Transcript Sustainability of groundwater use for irrigation in

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
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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