Student Advising

M. Shah Alam Khan

 

 

 

Name of the student: KHOKON SONA RAJBHAR

Program: PG. Dip. (WRD)

 

Title: ASSESSMENT OF CHANGES IN WATER RETENTION AREAS IN EASTERN DHAKA USING RS AND GIS

 

 

Background and present state of the problem:

 

Low lands and water bodies play important roles in water retention as well as sustenance of natural ecosystem. Historically, the low lands and natural depressions in Dhaka have been efficient in storing stormwater while numerous khals gradually drained the water to the surrounding rivers. However, because of increasing population pressure, unplanned development and encroachment the water retention areas have been diminishing, causing frequent stormwater flooding in the city. A master plan (JICA, 1991) was prepared to protect the city from river floods and to improve stormwater drainage, which has been partially implemented for western Dhaka. The plan for the 124 km2 of eastern Dhaka is yet to be implemented. The master plan is based on projected land use of the city and demarcates stormwater retention areas that would be vital for pumped drainage from the planned compartments (JICA, 1992). Halcrow (2006) gives an updated plan for eastern Dhaka and proposes land use and water retention areas. Dhaka Metropolitan Development Plan (DMDP) (RAJUK, 1997) gives an indication of demographic densification of the area. However, the actual land development in this part of the city has deviated significantly from the projected land uses. Chowdhury et al. (2001) assess land use distribution for the years 2000, 2005 and 2015 in the northern compartment of eastern Dhaka and observes that the area is undergoing rapid land use change because of urban expansion. Hoque (2004) observes that vast extent of the open low-lying areas in eastern Dhaka has been undergoing urban development activities, particularly development of housing estates. Based on analysis of an aerial photograph (1968) and a SPOT image (2001), Sultana (2005) concludes that the wetland in both eastern and western parts of Dhaka has reduced. However, these studies do not compare the land use change with the projected land use in the master plan. Thus an assessment of the land use change in eastern Dhaka, with particular attention to water retention areas, will be helpful in determining whether implementation of the master plan for eastern Dhaka would be successful.

 

 

Objectives with specific aim and possible outcome:

 

The objective of the study is to assess the change in land use, particularly the water retention areas, in eastern Dhaka over a period of 15 years.

Possible Outcome: This study is expected to present how the land use change and aerial extent of water retention areas have deviated from the projections in the master plan because of development activities in eastern Dhaka.

 

 

Outline of Methodology:

 

Several time-series land use maps (1989, 1999 and 2004) of eastern Dhaka over a period of the 15 years (1989-2004) will be prepared from satellite images. From these maps, drainage routes will be identified and changes in land use classes will be detected using RS and GIS techniques. Details of the methodology are described below:

 

Data Collection: The study will use satellite data (Landsat Thematic Mapper (TM), Landsat Enhanced Thematic Mapper Plus (ETM+) and IKONOS) available from secondary sources, Snowy Mountain Energy Corporation (SMEC) and GaniBangla Ltd., for identifying land use change over time. This study will also use updated topographic and physical feature survey data available from secondary sources for special attention to the proposed retention pond areas.

 

Field Visits: Field visits in the study area will be conducted in two steps. First, reconnaissance visits will be performed for understanding the present situation of the area. Second, after the land use classification other visits will be required for field verification.

 

Image Processing and Analysis: Image processing for the study will include geometric correction, image subset operation, image enhancement, and land use or land cover classification. The classified thematic images will be converted into shapefiles to support calculations of different land use areas. Different time series maps will be presented using ArcGIS software. ArcView with compatible extensions will be used, if necessary.

 

 

References:

 

Chowdhury, J.U., Kamal, M.M., Khan, N.I., Akhtar, M.K., and Salam, M.A. (2001), Impact of Landuse Change upon Strom Water Drainage and Wetlands in Eastern part of Dhaka City, IFCDR (presently IWFM) BUET, Department of Geography and Environment (DU), and SWMC (Presently IWM), Dhaka.

 

Halcrow (2006), Updating/Upgrading the Feasibility Study of Dhaka Integrated Flood Control Embankment cum Eastern Bypass Road Multipurpose Project, Final Report, Vol. 1: Main Report, Bangladesh Water Development Board, Govt. of the People's Republic of Bangladesh, Dhaka.

 

Hoque, M.J. (2004), Impact of Land Development on the Environment of the Eastern Fringe Area of Dhaka, Unpublished M. Phil thesis, Department of Urban and Regional Planning, BUET, Dhaka, Bangladesh.

 

JICA (1991), Master Plan for Greater Dhaka Protection Project, FAP 8B, Main Report and Supporting Reports I & II, Flood Plan Coordination Organization (presently WARPO), Dhaka.

 

JICA (1992), Feasibility Study on Greater Dhaka Protection Project, FAP 8A, Main Report, Flood Plan Coordination Organization (presently WARPO), Dhaka.

 

RAJUK (1997), Dhaka Metropolitan Development Plan (1995-2015), Vol-II: Urban Area Plan (1995-2005), Rajdhani Unnayan Kartripakkha, Dhaka.

 

Sultana, M.S. (2005), Analysis of Changing Scenario of Wetlands of Dhaka City Using Remote Sensing and GIS, Unpublished PG. Dip (WRD) Project, IWFM, BUET, Dhaka.

 

 

 [  BUET Home ]         [ IWFM Home ]