Project vinh phuc flood risk and water resource management phu luc

In addition, it has also used to prevent flooding for communes in the lowland area of Binh Xuyendistrict, supplying the living water for residents in the beneficial area in the dryseason

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APPENDIX 1 HYDROLOGICAL CALCULATION

I GEOLOGICAL AND HYDROLOGICAL CHARACTERISTICS OF THE STUDY AREA

II Location of basin

Thanh Lanh reservoir was built in Trung My commune, Binh Xuyen district,Vinh Phuc province The Reservoir was started the construction in 2001 and put intouse in 2006 Headworks cluster includes 1 main dam, 1 intake culvert placed leftabutment of the main dam, 2 auxiliary dams and 1 spillway located in the middle ofthe Auxiliary Dam No 2 line

Thanh Lanh reservoir was built with the tasks to irrigate agricultural land of1200ha of four Communes of Trung My, Thien Ke, Ba Hien and Son Loi In addition,

it has also used to prevent flooding for communes in the lowland area of Binh Xuyendistrict, supplying the living water for residents in the beneficial area in the dryseason…

Table 1-1: The morphological features of Thanh Lanh reservoir basin

Elevation of parapet wall crest m +79.10

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Elevation of downstream

2 Auxiliary dam 1

3 Auxiliary dam 2

III Intake culvert

Elevation of intake-culvert sill m +60.0

IV Spillway

Form of spillway Spill of pragmatic ophixerop with

valve gate

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Figure 1-1 Basin of Thanh Lanh Reservoir

II.1 Topographical and geomorphological characteristics

The study area is generally characterized as hilly terrain The Northeast of thebasin is limited by high mountain range with the elevations lowerinf from theSoutheast from + 1000m to 400m

The sloping direction is from the Northwest - Southeast towards the Thanh Lanhreservoir

II.2 Hydrological Measurement of the project area

Near the study basin, Vinh Yen meteorological station managed by theDepartment of Meteorology and Hydrology has a long-time measurement with assuredquality of measurement and is about 8km Southwest of reservoir Thus, the report isproposed to use data of Vinh Yen meteorological station to calculate the study basin

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II.3 Tốc độ gió

II.3.1 Average wind speed

Average wind speed in the project area is summed up from the data measured inthe reality of Vinh Yen meteorological station The results are presented in thefollowing table:

Table 1-3: Average wind speed in the project location

Vinh Yen (m/s) 1,6 1,9 2,0 2,3 2,2 1,9 1,9 1,5 1,3 1,3 1,3 1,4 1,7 II.3.2 Maximum indirection wind speed

Maximum indirection wind speed in the study area is calculated according to data

of Vinh Yen station The results of calculating maximum wind speed corresponding todesign frequencies are shown in table 1-6 The details of calculation and frequencylines are mentioned in the table

Table 1-4: Maximum indirection wind speed corresponding to design frequencies

II.4 Precipitation causing flood

Because Thanh Lanh reservoir has no precipitation measuring data so the reportused precipitation data of Vinh Yen station to calculate the characteristics ofprecipitation causing flood The calculation results are as follows:

Table 1-5: Maximum daily precipitation in Vinh Yen station (mm)

X1maxTB Cv Cs X0.01% X0.1% X0.2% X0.5% X1% X1.5%128.9 0.51 1.80 655.4 504.5 460.0 401.7 358.1 332.7Frequency line and detailed calculation are shown in the table

III HYDROLOGICAL CHARACTERISTICS

III.1 Design flood flow

Because Thanh Lanh has no flow measuring data while the area of reservoir’sbasin is 22.3 km2, so according to Standard C6-77, the report of design floodcalculation of Thanh Lam reservoir is conducted by using limited intensity experienceformula method

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QP = Ap..Hnp.F+ : The highest discharge corresponding to frequency P

+ : Coefficient of flood flow– with = 0.75

+ HP : Maximum daily precipitation corresponding to design frequency p + F : Basin area (km2), F = 23.0 km2

The calculation results are presented in the below table

Table 1-6: Results of design flood peak calculation in Thanh Lanh basin

Formula to calculate total design flood discharge: WP =HPF * 1000

The calculation results are presented in table 1-7 as follows:

Table 1-7: Results of total design flood peak calculation in Thanh Lanh basin

Wp (106m3) 11.306 8.702 7.935 6.929 6.177 5.739Design flood hydrograph of the study basin is established by triangular shape with the time of water lowering by 1.5 times time of flood rising

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FFC 2008 © Nghiem Tien Lam

TB=128.86, Cv=0.51, Cs=1.80

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FFC 2008 © Nghiem Tien Lam

TB=18.64, Cv=0.25, Cs=0.05

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Design flood of Xa Huong reservoir corresponding to various frequencies

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APPENDIX 2 CALCULATION OF FOLLD REGULATION

V CALCULATION OBJECTIVE

The flood regulation calculation is aimed to examine the possibility of discharge ofthe flood discharge work, the flood water level is the basis for determining the damcrest elevation

VI CALCULATION FREQUENCY

Thanh Lanh Reservoir was built in the years of 2001 to 2006 following the designregulations of that period, of grade III, the frequency of desing and check floodpevention of the reservoir is Pdesign = 1.5% and Pcheck = 0.5%

Under the current regulation QCVN 0405: 2012 / BNNPTNT: irrigation works The main provisions of the design and Thanh Lanh reservoirs belongs to Work ofgrade II, so that Pdesign = 1% and Pcheck = 0.2%

-In addition, at the request of the World Bank, the reservoir has a large number ofhouseholds of 25 households living downstream, hence it is required to calculate thefrequency of check flood with P = 0.01%

Table 2-2 Calculation sequency of flood regulation

Name of

reservoir Work grade PTK (%) PKT1 (%) PKT2 (%)

VII CALCULATION CASES

Conducting calculating the flood regulation for different combinations todetermine flood levels and discharge flow corresponding to current spillway Bspillway =10m, Bincidental spiwwal = 30m

VIII CALCULATION METHOD

Flood regulation calculation is conducted by using DTL2002 program of WaterResources University Algorithm of the code is based n equilibrium equation asfollows:

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With the following marginal conditions:

- Volumetric characteristic of reservoir V = f1 (Z) (2.2)

- Downstream water level characteristic Zh = f2 (q) (2.3)

Where:

V: volume;

t: time;

Q: flood inflow;

q: discharge through spillway;

Z: water level of reservoir;

Zh: downstream water level

In the case of multi-spillway working together:

Where Qxi is discharge through water outlet number, it can be separated:

- Superfacial spillway with entirely opened water gate

- Discharge overtopping the accidental spillway: Applying calculation formulafor flow overtopping the broad-crest spillway, hydraulic calculations of spillwaycorresponding to designed structures

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Where computational terms were determined according to hydraulic handbook

and procedures for spillway hydraulic calculation (TCVN 9147-2012) and technicalrequirements for and bottom water outlet hydraulic calculation (TCVN 9151-2012).For calculation, equation (1) is differentiated as follows:

1 2 2

1 2

2

1 ) (

2

1

V V t q q t Q

- Form of spillway: spill coefficient: m; the side-narrow coefficient ε

- Parameter of water level: NWL (m); spillway sill elevation (m);

- Relationship graph-line Z ~ V;

- Flood flow hydrograph Q ~ t ;

- The parameters of the main spillway and other spillways if it can be parallelcalculated;

+ The calculation steps:

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Block diagram of software

Figure 2.37: Block diagram of software

* Calculation results

- Relationship graph-line Q ~ t

- Relationship graph-line q ~ t (can separate components of qi)

BeginRead data

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IX PARAMETERS OF WORK

Form of spillway:

- Main spillway

+ Number of spill chambers: 1 chamber Btr = 10m

+ Elevation of spillway sill: +71,6 m

+ Elevation of normal rising level: +76,6 m

+ Flow coefficient m= 0,41

- Incidental spillway

+ Number of spill chambers: 1 chamber Btr = 40m

+ Elevation of spillway sill: +77,0m

+ Elevation of normal rising level: +76,6 m

+ Flow coefficient m= 0,34

X CALCULATION RESULTS

X.1 Case of current status: B tr = 10m, B trsc =30m

X.1.1 Calculation of flood regulation with frequencyP =1%

FLOOD REGULATION CALCULATING PROGRAM DTL2002 - KET QUA TINH TOAN

The work: Thanh Lanh reservoir Option with Bspill = 40 (m) Qfrequent flood 1% = 329.40 (m3/s)

A.\ SPILLWAY PARAMETERS ========================================================================== Spill 1 Spill 2 Spill 3 Spill 4 Spill chamber : 1 1 0 0 The Width (m) : 10.00 30.00 0.00 0.00 Sill elevation (m): 71.60 77.00 0.00 0.00 Flow coefficient : 0.41 0.34 0.00 0.00 Side-narrow coeff.: 1.00 1.00 0.00 0.00 Crest elevation(m) : 0.00 0.00 Flip elevation (m) : 0.00 0.00 HSLL after flip: 0.00 0.00 -

B.\ DETAILED CALCULATION RESULT ==========================================================================

T Qto Qculv Qspill1 Qspill2 Qspill3 Qspill4 Qx¶tæng Zhå (giê) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m) -

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0.40 31.6 0.0 31.6 0.0 0.0 0.0 31.6 76.60 0.90 71.1 0.0 71.1 0.0 0.0 0.0 71.1 76.60 1.40 110.6 0.0 110.6 0.0 0.0 0.0 110.6 76.60 1.90 150.1 0.0 150.1 0.0 0.0 0.0 150.1 76.60 2.40 189.6 0.0 189.6 0.0 0.0 0.0 189.6 76.60 2.90 229.1 0.0 197.9 0.0 0.0 0.0 197.9 76.62 3.40 268.6 0.0 202.1 0.0 0.0 0.0 202.1 76.68 3.90 308.1 0.0 209.3 0.0 0.0 0.0 209.3 76.79 4.40 317.3 0.0 218.7 0.0 0.0 0.0 218.7 76.93 4.90 290.9 0.0 226.0 0.1 0.0 0.0 226.1 77.03 5.40 264.6 0.0 230.4 0.9 0.0 0.0 231.3 77.09 5.90 238.2 0.0 232.1 1.3 0.0 0.0 233.4 77.12 6.40 211.9 0.0 231.4 1.1 0.0 0.0 232.5 77.11 6.90 185.5 0.0 228.5 0.5 0.0 0.0 229.0 77.07 7.40 159.2 0.0 223.6 0.0 0.0 0.0 223.6 77.00 7.90 132.8 0.0 217.0 0.0 0.0 0.0 217.0 76.90 8.40 106.5 0.0 208.8 0.0 0.0 0.0 208.8 76.78 8.90 80.1 0.0 199.2 0.0 0.0 0.0 199.2 76.64 9.40 53.8 0.0 53.8 0.0 0.0 0.0 53.8 76.60 9.90 27.4 0.0 27.4 0.0 0.0 0.0 27.4 76.60 10.40 1.1 0.0 1.1 0.0 0.0 0.0 1.1 76.60 10.90 0.0 0.0 0.0 0.0 0.0 0.0 0.0 76.60 -

MAX DISCHARGE FLOW= 233.46 (m3/s) TIME AMOUNT = 6.00 ( hr)

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Figure 2-2 Calculation results of flood regulation P =1%

X.1.2 Calculation of flood regulation with frequencyP =0,2%

The work: Thanh Lanh reservoir Option with Bspill = 40 (m) Qfrequency flood 0.2% = 449.90 (m3/s)

CALCULATION RESULTS OF FLOOD REGULATION

Work: Thanh Lanh reservoir

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T Qto Qculv Qspill1 Qspill2 Qspill3 Qspill4 Qx¶tæng Zhå (hr) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m) - 0.40 45.9 0.0 45.9 0.0 0.0 0.0 45.9 76.60 0.90 103.3 0.0 103.3 0.0 0.0 0.0 103.3 76.60 1.40 160.7 0.0 160.7 0.0 0.0 0.0 160.7 76.60 1.90 218.1 0.0 197.2 0.0 0.0 0.0 197.2 76.60 2.40 275.4 0.0 201.3 0.0 0.0 0.0 201.3 76.67 2.90 332.8 0.0 209.9 0.0 0.0 0.0 209.9 76.80 3.40 390.2 0.0 222.7 0.0 0.0 0.0 222.7 76.98 3.90 447.6 0.0 239.7 3.8 0.0 0.0 243.4 77.23 4.40 413.2 0.0 256.1 12.1 0.0 0.0 268.2 77.45 4.90 374.9 0.0 267.2 19.4 0.0 0.0 286.6 77.60 5.40 336.7 0.0 273.3 24.0 0.0 0.0 297.3 77.69 5.90 298.4 0.0 275.0 25.4 0.0 0.0 300.5 77.71 6.40 260.1 0.0 273.1 23.9 0.0 0.0 297.0 77.68 6.90 221.9 0.0 268.1 20.1 0.0 0.0 288.2 77.62 7.40 183.6 0.0 260.5 14.8 0.0 0.0 275.3 77.51 7.90 145.4 0.0 250.7 9.0 0.0 0.0 259.7 77.38 8.40 107.1 0.0 239.1 3.5 0.0 0.0 242.7 77.22 8.90 68.9 0.0 225.8 0.1 0.0 0.0 225.9 77.03 9.40 30.6 0.0 210.8 0.0 0.0 0.0 210.8 76.81 9.90 0.0 0.0 0.0 0.0 0.0 0.0 0.0 76.60 10.40 0.0 0.0 0.0 0.0 0.0 0.0 0.0 76.60 10.90 0.0 0.0 0.0 0.0 0.0 0.0 0.0 76.60 -

MAX DISCHARGE FLOW = 300.47 (m3/s) TIME AMOUNT = 5.90 ( hr)

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Figure 2-3 Calculation results of flood regulation P =0,2%

X.1.3 Calculation of flood regulation with frequencyP =0,01%

The work: Thanh Lanh reservoir Option with Bspill = 40 (m) Qfrequent flood 0.01% = 704.30 (m3/s)

A.\ SPILLWAY PARAMETERS

==========================================================================

Spill 1 Spill 2 Spill 3 Spill 4 Spill chamber : 1 1 0 0 The Width (m) : 10.00 30.00 0.00 0.00 Sill elevation (m): 71.60 77.00 0.00 0.00 Flow coefficient : 0.41 0.34 0.00 0.00 Side-narrow coeff.: 1.00 1.00 0.00 0.00 Crest elevation(m) : 0.00 0.00 Flip elevation (m) : 0.00 0.00 HSLL after flip: 0.00 0.00

-CALCULATION RESULTS OF FLOOD REGULATION

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B.\ DETAILED CALCULATION RESULT

==========================================================================

T Qto Qculv Qspill1 Qspill2 Qspill3 Qspill4 Qx¶tæng Zhå

(hr) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m)

0.40 78.9 0.0 78.9 0.0 0.0 0.0 78.9 76.60 0.90 177.6 0.0 177.6 0.0 0.0 0.0 177.6 76.60 1.40 276.2 0.0 199.5 0.0 0.0 0.0 199.5 76.64 1.90 374.8 0.0 210.0 0.0 0.0 0.0 210.0 76.80 2.40 473.5 0.0 228.3 0.5 0.0 0.0 228.8 77.06 2.90 572.1 0.0 253.9 10.8 0.0 0.0 264.7 77.42 3.40 670.8 0.0 285.9 34.5 0.0 0.0 320.4 77.85 3.90 660.8 0.0 319.1 68.0 0.0 0.0 387.2 78.28 4.40 594.8 0.0 341.6 94.5 0.0 0.0 436.1 78.56 4.90 528.9 0.0 353.4 109.5 0.0 0.0 462.9 78.70 5.40 462.9 0.0 356.5 113.4 0.0 0.0 469.9 78.74 5.90 397.0 0.0 352.5 108.3 0.0 0.0 460.8 78.69 6.40 331.0 0.0 343.2 96.5 0.0 0.0 439.7 78.58 6.90 265.1 0.0 329.8 80.2 0.0 0.0 410.0 78.41 7.40 199.2 0.0 313.1 61.5 0.0 0.0 374.6 78.20 7.90 133.2 0.0 294.0 42.0 0.0 0.0 336.0 77.96 8.40 67.3 0.0 272.7 23.6 0.0 0.0 296.3 77.68 8.90 1.3 0.0 249.6 8.3 0.0 0.0 257.9 77.36 9.40 0.0 0.0 227.4 0.3 0.0 0.0 227.7 77.05 9.90 0.0 0.0 208.1 0.0 0.0 0.0 208.1 76.77 10.40 0.0 0.0 0.0 0.0 0.0 0.0 0.0 76.60 10.90 0.0 0.0 0.0 0.0 0.0 0.0 0.0 76.60 -

-MAX DISCHARGE FLOW = 469.88 (m3/s) TIME AMOUNT = 5.30 ( hr)

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Figure 2-4 Calculation results of flood regulation P =0,01%

X.1.4 Calculation of flood regulation with case of blocked valve

The work: Thanh Lanh reservoir Option with Bspill = 40 (m) Qfrequent flood 1% = 329.40 (m3/s)

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T Qto Qculv Qspill1 Qspill2 Qspill3 Qspill4 Qx¶tæng Zhå (hr) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m3/s) (m) - 0.40 31.6 0.0 0.0 0.0 0.0 0.0 0.0 77.02 0.90 71.1 0.0 0.0 0.7 0.0 0.0 0.7 77.08 1.40 110.6 0.0 0.0 3.0 0.0 0.0 3.0 77.20 1.90 150.1 0.0 0.7 8.2 0.0 0.0 8.9 77.36 2.40 189.6 0.0 2.9 17.2 0.0 0.0 20.1 77.56 2.90 229.1 0.0 6.7 30.8 0.0 0.0 37.5 77.80 3.40 268.6 0.0 12.2 49.4 0.0 0.0 61.5 78.05 3.90 308.1 0.0 19.4 72.7 0.0 0.0 92.0 78.33 4.40 317.3 0.0 27.8 99.3 0.0 0.0 127.1 78.60 4.90 290.9 0.0 35.1 121.9 0.0 0.0 156.9 78.81 5.40 264.6 0.0 40.4 138.2 0.0 0.0 178.5 78.95 5.90 238.2 0.0 43.5 147.9 0.0 0.0 191.4 79.03 6.40 211.9 0.0 44.9 152.2 0.0 0.0 197.2 79.07 6.90 185.5 0.0 45.0 152.4 0.0 0.0 197.4 79.07 7.40 159.2 0.0 43.9 149.1 0.0 0.0 193.0 79.04 7.90 132.8 0.0 41.9 142.9 0.0 0.0 184.8 78.99 8.40 106.5 0.0 38.9 133.8 0.0 0.0 172.7 78.92 8.90 80.1 0.0 35.4 123.0 0.0 0.0 158.5 78.82 9.40 53.8 0.0 31.6 111.1 0.0 0.0 142.6 78.71 9.90 27.4 0.0 27.5 98.3 0.0 0.0 125.7 78.59 10.40 1.1 0.0 23.2 84.9 0.0 0.0 108.2 78.46 10.90 0.0 0.0 19.4 72.8 0.0 0.0 92.1 78.33 11.40 0.0 0.0 16.3 62.9 0.0 0.0 79.2 78.22 11.90 0.0 0.0 13.8 54.9 0.0 0.0 68.7 78.12 -

MAX DISCHARGE FLOW = 197.87 (m3/s) TIME AMOUNT = 6.70 ( hr)

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Figure 2-5 Calculation results of flood regulation with blocked valve-gate

X.2 Summary of calculation results

Table 2-3 Summary of Calculation results of flood regulation

Calculation cases

Case Btr = 10m, Bincidental spillway = 30m

P= 1,0% P = 0,2% P= 0,01%

P= 1,0%,kẹt cửa van

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APPENDIX 3 CALCULATION OF DAM REST ELEVATION

I CALCULATION SEQUENCE

The dam crest elevation is determined at 2 water levels: Normal water level anddesign flood water level (NRWL and DFWL) (corresponding to the design floodP=1.0%) and must be higher than CFWL1 (corresponding to the check flood level,P=0.2%), CFWL2 (responding to the check flood level, P=0.01%)

sl are the height of wave run-up on slope (reliability of 1%) corresponding

to the max calculation wind and the max average wind

a, a’, a”- safe freeboard corresponding to NWL, DFWL and CFWL with the work

of grade II (refers to Table 2 in design standards for compatced soil dam, TCVN 2009), then a =0.7 m; a’ = 0.5 m; a” = 0.2 m

8216-Wind frequency calculations is referred to Table 3 in design standards of compactedearth dam TCVN 8216-2009, then the largest and the largest average calculated windfrequencies are 2% and 25%, respectively

The dam crest elevation to be selected is the elevation with the max value amongthe above 5 results

- Determine h:

h = kw

2( 0,5 )

V D

+ : angle between the vertical axis of the water storage area and wind direction

+ V: calculated velocity of the wind+ D: wave momentum

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