ho vdi 62.394 dan, nhu vay se cd rat nhieu khu tai dinh cu (TDC) mdi dugc laHairBooj Ndng nghiep va Phat tridn Nong thon, 2002)

Thuc te cho tha'y nhieu khu TDC da khdng dap irng dugc cac nhu cau cua cdng ddng (Pham Hoang Hai, 2003) Day la mgt trong nhirng nguyen nhan lam cho tai nguyen bi khai thae, sir dung qua kha nang cua tu nhien, ddi sdng ciia cdng ddng TDC khdng dn dinh Nhung hanh dgng nay tat yeu se dan tdi ddi ngheo tai cac khu TDC d nudc ta Hon nira nd da va dang gay tac dgng rat xau tdi mdi trudng, lam cho cgng ddng khu TDC thudng khdng dn dinh va rat khd khan trong viec bao dam sir phat trien ben virng

Bao ve mdi trudng la mdt van de mang tinh chat toan cau, nd cd y nghla quyet dinh den sir sdng cdn cua nhan loai, la ITnh vuc thugc trach nhiem ciia mgi Qudc gia, dan tgc tren The gidi Ddi vdi cac viing ddi mii nudc la, day cdn la mgt nhiem vu mang tinh xa hgi sau sac, gan lien vdi cugc dau tranh xoa ddi, giam ngheo, tirng budc cai thien nang cao chat lugng cugc sdng ciia nhan dan, tien tdi mgt xa hgi giau manh hanh phiic va van minh Dac biet la viec khai thae sir dung tai nguyen thien nhien, ma trude het la tai nguyen dat ddc cac tinh trung du mien niii phia Bac, phu xanh dat trdng ddi niii trgc, phuc hdi tai nguyen thien nhien, thuc hien xoa ddi, giam ngheo d nhung viing ddng bao dan tgc mien niii dang la nhirng chuong trinh trgng diem ciia Nha nudc

Trong nhirng nam gan day, hg ndng dan dugc xac dinh la don vi kinh te tu

chil nen viec ^'tien qudn len doi mu"v3 sir dung dat ddc da dat dugc nhirng ket qua

nha't dinh trong chuyen ddi co cau cay trdng, he thdng canh tac Tren thuc te

phong trao 'ldm gidu " trong ndng thdn mien niii da bat dau chuyen dgng va phat

trien Nhieu hg gia dinh da san xuat tham canh, tang vu, dua gidng mdi va cay trdng cd gia tri kinh te vao san xuat, dau tu phat trien theo md hinh VAC, RVAC,

md hinh kinh te trang trai vudn rirng, vudn ddi mang lai hieu qua kinh te cao va thiet thuc Nen kinh te thi trudng cd sir quan ly va dieu hanh ciia Nha nudc da dugc ndng dan tiep thu va van dung kha tdt trong nhirng dieu kien cu the

Tuy nhien qua trinh chuyen ddi co cau kinh te ndi chung va chuyen ddi loai hinh sir dung dat canh tac ndi rieng d cac viing ddi mii nudc ta van cdn nhieu tdn tai, hieu qua kinh te thap San xuat ndng nghiep ve co ban van la san xuat thuan ndng, tu cung, tu cap, manh miin, phan tan thieu ddng bg Ben canh dd siic ep ve dan sd ngay cang tang, viec dam bao nhu cau luong thuc cho ngudi dan van cdn nhieu khd khan, ndng nghiep du canh, chat pha rirng lam nuong ray van dien ra phd bien Mat rirng da keo theo nhieu hau qua nghiem trgng nhu xdi mdn thoai hoa dat, can kiet ngudn nudc va suy thoai da dang sinh hgc

Ngay tir nam 1937, tdng thdng My Frank D Roosevelt da ndi rang ''Mgt

dan tgc pha huy da't dai cua minh nghia la tu huy hoai chinh minh - A nation that

destroys its soil destroys itself Sir phat trien ciia mdi qudc gia chi cd the ben

vung khi biet sir dung cd hieu qua tai nguyen dat, nudc va khf hau de duy tri mdt n^n san xua't luong thuc, thuc pham an toan ben vung Bao ve cac thanh phan co ban cua moi trudng dugc chinh la bao ve sir an toan cho sir tdn tai, phat trien ciia mdi qudc gia

Dat ddi mii d Mai Son cd mgt tiem nang da dang va phong phii, nhung khai thae va sir dung cdn nhieu han che Qua trinh canh tac lac hau dien ra nhieu nam d day da bien nhirng vimg dat mau mo thanh dat ngheo kiet ve dinh dudng, mat kha nang san xuat, nang suat cay trdng giam siit Mac khac viec khai thae lgi the ciia vung de bd tri san xuat hgp ly, sir dung cd hieu qua ngudn lire bang each lira chgn diing hudng san xuat va cdng nghe cdn la bai toan khd giai VI vay, viec tlm ra cac loai hinh sir dung dat ddc hgp ly khdng nhirng nham sir dung cd hieu qua viing dat mSu md ma cdn tai sir dung nhirng viing dat thoai hoa de san xuat ndng lam nghiep ben virng la mgt viec lam cd tfnh chien luge ddng thdi la mgt thir thach ldn

De giai quyet nhirng van de tren, khdng cd con dudng nao khac la phai xuat phat tir tinh hinh cua dia phuong, thuc hien chuyen ddi he thdng canh tac tren dat nuong ray den phat trien nghe lam vudn, chan nudi, nudi trdng thuy san, phii xanh dat trdng ddi niii trgc, kien thiet ha tang, nang cao dan trf Trong dd chuyen ddi he thdng sir diing dat dugc xem la khau trung tam, cd y nghia quyet dinh den toan bd qua trinh chuyen dich co cau kinh te ndng thdn d mien niii

Mai Son la mgt huyen mien mii thugc tinh Son La, nen san xuat chfnh la ndng nghiep, tren 85% dan sd sdng bang nghe ndng, ddi sdng nhan dan gap nhieu khd khan, vat va Tuy nhien tai nguyen dat kha phong phii va mau md nhung chua dugc sir dung hgp ly, ty le dat trdng ddi niii trgc cdn cao San xuat ndng nghiep chiem uu the va van d trong tinh trang cua mdt nen san xua't ndng nghiep lac hau, hien tugng du canh, phat nuong lam ray van xay ra Phuong thiic canh tac lac hau

la nguyen nhan lam suy giam tai nguyen rirng, xdi mdn dat d nhidu noi

Den nay d Mai Son dang tdn tai nhieu loai hinh sir dung dat dac biet la dat ddc Da khdng ft nhirng md hinh sir dung dat cd hieu qua cao, song cung cd khdng

ft md hinh sir dung dat kem hieu qua Qua trinh chuyen ddi he thdng sir dung dat ddc d Mai Son khdng chi don thuan la thiet lap dugc md hinh va giai phap diing cho viec sir dung cd hieu qua tiem nang dat dai, dac biet dat ddi niii ma cdn hudng tdi thay the cac kieu canh tac truyen thdng lac hau hien nay va chuyen tir nen kinh

te tu cung, tu cap sang nen kinh te hang hoa ma van dam bao dugc sir phat trien ben vu'ng va dugc ddng bao cac dan tdc chap nhan va phat trien

Mac dil vay, hien nay d Mai Son ndi rieng, va d tinh Son La ndi chung dang phai ddi mat vdi nhirng van de suy giam tai nguyen rirng, xdi mdn dat dien ra vdi tdc do cao Qua trinh di dan tai djnh cu tir cac du an xay dung va cdng trinh thuy dien dang gay sue ep rat ldn ve mat sir dung tai nguyen va mdi trudng Chi tfnh rieng ddi vdi cdng trinh thuy dien Son La hien dang dugc xay dung, tinh Son La se

cd khoang 400.000 ha dat bi ngap liit va khoang 100,000 ngudi phai di chuyen sang nhirng noi d mdi Vi vay ap luc sir dung dat va nhu cau ve luong thuc se la nhirng van de ldn can dugc quan tam giai quyet d trong viing Neu khdng day se la mdt nguydn nhan cd tac ddng manh den ddi sdng ngudi dan va pha huy mdi trudng, dan den lam giam tfnh dn dinh cua nhieu viing tai dinh cu d Son La

Viec dap iing luong thuc va bao dam ddi sdng cho ngirdi dan dugc xem la nguyen nhan quan trgng nhat bao dam cho tfnh dn dinh ciia cac viing tai dinh cu

do di dan tir nhirng cdng trinh xay dung thuy dien d midn niii nudc ta Do vay viec danh gia thuc trang mirc do ben virng tai mgt sd khu TDC tim ra nhirng bai hgc kinh nghiem va cac giai phap nham dn dinh cho cac khu TDC la rat can thiet, tien tdi xay dung cac khu tai djnh cu cd tfnh ben vung cao d nudc ta ndi chung va d tinh Son La ndi ridng

Xuat phat tir nhirng van de neu tren, de tai " Ddnh gid thuc trang vd de

xudt gidi phdp nhdm tdng cu&ng su on dinh cdc viing tdi dinh cu a Mai San thupc nhd mdy thuy dien San La'' se cd nghla ly luan va thuc tidn gdp

phan thuc hien thanh cdng cac du an di dan tai dinh cu d nudc ta ndi chung

Muc dfch ciia de tai la nham phan tfch thuc trang va tim cac nguyen nhan gay mat dn dinh cac khu tai dinh cu (TDC) d Mai Son, Son La Trdn co sd dd de xua't giai phap nham tang tfnh ben virng cho cac khu TDC nghien ciru Xay dung

CO sd Khoa hgc va thuc tiln gdp phan dn dinh san xuat va tang cudng su ben virng cac viing tai dinh cu nghidn cun

De tai dugc thuc vdi cac ndi dung chii yeu sau:

- Phan tfch cac dieu kien tu nhien, kinh te xa hdi, va van de sir dung ngudn tai nguyen thien nhien tren dia ban huyen Mai Son, tap trung vao cac xa diem nghien

Clin

- Phan tfch cac he thdng sir dung da't va hieu qua cac md hinh canh tac hien cd

- Xac dinh tfnh ben vu'ng va nhirng nguyen nhan gay mat dn dinh d cac khu tai dinh cu

- De xuat cac giai phap nham tang cudng sir dn dinh cac viing lai dinh cu tren co

sd sir dung hgp ly tai nguyen thien nhien d dia phuang

2 DOI TirONG VA PHlTONG PHAP NGHIEN CUU

2.1 Doi tirong nghien curu

Du an di dan tai dinh cu d Son La cd qui md ldn va pham vi thuc hien rdng, dugc tridn khai hau nhu d ta't ca cac huyen trong tinh Trong pham vi ciia de tai chi tap trung vao danh gia tinh hinh mdt sd khu tai dinh cu d Mai Son va Mudng La

Do dac diem ve dia ly va cac dieu kien tu nhien cung nhu kinh te xa hdi, huyen Mai Son da dugc qui hoach la viing trgng diem ciia cdng tac di dan va tai dinh cu

do xay dung cdng trinh thuy dien Son La Theo ke hoach, Mai Son se la noi tiep nhan hon 1 nghin hg dan de'n tai dinh cu Chfnh vi vay ma Mai Son dugc coi la mot trong nhirng vung trgng didm ciia cdng tac tai dinh cu ciia cdng trinh thuy dien Son La Do vay nghien ciin nay se cd y nghia ldn ddng thdi cd kha nang md rdng ra toan tinh Son La, tham chf cho cac tinh thugc viing mii Tay Bac ciing nhu mdt sd tinh mien niii khac cd didu kien tuong tu

Trong pham vi gidi han cua de tai, nghien ciiu chi tap trung thuc hien tai 4 khu tai dinh cu (Hinh 1), cu the la:

- Ban Tie'n Son xa Hat Ldt, huyen Mai Son tinh Son La, la cdng ddng TDC Cdng trinh thuy dien Hoa Binh, chuyen den tir nam 2001

- Ban Na Cang xa Hat Ldt, huyen Mai Son tinh Son La, la cdng ddng TDC trong Chuong trinh di dan lam kinh te mdi dinh cu tir nam 1976

- Ban Pu Nhudng xa Mudng Bii, huyen Mudng La tinh Son La, la cdng ddng TDC Cdng trinh thuy dien Son La, da chuyen den tir cudi nam 2005

- Ban Na Nhung xa Mudng Chiim huyen, Mudng La tinh Son La, la cgng ddng TDC Cdng trinh thuy dien Son La, chuyen den tir nam 2004

Trong dd 3 ban Na Nhung, Tien Son va Na Cang dugc chgn lam ddi tugng

de danh gia mirc do ben virng Day la 3 ban dien hinh cho cac diem di dan TDC dugc thuc hien theo cac hinh thiic khac nhau d tinh Son La Danh gia mirc do ben vung ciia 3 ban nay de thay dugc nhung diem manh va yeu trong viec xay dung mdt cdng ddng ben vung, tir dd rut kinh nghiem de xay dung cac cgng ddng TDC khac trong khu vuc cung nhu nhirng noi cd dieu kien tuong tu

De tai tap trung nghien ciiu ve dieu kien tu nhien kinh te xa hgi tinh hinh sir dung tai nguyen thien nhien d cac khu tai dinh cu, trong dd rat chii trong den van de su dung tai nguydn dat ddc d Mai Son

Cac mau da't dugc lay d tang canh tac (0-20 cm) trdn cac nuong ray ciia ngudi dan de danh gia chat lugng do phi nhieu ciia dat Ky hieu cac mau dat duac dugc trinh bay d Bang 1

Hmh L V i tn cac khu tai dinh cu nghi6n cihi

Bang 1 Cac miu dayt nghien ciiu

Dia diem lay miu Ban Yen Son - Hat Lot - Mai Son, dai trdng mia, ngo

Ban Tl^n Son - Hat Ldt - Mai Son, dat trong ngd

Ban Yen Son - Hat Lot - Mai Son, dai trong sdn, ngd

Ban Na Luong - Co Noi - Mai Son, dai trong mia

Ban Na Ludng - Co Noi - Mai Son, dat trdng mia

* YS Yen Scm TS Tien San, NL La Nuong

2.2 Phirofng phap nghien curu

2.2.1 Phuang phap dieu tra thuc dia

- Thu thap, phan tich tai lieu thu cap: Thu thap cac thdng tin can thiet tir cac tai

lieu va cdng trinh nghien ciiu cd Iidn quan Cac thdng tin thu thap dugc xac minh, xir ly, phan tfch de xac dinh nhirng van dd can danh gia

- Phong van ban chinh thurc (Semistructural Interview - SSI): Gdm cac hinh thu'c

nhu phdng van ca nhan, dac biet la nhirng ngudi cd trach nhiem va hieu biet ve van

de di dan taf djnh cu, phdng van nhdm

- Dieu tra thuc dia duac thuc hien cu the nhu sau:

Sir dung phuong phap danh gia nhanh mdi trudng cd sir tham gia ciia cdng ddng (Participatory Environmental Rapid Appraisal - PERA) trong viec thu thap thdng tin va nghidn ciiu thuc dia Day la he phuang phap thu thap kinh nghiem sau

cd he thdng nham khai thae thdng tin ve sir phat trien ciia cdng ddng, dua vao ngudn tri thii:c cua cdng ddng ket hgp vdi kiem tra thuc dia

+ Lira chgn cap dieu tra thu thap thdng tin: Bao gdm cac cap lanh dao tinh, huyen,

xa, thdn ban va cgng ddng dan cu Vdi cdng ddng TDC dugc chgn theo nguyen tac lira chgn ngau nhidn dai dien cho cac do tudi, gidi tfnh va dan tdc

+ Sd lugng ngudi dugc hdi: Dua tren ty le tuong ddi dan sd d cac diem dan cu nghien ciiu, vdi ban Pii Nhudng la 10 ngudi, ban Na Nhung la 25 ngudi, ban Tien Son la 20 ngudi, ban Na Cang la 35 ngudi

Cac phie'u thu thap thdng tin sau khi khao sat dugc phan tfch, danh gia va chgn Igc mgt each ky ludng Nhirng thdng tin cd chat lugng dugc tdng ket lai, nhirng thdng tin khdng dat ydu cau dugc loai bd

2.2.2 Phuang phap danh gia mure ben vurng cua cgng ddng

Khi ap dung cac each tiep can ve PTBV trong danh gia tfnh ben vu'ng ciia cdng ddng ddi hdi cac chi tieu lira chgn danh gia phai dugc cu the, rd rang va cd the thuc hien dugc trong thuc te Trong thdi gian qua tren the gidi cung nhu d nudc

ta da cd nhieu phuong phap dugc dua ra de danh gia miic ben virng ciia cac cgng ddng dan cu khac nhau Trong dd 3 phuong phap dugc xem la cd nhieu uu diem va

de ap dung la phuong phap thude do tfnh ben virng BS (Barometer Sustainability), phuang phap danh gia sir phat trien ben virng cdng ddng bang chi sd ben virng dia phuong LSI (Local Sustainability Index), phuong phap danh gia miic do ben virng cdng ddng CSA (Community Sustainability Assessment)

Trong nghien cuu nay, phuong phap BS da dugc sir dung de danh gia rnirc

do ben virng cua cac khu tai dinh cu Day la phuang phap do ludng va truyen thdng phiic lgi tdng the ciia xa hdi va sir tien bd theo hudng ben virng do lUCN de xuat nam 1994 BS bao gdm cac chi thi ve phiic lgi sinh thai va phiic lgi nhan van cac chi thi nay dugc gan ket thanh cac chi thi tdng hgp ve tfnh ben virng ma khdng

gay siic ep len nhau Sir dung BS se giiip cho cdng ddng dd dang dua ra cac ket luan ve dieu kien sinh thai, nhan van va biet dugc cdng ddng cua hg dang d dau va

se di ve dau trong tuong lai BS cd the sir dung d cap do dia phuong (mdt cdng ddng) hay d cap dd mgt qudc gia BS sir dung 10 mang van de trong dd cd 5 mang thude phiic lgi sinh thai, 5 mang thugc phiic lgi xa hdi nhan van (Bang 2)

Bang 2 Cac mang van de sir dung theo danh gia cua phuong phap BS

Phuc loi sinh thai

Trat tu an toan xa hgi Binh dang xa hdi

Dua tren hai phan he va 10 mang va'n de ma BS dua ra, cac van de cdt ldi va chi thi don dugc de tai lira chgn dugc trinh bay d Bang 3 Mirc ben virng BS ciia cdng ddng dugc danh gia dua vao tdng diem ciia cac chi thi don theo 5 mirc nhu sau: 81- 100 Ben virng, 61 - 80 Ben virng tiem nang, 41 - 60 Ben virng trung binh, 21-40 Kem ben virng, 0 - 2 0 Khdng ben virng

Bang 3 Cac budc kien tao chi thi don ciia BS cho cac cdng ddng TDC nghien ciiu

Kha nang dap irng dugc nhu cau ve nudc sinh hoat

Chi thi dan

Ty le dien tfch dat san xuat dugc cap so vdi dien tfch thoa thuan

Ty le sd thanh cd dii nudc sinh hoat trong nam (thang cd dii nudc la thang cd trdn 15 ngay

Sir dung hgp

ly tai nguydn

Dan sd - Siifc khoe

Dieu kien sdng Tri thiic

Hanh vi va td chirc

Binh dang

Chat lugng khdng khf Mirc do xam hai tai nguydn rirng

Sir dung hgp ly tai nguyen dat Dieu kien cham sde y te Kinh te Giao due

Miic do chap hanh phap luat

Binh dang gidi

Ty le tre em dudi 5 tudi khdng

Ty le tre so sinh khdng bi tir vong

Ty le thu nhap ngoai phan chi cho an udng

Ty le ngudi trdn 15 tudi bie't chir

Ty le hg gia dinh chap hanh chfnh sach ciia Nha nudc va huong ude dia phuong tir trung binh trd ldn

Ty le nir so vdi nam tham gia trong cac budi hgp thdn ban

2.2.3 Phuang phap thdng ke toan hgc va danh gia kinh te sir dung dat

Tdng hgp sd lieu, dir lieu, xay dung cac tieu chf de danh gia hieu qua kinh

te dua tren co sd hg gia dinh trong danh gia loai hinh sir dung dat ddc, tir dd cd anh hudng den qua trinh chuyen ddi he thdng sir dung dat ddc Cac sd lieu dugc tfnh toan va xir ly tren phan mem Excel

2.2.4 Phuang phap phan tich dat trong phong thi nghiem

Mau da't sau khi lay ve phoi khd, nhat sach rd cay, gia nhd va qua ray 1 mm

de phan tfch cac chi tieu tai phdng thf nghiem bg mdn Thd Nhudng - Mdi trudng Dat, Trudng Dai hgc Khoa hgc Tu nhien - Dai hgc Qudc gia Ha Ngi

Cac phuong phap sau dugc sir dung de phan tfch cac tfnh chat ly, hoa hgc cua dat bao gdm:

- Chat hihi co tdng sd: Phuong phap Walkley - Black

- pHKCh Lac dat vdi dung dich KCI IN vdi ty le 1: 2,5 trong thdi gian 30 phut, dd

30 phiit rdi do bang may pH - meter

- CEC: Phuong phap Schachtschabel

- Nxs: Pha mau bang H2SO4 va HCIO4, dinh lugng bang phuong phap Kjeldahl

- Nyp: Phuong phap Chiurin - Cononova

- PTS: Pha mdu bang H2SO4 va HCIO4, xac dinh bang phuong phap so mau xanh molipden

- PDT^ Phuong phap Onianị

- Kjs: Pha mau bang hdn hgp dung dich H2SO4 va HCIO4, sau đ xac dinh bang phuong phap quang ké nggn lirạ

- AP"*^: Phuong phap Xocolop

- Fế': Phuong phap so mau vdi thude thir axit sunfosalicilic

- Thanh phSn co gidi (cat, set vat ly) theo phuong phap pipet ciia Katrinskị

- Câ^, Mg^"": Phuong phap chuan do bang trilon B, chiet nit bang KCI IN

/ y ^

3 DIEU KIEN TV NHIEN, KINH TE XA HOI CUA SON LA

3.1 Dieu kien tir nhien cua San La

3.LL Vi tri dja ly, dia hinh

Son La la tinh mien mii Tay Bac Viet Nam, nam trong toa do 20"39 22**00' vT do Bac va 103"ir-105''02' kinh do Ddng Phfa Bac giap tinh Yen Bai va Lao Cai, phfa Ddng giap tinh Phii Thg va Hoa Binh, phfa Tay giap tinh Lai Chau, phfa Nam giap tinh Thanh Hoa va nudc Lao vdi chidu dai bien gidi 250 km Tinh Son La each Ha Ndi 320 km theo true qudc Id 6

-Dien tich tu nhien cua Son La la 14.055 km", diing thir 5 trong 53 tinh, thanh phd d nudc ta, bao gdm 11 don vi hanh chfnh (1 thi xa, 10 huyen) vdi 975.460 ngudi vdi mat do 69 ngudi/kml

Dia hinh toan tinh bi chia cat manh liet bdi cac day mii cao trung binh trdn 2000m, xen ke vdi cac thung lung sau va cac manh sdt ciia cao nguydn, hau het chay theo hudng Tay Bac - Ddng Nam Dinh cao nhat ciia Son La thugc cac day niii giap Lao Cai, Ydn Bai (tren 2000m) Dia hinh cd do đc ldn, chi cd 11,3% dien tfch cd do đc dudi 25'\

Tinh Son La nam tren mien udn nep phfa tay nudc ta, cau triic dia hinh tao thanh cac đi hep ngang, keo dai theo hudng Tay Bac - Ddng Nam, tao nen nhirng day mii, cao nguydn:

- Phan phfa Ddng la phan keo dai cua day Hoang Lien Son vdi nhirng dinh niii cao tren 2000 m

- Hudng Tay Bac - Ddng Nam la day Su Sung Chao Chai cd do cao dudi 2000 m Day Su Sung Chao Chai la phan luu giiia luu vuc sdng Da d phfa Ddng va luu vuc sdng Ma d phfa Taỵ

- Tan cung phfa Tay Nam la day mii Pu Sam Sao (1897 m) trung binh thap d bien gidi Viet - Lao

Son La cd 2 cao nguyen kha rdng: Cao nguyen Son La keo dai tir Yen Chau den tan Thuan Chau, dai khoang 100 km, rdng khoang 25 km, cao khoang

600 m Cao nguyen Mdc Chau nam d phfa nam cao nguyen Son La, keo dai tir Yen Chau den Ban Bung tiep giap tinh Hoa Binh, cao khoang 600-800 m va cd mot sd dinh niii da vdi cao tren 1000 m Hai cao nguyen nay nam tren dudng phan thuy cua he thdng sdng Da va sdng Ma, dia hinh bang phang, cd nhieu tiem nang phat trien kinh te va san xuat ndng nghiep

Ngoai ra, trong tinh Son La cdn cd kieu dia hinh bdn dia dang ldng chao nhu bdn dia Sdp Cdp d thugng ngudn sdng Ma, bdn dia long chao d viing Ydn Chau tren cao nguyen Son La Ty le dien tfch dat cac kieu dia hinh trong tinh Son

- Son nguyen va cao nguyen chiem khoang 22%;

- Nui thap vdi do cao 600-800 m, ft ddc hon, chia cat ndng, chiem khoang 28%;

- Bdn dia, mang trung hep, long chao hep chiem dudi 16%

Trdn cac cao nguyen la nhirng ddi da phien lugn sdng va mii da vdi Trdn cao nguyen Mdc Chau cd nhung liing da vdi, tao thanh nhirng canh ddng cacxto rdng rai Dat trdn cac lung va canh ddng la dat dd da vdi, tuy phi nhidu nhung do set chiem phan chii yeu nen bf nudc va thudng bi han Da vdi trdn cao nguyen Son

La chie'm dien tfch ft hon, phan bd thanh tirng dai hep, ngoai ra cdn cd nhirng canh ddng tuong ddi tru phii nhu Chieng Ddng, Na San, Mai Son Day chfnh la nhirng viing thung lung thap d tinh Son La

Do hien tugng cacxto nen sdng sudi tren cao nguyen da vdi cd khi chay ngam trong nhirng hang ddng da vdi Sdng sudi dang chay tren be mat dot nggt bien mat va rdi xuat hien d chd khac, thudng d dudi chan cao nguyen

va sudt miia duy tri mot tinh trang khd hanh dien hinh cho khf hau gid miia [6]

Dd la do viing Tay Bac ndi chung va tinh Son La ndi rieng nam d phfa lay day Hoang Lien Son nhu binh phong ngan chan khdng khf cue ddi true liep tran vao

vung mii khuat nay Khdng khf lanh chi cd the xam nhap vao vimg Tay Bac tir phfa ddng nam theo thung lung sdng Da, sau khi da trai qua mdt qua trinh bien tfnh kha sau sac do nhiet do tang ldn va do am giam Vi the, anh hudng ciia gid miia cue ddi den viing Tay Bac da giam di nhidu, nen miia ddng d vting nay am hon viing nui Ddng Bdc va vung ddng bang Bdc Bd, bidn do nhiet do nam ciing giam so vdi cac viing khac d Bdc Bd va Bdc Trung Bd Tuy nhien, viing mii nay cd do cao dia hinh kha ldn, ke ca cac vung thung lung, ndn thuc te, miia ddng d day van lanh do sir giam cua nhiet do theo sir tang ciia do cao dia hinh va van cd kha nang suong mudi va bang gia d nhirng vanh dai cao

Sir giam siit lugng dm khdng khf cue ddi va khdng cd nhirng front cue ddi that sir, da hinh thanh d viing niii nay mdt che do khd hanh, nhat la vao cudi miia ddng (thang II, III, IV), trong khi dd d vimg Ddng Bdc va ddng bdng Bdc Bd lai xay ra mua phiin, am uot nhat trong nam Thdi tiet quang may va lang gid thinh hanh trong sudt miia ddng ket hgp vdi dia hinh khu vuc da gay nen sir dao dgng ngay dem cua nhiet do trong cac thung lung, nen d day cung cd nhieu kha nang xdy ra suong mudi, mac dii nhiet do trung binh cao han cac viing niii Ddng Bdc

Mdt dac diem quan trgng khac ciia khf hau Tay Bdc la miia he den sdm hon

so vdi viing Ddng Bdc va ddng bdng Bdc Bg Dd la do tac dung hut gid d ria phfa nam ciia ap thap khu vuc (ap thap Mianma) da tao dieu kien dua khdng khf ndng

am tir phfa vinh Ben Gan tdi viing nay sdm hon Ngay tir thang III da cd nhirng ngay nhiet do tdi cao trdn 30'C, va thang cd nhiet do trung binh cao nhat la thang

VI, trong khi dd d ddng bdng Bdc Bd la thang VII Mat khac, mua mua bat dau va ket thiic sdm hon khoang 1 thang so vdi phan ldn cac noi d Bdc Bg

Thdi tiet khd ndng vao dau miia ha trong cac thung lung la do ludng gid miia tir phfa tay vugt qua cac day niii d bien gidi Thugng Lao sang phfa ddng da gay ndn hieu iing "phon" Tinh trang khd ndng nay khdng kem, cd khi cdn tram trgng hon so vdi viing Bdc Trung Bd Thf du, trung binh hang nam d Yen Chau cd tren 40 ngay khd ndng, trong dd cd 10 ngay khd ndng dac biet Tuy nhien thdi ky

cd gid tay khd ndng (thudng dugc ggi la gid Lao) d viing niii Tay Bdc thudng ngdn hon, vao khoang 2 thang, tir giira thang IV den giira thang VI Mdt trong nhirng hien tugng khf tugng nguy hiem la mua da Viing nui Tay Bdc la noi cd mua da nhieu nhat so vdi cac noi khac d nudc ta, thudng xay ra vao cudi miia ddng sang dau mua ha

So vdi cac noi khac d Bdc Bd thi bao va ap thap nhiet ddi khdng anh hudng true tiep nhung vdn cd the anh hudng gian tiep den viing nay Nhirng ap thap tan

du ciia bao di chuyen tdi viing nay cd the gay ra mua ldn keo dai va do dd gay ra

lu ldn tren cac trien sdng

Ngoai ra, do dia hinh chia cdt manh va da dang nen khf hau phan hoa rat manh trong viing Tay Bdc ndi chung va tinh Son La ndi ridng Nhirng khac biet quan trgng ve khf hau giira cac khu vuc dugc quyet dinh bdi tuong quan da dang giira cac he thdng hoan luu vdi cac day mii, sir khac biet ve vi trf dia ly va dd cao dia hinh,

6 trong tirng khu vuc, khf hau cung cd sir khac nhau giira cac viing cd do cao dia hinh khac nhau, giira viing thap, vung cao trung binh va viing cao Viing tha'p cd do cao dudi 300 m, bao gdm thung lung sdng Da, sdng Ma Viing nay cd nen nhiet do khdng khac nhieu so vdi ddng bdng, nhung miia ddng am hon, va bien do dao ddng ngay ciia nhiet do (tiic la chenh lech nhiet do cao nhat va thap nha't trong ngay) kha ldn; lugng mua nam d vimg nay thugc loai nhd nhat (1200-

1400 mm) Viing cd do cao trung binh (300-800 m), bao gdm mot sd thung lung d thugng ngudn, nhirng mii tha'p va cao nguydn Vimg nay chiem phdn ldn dien tfch trong tinh Nhiet do giam 2-4**C so vdi cac viing khac, nhiet do miia ddng cd kha nang dudi 0"C, lugng mua tuy cd ldn hon viing thap nhung khdng nhieu Viing mii cao bao gdm nhiing day niii cao tir 700-800 m trd ldn So vdi viing thap, nhiet do trung binh nam cd the giam 4-5"C d do cao 700-800 m va tren 10"C d do cao trdn

800 m, miia ddng lanh va cd nhieu kha nang nhiet do thap nhat dudi 0"C, lugng mua nam tuong ddi ldn, cd the tdi 2000-3000 mm

Nhiet dp khong khi:

Nhiet do khdng khf trung binh nam bien ddi trong pham vi tir khoang tren dudi 15"C d viing niii cao trdn 1500 m den khoang 23*C d cac thung lung, cd xu the giam dan theo sir tang cua do cao dja hinh: tren 23'C trong cac thung lung cd

do cao dudi 200 m, 20-23'C d do cao 300-700 m va dudi 20"C d do cao tu 700 m trd ldn (bang 2.1) Tdng nhiet do trung binh nam tir dudi 6000*C d vimg nui cao tir

1000 m trd ldn den 8000-8500"C d viing thap

Nhiet do bien ddi theo miia Nhiet do trung binh thang ciia cac thang miia ddng (XI-XII, i-III) thudng dudi 20"C (12-20"C) va tuong ddi cao trong cac thang mua he (20-27"C) Nhiet do trung binh thang thap nhat xay ra vao thang I (12-15'C), va cao nhat vao thang VI, cd noi vao thang VII Tir thang III, nhiet do da tang ldn dang ke (17-22'*C), va sang thang IV thi nhiet do d cac noi deu tren 22"C rieng cao nguyen Mdc Chau chi dat 20,4'*C Den thang XI, nhiet do trung binh thang d phan ldn cac noi dudi 20"C

Nhiet do thap tuyet ddi d phan ldn cac noi deu dudi 0*'C: Cd Ndi -4,7"C (1/1974), Yen Chau -1,5"C (1/1974), Mdc Chau -1,5T (1-1975), Phii Yen -0,9'C (XII/1975), Son La - 0,8"C (1/1940), rieng mgt sd noi tren 0"C: Quynh Nhai 2 , r C (1/1974) va Bdc Yen 2,5"C (1/1983) Nhiet do thap nhat tuyet ddi thudng xuat hien vao thang I, cung cd noi vao thang XII

Bien do ngay trung binh nam ciia nhiet do khdng khf bdng khoang 11,5"C, nhd nhat d Mdc Chau va Bdc Ydn (khoang 8'C) va ldn nhat d Sdng Ma ( l l , 3 X ) v a C d N d i ( 1 0 , r C )

8-Bidn do ngay trung binh cua cac thang miia ddng kha ldn (9-14,5*C) ldn nhat vao cac thang II-IV; nhung tuong ddi nhd hon vao cac thang miia he 7-12"C, nhd nhat la vao thang VII, VIII, cd noi vao thang X

So gi& ndng:

Sd gid ndng trung binh nam bien ddi trong pham vi tir 1728 gid den 2105 gid (bang 2.2) Khu vuc mii cao phfa bdc, tay bdc va ddng nam cd sd gid ndng tuong ddi it (1738 gid d Quynh Nhai, 1728 gid d Phii Yen), viing trung thap tren cao nguyen Son La cd sd gid ndng tuong ddi ldn: 1938 gid tai Ydn Chau, 2000 gid tai Son La va 2105 gid tai Cd Ndi; viing cao nguydn Mdc Chau va viing Sdng Ma

cd sd gid ndng bdng khoang 1900 gid

Sd gid ndng ciing bien ddi theo mua, trong cac thang miia ddng, tir thang XI den thang II nam sau, sd gid ndng trung binh thang bdng khoang 90-180 gid Sd gid ndng tang manh vao cac thang III-V (150-210 gid) Sau dd, sd gid ndng giam trong cac thang miia mua (thang VI-VIII) va lai tang len trong thang IX, X do trdi quang may, mua it Nhu vay, bien trinh sd gid ndng trong nam cd dang 2 dinh Dinh cao nhat vao thang V (195-210 gid) va dinh phu vao thang IX, cd noi nhu d Son La vao thang X (150-190 gid) Tuong iing vdi 2 dinh ndu tren la 2 chan thap xuat hien vao thang I hay thang II (90-150 gid) va thang XI (127-165 gid)

O cao nguydn Mdc Chau, trir viing mii phfa tay nam tiep giap tinh Hda Binh

va Thanh Hoa cd lugng mua nam trdn 1800 mm, phan ldn cac noi khac cd lugng mua nam dudi 1400 mm, ridng khu vuc phfa ddng bdc (cac xa Tan Hgp, Tan Lap, Chieng Hac, Na Mudng va ndng trudng Mdc Chau) cd luong mua nam khoang 1200-1400 mm

Cung nhu cac yeu td khf hau khac, mua cung bien ddi theo miia Lugng mua thang IV d phan ldn cac noi da tren 100 mm (trir 2 tram Yen Chau va Sdng

Ma dudi 100 mm (90-99 mm) Do dd, cd the nhan thay: miia mua d Tay Bdc ndi chung va d Son La ndi ridng bdt dau tuong ddi sdm tir thang IV va cung ket thiic sdm vao thang IX, tiic la lugng mua trung binh thang cua cac thang IV-IX ddu ldn hon 100 mm (ldn hon 200 mm vao cac thang VI-VIII), mot sd noi cdn keo dai sang thang X Ridng d sdng Ma, lugng mua trung binh ciia thang IX giam dang ke

so vdi thang VIII, chi cdn tren 100 mm Lugng mua trung binh thang ldn nhat (280-350 mm) xuat hien vao thang VIII (rieng d Quynh Nhai vao thang VII) va nhd nha't (9-25 mm) xuat hien vao thang XII Tdng lugng mua ciia cac thang IV-

IX chiem tdi 80-90% tdng lugng mua nam

So vdi nhieu noi d nudc ta thi sd ngay mua trung binh trong nam d Son La tuong ddi ft hon, bdng khoang 110-180 ngay, nhieu nhat d Mdc Chau (180 ngay)

It nhSit d Sdng Ma va Yen Chau (110-115 ngay), phan ldn cac noi cd khoang

120-130 ngay mua trong nam

Dp dm khong khi:

Do dm khdng khf tuong ddi trung binh nam d Son La bien ddi trong pham

vi 79-86%, tuong dd'i tha'p hon so vdi phan ldn cac noi d Bdc Bd Nhin chung, nhii'ng khu vuc mua ft la nhirng noi cd do am thap, nhu d cao nguydn Son La va viing Sdng Ma (79-82%), nhung lai tuong dd'i cao (85-86%) d cao nguyen Mdc Chau va khu vuc Quynh Nhai (bang 2.4) Ba thang giira miia mua (thang VI-VIII)

cd do am trung binh thang ldn nha't, ldn nhat la vao thang VIII (84-89%), 2 thang III-IV cd do am tha'p nhat d khu vuc Son La - Ydn Chau, do am trung binh ciia cac thang I-V deu vugt qua 70% (72-80%), nhung d Mdc Chau va Quynh Nhai thi

do dm trung binh cua cac thang trong nam deu trdn 80% (80-89%), tuong ddi thap vao 3 thang III-V (80-84%) va tuong ddi cao vao thang VIII-IX (87-89%) va MI (88%)

Boc hai

Lugng bdc hoi trung binh nam, d Son La bien ddi trong pham vi tir dudi

800 mm den hon 1100 mm (bang 2.6), cd xu the giam theo sir tang ciia do cao dia hinh Lugng bdc hoi trung binh nam nhd hon 900 mm d viing mii Quynh Nhai va cao nguydn Mdc Chau (Quynh Nhai 808 mm, Mdc Chau 878 mm), d viing thap trdn cao nguyen Son La, lugng bdc hoi trung binh nam tren 900 mm, ldn nhat d Yen Chau (1120 mm), Cd Ndi (1083 mm)

Trong cac thang dau miia he (thang III-V), do nhiet do khdng khf cung nhu

sd gid ndng cao, lugng may nhd, ndn lugng bdc hoi trung binh thang kha ldn, thudng ldn hon 100 mm, ldn nha't vao thang III d cao nguydn Son La, thang V d cao nguyen Mdc Chau va Quynh Nhai Cac thang XI-XII va thang I la 3 thang cd lugng bdc hoi thap nhat (50-90 mm)

Cdc hien tuang thoi tiet dac biet:

- Ddng: Trung binh hang nam cd khoang 50-70 ngay ddng, nhieu nhat d Sdng Ma, Bdc Yen va Mdc Chau, ft nhat d Quynh Nhai (51 ngay), Ydn Chau (48 ngay) cac thang IV-VIII la cac thang cd nhieu ngay ddng (tren dudi 10 ngay mdi thang) cdn cac thang miia ddng rat ft ngay cd ddng [3]

- Mua da: Mua da thudng xuat hien vao cac thang IV, song thang II va thang III cung cd the cd mua da

- Suong mil: Trung binh hang nam cd 20-100 ngay cd suong mil Cao nguyen Mdc Chau va cac vimg phfa nam va ddng nam la nhirng nai cd nhicu ngay cd suong mu (Mdc Chau, Yen Chau: 95-100 ngay), nhung khdng ft noi chi cd 20-40 ngay cd suong mil trong nam: Phii Yen 22 ngay, Cd Ndi 39 ngay Son La 40 ngay

Do phu thugc vao dieu kien dia hinh, vi trf dia ly nen thang cd nhieu ngay suong mil cung xay ra khdng ddng thdi d cac noi d cao nguydn Mdc Chau, cac thang miia ddng (thang XII, I-IV) deu cd trdn 10 ngay suong mil, cdn thang VI-VIII chi cd 1,5-3 ngay d cao nguyen Son La cac thang IX-X la 2 thang cd nhidu ngay suong mil, cdn thang II-IV la cac thang cd ft ngay suong mil O Bac ydn, thang VII-VIII la 2 thang cd nhidu ngay suong mil (11-12 ngay), thang XI, XII la

2 thang cd ft ngay suong mu (3-4 ngay)

- Suong mudi: Tuy mua ddng d Son La ndi ridng va d Tay Bdc ndi chung am hon

so vdi cac viing mii va cao nguydn vimg Ddng Bdc, nhung miia ddng d day khd va

ft gid nen d noi cd do cao tir 200 m trd ldn deu cd kha nang cd suong mudi, nhat la tir do cao 500-600 m trd len Suong mudi thudng xuat hien vao thang XII va thang

I Mdc Chau la noi cd nhieu ngay cd suong mudi, trung binh hang nam cd 5 ngay, nhung d mgt sd noi nhu: Quynh Nhai, Phu Ydn, Sdng Ma, Ydn Chau, chi cd khoang 1 ngay

- Thdi tiet khd ndng: Vao nhirng thang miia he, thudng xuat hien nhirng ngay thdi tiet khd ndng d cac thung lung va bdn dia, trung binh hang nam cd khoang 30 ngay, nhieu nhat la 2 thang IV, V d cao nguyen, miic khd ndng giam hdn so vdi cac thung liing

3.L3 Thuy van

Chay qua dia phan tinh la hai he thdng sdng chfnh: sdng Da dai 280km vdi

32 phu luu; sdng Ma cd 90km vdi 17 phu luu Trdn dia ban Son La, dien tfch luu vuc sdng Da la 13110 km^, Sdng Ma la 7210 km*^ Miia lu thudng didn ra trong cac thang tir thang 6 den thang 10, nhung didn ra sdm hon d cac nhanh thugng luu va mudn hon d ha luu Cd den 65 - 80% tdng lugng ddng chay nam tap trung trong cac 4 - 5 thang mua lu Mat do sdng sudi trong tinh kha day (l,7km/km^) do ddc ldn

Mang ludi sdng sudi trong tinh San La thugc hai sdng chfnh la sdng Da

va sdng Ma

Sdng Da la mdt trong nhirng nhanh ldn ciia sdng Hdng Bdt ngudn tir viing mii cao d tinh Van Nam Trung Qudc, sdng Da (phdn d lanh thd Trung Qudc dugc ggi la sdng Ly Tien Do) chay theo hudng tay bdc - ddng nam qua tinh Van Nam Trung Qudc rdi dd vao nudc ta tai xa Ka Long huyen Mudng Te tinh Lai Chau Sau dd, sdng Da chay qua thi xa Lai Chau rdi chay vao dia phan tinh Son La lai xa Nam Ca Nang huyen Quynh Nhai, chay den xa Tan Hgp huyen Mdc Chau, sdng

Da chuyen hudng gan tay - ddng, chay ra khdi dia phan tinh Son La tai Song Khiia huyen Mdc Chau va xa Nam Phong huyen Phii Yen, chay vao dia phan tinh Hoa Binh, cudi ciing dd vao sdng Thao tai Trung Ha Trong dia phan tinh Son La, sdng

Da dai khoang 250 km, dien tfch luu vuc sdng Da tfnh den Quynh Nhai (vi trf dugc xem xet xay dung thiiy dien Quynh Nhai) la 38.340 km", den vi trf cdng trinh thiiy dien Son La tai Pa Vinh la 43.760 km" va den vi trf chay ra khdi tinh Son La

la 48.950 km" ' '

b A l H O C Uv_L C G i ^ HA N

17 I i P U N G T A M T H C \ , i i N l M U i E r s j

Song Ma bdt ngudn tir sudn phfa nam cua day P-Hudi Long (cao 2179 m) d huydn Dien Bien tinh Lai Chau, theo hudng tay bdc - ddng nam chay vao tinh Son

La tai xa E-Tdng huyen Sdng Ma rdi chay ra khdi tinh Son La vao tinh Sam Nua (Lao), Thanh Hoa, cudi ciing dd ra bien tai 3 cira: Sung, Lach Tudng, Hdi Trong dia phan tinh Son La, ddng chfnh sdng Ma dai khoang 100 km Dien tfch luu vuc sdng Ma tinh den chd sdng Ma chay ra khdi tinh Son La tai cira sudi Nam Le (xa Mudng Lam huyen Sdng Ma) bdng 6730 km^, trong dd khoang 1525 km" ndm trong tinh Lai Chau, tiic dien tfch luu vuc sdng Ma ndm trong tinh San La bdng khoang 5205 km^ Tren phan dien tfch luu vuc nay cd 6 sdng nhanh tuong ddi ldn chay true tiep vao sdng Ma Dd la cac sdng: Nam Khoai (F = 1640 km") Nam Khdn (F = 148 km^), Nam Thi (F = 705 km^) Nam Cdng (F = 893 km^), Nam Le (F = 298 km^) va 1 phu iuu tuong ddi ldn (F = 455 km^)

Cung nhu nhieu noi khac d Bdc Bd, nudc sdng sudi d tinh Son La cung bien ddi theo miia: miia lu va miia can Hai miia ddng chay (nudc sdng) nay tuong irng vdi hai miia cua mua: miia mua va mua khd (miia ft mua) Tuy nhien, miia lu/miia can thudng bdt dau va ket thiic mudn hon miia mua/miia khd khoang 1 thang

Miia lu hang nam trdn cac sdng thudng bdt dau tir thang VI va ket thiic vao thang X Miia can keo dai tir thang XI den thang V nam sau Tuy nhien, cung cd nam mua lu va miia can cd the bdt dau va ket thiic sdm hay mudn hon binh ihudng khoang 1, 2 thang

Lugng ddng chay trong 5 thang miia lu (thang VI - X) trung binh chiem khoang 70 - 80% tdng lugng ddng chay nam, tuong ddi ldn d Nam Bii (80% tai tram Thae Vai) va Nam Sap (79,6% tai tram Thae Mdc), tuong ddi nhd d sdng Ma (70 - 75%) Lugng ddng chay miia lu lai tap trung vao ba thang VII - IX vdi 40 -60% tdng lugng ddng chay nam tap trung vao ba thang nay Lugng ddng chay trung binh thang ldn nhat xuat hien vao thang VIII d phan ldn cac sdng, rieng d Nam Sap va Nam Ty xuat hien vao thang IX Lugng ddng chay cua thang nay chie'm tdi 18 - 27% lugng ddng chay nam

Miia can keo dai 7 thang, tir thang XI den thang V nam sau Lugng ddng chay miia can chi chiem khoang 20 - 30% lugng ddng chay nam Nudc sdng trong miia can chii yeu do nudc dudi dat cung cap, nen ddng chay sdng sudi giam dan tir dau miia can den giira miia can, sau dd cd the tang ldn do nhflng tran mua ddu miia vao cudi thang IV dau thang V Cho ndn, cac thang II - IV la ba thang hen tuc cd ddng chay nhd nhat Lugng ddng chay ciia ba thang nay chi chiem tu 5 - 10% lugng ddng chay nam Thang III la thang cd lugng ddng chay trung binh thang nhd nhat, lugng ddng chay cua thang nay chi chiem 1,4 - 2,9% lugng ddng chay nam

Sir phan bd rat khdng deu trong nam ciia ddng chay sdng sudi gay khd khan cho viec khai thae ngudn nudc va thudng gay ra nhirng thien tai ve nudc nhu lii lut

va han han Trong miia mua lu, thudng xay ra lu ldn, iQ quet, cdn trong miia can thi thieu nudc cho san xuat va sinh hoat

3.1.4 Thien tai va su cd moi trudng

Dac diem ca ban cua lu va lu quet

Dac diem cua lii tren ddng chinh song Dd

Hang nam, mua lii tren ddng chfnh sdng Da thudng bdt dau tu thang VI va ket thiic vao thang X Trong miia lu, cac tran mua trdn luu vuc gay nen nhirng tran

lu ke' tie'p nhau xay ra, nhat la vao cac thang VI - VIII Trung binh hang nam cd 5 tran lu, nam nhieu nhat cd tdi 7 - 8 tran va nam ft nhat cung cd vai tran Theo sd lieu quan trdc lu tai tram thuy van Ta Bii, trong 41 nam (1961 - 2001), sd tran lu ldn nha't trong nam xay ra va cac thang nhu sau: thang VI: 3 tran, thang VII: 21 tran, thang VIII: 14 tran, cac thang IX, X va XI mdi thang 1 tran Nhu vay, cd tdi 85,4% sd tran lu ldn nhat trong nam xay ra vao 2 thang VII va VIII

Trong vdng 100 nam qua, mdt sd tran lii lich sir tren sdng Da deu xay ra vao thang VIII, nhu cac tran lu VIII/1996, VIII/1945 luu lugng dinh lu ciia tran

lu VIII/1996 tai tram thuy van Ta Bii bdng 22700 mVs

Ddc diem lu tren ddng chinh song Md

Miia lu d sdng Ma cQng thudng xuat hien tu thang VI den thang X Lu ldn nha't hang nam thudng xuat hien vao cac thang VII - IX Trung binh hang nam cd khoang 3 - 5 tran lu Tai tram thiiy van Xa La, bien do lu ldn ciia mgt tran lu trung binh bdng 1,50 m, ldn nhat cung chua vugt qua 3 m (2,74 m trong tran lu 24/VII/1971) Tdc do nudc lu ldn nha't tdi 3,83 m/s (tran lu 15/VI1/1991) Tran lu dau thang IX/1975 la tran lu ldn nha't trong vdng 40 nam qua ke tir nam 1961 Luu luong dinh lu ciia tran lu nay dat tdi 6930 mVs, tuong irng vdi md dun dinh lu 1,08 l/s'.kml

Ddc diem lu tren cdc song suoi vita vd nho

Miia lii hang nam trdn cac sdng sudi vira va nhd ciing thudng bdt dau tir thang VI va ket thiic vao thang X, cd xu the mudn d cac sdng tren cao nguyen Mdc Chau va trdn cac nhanh cua sdng Ma Do tfnh dieu tiet ciia sdng sudi nhd kem nen miia lu tren cac sdng sudi nhd cd the xuat hien sdm tir thang V va ket thiie sdm vao thang IX

Trung binh hang nam tren cac sdng sudi vira va nhd cd khoang 3 - 8 tran lu nam ft nhat cung cd vai tran lu va nam nhieu nha't cd tdi 7 - 8 tran lii Bidn do lii len ciia mdt tran lu trung binh bdng 0,7 - 1,5 m, ldn nhat ciing chi tdi 1,5 - 3 m

Lu ldn va dac biet ldn xay ra dot nggt, cudng suat lii va tdc do lu ldn cd the gay ra nhu'ng thiet hai rat ldn ve ngudi va ciia cai, dac biet la lu quet, lu dng

Lu quet

Trong vai thap ky gan day, lu quet xay ra ngay cang nhieu va ac liet hon d nhieu viing trong nudc ta ndi chung va d tinh Son La ndi rieng

Lu quet la loai IQ thudng xay ra ba't ngd, len nhanh, nit nhanh, duy tri trong mgt thdi gian ngdn, tdc do nudc lu rat manh, eudn trdi nhieu biin da, siic tan pha ra't ldn Lu quet thudng xay ra trdn cac sdng sudi vira va nhd (F < 500 km") d mien mii, noi cd dieu kien thuan lgi de hinh thanh lu quet nhu dia hinh chia cdt manh,

do ddc luu vuc va do ddc long sdng ldn, do dn dinh ciia ldp dat trdn be mat luu vuc yeu do qua trinh phong hoa manh, ldp phii thuc vat bi tan pha d nhirng noi nay, khi xay ra mua ldn, tap trung trong thdi gian ngdn thi dd xay ra lu quet Co che hinh thanh va dac diem co ban cua lii quet khac vdi lu thdng thudng

Didn hinh trong thdi gian gan day la tran lu quet ngay 27/VII/1991 xay ra tren sudi Nam Bii, Nam Pan va Nam La thugc cac huyen Ydn Chau, Mai Son va thi xa Son La Tran lu quet nay la do xoay thap Bdc Bd gay ra mua ldn va tap trung

d nhieu noi d Son La va Lai Chau, va da gay ra lu quet tren luu vuc Nam Lay thugc tinh Lai Chau va mgt sd luu vuc neu tren d tinh Son La Lugng mua ngay 27/VII/1991 d tinh Son La rat ldn, ldn nhat dat tdi 403 mm tai Ban May

Dong chay cat biin la lung

Dudi tac ddng ciia mua, gid va cac yeu td khac, dat trdn be mat luu vuc bi bao mdn, xam thuc rdi sau dd dugc ddng nudc eudn trdi vao mang ludi sdng sudi

Ciing nhu nudc sdng, cat bun trong nudc sdng sudi cung bien ddi theo miia Trong miia lu, nudc sdng due ngau, cdn trong miia can nudc sdng trong Ngay tir cac tran mua lu dau miia vao thang IV, V, do due nudc sdng tang ldn dang ke Tai tram thuy van Ta Bii tren sdng Da, trong cac thang I - III, do due cat bim lo lirng trung binh thang bdng khoang 45 g/m\ tang ldn tren 100 g/m^ vao thang V, tren

1000 g/m"^ vao thang VI va thang IX va tren 2000 g/m"^ vao thang VII, VIII, giam cdn dudi 1000 g/m^ vao thang X, XI va tren 150 g/m^ vao thang XII (bang 2.9), hinh 2.8 Do due trung binh nam bdng 1430 g/m^ Do due cat biin lo lirng ldn nhat

da do dugc dat tdi 16600 g/m"* vao tran lii ngay 15/VII/1984, do due nhd nhat chi bang 0,01 g/m- vao ngay 10/XII/1970'

Luu lugng cat bun lo lirng bien ddi theo miia Trong cac thang I - IV, luu lugng cat biin lo lirng trung binh thang deu dudi 50 kg/s, nhd nhat vao thang III (15,4 kg/s) Luu lugng cat bun lo lirng trung binh thang trong cac thang miia lu deu trdn 1000 kg/s, ldn nhat xuat hien vao thang VII va VIII (8200 - 8300 kg/s) Luu lugng cat bun lo lirng trung binh nam bdng 2110 kg/s, tiic la tdng lugng cat biin lo lirng ciia sdng Da chuyen qua mat cdt Ta Bii trong 1 nam bdng 66,6 trieu tan

Trong miia lii, do due cat bun lo lirng trung binh thang d cac sdng sudi ddu ldn hon 100g/m\ ldn nhat vao thang VII hay thang VIII, rieng tai tram Phieng Hieng tren Sudi Sap va tram Thae Mdc tren Sdng Nam Sap xuat hien vao thang VI Trong miia can, do due cat bun la lirng trung binh thang kha nhd, deu dudi 20 g/m\ nhd nhal vao thang I

Do due cat bun lo lung ldn nhat tren sdng sudi vira va nhd dat den tren

10000 g/m- a tram Nam Ty (11800 g/m- vao ngay 29/IV/1973) va tram Phieng

Hieng (10100 g/m^ vao ngay 25/IV/1970) Cdn cac sdng sudi khac chi dat tdi

2000 - 3000 g/ml

Tinh hinh thien tai

- Set ddnh: Nam 2004 da say ra set danh tai nhieu diem lam chet 4 ngudi va bj thuong 5

ngudi

- LU quet: nam 2004 da xuat hien lu quet va kem theo mua da vdi cudng do ldn gay chet

ngudi dang chii y la tran lu quet tai xa Na Cang huyen Quynh Nhai, xa Nam Ddn, Chieng Lao huyen Mudng La, Xa Nam Lanh, huyen Sdp Cop

- Sat Id ddt: Nam 2004 cd hien tugng sat nd ran mit ddi niii vdi cudng do ldn Dac biet la

trien niii dgc Sdng Da tir Ta Bii Mudng La den xa Ca Nang huyen Quynh Nhai

Tdng hgp thiet hai do thien tai trong nam 2004 da cd 25 ngudi chet, trong dd bi chet

do set danh 4 ngudi, lu eudn trdi 19 ngudi, sat Id dat 2 ngudi Sd ngudi bi thuong la 29 ngudi, do set danh 5 ngudi va do mua lii la 24 ngudi Ve thiet hai vat chat do thien taowcsnawm 2004 ude tfnh ldn tdi 21,649 ty ddng

3.2 Dac diem kinh te, xa hoi d Son La

3.2.1 Dan sd

Dan sd trung tinh Son La la trdn 995 nghin ngudi, mat do binh quan 69 ngudi/km^ trong dd nam la 489.455 ngudi (chiem 50,18%), nir la 486.005 ngudi (chiem 49,82%) Dan sd khu vuc thanh thi chiem 10,94%, dan sd sdng d khu vuc ndng thdn chiem 89% tdng sd dan toan tinh Tdc do tang dan sd nam la 1,71%/nam Du bao den nam 2020 dan sd se dat tdi trdn 1,2 trieu ngudi (Bang 4)

Bang 4 Du bao tang dan sd va lao ddng tu nhidn

513 592,4 660,9 726,6

Lao dong/dan so

'(%)

51,5 54.4 56.7 58.2

Lao ddng trong do tudi hien cd khoang 492.600 ngudi chiem 50.5% dan sd toan tinh Trong dd nam la 275.500 ngudi, nir la 217.100 ngudi Lao dgng thanh

thi 83.300 ngudi chiem ty le 16,91%, lao ddng ndng thdn 409.300 ngudi chiem ty

le 83,09% tdng lao dgng toan tinh

La mgt tinh mien mii nen co ca'u dan sd rat dac thii bao gdm 12 dan tgc anh

em chung sdng trong dd dan tgc Thai chiem 55,5%; Kinh chiem 17,8%; H'mdng chie'm 12%; Mudng chie'm 8%; cdn lai la cac dan tgc khac nhu Dao, Kho Me, Khang, Xinh-Minh, La Ha, Lao, Lu Theo thdng ke ty le tang dan sd binh quan mdi nam la 2,6%, la mgt trong nhirng tinh cd tdc do gia tang dan sd cao nhat khu vuc Tay Bdc Mat do dan sd binh quan nam 2000 la 64 ngudi/km" nhung phan bd khdng deu, chii ye'u tap trung d cac vimg dd thi va rat thua thdt d cac vimg mii cao Trong nhii'ng nam qua dan sd Son La bi bie'n ddng manh giira cac viing do viec di dan chuan bi xay dung thuy dien Son La trong thdi gian vua qua Van de di dan, dinh canh dinh cu hien la mdt van de biic xiic nhat va cd tac ddng manh me den dieu kien ve sinh mdi trudng trdn mgt sd khu vuc ciia tinh

3.2.2 Dien bien do thi hoa

Tuy la mdt tinh mien niii, nhung Son La cd nhieu didu kien phat trien cac khu dd thi va cdng nghiep, nhat la khi Nha may thuy dien Son La hoan thanh Hien nay tren dia ban tinh Son La da hinh thanh 3 khu dd thi ldn gdn lien vdi phat trien kinh te xa hdi, dd la khu dd thi thi xa Son La, khu vuc Mdc Chau-Thao Nguydn va khu vuc Mai Son-Na San Day ddng thdi cung la nhirng trung tam thu hiit va lan tda den sir chuyen ddi co cau kinh te viing xung quanh

-f- Khu vUc thi xd San La :

Hien nay vdn la thi xa Son La, nhung theo qui hoach se phat trien trd thanh thanh phd dd thi loai III Day la trung tam chi'nh tri, van hda khoa hgc ky thuat va trung tam kinh te, dich vu, du lich ciia tinh Hudng phat trien cdng nghiep vdi cac

nganh san xuat chfnh la vat lieu xay dung {xi mdng, gach, ngoi, cdt, soi, dd) cdng

nghiep che bien ndng lam san cd chat lugng cao nhu uom to, det lua, tinh bdt sdn

ca phe CO khf san xuat va sira chua may mdc, thiet bi phuc vu san xuat Phat trien manh dich vu thuong mai va du lich

+ Khu Mai San- Nd Sdn :

Phat trien thanh thi xa la trung tam phat trien dich vu cho ndng lam nghiep, xay dung cac viing ndng thdn mdi va viing phat trien ndng nghiep che bien: mia dudng, ca phe, che, tinh bdt, thiic an gia siic, ngd, dau tuong ddng thdi cung la vimg hau cu: vanh dai thuc pham cho thi xa Son La va cdng trinh thuy dien Son

La Xay dung nha may xi mang Id quay cdng suat 1 trieu tan/nam, phat trien dau mdi giao thdng hang khdng (San Bay Na San) va dudng thiiy (cang Ta Hoc) la trung tam giao luu hang hda

-I- Khu Mpc Chdu- Thdo Nguyen :

Quy hoach phat trien thanh thi xa cd ndn kinh te da dang va la ciia md de giao luu kinh te- xa hgi vdi cac tinh trong nudc va vdi nudc ban Lao, phat trien

cay cdng nghiep, cay an qua, chan nudi bd siia ket hgp vdi cdng nghiep che bien ndng san Phat trien du lich tdng hgp: sinh thai canh quan, vui choi, the thao, nhan van nghi duong phat tridn thanh trung tam chuyen giao hang hda dich vu trong nudc va nudc ngoai Day cung la noi dugc qui hoach ddn tiep kha nhieu dan di cu Trong thdi gian tdi se tiep nhan 4.500 hd vdi 22500 ngudi chiem 35,7% sd dan lai dinh cu tir cdng trinh thiiy dien Son La

3.2.3 Hien trang phat trien nong nghiep va ndng thon

Viing ndng thdn Son La chie'm 80% dien tfch Do tfnh chat ndng thdn mien mii nen hoat ddng san xua't ndng nghiep cua ndng dan kha da dang, vira canh tac nuong rdy, rudng vudn, chan nudi, vira dugc giao dat giao rirng, tham gia nhirng chuong trinh, du an ve lam nghiep Mac dii vay vdn cd tinh trang thieu an 1 den 2 thang trong nam, do che phii thap gay ra nhieu birc xiic ve mdi trudng d ndng thdn

Thuc te cac yeu td mdi trudng dat, nudc, khdng khf d ndng thdn Son La chua cd nhieu van de d nhidm nang ne nhu d dd thi Tuy nhidn do do che phii thap

da khien tai nguyen dat bi suy thoai, dd bi xdi mdn rira trdi, tai nguyen nudc mat vao miia lu cd do due cao, lugng bun cat nhieu, vao mua khd thi can kiet, ca hai miia deu gay sir thieu thdn, khd khan cho sinh hoat ciia ngudi dan Mat khac ngudi dan cdn giir nhieu phong tuc tap quan lac hau gay tdn hai den mdi trudng thien nhien va cho chfnh mdi trudng sinh hoat cua minh

Cd the ndi ve sinh mdi trudng ndng thdn mien niii cd mdt khoang each kha

xa so vdi mien xudi Mdt nguydn nhan can ndi den la sir han che ve giao thdng ddn tdi han che ve giao luu, tuyen truyen, hgc hdi nhii'ng tien bg d ben ngoai cdng ddng Nguydn nhan khac bdt ngudn tir nhung phong tuc, tap quan lac hau do chfnh cudc sdng ddi hdi Chdng han: Viec khdng nudi nhdt gia siic dudi gan san cd nhung noi da thuc hien sau dd lai bd vi gia sue bi mat trdm hoac bi thii du tan hai Nha d, dudng lang, ngd ban cdn ban vi rac, vi phan gia siic khdng dugc dgn Nhirng khd khan ve ngudn nudc va nhirng tap tuc tren cdng vdi sir tha rdng gia sue hoac nudi nhdt dudi gam san khien mdi trudng sinh hoat d ndng thdn midn mii rat kem ve sinh

3.2.4 Phat trien kinh te

Tdng san pham qudc ngi (GDP) trdn dia ban tinh Son La nam 2003 dat 1.607.299 trieu ddng (gia 1994), tang 2,03 ldn so vdi nam 1995, gap 1,31 lan so vdi 2000 Tdc do tang trudng kinh te toan tinh nam 2004 ude dat 14,2%

Tdc do tang trudng GDP binh quan/nam thdi ky 1995- 2000 la 9,15%/ nam thdi ky 2000- 2003 la 9,44%/ nam (ca nudc la 7,05% / nam) Nhu vay tdc do tang trudng binh quan giai doan sau cao hon giai doan trude, chii yeu do sir tang trudng manh cua khdi nganh cdng nghiep- xay dung, giai doan 2000- 2003 binh quan nganh cdng nghiep - xay dung tang trudng 20,88% / nam Nam 2004, tdc do tang

trudng nganh cdng nghiep uac dat 43,68% mgt mirc tang trudng rat cao (Bang 6)

100 71,5 9,75 18,75

2000

1.226.266

1.837.352

760.212 129.314 336.740

100 60,96 9,49 29,55

2003

1.607.299

2.848.736

868.122 228.423 510.754

100 52,77 13,17 34,06

100 45,95 18,09 35,96

2005 Toc do tang truong 1996-

2000 9,15

6,37 10,68 16,73

2001-2005 11,73

5,05 23,87 48,44

(Nguon NGTK 2003, ke hogch ndm 2004, 2005)

3.2.5 Ket qua thirc hien cac muc tieu phat trien van hoa - xa hgi

Van hoa xa hdi cd nhieu tien bd mdi, ddi sdng vat chat, tinh than ciia nhan dan dugc cai thien, cdng tac XDGN cd ket qua, tirng budc giai quyet cd hieu qua nhirng van de xa hdi biic xiic

- Giao due dao tao: Dugc cung cd va phat trien kha toan dien d cac cap hgc, nganh hgc vdi nhieu loai hinh dao tao theo hudng chuan hoa, hien dai hoa, xa hdi hoa Mang ludi va quy md giao due phat trien manh, he thdng cac trudng phd thdng, trudng dan tdc ndi trii dugc tang cudng Cac trudng trung hgc va day nghe tiep tuc dugc ciing cd va md rdng Thanh lap Trudng Dai hgc Tay Bdc, nang trudng Trung hgc sir pham ldn cao dang Ddi ngu giao vidn duoc tang cudng ve ca

sd lugng va chat lugng Cung cd ket qua phd cap giao due tidu hgc va day manh phd cap giao due trung hgc co sd Nam 2002 - 2003 cd 18 xa dugc cdng nhan dat chuan phd cap tieu hgc diing do tudi, 43 xa dugc cdng nhan dat chuan qudc gia phd cap giao due trung hgc co sd Tuyen sinh vao cac trudng dai hgc, cao ddng, trung hgc va cdng nhan ky thuat gan 2 van ngudi Hang van lao ddng dugc chuyen giao ky thuat san xuat, day nghe, tiep can vdi khoa hgc, cdng nghe mdi Hang nghin can bd dugc dao tao tap huan ve ly luan, quan ly kinh te, quan ly nha nudc, dac biet la tap chung manh dao tao, bdi dudng can bd co sd: Sd can bg cd trinh do dai hgc, cao ddng tang 3,3% so vdi nam 1999

- Khoa hgc cdng nghe: Dugc day manh theo hudng ung dung nhirng thanh tuu khoa hgc cdng nghe mdi vao san xuat Hon 4 nam qua da cd hon 40 dd tai dugc nghiem thu: Trong dd 21 de tai dugc dua vao ap dung va budc dau cd ket qua Nhieu loai cay gidng luong thuc, cay cdng nghiep nang xuat, chat luong cao;

ky thuat chan nudi bd sira, bd thit chat lugng cao; cdng nghe mdi trong che bien

sira, che, san xudt thiic an chan nudi gia siic dugc dua vao san xuat, dap ii'ng tdt hon yeu cau, nang cao chat lugng, hieu qua va siic canh tranh ciia nen kinh te

- Y te: Thuc hien cd hieu qua cac chuong trinh y te qudc gia He thdng

benh vien tuyen tinh, huyen va cac phdng kham da khoa khu vuc trung tam cum

xa tiing budc dugc nang ca'p De'n nay, 100% sd xa cd tram xa, 15.9% xa da cd bac

sy, 90,6% sd ban cd y te' ban Toan tinh cd 2.285 gudng benh, trong dd tuyen tinh chiem 43% Cha't lugng chudn doan va dieu tri benh, y te du phdng cd nhieu tien

bd, da ngan tran va day liii dugc mdt sd dich benh nguy hidm

- Van hoa - thong tin - the thao: Cac hoat dgng van hoa, van nghe, the

due the thao, bao chf, phat thanh, truyen thanh, truyen hinh phat tridn kha Cudc

van dgng 'Todn ddn xdy dung ddi song vdn hod khu ddn cu" phat huy tac dung tdt

Den nay, 68% dan sd dugc xem truyen hinh, 82% dan sd dugc nghe dai, 158 nha van hoa xa da dugc dua vao sir dung va phat huy hieu qua, 55.600 hg dat tieu chudn gia dinh van hoa, 8% sd hg luyen tap the due the thao thudng xuydn

- Cdng tac xoa doi giam ngheo: Bdng each long ghep cac chuong trinh du

an nhu: Chuong trinh muc tieu qudc gia xoa ddi giam ngheo va giai quyet viec lam, du an EU, du an giam ngheo, cac chuong trinh muc tieu qudc gia, chuong trinh 925, 661 cdng tac xoa ddi giam ngheo da dat dugc nhirng kel qua dang kfch le; ddi sdng nhan dan cac dan tdc dugc nang ldn, tuyet dai bd phan dugc cai thien rd ret, hd trung binh, kha gia tang ldn, ty le hg ddi ngheo nam 2003 cdn 15%; tao thdm viec lam cho 38.000 lao ddng, trong dd tao viec lam mdi dn dinh cho 6.500 lao ddng

3.3 Thirc trang tai nguyen cua Son La

3.3.1 Tai nguyen nirdc mat

Mat do sdng sudi tuong ddi ldn (l,7km/km^), trong dd cd hai he thdng sdng ldn chay qua dia ban tinh la sdng Da va sdng Ma, lugng bun cat trong sdng thugc loai ldn nhat Viet Nam

Tai nguyen nudc mat phu thugc vao ngudn nudc den tir Trung Qudc va cac tinh dau ngudn nhu Lai Chau, Dien Bien, Yen Bai ngoai ra cdn phu thugc vao sir dieu hanh cac cdng trinh thuy dien ldn trong luu vuc sdng Da nhu Hudi Quang, Ban Chat, Lai Chau, Hoa Binh

Tdng lugng ddng chay nam trung binh thdi ky quan trdc (1961-1990) ciia sdng Da tai tram thuy van Ta Bii (W) bdng 46,7 ty m^ tuong ung vdi luu lugng trung binh nam (Q) bdng 1480 mVs Neu tfnh den vi trf sdng Da chay ra khdi tinh Son La, thi W ^ 56,8 ty m \ Q = 1800 mVs

Tren sdng Ma, tai tram thuy van Xa La cd W = 3,82 ty m^ va tfnh den vi trf sdng Ma chay ra khdi tinh Son La bdng khoang 4 ty m"^, tuong iing vdi gia tri luu lugng bdng 121 mVs va 127 mVs

Ngudn nudc ciia cac sdng nhanh cua sdng Da va sdng Ma phu thugc rat ldn vao dieu kien khf hau, nha't la mua va bdc hoi, va dieu kien mat dem (dia hinh, dia cha't, thd nhuong, thuc vat )

Tdng lugng ddng chay nam trung binh nhieu nam dugc hinh thanh trong tinh Son La bdng khoang 14 ty m\

Nhin chung tren dia ban tinh Son La, viec khai thae sir dung tai nguyen nudc mat la chii yeu Chat lugng va trir lugng tuong ddi tdt Tai nguyen nudc phu thugc chat che vao lugng mua Tuy cd lugng mua kha ldn dao ddng trong khoang 1.200 - 2.800 mm/nam nhung lugng mua phan bd khdng deu, vimg mua ft la Mdc Chau, Ydn Chau, Mai Son, Thuan Chau, Son La, Sdng Ma Mua nhieu d cac viing Mudng La, Phii Ydn, Bdc Yen, Quynh Nhai He thdng sdng sudi thudng bi can trong mua khd va cd nhieu sudi cut chay vao cac hang Karst ngam d viing mii cao nudc xuat Id vdi mat do khdng day, luu lugng nhd va nhieu diem ve miia khd khdng xuat hien

Tai nguyen nudc ngam ciia Son La han che, chii yeu tap trung trong 2 tang nudc Id hdng va nudc khe nut viing mii da vdi Trir lugng ciia nudc dudi dat phu thugc rat nhieu vao dieu kien dia ly, dieu kien tu nhien ciia khu vuc Nhin chung viec khai thae, sir dung tai nguyen nudc ngdm tren dia ban tinh Son La chua phd bien, mgt phdn do dieu kien phan bd nudc dudi dat trdn dia ban rat han che, chii yeu tap trung vao viing cao nguyen Mdc Chau va Phii Yen, khu vuc thi xa Son La bun lap nhieu nen chira ft nudc

3.3.2 Tai nguyen dat

Dien tfch tu nhien toan tinh la 1.405.500 ha, trong dd dat dang dugc sir dung 702.760 ha (chiem khoang 50% dat tu nhien cua tinh) Nhu vay, den het nam

2005, da't chua su dung va sdng sudi cdn 611.395 ha, chiem 43,5% dien tfch tu nhien (Bang 5) Trong dd cd 557.088 ha la da't ddi mii khdng cd rirng cdn phai dugc khai thae de trdng rirng phdng hd, rirng kinh te, trdng cay cdng nghiep dai ngay, ket hgp trdng ngd, khoai sdn tao them luong thuc

La mgt tinh viing cao nhung quy dat ndng nghiep han che chi cd 0,2 ha/ngudi, trong dd cho san xua't luong thuc la 0,16 ha (rieng liia nudc 0,017 ha/ngudi) Theo danh gia ciia Sd Tai nguyen va Mdi trudng Son La (2005) thi chi

cd 138.500 ha dat (gdn 10% dat tu nhidn) la thfch hgp cho cac loai cay nong nghiep, tuy nhien tren thuc te dien tfch dat san xuat ndng nghiep d Son La da la 195.156 ha, chiem 13,89% dien tfch toan tinh (Bang 7) Do vay ngoai viec triet dd khai thae cac dat bdng Son La cung can phai su dung mot phan dat ddc cho san xuat ndng nghiep Ben canh dd cung can mgt dien tfch dang kd cho phat trien cay cdng nghiep dai ngay nhu ca phd, che, cay an qua

Bang 7 Hien trang sir dung dat tinh Son La nam 2005

Loai su dung dat

Tong dien tfch da't tu nhien

I Nhom dat nong nghiep

- Dien tich dat nong nghiep

- Dien tich dat lam nghiep

II Nhom dat phi nong nghiep

- Dat a

- Dat chuyen diing

III Nhom dat chua sir dung

Dien tfch

ha 1.405.500 761.097 195.156 565.941 33.008 6.212 26.796 611.395

%

100 54,15 13.89 40,27 2,35 0,44 1,91 43,50

Theo ke't qua dieu tra xay dung ban dd dat ty le 1/100.000 cua Vien Quy hoach va Thiet ke' Ndng nghiep nam 2006, Son La cd 7 nhdm dat khac nhau va mdt dien tfch dang ke niii da, mat nudc sdng sudi (Bang 8)

Bang 8 Dien tfch cac loai dat ciia tinh Son La

Tong dien tich ddt

Dat mat nudc nuoi trong thuy san Dat mat nuac chua six dung la Song suoi

Niii da

Tong dien tich tu nhien

Dien tich (ha)

65,4 19652,9 6859,2 763108,3 505607,2 25959,9 8391,0

(Nguon: Vien Quy hoach vd Thiet ke Nong nghiep, 2006)

Cac nhdm dat chii ye'u la dat dd vang (F) va dat miin dd vang (H) Chiem tdi 89,7% tdng dien tfch tu nhien toan tinh Dat cd do ddc cao > 25" chiem tdi 85%, chl gan 7% dat cd do ddc <15" Hau het cac loai dat d Son La cd do day tdng dat tir trung binh den kha, da't cd tang day trdn 100 cm chiem 33,5%; tang day 50 -

70 cm chiem 36,1% va dudi 50 cm chiem 30,4%, thanh phan co gidi tir trung binh den nang, ty le miin va cac chat dinh dudng tir trung binh den kha, do chua khdng