Luận văn performance evaluation of the lien son irrigation system north vietnam

Data colleetien...à nen naeririrraiinoo.TE CHAPTER V ANALYSIS, RESULTS AND DISCUSSION...21 5.1.6 Annual irrigation water delivery per unit irrigated area.... In 1962,the Bach ac pumping

PERFORMANCE EVALUATION OF THE LIEN SON IRRIGATION SYSTEM,

NORTH VIETNAM

by

Neuysn Van Tinh

A thesis submilted in partial ful filment of the requirements for the

dogrec of Master of Enginccring

Examination Committee: Prof A Das Gupta (Chairman)

Dr Mukand 8 Babel (Co-chairman)

Previous Degtee: Bachelor of Engineering

Hanoi Wator Resourecs University, Victnam

Scholarship Donor Ministry of Agriculture and Rural

ABSTRACT

Inrigation performance indicators, which comprise engineering and economic indicators, allow an assessment on performance of irrigation systems Indicators can be use to

compare the system 10 other systems Within the system, Ihey can compared frorn year to

year to indicat relative performance or trend

Dozens of irrigation performance indicators have becn proposed over the years But they still receive relatively little use, and that use is mostly by researchers rather than managers According to Nelson (2002), each irrigation community needs to select a group of key indicators, that are applied often enough to establish and appropriate range

of values inlerprelation

TWMI provided « gnidsline with a sot of 25 indicators, which consist of 4 groups: service delivery performance, productivity cfficicney, financial and cnvironmental performance This guideline is base to determine performance indicators for irrigation and drainage systems in the world,

‘The Lien Son imgation system located within the Red River Delta of Vietnam is chosen

as study area, Based on available data of the study area, performance indicators will be determined analysed and compared ‘hen some recommendations can be provided to improve imtigation performance for the study arca

ACKNOWLEDGEMENT

I would like to express my extreme gratitude to Prof A Das Gupta, my advisor and Dr Mukand §, Babel, my Co-advisor, for their guidance and invaluable suggestion throughout my work Gratitude is also extended to the committee members, Dr Roberto Clemente for his comments and suggestion during the completion of this work

Deep appreciation is also lo the MARD/DANIDA in Vietnam for providing me with the scholarship to study al ATT T also wish lo express my appreciation la leadzrs, managers, lecturers of Hanoi Water Resources University for supporting me throughout my study at AIT Sincere thanks present to AIT for providing facilities throughout my study

1 also Would Like to thank to all members of the Vinh Phuc Agriculture Department and

the Lien Son Irrigation Management Company, who helped me enthusiastically during

my data collection

To entire WEM faculty and staf0, thank you very much for your support To all classmate

in WEM, thank yon for your friendship To alll fricnds in Vicinamess Student Association, thanks for cverything

Finally, I want to cxpress my especial thank to my family, especially to my beloved parents, my lovely wife and son for their love, moral support during my study

1.2 Need for study -

CHAPTER Tl DESCRIPTION OF STUDY AREA

2.1 Location and aea neee

2.2 Climate and hydrology

2.3 Topography and soil

2A Land use

25 Crop cultivation

2.6 Imigation system and facilities

2.7 Present operation and management

4.1, Benchmarking in the Irrigation and Drainage sector 14

42.1 Data colleetien à nen naeririrraiinoo.TE

CHAPTER V ANALYSIS, RESULTS AND DISCUSSION 21

5.1.6 Annual irrigation water delivery per unit irrigated area

5.2 Productive efficiency indicators

5.2.1 Gross annual agricultural production

5.2.2 Total annual agricultural production a -

5.3 Finaleial parformanee inđieafOrS + nở HH2 H1 rerrrdeiide

5.3.1 Total mumber of personnel «issn statesmen nanan

3.3.2 rigated area per person unit

533 Total costs

53-4 Maintonance Budget Ratio

3.3.5 Parsonncl Cost Ratio

3.3.6 Cost of inrigated area unit

3.3.7 Total water fee colleetion

5.3.8 Water [se collected per irrigated are

5.3.9 Ratio of water fee collection per

LIST OS TABLES

Table 2.1: Arca distribution on clevation 5

Table 2.3 Percentage of Production yield as water f2€ eseeeemmninaneneane

Table 2.4 Total budget reecived by LIMC fram Vinh Phue PPC §

Table 4.1: Data and information for evaluating indicators

‘Table 4-2: Data processing

‘Table 5.1: Average monthly value of chưnatic parartietsr is sec s22 Table 5.2.: Telal rainôil, cs-<ee -33 Tablc 5.3: Rcftrcnec Evapolranspiration 24 Table 5-4, Irrigated arca under ¢t {ferent crops 24

‘Table 5-7: Water volume derived to the system through Lien Son diversion and

‘Table 5.8: Over all efficiency (OAE)

‘Table 5.9: Annual irrigation water delivery per unit imgated area

Table 5.10: Total crop Area, Productivity and Yield

Table 5.11: Total anmual agriculture production

Table 5.12; Number of personnel

Table 5.16,: The Personnel Cost Ratio container Table 5.17; Ratio of total cost per imigated area

Table 5.18; Water fee collection

Table 5.19 : Water fec collected per imtigated arca unit

Table 5.20.: Ratio of water fee collection per total cost 41

Figure Tite

Higure 2.1 Map of the study area

Figure 5.2: Crop calendar

LIST OF FIGURES

Page

iy a

LIST GF ABBREVIATION AND SYMBOLS:

Drainage

for Tochnology and Rescarch in Irrigation and Drainage

to compare irrigated land and water use to learn how izrigation systems are performing relative to each other and what the appropriate targets for achievement are

With about 80 millions ivihabilanls and 331,700 square kilometers lolal area, of which onc third enly is covered by plains, the irrigaled agricniturc in Victuam has beoome anc

af the major scctors in the national cconomy and food sccurity stratagy Trrigation water management thus has enormous economies implications for this country While the structural inffastructure for irrigation- comprising of reservoirs, canal networks, drainage works and delivery systems-is created at a huge financial investment, a commensurate cffort is alse csscntial on developing scicntific watcr management policics Development

im systems science, operation research and mathematical modeling for decision making under uncertainty have been usefully exploited for water resources management in many technologically advanced countries Applications of snch mathematical techniques in irrigalion water management in developing country — al both macro as well as micro level will lead to significant economic benefits

In most of the iztigation system in the North of Vietnam, water is incrcasingly becoming

a scare resources due to the pressure from increasing water requirement In addition, due

to change climate, the serious deforestation in the watershed, etc, water resources, especially in the dry season, 15 mich more reduced comparing to the time when the system was designed

Tn view of the foregoing discussion, an offective method in mamagement of natural resources for irrigated agricultuc on the sustainable basis is csscntial since the efficiencies of both water and land use are low, and fewer opportunities are there to increase irrigated areas by the development of new system

By considering all the different criteria, a better management of the utilization of water resources is requiredto promote the water use efficiency

In this study, the Lien Son Irrigation and Drainage System is chosen as study area

1.2 Need for study

According to survey and assessmnent of the Ministry of Vietnamese Agriculture and Rural Development (Diem, 2000), many of the irrigation systems arc performing with low efficiency, the operation cost is high, especially for pumped irrigation of the Red River Delta in the North area of Vietnam ‘The major reasons causing low efficiency of

inigation systems are; a) many of them had been operated for years, but insufficiently rehabilitated; b) investment for isrigation systems had not been properly planned; and c) policies of institutional management had some problems, especially regulations of water fos collection In addition, im the irrigation systems of tho Red River Della, low cffcicncies for water delivery and water usc arc major impediments to increasing crop productivity (ACIAR, 1999)

The Lien Son Inigation and Drainage System belongs to the Red River Delta of Vietnam, The total area is 44439 ha, It has been built since 1914 with water resources from Pho Day river at the Lien Son diversion The system started operation in 1917 with

initial intigation area of 17,000 ha In 1962,the Bach ac pumping station with capacity

of 11.2 m3/s was constructed, it take water from Red River for supplying water to system , and the irrigated area of system was expanded up to 23,000 ha

Inrecent years, many rehabilitation projects for the Lien Son irrigation canal system have been implemented for improving delivery efficiency reducing water percolation Tlowever, the question is whal is reasons of low irigation performance and how Lo

iniprove il?

For those reason, the study is essential to find out the appropriate management strategy which will overcome the existing problems ofthc Licn Son imigation system

1.3 Objectives and scope af study

The main objecti

Son system and bas:

system management

‘The Benchmarking Performance procedure recommended by IWMI is issued for analysis and evaluation of irrigation performance of Lienson ligation System with the scope of work as following:

of study is to analyze and cvatuate irrigation porformanecs of Lion

on these results provide recommendations for improving irrigation

@) Collection data: Including data of hydrometearology, crops, irrigation management

costs, water fee,

1b) [istimating of data: Calenlate crop water requirement, irrigation requirement,

©) Calculating indicators: Including 3 groups of indicators as service dehvery performance, productive efliciency and financial performance

a Discuss of remilts: Tased on results of indicators calculated to đỉscnss and give comment for thom

¢) Recommendations ; Based on above results for provide some recommendations on to improve irrigation performance for the study area

CHIAPTER II DESCRIPTION OF STUDY AREA

2.1, Location and area

The Lienson litigation system is the midland plain at the left-bank of Red River It

includes 5 districts Mong Cau, Tam Duong Vinh Tuong, Yen Lac, Binh Xuyen and

‘Vinh Yon town of Vinh Phuc Province It is within the longitude of 104955” to 106012”

East and the latitude of 21°12” to 21°48’ North The system has boundaries with Tam Tao mountain at the North and North-East, Ilanci city al the Soulh-Fast, Red river al the

South and Sonth-Wesl The tocalion of sindy arca along with ils layout is shown in Figure 2-1

This system covers an area of 44439 ha in which 23.000ha cultivated area with irrigation

It plays the substantial rele of agriculture in the economic development of the Vinh Phuc

province ‘The total population hving 1n this area is 748,568 inhabitants (Vinh Phuc slalistical Department, 2002)

2.2 Climate and hydrology

‘The climate of the study area belongs to the tropical monsoon zone, consisting of the dry season, November lo March and the rainy season, Aprit to October As the records in

20 years (1983-2002) duration at the Vinh Yen melzorotogical slation, the mean annual

rainfall is 1662 mm, of which 84.5% fall in the rainy season, specially in July to September, In dry season, the mean monthly rainfalls are recorded at 16-45 mm, The average sunshine is short 4.2 hours per day and specially short in dry season as 2.4 hours per day The annual mean temperature is 23.7 °C, the hottest month is July in terms of montlily ean temperalure(28.7°C), and the lowest is in January (16.2 °C) The annual relative humidily is high, as 84.5%

- In dry season: Max discharge of 11 m3/s to 13 m3/s in Apuil and min of 4.5 m3/s to 6.0

m3/sin March

- Inrainy season: Max discharge of 60 m3/s to 83 m/s in June and min of 12 m3/s to 15 m3/s in September.

2.3 Topography and soil

‘The direction of the surface slope is ftom North-West down to SouthEast and from West to East The ground surface elevation varies from 15 to | 16.5 m above the MSL, in which 57.49% of area is from +8 to+11 m above the MSL, The cultivated land, build up

by alluvial soil of Red river, is light loamy sand, The low land near by the rivers are glay

or medium loam The high land near by the mountain or hill are feralitic Area distritution on clavation are shown in tabte 2.1

‘Table 2.1.: Area distribution on elevation

‘The study area with 6 districts which have 23,000 ha of agricultural land of which 20,400

ha has devoted to rice cultivation, 2,600 ha was dedicaled for upland crops (maize, soybean, vegetables) Winter crops as vegetables occupies sinall area of 1,250 ha, accounting for 5.4% total agricultural area About 1,600 ha produces only one crop of dry season because it is subjected to deep dlooding dating the rainy season,

The present cultivation area per farmer is 360 -540 m2 which consist of | -3 ptots

(Source: Vinh Phuc statistical Department)

2.5 Crop cultivation

In general, the crop yield of study area is a litte bit higher than the national average yield

‘The cropping intensity in the area is 1.98

Rice (paddy)

Rice is the staple food crop in the study area, providing, the people with about 80% of carbohydrate and 35% protein intake

According to statistical data (Vinh Phuc statistical Department, 2002), average rice yield

of study area(4.67 tons/ha) exceeded the yield capacity of national level (4.4 tons/ha) in which Vinh Tuong district occupied the highest yield (3.50 tens/ha) and Mong Cau is the lowest (4.07 tons/ha) However, sice yield remain relatively low compared with neighbor

provinces in the Red river Delta, such as Ha Tay and Thai Binh provinces has raised rice yields to more than 5 tons‘ha/crop

Maize

It has two crop seasons a year: spring maize and summer-autumn maize The average maize yield of this area in 2002 of 3.35 tons/ha is higher than the national average of 2.9 tons/ha, in which Vinh Tuong district occupied the highest yield (3.9 tons/ha) and Vinh Yer is the howest (3.0 tons/ha)

Soybean

It has two orop seasons a year: spring and summer-autumn soybean as maize too, Yen Lac district ocoupied the highest yield (1.38 tons/ha) and Mang Cau is the lowest (1.8

tonsha)

2.6 Irrigation system and facilities

‘The inrigation in the study area is supplied by two head works of Lien Son diversion and Bach Ilac pumping siation, in which Bach Tlac has main responsibiHly lo supply in dry

scason while Lien Son is in wet season

1 The Lien Son diversion: It was built in 1914 on the Pho Day river Its long is 105m,

compriscs 3 spans, height of 5.16m, the clevation of spillway is 21.13m Ils design

inrigation area is 17,000 ha cultivated area

Main intake sluice: located at head of main canal of 15m upstream of diversion dam

including § units with dimension of 1.3x2.3 m, levation of bottorn on upstream is +14m

and downstream +13m, design discharge is 17 4

2 Bach Hac pumping station

It was built upan 1962, take water fiom Red river Capacity of pumping was designed of 11.2 m3/s with 6 units in which of 2.225 m?/s ‘unit Head of design is 9m As survey in

2001, it was still in good performance

3 The canal system:

Alt the present, the canal system of the study area is in good condition because almost of canal from main canal to on-farm canal has been ined by conrete or brick from 1995 to present In this area, 86km of main canal, 263 in-take structure and 13 secondary canal,

294 over fovel sluices and many ather struciurc such as siphons, divert sluices, checks,

On-farm canal nictwork: Sel up completely to reach to all farm, cstimaled abont 60% this

level canals lincd by brick al the same time in 2002

Local scale pumping station: Water on the irrigation canals flow down to drainage canal system due to underdeveloped on-farm ditches, insufficient and inoperative check structures, and poor management Therefore, it is necessary to pump up again to the field

It has total 11 local pumping stations with capacity of 1000 to 2500 m3/nc, managed by communes or cooperatives In addition, 4 drainage pumping stations within the study area are responsible to drainage by flooding in rainy season

2.7 Present operation and management

‘The irrigation system in the study area is operated and managed by the Lien Son irrigation management company(LIMC) as state company of the Vinh Phuc province Central office of company is located in Vinh Yen town The functions of the company arc under the supervision of a director and two deputy Under (hom are 4 departments for finance, administration, planning and technical activities

The contra! offte is responsible to admninistrale main activitics of company consisting af operation, maintenance the main vanal system and two head works of Lien Son diversion

and Bach [lac pumping station

‘The LIMC is assisted by 6 sub-companies, one per concemed district, those are Mong Cau, Tam Duong, Vinh Yen, Vinh Tuong, Yen Lac and Binh Xuyen ‘The sub-company

ple for inigation, drainage in each area of district Rach sub-company has a sel

of irigation group, cach being responsible for about 1000 ha The imigation group works with cooperatives to manage water, maintain facilities and collect water fe The company have to pay expenses for cooperatives to collect water fee The number of cooperatives of each district is givenin Table 2 2

District Mong | Tam | Vinh |YenLac| Binh | Vinh | Total

Cau | Duong | Tuong Xuyen | Yen

cooperatives

The water fs arc cslimated bassd on average production yicld and waler supply condition, Waler feas are determined by percentage (%) of average production yield as stipulated by Provincial People Committee (PPC) These percentage for different water supply condition in dry and wet season are given in Table 2.3

Table 2.3 Percentage of Production yield as water fee

is supplied directly by gravity into farmer fields of about 60% iztigated area and about 40% of the irrigated area of firmers need a manual lift with a scoop handled or portatle

pumping to get for water to the farm

‘The water fee varies fom one cooperative to another, this fee of each cooperative obey the regulation of PPC and plus extra fee (if any) for electric fee of cooperative pumping, slation, fictd application costs

Every six months farmors have to pay an individual walor foc which is colleclad by cooperatives, The waler fee is expressed in kito of paddy bul farmers can pay in cash or

in Kind Standard of water fee amount sanges fiom 380 kg/ha/year in Tam Duong district

to 644 kg/ha/year in Vinh Yen district

The central office manages the financial and personnel affairs of company All costs Galary, maintenance, operation ) and revenues(water f2e, ) of sub-companies must be reported and approved by Board of Director The general costs of company such as tax, insurance, arc paid by centzal office

The Government still maintains the policy of subsidizing Lotal cost of drainage works for Tigation Management Company such as oleciric foc of drainage pumping station, maintenance costs of drainage canals, structures, Every year, PPC approve total budget

of these costs for the Ligation Management Company based on report submitted, Table 2.4 shows total budget which LLMC has received from Vinh Phuc PPC during 5 years (1998-2002)

Table 2.4 Total budget received by LIMC from Vinh Phuc PPC

* Source: Lien Son Irrigation Management Company

~ Cumrency exchange rate: Appendix 4

CHAPTER HI

LITERATURE REVIEW

Nelson et at, (2002} provided a set of performance indicators for irrigation canal system managers or water user associations which oan be applied within limited time, money, and information tesources available to the typical manager ar water usar associations Indicalors are oriented toward items thal directly or indirectly affect waler deliveries, rather than indicators like crop yields that are also affected by other factors, Indicators also oriented toward the existing system, aspects which do not require major modification

of the infrastructure

Peter et ai (2002) summaries the background to irrigation water provider benchmarking

in Australia, summaries why the imrigation providers participate in the annual benchmarking report, outlines what has been achieved by providing the benchmarking reports and explores the challenges for benchmarking in the fature

Molden et al, (2001) provided a set of comparative performance indicators, which relates outputs from imtigated agricultuze to the major inputs of water, land, and finance Nine indicators are presented with the objective of providing a means of comparing performance across irrigation systems These indicators require a limited amount of data that arc generally available and readily analyzed Results of application of the indicators

at 18 imtigation systems are presented and large differences in performance among systems are shown In spite of uncertainties in estimation of indicators, the large differences discerned by the indicators justify the approach taken

IPTRID Secretariat, FAQ(2000) provided Guidelines for Benchmarking Performance

in the Irvigation and Drainage sector supporl procedures to assist in The process of dala

identification, collection, entry, processing and analysis for the imigalion and drainage benchmarking exercise

Sakthivadive et al (1999; introduced comparative performance indicators that make it possible to see how well imigated agriculture is performing at the system, basin or

national scale, As a tool for measuring the relative performance of irrigation systems or tracking the performance of individual systems the I'WMI comparative performance

indicators help:

« Policy nikers and planners ta evaluate how productively land and waler

reas are baing used for agricattarc, and to make tore informed slralegic decisions regarding istigation and food produetion,

environmental performances of intigation systems The aim of applying comparative

indicators is to evaluate outputs and impacts of irrigation management practices,

interventions across different systems and system levals, as well as to compare various irrigation seasons and lechnologics with onc another The application of comparative indicators should provide system manages, rescarchers, and policy makers with information on differences in performance and, as a consequence, enable them to identify gaps in irrigation management policies Generally, process indicators are used to assess acual irrigation performance relative lo syslemespecific management goals ard operational targels It is believed thal, in comparison with process indicators, the application of comparative indicators requires data collection procedures that are less time- and resource-consuming

Bos ef al (1994) introduced a framework isrigation managers can usc in asscsing performance of istigation and recommends a specific set of indicators for measuring performance that the authors believe are practical, useful, and generally applicable Although the primary focus is on the management of canal systems for agricultural production, Ihe paper also discusses indivalors thal can be used for assessing longer term performance, including physical, economic and social sustainability Finally, the paper highlights the crucial importance of strategic, as well as operational management performance, and the necessity of having an incentive system that encourages managers

fo improve parformance

Bos (1997) summmarisd the performance indicators currely used in the Research Program on Irrigation Performance Within program ficld dala are mucasurcd and collected to quantify and test about nmiltidisciplinary performance indicators, These indicators cover water delivery water nse efficiency, maintenance, sustainability of

imation, environmental aspects, socio-economics and management ‘he indicators now

are sufficicnlly maturz to be rooommcnded for usc in irrigation and drainage performance assessment,

10

autonomy, financing their activities primatily from inigation fees collected from the farmers The power to set the fees, however, resides with the provincial government and not with the srigation enterprises The fee, which is an area-based fee differentiated by crop and scason, is scl in terms of paddy lo Gicilitalc maintaining its roal value in the face of inflation Both cost and oquity factors arc taken into consideration in setting the schedule of fees The fees in government gravity irrigation schemes are fairly high by comparison with other Asian countries; however they are lower than typically paid by fariners ivr the small pump irrigation schemes operated by the agricultural cooperalives Lank Ford & John Gowing (1995) provided a method is presented to analyse the impact

of the selection of irrigation gates on operational performance of the Sungai Muda Inigation Scheme in Malaysia The method cxamiines the discharge capacity of the watcr control gates at all levels in order to compare the specific water supply (the ratio of supply to command area) with the specific water demand which is the required hydromodule, The lerm hydromodule is the reciprocal of *“waterduty” and thus has unils

of tites/sccond/heetare The greater the deviation belwosn the two, the greater (he potential loss of control during the operation of the scheme The method is relatively simple but is more complex in this particular example as two hydromodules are used for the irrigation of basin tice; one for the presaturation period and one for the normal supply porind The mos! common causc of loss of water control is found to be provision af oversized tumout gates at the head of scconduy and tertiary canals Such design approximations enable more water to be used in those command areas thus leading to waste and to shortage of water in other areas It is suggested that during design and

of irrigation schemes, the operational implications of design approximations should be cxaminsd morc carefully

by cach in trying to match waler supply and demand The analysis shows that, everything else being equal, the famer managed system performs better than the government system in matching supply and demand This means that the farmer managed systems should be encouraged for fiture small holder irrigation development in 7imbnbwe

Small & Rimal (1995) Based on a simulation model reflzcting physical and

coniitions typically found in rice irrigation syslcms in Asia, the irrigation performancs implications of alternative watcr distribution rules for dry scason imtigation are ovaluated under varying degrees of water shortage ‘Ihe rules examined reflect differing water distribution strategies designed either te maximize conveyance effiaency, economic aflicieney, or aquity; or to achieve a balance belwasn officicncy and cyuity objcetives Inigation performance is evaluated using several clficicncy measures reflcoting thre physical, agronon-de and economic productivity of water, and one measure of equity Economic efficiency and equity among farmers within the portion of the irrigation system that is "on" in any given season are shown to be complementary, and nol competing objectives Economie efficiency and cquily among all farmers within the command arca

11

of the irtigation system are largely complementary strategies at the lower levels of water shortage, but with increasing shortage, significant tradeoffs develop between these objectives An operational rule for water distribution under a goal of maximizing cconomic officiency is doveloped, and the dala requiroments for its implementation arc shown to be modest, Under the model's assumed conditions of dry scason tice production dependent solely on surface isrigation for water, the distribution stateey designed to maximize conveyance efficiency results in only modestly lower levels of economic efficiency and equity than could bs achieved by Ihe strategy designed (o maximize coanomia efficiency,

Zalidis ot al, (1997) provided a method for estimating of a network irrigation ofli¢ioncy

to cope with reduccd water supply The ovcrall irrigation efficiency, cp, for the intigation networks in the Thessaloniki plain, in Northern Greece, was estimated from historical data, spanning eight years, Irrigation networks differ regarding the method of water delivery and the method of field application

Overall isrigation efficiency is the parameter which helps to adjust water supply to meet the actual crop waler roquiremants A method is introduced which calculates networks op using spatially distributed data, Efficicney valucs for all systems were calculated using, the proposed method Seasonally averaged ep values for eight years for 32 (surface and

sprinkler) irrigation networks ranged from 0.38 to 0.8 1 Analysis ofthe time series ep

values canidentify operational factors that might affect network ep Sprinkler and surface nolwork irrigation efficiencies did nol show any significant differonce

Thoreson et al (1997) provided a framowork for delermining the effect of maintenance

events on irrigation system flows is described Standard definitions for courcctive and preventive maintenance are presented and two maintenance objectives and six

classifications are established Maintenance activities and decision criteria common to

many irrigation systerns are suggesied A format for describing these and other maintenance activities is proposed A methodology for selling decision levels for

maintenance activities is presented Maintenance cost is compared with income lost as a

result of less than maximum production because water supplied was insuflicient for crop requirements, [his comparison demonstrates that maintenance decision levels should be scl so thal maximum evapolranspiration can be achisved Budgel request forms and

report forms are presented with cxamples of actual maintenance cvents showing the expected and actual impact on system dows

Cross (1999) developed a general introduction into the concepts of a flexible irrigation water supply in rate, frequency, and duration together with the benefits to the farmer tor doing 50 A flexible water supply allows the farmer the opportunity to choose an on-farm irrigation practice thal, best mols the necds of the desired crap, the cost and availability

of labor, and other local coonomtc or social situations, As walcr quality issucs arc morc closely tied to the issues of water quantity, water use efficiency must improve, A flexible irigation water supply can lead to improved efficiencies, Non-point-source pollution and in-stream flows also become factors in other social issues such as the care of threatened and cudangered spocics Flextble supplics can again help This paper also shaws, through

a casc study, the application of a limited rate arranged system to an irtigation distiict in Washington State where significant flexibility has led to efficient water use and economic and environmental benefits

FAO (1990) provided Guideline for computing crop water requirement

This publication prescnts an updated procedure for calculating refercnec and ciop evapotranspization trom meteorological data and crop coefficients, The guidelines are

intended to provide guidance to project managers, consultants, irrigation engineers,

hydrologisis, agronomists, meteorologists and students for the calculation of reference and crop cvapolranspiratiơn Thzy can be uscd for computing crop waler requirements for both ñmigated and rained agriculture, and for computing water consumption by agricultural and natural vegetation

Agricultural College of Velp, Netherlands (1992) provided Cropwat 7.0: User guide

CROPWAT version 5.7, issued in 1992, is written in BASIC and runs in the DOS envitonment (FAO of the UN, 1992) The English version of CROPWAT 5.7 is replaced

by CROPWAT version 7.0, which contains a completely new version in Pascal, developed with the assistance of the It overcomes many of the shortcomings of the original 5.7 version

The program uscs the same Penman Montcith methodology as used in CROPWAT versions 5.7 and uscs the sam: data such as the CLIMWAT climnatc and rainfall files

The program uscs a flexible mem system and file handling, and extensive usc of graphics, Graphs of the input data (climate, cropping pattern) and results (crop water requirements, soil moisture deficit} can be drawn and printed with ease, Complex cropping patterns can be designed with several crops with staggered planting dates

CropWat 7.0 uses the same equations as in CROPWAT 5.7, but there are some

differences between the mem systems and the types of calculation permitted

4.1, Benchmarking in the Irrigation and Drainage sector

CHAPTER TV

METHODOLOGY

Benchmarking has only recently been introduced into irrigation and drainage sector The

first Benchmarking report for 1997/98 reported by the Austialia National Committee of

Irrigation and Drainage (ANCID) on 33 irrigation systems and used 15 performance

indicators and the 1998/99 Benchmarking report reported on 46 systems and used 47

performance indicators,

An international initiative on Benchmarking in the irrigation ancl drainage sector bogan in

1999 Initially coordinated by IPTRIN this is joint imtiative of the WD, IPTRID, IWMI,

ICID and FAO The initiative was launched at a workshop held in Rome, August 2000 in

which the principles and objectives of benchmarking were discussed, As results, a set of

guidelines for benchmarking were prepared and widely disseminated (Malano & Burton,

2001), a dedicaicd website to disscminate benchmarking information wa tablished

by TWMI (IWMI, 2001) This guideline provides a sct of 27 indicators, which consist of 4

efficiency, financial and

groups: service delivery performance,

environmental performance

Based on guideline and particular characteristies of the study area , this chapter deals

with the details of data collection, data processing and comparative analysis,

4.2 Data collection and analysis

4.2, 1, Data collection

productivity

Thre are 3 groups of indicators for cvalualing sorvice detivery performance, productive

cfficicney and financial performance Data necd for evaluating cach indicator, ficqucncy

of observation and the sources for data collection are provided in table 4.1

Table 4.1: Data and information for evaluating indicators

1 Totalannualvelume ® f@realcdlaing svaperaion | Momhly Vinhyen

humidity, wind speed, sunshine ‘AD hour,

average percolation ratc

- crop coefficient

- area planted to each crop

2 Total annual valume Daily average discharge at ‘Atleast _Lienson Secondary

of irrigation water LiensandivesionandHachhae | twice/day Irrigation

company LIMC

3 Total annual volume —-Inflow al Licnson diversion and | annual TÌMG Secondary

oftotal water supply Bachhac pumping station

- daily rainfall at Vinhyen meteorological station -discharge purnping from groundwater

4 Total arnmual irrigated —- Trrigalcd crop arca for cach ammual TIMG and Secondary

crop area individual crop of 2 season:wet, Agticultural

1 Gross annual - Planted area of each crop and Annual’ LIMC and Secondary

production

2 ‘Total annual -Looal price of each orop Every LIMC and Secondary

production

Financial

performance

1 Total mmber of ‘Number personnel of station and = annual LIMC Secondary

personnel engagedim center offios

T&D services

person unit

‘Total MOM* cost - staff cost

- operation cost (electricity for operation pumping station and equipment, )

= mainlenazice cost (canal, facilities, )

- Overheads(inehide administrative expenses, insurances, taxes, )

Ratio

s Gross water foc - costs for cultivated plants Every LIMC and

collected - yield of crop season = AD

- lecal price of crop productions

Secondary

Water fee per inrigaled area amit

Ratio of waler fee

Data collected have to be processed before calculating indicators Procedures of

processing of each set of data collected (refer ‘Table 4.1) are provided in Table 4.2

Table 4-2: Data processing

TH air humidity, VET ya = Total volume of water

ind speed, sunshine consumed by crops less effective

* avetage percclation rate i Chop type

* top coefficient Ke Etc, — Evapotranspization from

* area planted to each crop cop i from planting to harvest

Œm) (reference the following

section)

R, = Mffective rainfall over crop

area from planting to harvest (m*)

A = Area planted to crop i hay

2 led crap arza for cach whole systcm arca in cach scason and ha

individual erop o[2 soasons:wet, dry _ whole year

3 -Inflow at Lienson diversion and Aggregate up for every year m3

Bachhac pumping station each month

- Operation cost (electricity for whole company

opcration pumping station

and equipment )

- Maintenance cos (canal,

facilities, )

- Ovarhoadstinchade administrative expen insurances, taxes, )

6 | -Salary, bonus, cost for travel,.of Aggregate up for cach distriel and US$

personnel al distriets and center whole company

Tho main aim of an irrigation system is lo supply irrigation waler to fulfill crop waler

requirement Therefore the determination of crop water requircment is esscatial in

assessment of irrigation performance, as it is needed both in efficiency and adequacy

indicators

During its growth, crop requires water for digestion, photosynthesis, transport of mineral

and photosynthesis, strucniral support, growth, and evapotranspiration Because other use

neads very small porcenlage of water, they can be considsred insignificant Crop walor

requirement can be approximated by evapotranspiration (ET)

Crop cvapotranspiration could bz determined by dircel measurcment or calculated from

crop and climate data, In this study, ETo is computed by using Penman-Monteith

approach which is currently considered as best performing combination equation

Reference evapotranspiration (FTo) is defined as the rate of evapotranspiration from a

hypolhotic crop with an assumed crap height of 12 cm, a fixcd canopy reaistanec of 70

smc! and an albedo of 0.23, closely resembling the evapotranspiration from an extensive

surface of green grass of uniform height, actively growing completely shading the

ground and not short of water (Smith, 1990)

The estimation of the ETo ean be determined with the combination formula based on ths

Penman-Montzith approach When combining the derivations found for the acrodynamic

and radiation terms as presented above, the combination foummla can be noted as (Allen

where; ETo reference crop evapotranspiration [mu/day|

R, net radiation at crop surface [MJ/ m’/day]

G soil heal Mux [MI mn” /day]

T average temperature [°C]

U2 wind speed measured at 2m height (m/s)

(ca-ed) vapour pressure deficit |kPal

A slope vapour pressure curve [kPa/*C]

psychomctric constant [kPaPC]’

ETo reference crap cvapolransgiration [min/day]

Ke, crop coefficient The crop coefiicicnt of a particular crop depends on crop charactcristies, time of planting, stages of crop development, length of growth season and climatic conditions

‘The crop growth duration consists of four main stages, which are:

In this study, ETo and ET will be compnted using CROPWAT (FAO of the LIN, 1992) CROPWAT is a decision support system developed by the Land and Water Development Division of FAO, Its main functions we (1) to calculate reference: cvapotranspiration,

crop water requirements and crop irigation requirements, (it) to develop inigation

schedules under various management conditions and scheme water supply, and also (iii)

to evaluals rained production and drought effects and efficiency of irrigalion practices The CROPWAT is meant as a practical tool to help agro-metearologists, agranomists and

irrigation engincers to garry out standard calculations for evapolranspiralion and crop water usc studies, and more specifically the design and management of inigation schemes, It allows the development of recommendations for improved isigation practices, the planning of irrigation schedules nnder varying water supply conditions and the assessment of production under rained conditions or deficit irrigation

The calculations of crop water requirements and irrigation requirements were carried out with The inpnls of climatic and crop data, The development of irrigation schedules and evaluation of rained and imigation practices were bascd on a daily soil-waler balance using various options for water supply and irrigation management conditions Scheme water supply was calculated according to the cropping pattem provided

CROPWAT version 5.7, issued in 1992, is written in BASIC and runs in the DOS environment (FAO of the UN, 1992) The English version of CROPWAT 5.7 is replaced

by CROPWAT version 7.0, which contains a completely new version in Pascal, daveloped with the assistance of the Agrienitural College of Velp, Netherlands Tl overcomes many of the shortcomings of the original 5.7 version CROPWAT for WINDOWS contains a CROPWAT version in Visual Basic to operate in the Windows environment It has been developed with the assistance of the International Irrigation and Development Institute (1113S) of the University of Southampton, UK (Clarke, 1998)

In this analysis, CROPWAT 7.0 is employed because in one hand it is an improved

version of CROPWAT 5.7 and on the other hand it 1s able to calculate crop water

requirement for rice which is unablc to calculate it, and CROPWAT for Windows is used

to calculate crop water requirement for upland crop To caloulate the crop water requirement, data needed in CROPWAT (FAQ of the UN, 1992 and Alien and others,

2, Humidity

The daily actual vapor pressure, ca, in kilopascals (kPa) is required The actual vaper pressure, where not available, can be derived ffom nuximum and mininram relative humidity (°%), psychometric data,(dry and wet bulb temperatures in OQ or dew-point

temperature ('C)

3 Radiation

The daily net radiation expressed in megajoules per square meter per day (MIImi” day") is required, These data we not commonly available but can be derived itom the (average) shortwave radiation measured with a pyranometer or from the (average) daily actual duration of brigh! sumshine (hours per day) measured with a (Campbell-Stokes) sunshine recorder

4, Wind speed

The daily wind speed in meler per second (rr/s) measured at 2m above the ground level

is required, TL is important to verify the height al which wind spced is measured, as the wind speeds measured at ditierent heights above the soil surface differ

2, Effective rainfait

Effective rainfall in relation to erop water requirement is the postion of total annual or seasonal rainfall that is usefid directly or indirectly for crop production at the site where it fills Effective rainfall can be measured directly or determined by formula, Among several formulae available, USDA SC method is the most appropriate to apply in this study le analyze effective rainfall Mathematically, he USDA SC method for monllily effective rainfall can be wrillcn as

Pe =(125 - 0.2 * Pmon)* Pmon/ 125 for Pmon < 250 mmimonth) (4-3)

Pe—0.1 *Pmon + 125 for Pmon > 250 mmémonth) (4-4)

in which

Pon; monthly rainfall (mm)

3 Deep percolation and land preparation

Sccpage and percolation are the lateral and vertical subsurface movernent of waler Texlure and structure of the soil profile, elevation of water lable, soit permeability, depth

of inpervious layer, and topography generally determine these natural phenomena Paddy field, characterized by nearly level or very gantly slopping soils with clay soils and with low water table level below the ground surface, is estimated to have a seepage and

percolation of 6.096 mrn/day (WASCOS, 1983)

The estimates assume thal the soil of the paddy is wal tilled priar lo lransptanting The decp of water required for land prcparation of paddy includes land soaking, through seepage and percolation and evaporation So that the water requirement for tand preparation is taken as 200 mm (Ministry of Agriculture of Vietnam, 1986) For other crops, land preparation can be neglecled

4 Irrigation requirement

The izrigation requirement of a crop is the total amount of water that must be supplied by imigation to a disease-fice crop growing in a large field with adequate soil water and fertility and achieving full production potential under the given growing environment oorenbos and Pruit, 1977) The imigation requirement includes water used for crop consumptive use, maintaining thvorable salt balance within the root zone and overcoming, non-uniformity and inefficiency of urigation, The irrigation requirement excludes water Fromm natural sources stich as pracipitation thal crops ean offactively usc

Irrigation requirement can be computed when E'T is known by using:

1= KT - Pe + RO+ Dp +L eccseneie wie snenianneneneseene (AS) where: 1 imrigation requirement [mny/day]

KT svapotransptration [rarn/day]

Pe effective rainfall [mm/day

Re run off due to irrigation [mav‘day]

Dp deep percolation due to irrigation [ram/day]

L leaching requirement [mnvday]

In this study, the irrigation requirement is also computed by using CROPWAT 7.0 for the whole system CROPWAT does not take into account leaching requirement and groundwater contribution to the soil moisture zone (FAO of the UN, 1992) Because the fields in the system are designed as rice fields bordered by bunds, the horivontal runoff does not occur Therefore, leaching requirement, L, and run off, Ro, in equation (4-5) were cancelled To obtain monthly ittigation requirement for the whole scheme, the input data needed are crop coefficient, planting date and percentage of planting area for each crop (FAO of the UN, 1992)

CHAPTER V ANALYSIS, RESULTS AND DISCUSSION

5.1, Service delivery performance indicators

5.1.1 Reference evapotranspiration

1 Climate

The general climatic condition of the Vinh Phuc province falls under category of tropical monsoon climate Itis influenced primary by the seasonal monsoons, namely Northeast (NF) and the Southzast (SF) the monsoons, The NE monsoons in the dry season normally cocurs from mid Getuber io April The characteristics of this period are less amonnl rainfall, lower humidity and less cloudiness The SE monsoons in the rainy season generally ftom May to September It is period of frequent and heavy rainfall, high relative hnmidity and cloudiness According to statistical data, more than 80% of annual rainfall falls in this period

Ctimatic parameters were taken from the record of Vinh Yen town weather station, this slation is located at the center of study area The study duration is 5 years (1998-2002) The average monthly value of climatic parameters of the study area is shown in Table 5.1 Inaddition, more detail value of the climate parameters can be found in Appendix I

* Source: Vink Yen weather station, 1995-2002

Table 5.1 indicates that the rainfall is distributed unevenly throughout the year The mean monthly rainfall varies from 17.7 mm in Febmary 10 270 tun in June The average maximum temperature varies from 20.9°C in February to 33°C in July while average minimum temperature varies fiom 15.4°C in December to 26.8°C in July The mean

21

montlily relative humidity value is rather high, it varies from 78.1% in Novenibar to 87.7

in March The wind speed varies from 1.4m/s (min) in August ‘to 2.0 nvs in February

(max)

‘Total rainfall of each year (1998-2002) is shown in Table 5.2

Table 5.2 Total rainfall

Total 8224 1338.6 | 11992 16228 | 1418.4 | 12803 rainfall)

The Table 5.2 shows that amount of rainfall varics fiom minimum value of 822.4 mm in

1998 to maximum value of 1622.8 mm in 2001 Mean amount of rainfall in duration 5 years is 1280.3 mm

2, Reference Evapotranspiration ETo

ETo is determined by using CROPWAT 7.0 The Table 5.3 shows the calculated results

of ETo for every month of study area during 5 years (1998-2002)

Table 5.3 Reference Evapotranspiration

‘There are the same pattern of To throughout years, it has usually minimum value in January or February and reaches fo maxiraum value in July

5.1.2 Irrigated area under different crops

Lien Son system has 2 planting season every year Rice is cultivated as major main crop about 90% lolal area Maize and soyhean also are cullivaled with considerable area

22

Other crop is considered negligible compare to the three main crop Table 5-4 shows the summary data of the irrigated area under different crops In addition, more detail value can

Figure 5.2 Crop calendar

The Figure 5.2 shows that for dry season rice, the time of sowing rice seeds is at the end

of December and harvesting date is at the end of April, while calendar for wet season is from middle of May to beginning of September For maize in dry season, transplanting date is at the end of January and harvesting date at the end of May, as wet season,

respectively time is from middle of June to end of September While, calendar of soybean

in dry season begin at the end of January and come to end at the beginning of June, the last calendar for soybean in wet season is fiom end of June to beginning of October

‘There are no crop cultivated at the left time of year

23

5.1.3 Invigation requirement

* Bifective rainfall

Effective rainfall of the study area in the period 1998 to 2002 is caloulated by using equations (4-3) and (4-4) as follows

Pe=(125 - 0.2 * Pmon)* Pmon/ 125 for Pmon < 250 mmimonth) (4-3)

Pe— 0.1 * Pmon + 125 for Pmon > 250 mmémonth) (4-4)

in which

Pmon’ monthly rainfall (mm)

The calculated results are shown in Table 5-5

Table 5.5 Effective Rainfall

‘There are big differences between total effective rainfalls throughout ysars Thøss vales

vatics widely from minimum valuc 619.9 mm in 1998 (o 1018 mn in 2001 The

effective rainfall of the year 1999 have approximats value to the year 2001

Considering the copping pallem and effective rainfall, irrigation requirement in mm/month for the whole scheme can be calculated and shown in Table 5.6 More detail inrigation requirement for each crop and planting date is represented in Appendix III

24

Table 5.6 Irrigation water requirement

Table 5.6 reveals that irrigation is usually high at the beginning of the dry season in

January when water need for land preparation There are far differences between total

inigation water requirements throughout years This value in 1998 is 1698 mm while it is

only 792 mm in 2001, equal to 46.6% Because of in the year 2001, the effective rainfall

is much higher than compare to correspondent value of the year 1998 (refer to Table 5.5)

2

5.1.4 Water supply

Surface water supplied (a Lien Son Irrigalion system is laken through Lien Son diversion

and Bach [lac pumping station Statistical data of duration 5 years (1993 — 2002) is

Lien [Bach |Lien ach Lien Bach Lien |Bach |Liẽn | Bach

Mar 208] 1253| 118 199 2678 597 2354| 1336| 1887| 4024 Apr 30.5] 1134] 132 138 1892 153 2135| 6512| 2182| 577

5.1.5 Over all efficiency

The over all efficiency is ratio of irrigation water requirement and total inflow into canal

system It indicates how many percent of water used actually by crop from total water

supply Table 5.8 shown these value throughout years

Table 5.8 Over all efficiency

Table 5.8 and figure 5.2 indicate that in general the overall efficiency of Lien Son system

is in range from 0.594 to 0.616, it mean that about 60% total water supply is used by crop and 40% lost in processes delivery, distribution and application of irrigation This performance indicator is rather good because of canal network of system has been lined rather much (refer to 2.7)

27

5.1.6 Annual irrigation water delivery per unit irrigated area

The AIWDPUA depend on irrigation requirement and ability of supply of water sources These values of duration (1998-2002) are shown in Table 5.9

Table 5.9 Annual irrigation water delivery per unit irrigated area

Year Water supply | Total irrigated | Water delivery

volume (10°m') | area (ha/year) (m/ha)

From table 5.9 and figure 5.3, it can be seen that the AIWDPUA varies in wide range

from 4,697 m3/ha in 2001 to 7,938 m3/ha in 2001 Because of irrigation requirement of

the year 1998 is less than much the year 2001 so that water supply is correspondent to

meet water demand

5.2 Productive efficiency indicators

5.2.1 Gross annual agricultural production

Planted area, productivity, yield of each crop and gross agricultural production of

duration 5 years (1998-2002) is show in Table 5.10

28

Table 5.10 Total crop Area, Productivity and Yield

Grand

Year tem Unit OW Dry Ory

season | Rainy season | season Rainy season | season Rainy season | — (ha)

From Table 5.10, we can see thai [he crop productivity and yield in study arza increase year lo yar while tolil arca are stable or oven decrease approximate 2,000 ha in 2002 Examples, for rice in dry season, crop productivity increases from 3.55 ton/ha in 1998 to 4.67 ton‘ha in 2002 while yields increase 15,799 tons fom 72,011 tons (1998) to 87,810 tons (2002), equivalent 21.9%, then maize respectively are 2.60 ton/ha to 3.35 ton/ha of crop productivity and 5,383 tons lo 6,332 tons of yield Total yield of rice of 141,826 tons

1n 1998 increased to 170,214 tons in 2002, different amount is 28,388 tans

5.2.2 Total annual agricultural production

Yictd, locat price and totat agricultural production of duration 5 yoars (1998-2002) are shown in Table 5.11

Year | Yield mee Production Yield Em Production Vield ae Production ‘Total prodacticn

don) | @NDMGu) | (1000VMD) | don) | (VNDAm) |(Œ000VND) Gon) | (VN3em) | Q000VND) | (000VNĐ) (08D)

1998 | 141,825.72] 1,850,000 | 262,377,382 | 6,492.95 | 2,000,000 | 12,985,894 10,119.54] 5,100,000 | 51,609,654 | 326,973,130 | 24,084,644

1999 | 152,264.84} 1,750,000 | 266,463,470 | 7,140.61 | 1,850,000 | 13,210,136 2,072.39 | 5,050,000 | 10,465,570 | 290,139,175 | 20,382,099

2000 | 166,573.26 | 1,700,000 | 283,174,542 | 6,783.85 | 1,600,000 | 10,854,154 2,253.96 | 4,900,000 | 11,044,404 | 305,073,100 | 20,528,379 oor | 164,476.00 | 1,550,000 | 254,937,800 | ¢,034.00 | 1,600,000 | 12,854.40 1,708.88 | 4,950,000 | 2,458,956 | 276251156 | 14,161,27:

2002 | 170,224.01 | 1,600,000 | 272,342,416 | 7,299.42 | 1,700,000 | 12409014 2,278.70 | 4,500,000 _| 11,165,630 | 295,917,060 | 19,038,606 Grand | 795,353.83 4,339,295,510 | 35,750.83 62,313,598 1843347 92,744,214 | 1,494,353,621 | 102,295,004

“Source: Vink Phue province statistical Department

31

The Table $.11 indicates thal although the crop yield is increased yoar aor ycar, but total production decreased fiom 24,084,644 USD in 1998 to 19,038,606 USD in 2002 because of local market price of erop production come down, In 1998, local price of rice

is 1,850 VND/ton while it is only 1,600,000 VNDiton in 2002, even 1,550,000 VNDiton

in 2001 Similarly, local price of maize and soybean are decreased also

5.3 Financial performance indicators

5.3.4 Total number of personnel

Total number of personnel of districts and whole company is shown in Table 5.12

Table 5.12 Number of personnel

Unit: person

Year | Mong | Tam Vinh = Yen | Binh Vinh | Offical | Total

Cau | Duong Tuong Lac | Xuyen Yen | Center

5.3.2 Trrigated area per person unit

Table 5.13, Irrigated area per person unit

Unit: ha‘person

Year Mong Tam | Vink ] Yen Binh | Vinh | Average

Cau Dueng | Tuong | Lac Xuyen | Yen

The Tabls 5.13 indicates that thore arc big differenec of irrigated arca per person unit

between districts The average value of Binh Xuyen district is 342.60 while Vinh Yen is

32