Assessment of Changes in Water Retention Areas in Eastern Dhaka Using RS and GIS

Water retention areas are major natural elements of an urban area.These areas have different functions of the physical environment.In Dhaka(Capital city of Bangladesh),these retention areas are encroached by different land development activities.In the recent years,water logging,drainage congestion and differrent types of problems have been generated by unplanned urban development.This study was conducted to estimate the change in the retention area in eastern part of Dhaka over a period of last 15 years based on satellite images.Three different satellites images(Landsat TM,Landsat ETM Plus and IKONOS)have been used in the study to observe the