This document discusses challenges in current and future irrigation management in Bangladesh. It identifies the key driving forces as water availability, economics, environment, climate change, social factors, and policies. Groundwater levels are declining across the country due to over-pumping. Bangladesh's geo-physical position and climate change are leading to more adverse weather conditions like droughts, floods, and salinity. Various strategies are proposed to cope with water shortage, including increasing supply through methods like rubber dams and recharge wells, and reducing demand through adjusted cropping patterns and irrigation scheduling.

1. Challenges in current & Future
irrigation management
1

2. Driving Forces in Irrigation management:
• Water availability (both surface and
groundwater)
• Economics
• Environmental factors
• Climate change issue
• Social factor
• Policy factor
2

3. Water Availability
0
10
20
30
40
50
60
Jan Feb Mar Ap May Jn Jly Aug Sep Oct Nov Dec
Rainfall
(cm)
3

4. Alarming situation of groundwater !!
Due to continuous pumping of groundwater, the
groundwater level is declining in most parts of the
country.
4

5. 5

6. Year
-1
4
-1
2
-1
0
-8
-6
-4
-2
0
2
4
85 87 89 91 93 95 97 99 1 3 5
Durgapur
Well-RJ68 Well-RJ1
2
Well-RJ30 Rainfall
Suc. Lift
6

7. Year
-30
-25
-20
-15
-10
-5
0
5
10
85 87 89 91 93 95 97 99 1 3 5
Mohanpur
Well-RJ23 Well-RJ28
Rainfall Suc. Lift
7

8. Year
-1
2
-1
0
-8
-6
-4
-2
0
2
4
85 87 89 91 93 95 97 99 1 3 5
Puthia
Well-RJ31 Well-RJ69
Well-RJ70 Well-RJ09
Well-RJ27 Rainfall
Suc. Lift
8

9. y = 0.2849x + 5.4208
R² = 0.414
0
4
8
12
16
0 5 10 15 20
Depth
to
WT
(m)
Relative year
Mymensingh Sadar
Well-24
y = 0.5383x + 3.6879
R² = 0.8023
0
4
8
12
16
0 5 10 15 20
Depth
to
WT
(m)
Relative year
Mymensingh Sadar Well-52
y = 0.0069x + 11.479
R² = 0.0009
0
4
8
12
16
0 5 10 15 20
Trishal Well-25
y = 0.3062x + 9.5868
R² = 0.3699
0
4
8
12
16
20
0 5 10 15 20
Trishal Well-56
y = -0.0157x + 4.0943
R² = 0.0313
0
4
8
0 5 10 15 20
Gouripur
Well-32
y = 0.097x + 4.0635
R² = 0.7634
0
4
8
0 5 10 15 20
Gouripur Well-46
9

10. Adverse situation ….
In our contest, we will be confined with the following
adverse conditions:
- Drought
- Flood
- Salinity
10

11. What is adverse climate ?
“Adverse” means acting in a contrary direction or
opposed to one’s interest.
Adverse weather condition means bad weather, or
contrary to normal weather conditions like
drought, flood, storms, cyclones, tornadoes, etc.
11

12. Why so adverse ?
• Geo-physical position
• Climate change issue
12

13. Geo-physical position of Bangladesh
13

14. Climate Change issue
 Climate change is any long-term significant change in the
“average weather” that a given region experiences.
 Climate change involves changes in the variability or average
state of the atmosphere over durations (ranging from
decades to millions of years).
14

15. Climate Change and Water Resources
Impact of climate change on water resources (WR):
 Varies directly with rainfall
Impact may be on:
 Rainfall
 River-flow
 Availability of GW
 Demand of water
15

16. Pattern of long-term Climatic parameters in Bangladesh
 Increasing or decreasing trend (variable with space and time)
16

17. y = 11.79 + 0.003x
0
2
4
6
8
10
12
14
16
0 5 10 15 20 25 30 35
Temp.,
0C
Relative year
Min. Temp. in Jan., Mym.
y = 25.23 - 0.052x
0
5
10
15
20
25
30
0 5 10 15 20 25 30 35
Temp.,
0C
Relative year
Max. Temp. in Jan., Mym.
17

18. y = 1586.3 - 3.2146x
0
500
1000
1500
2000
2500
1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
Rainfall
(mm)
Relative Year (from 1976)
Trend of rainfall at Rajshahi
18

19. River during dry period (at the end of January)
19

20. 20

21. Arsenic concentration map
21

22. Schematic of Aerobic condition in GW around a
heavy-duty tubewell
22

23. Relation of Water Quality with depth
23

24. Salinity map
24

25. Solution Options / Mgt. Strategy
25

26. Can development be sustainable when the
climate is not sustainable?
Climate change and increasing climate variability may seriously
complicate sustainable development.
- New or adapted preparedness strategies have to be developed as
responses, differentiated after farming systems!
26

27. Coping strategies_Weather variability
Coping strategies for weather phenomenon may be broadly
classified as:
(i) preparedness, and (ii) mitigation practices.
- Preparedness as a coping strategy means preparedness what
cannot be prevented.
- Mitigation practices as a coping strategy means preparedness
what can be prevented.
27

28. Climatic potential yield and actual yield
(total dry-matter, t/ha/year)
Assuming:
- Photosynthetic effi. = 6.6 %
-Energy needed to produce 1 gm dry-matter of field crop is 4226
cal (0.01768 MJ).
-
Potential Actual % of Pot.
Mym. (Boro + T.aman) 92 28 30
Rangpur(Jute+T.aman+wheat) 116 34.7 30
Comilla(Mustard+Boro+T.aman) 117 32.6 28
(Ali et al., 2004; 2005)
28

29. Principles or Strategies for mitigating water
shortage
 Increasing availability of water (supply management)
 Reducing water demand (demand management)
29

30. Integrated approach for Reducing water demand
Drought escape: agronomic manipulation
 Shifting time of sowing/transplanting
 From “Boro – T.Aman ” to “Late T.Aus – Late T.Aman”
30

31. Reducing water demand:
Proper irrigation scheduling
For rice: “Alternate drying and wetting” approach
For cereals: Omitting irrigation after soft-dough stage
• Reducing irrigation frequency/number (giving irrigation only at
sensitive growth stages)
• Optimal sequencing of irrigation (or deficit) (e.g., irrigation +
deficit + irrigation + deficit….)
31

32. Increasing Supply: Rubber Dam
32

33. Typical Cross-section of a Rubber Dam
33

34. Increasing supply: Recharge well
34

35. Schematic of special design of DTW in Dry/Barind
Area
35

36. Agricultural Cropping Patterns in relation to Water
availability
Jan Feb Mar Apr M Jun Jul Aug Sep Oct Nov D
Wheat-pulses
Rice -1
Rice -2
Rice -3
0
10
20
30
40
50
60
Jan Feb Mar Ap May Jn Jly Aug Sep Oct Nov Dec
Rainfall
(cm)
36