Sustainability of Groundwater Use for Irrigation in Northwest Region of Bangladesh

Sujit K BalaAKM Saiful Islam

Workshop onResearch to Inform Food and Nutrition Security Policies

3-4 July, Ball Room, Rupashi Bangla Hotel, Dhaka

Workshop onResearch to Inform Food and Nutrition Security Policies

3-4 July, Ball Room, Rupashi Bangla Hotel, Dhaka

Research Team

Nepal C DeyMd. Abdur RashidRatnajit Saha

Research AdvisorMahabub Hossain

Sujit K BalaAKM Saiful IslamAhsan A Shopan

Challenges Sustainability of GW use is becoming a vital concern in many countries of the world, Bangladesh in particular, mainly NW of Bangladesh-where GW declines 5-10m in the dry period

Below-average rainfall, higher temp causing drought, increased ET, delayed

monsoon, dry up of surface water bodies & thuslowering of GWT leading water crisis are somebarriers to ensure sustainability in the NW Bangladesh.

Withdrawal of GW

WB ‘s concern is that expected 2°C rise in world’s aver Temp in next decades and shifting of rain patterns could leave some areas under water & others without enough water for irrigation or drinking which threatening food production, livelihoods & reduction on poverty in South Asian Countries.

Contribution of GW use for irrigation has increased 2.5 times over 20 years

2ºC

June 19, 2013

Challenges (contd.)

Defects in present IWM practices has been identified. If water is managed properly, BGD can save addl. amount ≈ 1/6 of the total BGD

Budget for FY 2003-4 (USD 8,962 million) (Deyet al., 2006), and also similar to the ADP budgetof Bangladesh for FY 2009-10 (USD 4072million).

www.iwaponline.com/wp/00806

Irrigation cost has increased many folds which threatens the economic viability of future crop production.

Irrigation cost in Bangladesh = > 4times higher than India, 6 times than Thailand and Vietnam. This is mainly because of dependence on GW irrigation

Objectives

Assess trends in groundwater table and 10 major crops for the past 30 years.

Financial and economic profitability of different crops along with likely changes over time due to declining GW tables.

Estimate cost of excess water lifted for irrigation.

Recommend policies for sustainable use of irrigation water in northwestern Bangladesh.

For assessing sustainability of GW use for irrigation, three objectives based

on ToR and one more have been selected

For assessing sustainability of GW use for irrigation, three objectives based

on ToR and one more have been selected

SocialEconomic

Environmental

Environmental River water contrib. to GW Precipitation Groundwater table Groundwater withdrawals Well intensity Excess water Ten major crops and areas Wetland area Change in crop type GW contamination Conservation

Social % of people practicing GW recharge methods% of people using alternative sources of water for irrigation or other purposes Peoples’ perception in water management

Economic Cost of GW use for irrigationFinancial Profitability Economic profitability

Sustainability Indicators

Sustainability

Methodology

for ASGUI, we have selected 16 indicators belong to E, E, S issues

for ASGUI, we have selected 16 indicators belong to E, E, S issues

Study Area

Rajshahi Pabna Bogra Rangpur Dinajpur } Northwest

Bangladesh

Geographically, the study area extends

230 48’ 14.3’’ to 260 03’ 16.8’’ latitudes and

880 18’ 44.99’’ to 890 43’ 50.71’’ longitudes.

Data for ET estimationLocation: Five Upazilas from five districts in NW region.

RS Data: MODIS satellite images & Landsat 7 ETM+ were used in this study.

Field coordinates of 131 Boro rice fields located in the selected 5-upazilas were collected using hand held GPS.

DataData Type Duration Source

Groundwater table depth 1981- 2011 BWDB, BMDA and BADC

Surface water level (25 stations data) 1981- 2010 BWDB

Surface water discharge 198 1-2011 BWDB

10 Major crops and area 1981- 2011 BBS

Meteorological data(Rainfall, Tmax, Tmin, Humidity, etc.)

1981- 2011 BMD

Primary data were collected from field survey of 450 hh

2011 Sample surveyWe have used

both P& S data

We have used both P& S

data

Data analysisSoftware SPSS 16.0 and MS Excel ILWIS 3.4 and Arc GIS 9.2 software for image processing and analysis Arc GIS 10 - used for mapping.

Financial profitability analysis of major crops : Formula used ∏ = P1Q1 + P2Q2 - ∑PiXi – TFC

Economic profitability/comparative advantage of major crops: Border price measured at Farm gate (Import Parity) : Pj = Pj

b + Cjm – Cjd

Border price measured at Farm gate (Export Parity): Pi = Pib E0-Ci

Nominal protection (NPC) expressed as: NPCi = Pid/Pi

b

Effective protectionEPC =

Value of output at domestic price - Value of traded inputs per unit of output at domestic price

Value of output at world price converted at the official exchange rate

- Value of traded inputs per unit of output of world prices converted at the official exchange rate

Comparative advantage of crop production

Domestic resource cost (DRC)

Forecasting of irrigation cost

Autoregressive Integrated Moving Average or ARIMA (p,d,q) models used.

An AR(p) model has the form: Yt = a1Yt-1 + … + apYt-p + et

Estimation of ET

SEBAL and FAO Penman-Moneith :

E H Go Rn

Where, Go – Soil heat flux, W.m-2

H – Sensible heat flux, W.m-2

λE – Latent heat flux, W.m-2 associated with ET;

Rn- Net radiation

FAO Penman-Monteith method

Figure : Components of the Energy Balance

Normalized Differentiate Vegetation Index (NDVI) Map

Vegetation indices over NW regionGoB-BRAC weather station for climatic data

ET++

Excess Water

Precipitation

42 98.0162.032.0100

15.237NDVIrr

r

T

R

Goo

o

o

n

Estimation of Excess Water

)(WirrrementwaterrequiIrrigation

dWaterTotalLifterExcessWate

ResultsGroundwater table

Declining trend of GWT overtime

Fig . Changes in depth of GWT depth (Jan-May) over time. Fig . Map of depleted upazilas in five districts

y = -0.014x - 4.218

R² = 0.313

7”/y

Fig. Intensity of TW

Fig. Increase of TW over time Fig. Increase of irrigated area over time

DTW became almost double STW reached more than five time higher

TW increased 8.5 times where irrigated land increased 1.6 times.

TW intensity: 6.9 to 36 nos/ km2

DTW became almost double STW reached more than five time higher

TW increased 8.5 times where irrigated land increased 1.6 times.

TW intensity: 6.9 to 36 nos/ km2

Why GWT declines?

River water level

Fig. Northwest region river water level fluctuation (yearly avg.)

Fig. Changes in river water level (a- maximum, and b-minimum)

River water discharge

RWL (Yearly avr.)

20.1m

18.3 m

RWD (Yearly avr.)

90.8

56.9m3/sec

Fig. Relationship between RWL & GWT

GW & SW appeared to be distinct sources of water,

basically they are one singular source of water

connected in the hydrological cycle.

GW & SW appeared to be distinct sources of water,

basically they are one singular source of water

connected in the hydrological cycle.

Change in Wetland area in selected Districts

About 1/3 of the wetlands in NW region has been lost over 21 yrs.

About 1/3 of the wetlands in NW region has been lost over 21 yrs.

Declining trend of annual rainfall (mm)

Figure Change in crop area over time at Boro area highest in Rangpur followed by Rajshahi, Dinajpur, Bogra and Pabna districts

Changes in crop areas

Sudden increase of B A during 1980/81-

2000/01 & Marginal 2000/01- 2010/11.

Sudden increase of B A during 1980/81-

2000/01 & Marginal 2000/01- 2010/11.

Sudden increase of BA is likely liberalization of govt policy (1979) on

procurement, installation and distribution, and management of

irrigation equipment & thus farmers installed huge nos. TW indiscriminately for getting higher production owing to

achieve food security

Sudden increase of BA is likely liberalization of govt policy (1979) on

procurement, installation and distribution, and management of

irrigation equipment & thus farmers installed huge nos. TW indiscriminately for getting higher production owing to

achieve food security

Increase of Boro area over time

AA

B=17AB=17A

Boro area

1980/81

2010/11

Why farmers produce boro?1. Most of farmers are marginal and small group and they have

peace of land to meet their principal food - Rice demand, they

produce rice.

Why farmers produce boro?1. Most of farmers are marginal and small group and they have

peace of land to meet their principal food - Rice demand, they

produce rice.

Second one is likely, if a farmer’s field is within the coverage of irrigation scheme, he has physical benefit of rice cultivation due

to intrusion of IW in his plot and thus refrain the farmer to opt for other crops

Second one is likely, if a farmer’s field is within the coverage of irrigation scheme, he has physical benefit of rice cultivation due

to intrusion of IW in his plot and thus refrain the farmer to opt for other crops

ET of boro rice

21 January 11 April21 January 11 April

ET estimated by SEBAL and Penman-Monteith methods.

Excess water extracted

Fig. Water requirement & Excess water lifted Fig. NW region Irrigation water requirement and extraction

Amount extracted was highest in Badarganj of Rangpur district

followed by Godagari of Rajshahi, Birampur of Dinajpur,

Chatmohor of Pabna district, and least in Dhupchancia of

Bogra district

Amount extracted was highest in Badarganj of Rangpur district

followed by Godagari of Rajshahi, Birampur of Dinajpur,

Chatmohor of Pabna district, and least in Dhupchancia of

Bogra district

Fig. Cost of excess water

Financial Profitability of Five Major Rabi Season Crops

Figure: Cost and return of different crops cultivation

Figure: Farm Category wise Benefit Cost Ratio of Boro Rice

Highest GR found for Potato followed by boro, lentil,

wheat, mustardHighest NR for Lentil

followed by potato, wheat, boro and mustard

Highest GR found for Potato followed by boro, lentil,

wheat, mustardHighest NR for Lentil

followed by potato, wheat, boro and mustard

Table : Domestic resource costs (DRC) for selected agricultural commodities

Year DRCRice Wheat Potato Mustard Lentil

Import parity

Export parity

Import parity

Import parity

Export parity

Import parity

Import parity

2005 0.881 1.881 0.924 0.733 1.328 0.705 0.6102006 0.927 1.889 0.883 0.666 1.056 0.600 0.5652007 0.942 1.965 0.759 0.509 0.706 0.712 0.6012008 0.447 0.625 0.695 0.483 0.685 0.793 0.5812009 0.507 1.006 0.812 0.536 0.820 0.814 0.5192010 0.662 1.281 0.774 0.437 0.719 1.104 0.5362011 0.689 1.262 0.702 0.507 0.891 1.123 0.553

Economic Profitability

DRC<1 Comparative advantage, we can

think for import substitute

DRC>1 not efficient for export

DRC<1 Comparative advantage, we can

think for import substitute

DRC>1 not efficient for export

Districts Major Cropping Patterns Suggested Crops according to cropping pattern and BCR

Dinajpur 1. Boro-Fallow-T.Amon2. Wheat-Jute/Maize/Mugbean-T.Amon

Wheat production should be emphasized

Rangpur 1. Potato-Boro-T.Amon2. Potato-Maize-T.Amon

Potato/ Maize production should be emphasized

Bogra 1. Potato-Boro-T.Amon2. Mustard-Boro-T.Amon

Potato/Mustard production should be emphasized

Rajshahi1. Wheat-Fallow-T.amon2. Mustard-Boro-T.Amon3. Chickpea-Fallow-T.Amon

Wheat/ Chickpea production should be emphasized

Pabna 1. Wheat-Jute-T.Amon2. Boro-Fallow-Lentil

Wheat/ Lentil production should be emphasized

Major Cropping Patterns and suggested crops in the study area

Crops BCRRajshahi Pabna Bogra Rangpur Dinajpur

Boro 1.12 1.13 1.25 1.22 1.18Wheat 1.34 1.36 - 1.31 1.37Potato - - 1.35 1.31 1.24Mustard 1.30 1.28 1.35 1.28 1.36Lentil - 1.49 - - -

Year Projected IC

2012 11136.742015 12085.352020 13562.452025 15041.482030 16520.502031 16816.31

Actual and projected

irrigation cost (Tk/ha)

0

5000

10000

15000

20000

Year

Tk

/ha

Actual Irrig. Cost Forecasted Irrig. Cost

Simulation of time path of boro rice production cost and GWT depth

1

Using forecasted irrigation cost (other costs reaming same) the financial and economic analysis of boro rice

Year Forecasted irrigation

cost (Tk/ha)

Total production

cost(Tk/ha)

Net return(Tk/ha)

BCR DRC

2012 11136.74 91928 15306 1.17 0.7142015 12085.35 92876 14358 1.15 0.7202020 13562.45 94353 12881 1.14 0.7302025 15041.48 95832 11402 1.12 0.7392030 16520.50 97312 9923 1.10 0.7482031 16816.31 97607 9627 1.10 0.750

Considering FIS, after 20 yrs, TPC will be

increased to 1.5 times &

Net return will be 1.5 less than now. In case

of economic Prof. DRC is increasing if it

reaches to >1 then production of boro will

be comparatively disadvantage

Considering FIS, after 20 yrs, TPC will be

increased to 1.5 times &

Net return will be 1.5 less than now. In case

of economic Prof. DRC is increasing if it

reaches to >1 then production of boro will

be comparatively disadvantage

Status of sustainability of GW use for Irrigation in NW Bangladesh

1 River water contribution to groundwater 2 Precipitation 3 Groundwater table 4 Groundwater withdrawals 5 Well intensity 6 Excess water 8 Wetland area 9 Change in crop type

10 Conservation 11 Cost of GW use for irrigation Social

14 Percent of people practicing GW recharge methods

15 % people using alternative sources of water for irrigation than before

16 % people know about harmful effect of stagnant water in the field than before

√ Satisfied

Not Satisfied

7 Change in crop area12 Financial profitability13 Economic profitability

To ensure sus, what are the statuses of

study findings

To ensure sus, what are the statuses of

study findings

Environmental Impact

OC N SP K ZnNutrient mining

12464.8T

(2010)

Pesticide use3895 T (‘73-90)

Polluted water percolation

Drought

Socio-economic impact

Jobless Time and Energy loss for collecting water

Health problemsEconomic loss from pisciculture - drought

Nutrition deficiency

If water is not managed properly, Days are coming when - possibilities of

Conclusion Sustainability of GW use for irrigation in northwest Bangladesh has been identified as a matter of concern.

Key impediments to sustainability has been identified as: over exploitation of GW, increase of boro rice cultivation, excess water use in irrigation, depletion of river water level and discharge, reduction of wetland areas, below average rainfall have caused the GW level fall to the extent of not getting fully replenished in the recharge season causing overdraft in northwest Bangladesh.

Findings reveal positive net return for all the studied crops. Highest benefit cost ratio was calculated for lentil followed by wheat and mustard. The domestic-to-border price ratio of studied crops was less than unity & significantly negative except mustard.

Estimates of DRC showed that Bangladesh had comparative advantage in the production of all studied crops. Production of potato & lentil would be highly efficient for import substitution. So, Bangladesh will need to enhance its supply-side capacity & pursue a broad-based diversified agricultural production & export strategy.

Recommendations

1. Encourage HYV crop rather than boro. Emphasis should be given on lentil in Pabna district and wheat (except Bogra), mustard and potato (except Rajshahi and Pabna) in other four districts because return is higher in these crops. Production of potato & lentil would be highly efficient for import substitution. 2. An estimated water budget should be prepared that includes recharge, extraction & change in storage in the aquifer(s). 3. Managed Aquifer Recharge should be undertaken as a national programme & strategy considering different regional contexts by adopting a series of activities like harvesting of surface & rain water & their storage & conservation through excavation of existing canals, ponds, khals, & water bodies in massive scale.

4. Local planners should consider recharge areas when planning land use that could reduce recharge or pose a risk to GW quality. 5. Strengthen appropriate monitoring organizations for tracking GW recharge, surface and GW use & improvement in surface and GW quality. 6. Regional cooperation can guarantee a sustained future in terms of water availability since the basin areas of the river systems is dissected by international boundaries. 7. Water User Association rooted strong small holder irrigation community should be given statutory powers to fix rate determined by WRAs/BADC/BMDA.

Policy recommendations (contd.)8. Irrigation water price should be determined as a rule on volumetric basis in order to meet equity, efficiency and economic principles. WUA should fix the rate of irrigation cost from private TW which is much higher than public TWs.  9. Optimization of command area of each DTW and STW though consultation with Water User Association where electric connection to pumps is key component for regulation on GW use & to be realized phase-wise i.e., with short-term, medium-term and long-term planning.  10. Modern water management technology like alternate wetting and drying (AWD), water saving technology like hose pipe irrigation, drip irrigation, climate change adaptive technology such as drought tolerant crop variety, etc. would bear no value without carrying out irrigation volumetrically.  

11. Awareness, campaign and advocacy on sustainable water management concepts, principles and methods. Department of Agriculture Extension can take a lead for this action.

12. Plan of Action in line with basic policies namely NAP 2010, NFP 2006, CIP 2011, NWP 1999, NAPA 2009, NSDS 2008, BCCSAP 2009 etc. might be formulated under existing BADC or BMDA or proposed GD or WRA on short-term, medium-term and long-term basis.

Thank you