Mapping Urban Encroachment in the Rivers around Dhaka City: An Example from the Turag River

Abstract

Dhaka, the capital city of Bangladesh, is one of the fastest growing and the most densely populated cities in the world. The city has 4 rivers all around which were once lifelines to it for economy and ecology. Being expanded rapidly in an unplanned way with the phenomenal increase of population, land scarcity and land price, the city’s peripheral zone reached the banks of the rivers. Consequently, an ill-motivated section of people began to use the riverbanks in a variety of ways leading to river encroachment. Gradual encroachment is narrowing down the rivers putting their existence to threat. This study was conducted to find out the major encroachment points, estimate the area and document the land use of each encroachment point in the Turag River, particularly from the Buriganga Third Bridge (Shaheed Budhijibi Bridge) at Bashila to Tongi Bridge. The study was carried out through field survey with Dhaka City (rivers) map and GPS. The field survey was supported by discussion with focus group of 60 people aged over 70 experiencing changes in the Turag River for over last 50 years. Encroachment map showing the location of encroachment points has been prepared through application of GIS and satellite image. During field survey, the area and land use of each encroachment site was estimated and noted down respectively on sketch map. However, the study found out 51 points where about 1.5 acre of the riverbanks have been grabbed and are being used mainly for trade and commerce as well as housing purposes.

Keywords: Dhaka, Economy, Ecology, River encroachment, GPS, GIS.