using arcswat for evaluation of water productivity and ... · saving just a small amount of water...

Using ArcSWAT for Evaluation of Water Productivity and Economics of Crops in Canal Irrigation Command

R.T.ThokalHead, Dept. of Irrigation and Drainage EngineeringCollege of Agril Engg. And Tech., Dr.BSKKV, DapoliMaharashtra State, INDIA

[email protected]

S.D. GorantiwarHead, Dept. of Irrigation and Drainage EngineeringDr. A. S. College of Agril Engg., Mahatma Phule Krishi Vidyapeeth, Rahuri, Dist. Ahmednagar, Maharashtra State, INDIA

SWAT International Conference 2012 – New Delhi

Importance of Irrigation Water Management in Water Scarce Regions

Development of framework using SWAT for irrigation water management of command area

Case study Application: Root zone moisture status, Crop

Net benefit and Water Use Efficiency

SWAT International Conference 2012 – New DelhiThokal, R.T.; S. D. Gorantiwar; Kothari Mahesh; Bhakar, S.R. and Purohit, R.C.Thokal, R.T.; S. D. Gorantiwar; Kothari Mahesh; Bhakar, S.R. and Purohit, R.C.

Water - most critical natural resource for agriculture in the twenty-first century

Use of water for irrigation is by far the greatest consumer of fresh water globally

Irrigated regions globally consume more than 70% of the world’s water resources

Saving just a small amount of water destined for irrigation and using it for drinking purpose instead, could improve the living conditions of millions of people

Increasing irrigation efficiencies seem to be the practical way to save water

Deficit irrigation strategy - application of water below full crop-water requirements

Deficit irrigation can lead to greater economic gain in case of drought and water scarce condition

Thokal, R.T.; S. D. Gorantiwar; Kothari Mahesh; Bhakar, S.R. and Purohit, R.C.Thokal, R.T.; S. D. Gorantiwar; Kothari Mahesh; Bhakar, S.R. and Purohit, R.C.Thokal, R.T.; S. D. Gorantiwar; Kothari Mahesh; Bhakar, S.R. and Purohit, R.C.Thokal, R.T.; S. D. Gorantiwar; Kothari Mahesh; Bhakar, S.R. and Purohit, R.C.Thokal, R.T.; S. D. Gorantiwar; Kothari Mahesh; Bhakar, S.R. and Purohit, R.C.Thokal, R.T.; S. D. Gorantiwar; Kothari Mahesh; Bhakar, S.R. and Purohit, R.C.Thokal, R.T.; S. D. Gorantiwar; Kothari Mahesh; Bhakar, S.R. and Purohit, R.C.Thokal, R.T.; S. D. Gorantiwar; Kothari Mahesh; Bhakar, S.R. and Purohit, R.C.SWAT International Conference 2012 – New DelhiSWAT International Conference 2012 – New DelhiSWAT International Conference 2012 – New Delhi

Components of Framework

Tool framework mainly comprises three modules: – Allocation rules module– SWAT modules– economic module

Framework also has a facility to use crop growth module externally Water allocation rules can be given as input according to water

availability in reservoir Soil water balance is done through SWAT module External crop growth model uses output of ETp and ETa from

SWAT Economic module computes cost of cultivation of crops, gross and

net benefits of individual crop as well as project net benefit for respective allocation rule

Tool framework is able to estimate daily updates of reservoir storage


Development of Conceptual Framework

SWAT

Provide various combinations of Water

Allocation Rules

Input Data: Allocation Units (AUs), crop, soil, weather related data, reservoir storage data

Initialize Reservoir Storage

Allocation Rules

AU = 1

Crop = 1

Soil = 1

Initialize soil moisture

Estimate root zone depth, ETo and effective rainfall

5

1


Allocation Rules



Allocation Rules

AU = 1

Crop = 1

Soil = 1



1


Allocation Rules



Allocation Rules

3

Day = 1 (Max. 365 days)

AU = 1

Crop = 1

Soil = 1



4

1

6

Continued …

SWAT1

Yes

5

Update soil moisture in root zone

Estimate ETa

Is the event day of irrigation?

No

Yes

All Crops over?

No Crop = Crop + 1

All Soils over?No

Yes

4

Soil = Soil + 1

NoAll AUs over?

Yes

Calculate Canal Water Release

Canal Network Model

2

1

Yes

Update soil moisture in root zone

Estimate ETa

Estimate depth of irrigation according to

Allocation Rule

No

Is the event day of irrigation?

All Crops over?

No Crop = Crop + 1

All Soils over?No

Yes

4

Soil = Soil + 1

NoAll AUs over?

Yes

Calculate Canal Water Release

Canal Network Model

2

AU = AU + 1

6

Continued …

SWAT

Output: Canal Water Storage, Net Benefit, Crop Yield for each Crop, Soil and AU, Carry over Storage

Estimate carry over storage

Estimate Net BenefitEconomics Model

Plant Growth Model Estimate Crop Yield

Obtain crop growth stage- wise ETo, ETa for each crop, soil and in AU

3

NoAll days over?

Yes

Update Reservoir Storage

2

TerminateIs reservoir storage less than or equal to dead storage or

predefined stage?

No

Yes

External Crop Growth Model

Stewart water production function (or any other suitable model)

s

ss

so

aons

sy

m

a

ETETET

KYY

1

1


Location of Study Area

Sina Medium Irrigation Project

Tributary of river Bhima in Krishna basin

Location: Nimgaon Gangarda village, Tal. Karjat, Dist. Ahmednagar

Location: Latitude 18o49’0”N Longitude 74o57’0”E

Topo-sheets No.: 47 J/13, 47 J/14, 47 N/1 and 47 N/2

Location of Sina Irrigation ProjectSWAT International Conference 2012 – New Delhi

Features of Study Area

Annual rainfall: 503.80 mm Reservoir gross capacity: 67.98 M cum Live storage: 52.33 M cum Dead storage: 15.65 M cum Observed percentage of live storage in reservoir over a

period of 25 years is 69.92 (36.57 M m3) Culturable Command Area (CCA): 9677 ha Irrigable Command Area (ICA): 8445 ha ICA under Right Bank Canal: 7656 ha


SRTM images (SRTM_51_091 and SRTM_52_091) were mosaiced and used for preparation of DEM

Pre-defined stream definition option was selected for watershed delineation

User-defined canal network (stream) and outlet command (sub-basins) were linked with each other and input to SWAT

Cropping pattern in study area

Kharif season (June to October) crops:– Sunflower (4154 ha)– Pearl millet (3320 ha)– Mung bean (89 ha)– Kharif sorghum (14 ha)

Rabi Season (November to March) crops:– Wheat (4154 ha)– Groundnut (3320 ha)– Rabi sorghum (89 ha)– Onion (14 ha)

Annual crops:– Sugarcane (78 ha)


Soils of study area

Mirajgaon series (Clay): 1566 ha

Ratanjan series (Silt clay): 1820 ha

Ghumari series (clay loam): 3084 ha

Nagalwadi series (Silt loam): 1185 ha


Soil Slope in study area

0-0.5% slope: 75 ha

0.5-1% slope: 1276 ha

1-3% slope: 6265 ha

3-5% slope: 38 ha

Above 5% slope: 2 ha


Water Allocation Rules

Percentage of area to be irrigated– 100% ICA– 80% ICA– 60% ICA– 40% ICA– 20% ICA

Release rate from reservoir– 5 m3/sec– 4 m3/sec– 3 m3/sec– 2 m3/sec– 1.5 m3/sec

Irrigation depth– 90 mm– 70 mm– 50 mm


Irrigation Rotations

Kharif season (June to October): 28 days Rabi season (November to February): 21 days Summer season (March to May): 14 days


Allocation Units Analysis

SWAT sub-divided irrigation command area (7656 ha) of 72 units in 305 AUs

First unit was allocated as Reservoir Most of the crops are concentrated in

0.5 to 1% followed by 0 – 0.5% slope category


Soil moisture status in root zone of sunflower due to water application

Sunflower

0

50

100

150

200

250

300

350

1 8 15 22 29 36 43 50 57 64 71 78 85 92 99 106 113 120Days after sowing

Soil

moi

stur

e av

aila

ble

in ro

ot z

one

(mm

)

0

50

100

150

200

250

300

350

Irrig

atio

n an

d pr

ecip

itatio

n (m

m)

Clay (90mm) Silt clay (90mm) Clay (70mm) Silt clay (70mm)Clay (50mm) Silt clay (50mm) PRECIPmm IRRmm


Clay and silt clay soils

Soil moisture status in root zone of sunflower due to water application

Sunflower

0

10

20

30

40

50

60

70

80

1 8 15 22 29 36 43 50 57 64 71 78 85 92 99 106 113 120

Days after sowing

Soi

l moi

stur

e av

aila

ble

in ro

ot z

one

(mm

)

0

50

100

150

200

250

300

350

400

Irrig

atio

n an

d pr

ecip

itatio

n (m

m)

Clay loam (90mm) Silt loam (90mm) Clay loam (70mm) Silt loam (70mm)Clay loam (50mm) Silt loam (50mm) PRECIPmm IRRmm


Clay loam and silt loam soils

Soil moisture status in root zone of wheat due to water application

Wheat

0

50

100

150

200

250

300

1 8 15 22 29 36 43 50 57 64 71 78 85 92 99 106 113 120Days after sowing

Soi

l moi

stur

e av

aila

ble

in ro

ot z

one

(mm

)

0

50

100

150

200

250

Irrig

atio

n an

d pr

ecip

itatio

n (m

m)

Clay (90mm) Silt clay (90mm) Clay (70mm) Silt clay (70mm)Clay (50mm) Silt clay (50mm) PRECIPmm IRRmm

Clay and silt clay soils


Wheat

0

10

20

30

40

50

60

70

80

1 8 15 22 29 36 43 50 57 64 71 78 85 92 99 106 113 120

Days after sowing

Soil

moi

stur

e av

aila

ble

in ro

ot z

one

(mm

)

0

50

100

150

200

250

300

350

Irrig

atio

n an

d pr

ecip

itatio

n (m

m)

Clay loam (90mm) Silt loam (90mm) Clay loam (70mm) Silt loam (70mm)Clay loam (50mm) Silt loam (50mm) PRECIPmm IRRmm

Clay loam and silt loam soils


Percent yield reduction in kharifseason crops

0

2

4

6

8

10

12

14

16

18

clay silt clay clay loam silt loam clay silt clay clay loam silt loam silt clay silt loam silt loam

sunflower pearl millet Mung beans kharifsorghum

Yie

ld re

duct

ion

(%)

90mm 70mm 50mm

Percent yield reduction in annual and rabi season crops


0

10

20

30

40

50

60

70

80

clay siltclay

clayloam

siltloam

clay siltclay

clayloam

siltloam

clay siltclay

clayloam

siltloam

siltclay

siltloam

Siltloam

wheat Sugarcane Groundnut Rabi sorghum Onion

Yie

ld re

duct

ion

(%)

90mm 70mm 50mm

Net Returns from kharif season crops


05000

10000

15000200002500030000

350004000045000

clay silt clay clayloam

silt loam clay silt clay clayloam

silt loam silt clay silt loam silt loam


Net

retu

rns

(Rs.

/ha)

90mm 70mm 50mm

Net Returns from annual and rabiseason crops

-30000

-20000

-10000

0

10000

20000

30000

40000

50000

60000

silt clay clayloam

siltloam


siltloam


siltloam

silt clay siltloam

siltloam

Sugarcane Groundnut Rabi sorghum Onion

Net

Ret

urns

(Rs./

ha)

90mm 70mm 50mm


Irrigation water use efficiency for kharif season crops


0

20

40

60

80

100

120

140


silt loam clay silt clay clayloam

silt loam silt clay silt loam silt loam


Irrig

atio

n W

ater

Use

Effi

cien

cy (k

g/ha

-cm

)

90mm 70mm 50mm

Irrigation water use efficiency for annual and rabi season crops


0100200300400500600700800900

clay siltclay

clayloam

siltloam

clay siltclay

clayloam

siltloam

clay siltclay

clayloam

siltloam

Siltclay

siltloam

Siltloam

wheat Sugarcane Groundnut Rabi sorghum Onion

Irrig

atio

n W

ater

Use

Eff

. (kg

/ha-

cm

90mm 70mm 50mm

using arcswat for evaluation of water productivity and ... · saving just a small amount of water...

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