REMOTE SENSING AND GIS APPLICATION FOR ASSESSING COASTAL 
GEOMORPHOLOGICAL CHANGES: A RIVER BASIN APPROACH 
Md. Saifuzzaman!, Prof M.Shamsul Alam! and Dr.Md. Shahedur Rashid? 
The purpose of this study is to understand the nature and state of geomorphic environment changes occurred in a 
southwestern coastal river basin of Bangladesh over a period of three decades (1967-2003). The study concentrates 
on the Kholpetua river basin, which receive fresh water flow from Betna in the upstream and tidal flow in the 
middle from Morichapa and finally drains to the Bay of Bengal through Kapotakshi River. The whole Kholpetua 
basin may be divided into three distinct parts: fresh water upstream, brackish water middle part and saline lower 
part. 
Large-scale population increase, both in the up and middle stream section; infrastructure development, in the form 
of road network and introduction of HYV rice in the floodplain of Betna and shrimp farming on the brackish water 
have lead to the loss of both quality and extent of wetland resources in the basin area, endangering the 
geomorphological systematic balance in terms of input and output between upstream and downstream. A large 
section of Betna has dried-up, and most of the tributaries and distributaries of the Morichapa have been silted up, 
partly because of extensive poldering effect of the sub-basin. As a result, energy exchange (through tide) between 
basin plains and channels ways has lost vitally. 
Multi-spectral remote sensing data, in conjunction with topographical maps and ancillary data analysis reveals that 
throughout the basin, a wide range of anthropogenic interference have physically altered the characteristic 
ecosystem of the basin. Such physical alteration has been initiated with the poldering of middle brackish water part 
of the basin and later with the introduction of extensive shrimp cultivation. Attempt has been made to explore the 
linkage of upstream landuse activities and drainage alteration to the hydrological and geomorphological behavior 
of the downstream basin areas, so that ecological sensitivity of the basin may be understood. 
1. Center for Environmental & Geographic Information Services (CEGIS), Gulshan, Dhaka, Bangladesh 
2. Department of Geography and Environment, Jahangirnagar University, Savar, Dhaka, Bangladesh 
1. Purpose: term project to document the changes and effects of 
human activities on the coast to provide a 
The aims of this paper is to describe and explain the comprehensive picture of the state in a river basin 
nature of environmental transformation that took approach. Unlike administrative units, a river basin 
place in the Kholpetua river basin since early *70's. is a form of hydrological unit, which provides a 
The specific objectives are: natural framework for a comprehensive evaluation 
of input-output relationship (Cooke & DoornKemp 
a. To identify & zoning the characteristics 1974). 
geomorphological, environmental setting 
of the coastal river basin; 
b. To identify & inventorying the land use 3. Study Area: The Kholpetua river basin 
and land cover change occurred in the 
basin area over a period of 3 decades Physical setting 
(1967-2001). 
c. To understand the manner in which they The river basin developed from the combination of 
are influenced by human interactions. two important channels; the Betna and the 
Morichapa at the upper and middle part 
respectively. It covers the Upazila of Kolaroa, 
2. Background: Satkhira upper part and part of Debhata, Asasuni in 
: the middle part and Shyamnagar in the lower middle 
Bangladesh’s coastal environment is changing under and lower estuarine part (Figure 1). 
the influence of human activities. This is happening Topographically, ridge and valleys are two common 
in the last few hundred years; human kind has features of the flood and tidal plain. Elevation 
deliberately changed the surrounding environment declines from 5m at the upper Betna to 0.6m at the 
to serve both immediate and long-term needs. The lower kholpetua (Figure 2a). Agro-ecologically, the 
extent to which this has occurred in ours coastal basin covers five characteristic zonation (Figure 2b): 
areas; however varies from coast to coast. There Lower Ganges flood plain, saline calcarious, salaine 
have been many unwanted side effects as a result of mixed, saline acid sulphate and mangrove areas 
human activities; some were predictable, others are (Table 1). 
yet to be known. This initiative is a part of long- 
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