Implication of Water Resources for Seasonal Shifting

of Livelihoods of the South-eastern Coastal Island Population in Bangladesh.

Presented By

Pronab Kumar Halder* &

Mahmud Hasan Tuhin**

* Jr. Specialist, CEGIS & ** Liaison Support Officer, SDBC-Sundarbans, GIZ

Introduction

Moheshkhali is the only hilly island in Bangladesh with an area of 362.18 sq km.

Total length of the island is 30 km in N-S direction with a width of 12 km in E-W direction.

Economic activities in the islands are based on the primary sector: salt production, shrimp culture, fishing and agriculture

The western flat part of the island is use to cultivate rice, betel, robi crops, shrimp farms and salt farms.

Rainfall runoff from the hilly regions passes through charra/khals/creeks into the plain land.

Study Area

Moheshkhali Island

Ghatibhanga Khal

- To assess the seasonal livelihoods in the study area.

- Role of the water resources to control the land use practice.

- Reveling the relation of water resources and livelihood shifting.

Objective of the Study

Methodology of the Study

• The study has been conducted through a collective socio-technical approach.

• Analysis of the rainfall pattern in the study area assisted in the overall understanding of fresh water flow in the island.

• Salinity was measured at regular interval (i.e. 1250m) in the Ghatibhanga khal for both dry and wet seasons.

• Satellite image analysis and field level ground truthing were carried out to depict the land use pattern in different seasons.

• Livelihood involvement at different sectors during dry and wet seasons has been estimated through different social survey tools- like KII, PRA and FGD

Methodology Satellite Images Moheshkhali

Area Spatial Resolution Spectral Resolution Acquisition Dates

Maheshkhali 5- m 5 Bands

(B, G, R, RE and NIR)

25-03-2011 and

28-03-2011

Information on spectral bands of Rapid Eye satellite images

Band ID Band Name Wavelength (nm)

1 Blue (B) 440-510

2 Green (G) 520-590

3 Red (R) 630-685

4 Red Edge (RE) 690-730

5 Near Infra Red (NIR) 760-850

RESULT AND DISCUSSION

Digital Elevation Map (DEM) of the study area

• The Hill is in North-South Direction

• Maximum Height 65-70 Meter.

• Flat land height about 1-2 Meter is dominant in seaward direction.

• The Ghatiabhanga Khal plays a major role in hydrological activity of that island.

Land Type and Soil Features

• High land is dominant.

• Medium high land

in foot hill region. • Medium low land

in after foot hill area.

Vegetable gardening in Medium high land and Betel Nut in High land

• Clay loam is dominant.

• High land is

sandy loam dominant.

Rainfall Variation

Average monthly rainfall

Source: (Cox’s Bazar BMD station, (1984-2013)

• Slightly Different from the country's’ average rainfall.

• More than 2300mm rainfall which is above country’s average rainfall.

• Rainfall Peak spikes in July (Unimodal), where in other part of the country doesn't have a regular peak (Bimodal) rainfall.

• Rainfall recharge the aquifer of the whole island and provide artesian flow during dry season (Nov/Dec to April/May).

• Flush Flood occurs in rainy season.

Tidal Water Level

Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb

Per-Monsoon Monsoon Post Monsoon Winter

Maximum water level 3.66 3.54 4.20 3.74 4.90 4.91 5.46 3.80 4.08 3.60 3.47 3.66

Minimum water level 0.50 0.30 0.46 0.61 0.50 0.60 0.31 0.50 0.72 0.60 0.34 0.60

Average water level 2.04 2.06 2.14 2.22 2.30 2.28 2.20 2.11 2.07 1.95 1.93 1.94

0.00

1.00

2.00

3.00

4.00

5.00

6.00

Wa

ter L

ev

el (m

PW

D)

Water Level, Lemsikhali,(1969-2012)

Water level analysis Source: (BWDB station at Lamiskahli: 1969-2012)

• During July, August and September tide intrude more landward direction.

• Lack of artesian flow is the main cause of salinity intrusion.

• Salinity intrusion have direct impact on livelihood and agricultural

practice.

Saline Water Progression

Spatial and Temporal variation of Salinity concentration (ppt) in Ghatibhanga Khal, Maheshkhali

Seaward Direction Landward Direction

• In Land ward direction fresh water flow is available for Artesian flow.

• In Seaward direction the flow is decreasing and salinity increase

gradually.

• Monthly variation is very clear and in dry season the salinity level

increases.

• Salinity level dominant agricultural practices and livelihood.

Land Cover Classification Land cover Dry Season (November-April) Wet Season (May – October)

Area (ha) Distribution

(% )

Area (ha) Distribution

(% )

Agricultural Land 5,400 14.5 7820 21.27

Hilly Forest Area 6,340 17.0 6340 17.25

Mangrove Forest 4,600 12.3 4600 12.51

Pond 50 0.1 110 0.30

Road 50 0.1 30 0.08

Settlements 3,500 9.4 3500 9.52

Water Body 4,000 10.7 5480 14.91

Intertidal zone 3,600 9.6 3580 9.74

Salt farming (dry season) or

Shrimp/Fish farm (wet season) 9,220 24.7 5300 14.42

Total 36,760 100.0 36760 100.0

• Due to change in fresh water availability, Main livelihood activities of the study

area change over season and in area.

• In wet season ponds are filled and fishing activities increases.

• Salt farming increase in dry season and in wet season salt fileds become shrimp

farm.

Livelihood Distribution Sectors Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

HYV Aus

HYV T. Aman

HYV Boro

Betel vine

Capture Fishing

Salt Farming

Shrimp Farming

Service

Forestry

Livelihood involvement in multiple sectors (high color gradient shows peak season)

Low land used for salt and shrimp cultivation

in seaward direction

Medium low land used for agricultural

practices in landward direction

Livelihood Shifting

• In dry season Salt farming and Capture Fisheries are the dominant livelihood options.

• Agricultural practice reduces due to lack of fresh water.

• In wet season Agricultural activities increases due to availability of fresh water

• Salt producing fields become agricultural fields in wet season.

KII with community people and local leaders (UP Members)

Available fishes in the study area

Some Photos from field

Artesian tube well in study area

Conclusion

• livelihood shifting phenomena observed in the Moheshkhali Islands.

• The study identifies water as the most important cause of changing land use pattern.

• which consequent the shifting livelihoods of the rural community.

• The diversified functions of water, problems and constraints in water management, spatial and temporal significance, and other relevant issues frequently contribute to the livelihood shifting of the study area.

• The availability of artesian flow in one of the major factor governing salinity intrusion.

Thanks to the Distinguish Audience

Special Thanks and Acknowledgment:

Center for Environmental and Geographic Information Services (CEGIS)