Sustainability of Groundwater Use for Irrigation in Northwest Bangladesh Research Team Nepal C. Dey Md. Abdur Rashid Ratnajit Saha Research Advisor Mahabub Hossain Sujit K. Bala AKM Saiful Islam Ahsan A. Shopan Sustainability ? R Sustainability t •R-Resource use •GW use indicates depth of GWT in negative value Sustainability Indicators Environmental Economic Environmental Indicators Groundwater table River water contri. to GW Precipitation Groundwater withdrawals Well intensity Evapo-transpiration (ET) Major crops and areas Wetland area Change in crop type Conservation Sustain -ability Social Social indicators No. of people practicing groundwater recharge methods No. of people using alternative sources of water for irrigation or other purposes Peoples’ perception in management Economic indicators Financial Profitability Economic profitability Challenges Withdrawal of GW Sustainability of GW use for irrigation is becoming a vital concern in many countries of the world, Bangladesh in particular, mainly NW of Bangladeshwhere GW declines 5-10m in the dry period (Extracting GW > Recharge capacity) Contribution of GW for irrigation has increased by 2.5 times after 20 years Contribution of GW for irrigation use 77% 31% 1982-83 Recurrent below-average rainfall, higher temp causing drought, increased ET, delayed monsoon, dry-up of surface water bodies including ponds, rivers and thus lowering of GWT in the aquifer leading water crisis are some important. 2005-6 Irrigation cost in Bangladesh = > 4times higher than India, 6 times than Thailand and Vietnam. This is mainly because of dependence on GW irrigation 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) (Dey et al., 2006), and also similar to the ADP budget of Bangladesh for FY 2009-10 (USD 4072 million). Irrigation cost (Tk.) Irrigation cost increased many folds causing threatens the economic viability of future crop production. Production cost Irrigation cost 60000 40000 20000 0 1990 2001 2003 2004 2005 2009 Variation in cost of irrigation 120 USD/ ha Challenges (contd.) 80000 117.6 80 40 25.58 17.96 17.98 Thailand Vietnam 0 Bangladesh India www.iwaponline.com/wp/00806 Objectives of the study quantitatively assess the trends in water table depths and crop areas in the designated study area for the past 30 years. financial and economic profitability of different crops along with likely changes over time due to declining water tables. recommend policies for sustainable use of irrigation water in northwestern Bangladesh. In addition, we worked on the following objective estimate cost of excess water lifted for irrigation. Methodology Study Area Rajshahi, Pabna, Bogra, Rangpur, Dinajpur District of 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 Collection Primary Data and Information Sample survey through structured questionnaire (Total number of farm household were 450 where 150 marginal, 150 small and 150 medium/large household) Focus Group Discussion (Five sub-district from five districts of NW Bangladesh) Consultation Meeting Workshop Secondary Data Data 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 Major crops and area 1981- 2011 BBS Meteorological data (Rainfall, Tmax, Tmin, Humidity, etc.) 1981- 2011 BMD Data for ET estimation Location: 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. Data analysis Software 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 = Pjb + Cjm – Cjd Border price measured at Farm gate (Export Parity): Pi = Pib E0-Ci Nominal protection (NPC) expressed as: NPCi = Pid/Pib Effective protection EPC = 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 : Rn Go H E 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 FAO Penman-Monteith method Figure : Components of the Energy Balance Normalized Differentiate Vegetation Index (NDVI) Map T 237.15 G o 0.32ro 0.62ro2 1 0.98NDVI 4 Rn 100ro Estimation of Excess Water Irrigationwaterrequirem ent(Wirr ) ExcessWater TotalLiftedWater ET + Precipitation + Excess Water GoB-BRAC weather station for climatic data Vegetation indices over NW region Result and Discussion Groundwater table depths Declining trend of GWT overtime Fluctuation of GWT (Yearly avg.) 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 20 20 20 20 20 20 20 20 20 20 20 20 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 -2 -4 -6 -8 -10 2011 2009 2007 2005 2003 2001 1999 1997 1995 1993 1991 1989 1987 1985 1983 1981 NW_GWT Depth (Jan-May) Groundwater table depth (m) GWT depth (m) 0 -5 -8 -11 -14 Bogra (Avg.) Rajshahi (Avg.) Dinajpur (Avg.) Rangpur (Avg.) Pabna (Avg.) Fig . Changes in depth of GWT depth (Jan-May) over time. Name of depleted upazilas: Fig . Map of depleted upazilas in five districts RWL (Yearly avr.) 20.1m 18.3 m 25 RWL (m) River water level Fluctuation of RWL (Yearly avg.) 20 15 1981198219831984198519861987198819891990199119921993199419951996199719981999200020012002200320042005200620072008200920102011 Fig. Northwest region river water level fluctuation (yearly avg.) River water discharge RWD (Yearly avr.) 90.8 56.9m3/sec Fig. Changes in river water level (a- maximum, and b-minimum) Fig. Relationship between RWL & GWT Changes in crop areas 10 major crops’ area has increased 31915 (hectare) where boro alone increased more than 9 times during 1980/81 to 2009/10. 7061 Dinajpur Pabna 27753 7035 33142 3355 Rajshahi 21158 10193 Rangpur_Shifting of crop area 750000 Rabi Chilies 600000 Potato 450000 Rape & Mustard Sugarcane 300000 Boro Rice Pabna_Shifting of crop area a Rajshahi_Shifting of crop area 750000 Potato 400000 Pulses (Mashkalai) Sugarcane Pusle (Masur) 200000 Boro Rice d Pusle (Masur) Rape & Mustard 300000 Jute Rape & Mustard Jute 1980/81 2000/01 2009/10 Wheat Rabi Brinjal Pusle (Masur) 400000 Onion 300000 Rape & Mustard Sugarcane 200000 Rabi Chilies Potato 100000 Sugarcane c Jute Boro Rice 0 Jute Wheat Sugarcane Bogra_Shifting of crop area Pulses (Kheshari) 450000 Pulses (Kheshari) 1980/81 2000/01 2009/10 Potato 200000 0 150000 0 Boro Rice Potato Rape & Mustard 100000 Onion Onion 300000 b Pulses (Mashkalai) 600000 Area (hectare) Area (hectare) 300000 Wheat Jute 400000 100000 Pulses (Kheshari) 31915 Onion Pulses (Mashkalai) 150000 1980/81 2000/01 2009/10 1980/81 2000/01 2009/10 Wheat Rabi Chilies Rabi Brinjal 500000 44076 2200 Dinajpur_Shifting of crop area Pulses (Mashkalai) 0 Rangpur Onion Area (hectare) Δ (09/1080/81) Area (hectare) Bogra Δ (09/1000/01 ) Area (hectare) Area (Hectare) Boro Rice 0 e a 1980/81 2000/01 2009/10 Wheat Figure (a-e). Change in crop area over time at (a) Rangpur; (b) Dinajpur; (c) Rajshahi; (d) Pabna and (e) Bogra district Financial profitability of Five major rabi season crops Costs of boro (Tk/ha) Rajshahi Yield (T/ha) 96,839 Pabna 96,080 5.819 6.483 Bogra 90,378 6.395 Rangpur 87,883 6.125 Dinajpur 86,583 6.192 Cost and return of crops 140000 Return (Tk/ha) District 105000 TC 70000 GR 35000 NR 0 Boro rice wheat Potato Lentil Figure: Cost and return of different crops cultivation Benefit Cost Ratio of Boro Region wise BCR of Boro 1.3 1.24 Rajshai BCR BCR Mustard 1.16 1.2 Pabna 1.1 Bogra 1.08 Rangpur 1 1 Marginal Rajshahi Pabna Bogra Small Rangpur Dinajpur Large & Medium Dinajpur Farm category Figure: Region wise Benefit Cost Ratio of Boro Rice Figure: Farm Category wise Benefit Cost Ratio of Boro Rice Major Cropping Patterns and suggested crops in the study area Districts Dinajpur Rangpur Bogra Rajshahi Pabna Suggested Crops according to cropping pattern and BCR 1. Boro-Fallow-T. Amon Wheat production should be 2. Wheat-Jute/Maize/Mugbean-T.Amon emphasized 1. Potato-Boro-T. Amon Potato/ Maize production should 2. Potato-Maize-T. Amon be emphasized 1. Potato-Boro-T. Amon Potato/Mustard production 2. Mustard-Boro-T. Amon should be emphasized 1. Wheat-Fallow-T. Amon Wheat/ Chickpea production 2. Mustard-Boro-T. Amon should be emphasized 3. Chickpea-Fallow-T. Amon 1. Wheat-Jute-T. Amon Wheat/ Lentil production should 2. Boro-Fallow-Lentil be emphasized Major Cropping Patterns Crops Boro Wheat Potato Mustard Lentil Rajshahi 1.12 1.34 1.30 - Pabna 1.13 1.36 1.28 1.49 BCR Bogra 1.25 1.35 1.35 - Rangpur 1.22 1.31 1.31 1.28 - Dinajpur 1.18 1.37 1.24 1.36 - Actual Irrig. Cost 20000 Tk/ha 15000 10000 5000 20 31 20 28 20 25 20 22 20 19 20 16 20 13 20 10 20 07 20 04 20 01 19 98 19 95 19 92 19 89 0 Year 160 0 -2 120 -4 80 -6 40 -8 0 GWT depth (m) Production cost (‘000 Tk.) Actual and projected irrigation cost (Tk/ha) Forecasted Irrig. Cost -10 Production Cost NW 5 Dist (Avg.) Simulation of time path of boro rice production cost and GWT depth 1 Using forecasted irrigation cost (other things reaming same) the financial and economic analysis of boro rice Year Forecasted Total cost irrigation cost (Tk/ha) (Tk/ha) Gross return (Tk/ha) Net return (Tk/ha) BCR DRC 2012 11136.74 91928 107234 15306 1.17 0.714 2015 12085.35 92876 107234 14358 1.15 0.720 2020 13562.45 94353 107234 12881 1.14 0.730 2025 15041.48 95832 107234 11402 1.12 0.739 2030 16520.50 97312 107234 9923 1.10 0.748 2031 16816.31 97607 107234 9627 1.10 0.750 Change in Wetland area in selected Districts Changes of NDVI and ET in 2010 21 January NDVI 11 April 21 January ET ET estimated by SEBAL and Penman-Monteith methods. 11 April 800 40.0 600 30.0 DTW 20.0 STW TW 10.0 0.0 a 1984-85 2010-11 Fig.(a) Intensity of TW 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 in '000 nos 50.0 400 STW DTW 200 0 1984-85 b 2010-11 Fig. b) Increase of TW over time Iirri. area in'000 ha TW (TW/Km2) Intensity of TW 2500 2000 1500 1000 Area, ha 500 0 1984-85 2010-11 c Fig.(c) Increase of irrigated area over time Excess water lifted (%) Excess water extracted 21% 79% Excess water Water requirement Fig. Water requirement & Excess water lifted 400 300 milion m3 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 200 Irrigation water requirement and extraction Total extracted water by STW & DTW 100 0 Irrigation water requirement Fig. NW region Irrigation water requirement and extraction Environmental Impact 12464.8 T (2010) OC N S K P 3895 T Nutrient mining Pesticides use (‘73-90) 800000 600000 400000 200000 0 Zn 2011 2009 2007 2005 2003 2001 1999 1997 1995 1993 1991 1989 1987 1985 1983 1981 Boro Rice -5 -8 -11 -14 Polluted water percolation Saline water intrusion Socio-economic impact Nutrition deficiency Time and Energy loss for collecting water 800000 600000 400000 200000 0 2011 2009 2007 2005 2003 1999 1997 1995 1993 1991 1989 1987 1985 -5 -8 -11 -14 12,000 Average Income Tk/ha 1983 1981 Boro Rice 2001 Jobless 8,000 4,000 0 Drought year Normal year (3 year average) Economic loss from pisciculture - drought Health problems Conclusion Sustainability of groundwater use for irrigation in northwest Bangladesh has been identified as a matter of concern. The key impediments of sustainability of groundwater use for irrigation are identified as over exploitation of GW with declining trend, increase of TW nos. and pumping of excess water, increase of boro area, decline of river water flow, decrease of wetland area, less rainfall in the dry period, increase of irrigation cost, poor water Policy recommendations 1. To harmonize boro rice cultivation with other high valued winter crops. 2. Managed Aquifer Recharge (MAR) should be undertaken as a national programme and strategy considering different regional contexts by adopting a series of activities like harvesting of surface and rain water and their storage and conservation through excavation of existing canals, ponds, khals, and water bodies in massive scale. 3. To establish independent Water Regulatory Authority (WRA)/Groundwater Directorate (DR) or any other existing bodies like BADC, DAE might be used for establishing governance and management of groundwater resource to fix and regulate the water tariff system and charges as per Policy Framework. 4. Water User Association (WUA) rooted strong small holder irrigation community should given statutory powers to fix rate determined by WRAs/badc/dae. 5. Optimization of command area of each DTW and STW though consultation with Water User Association where electric connection to pumps is the key component for regulation on GW use and to be realized phase wise i.e., with short term, medium term and long term planning. 6. Irrigation water price should be determined as a rule on volumetric basis in order to meet equity, efficiency and economic principles. Policy recommendations (contd.) 7. Modern water Management technology liker alternate wetting and drying (AWD), water saving technology like hose pipe irrigation, drip irrigation, drought tolerant crop variety, etc. would bear no value without carrying out irrigation volumetrically. 8. Plan of Action (PoA) in line with basic policies like NAP, PRSP, CIP, NAPA, etc might be formulated under proposed GD or WRA or exsisting BADC or DAE on short term (ST), medium term (MT) and long term (LT) basis. 9. National Sustainable Development Strategies by the government is a good effort to achieve sustainability in all developmental activities specially GW resources of the country under one umbrella. 10. Global Best Management Practices on GW might work as guidelines for going into action for the GW management of the country. If water is not managed properly, Days are coming when - possibilities of Thanks