Detecting Temporal Changes of Small Water Bodies Using GIS Techniques: Northern part of Bangladesh as a Case Study

Small water bodies are the common term, which includes pukur (pond), doba (man-made or natural pit or ditch with full of water), dighi (man-made tank or reservoir), khal (Canal), beel (lake-like wetland with static water) etc. In the rural area, especially in the flood-affected area, small water bodies are the common physical features in landscape and the most important part of the wetland ecosystem. The study area of this research is Khordo Gojail mouza under the Sirajganj district where different kinds of small water bodies are found. In spite of having the role of small water bodies in maintaining ecosystem balance and every day livelihood of the surrounding communities, these are being changed and distorted drastically due to unexpected human interfere. The main objective of this study was to detect the changes of small water bodies for the period of 1981 to 2013 in the study area. As a prime method the present study used Geographic Information Systems (GIS) to delineate the changes of small water bodies. However, GPS Survey and focus group discussions were done in order to fulfill the other data requirement. The study found that almost all the small water bodies were changes in terms of area, size, shape and depth over the studied period and till are now in under changes. Both natural and manmade causes are closely related for such changes of small water bodies in the study area such as flood, sedimentation, drainage, agriculture, settlement etc. The study concluded that urgent measures should be taken as immediate to prevent the water bodies’ transformation to other land use in order to keep the balance of the wetlands in the study area as well as other areas in Bangladesh.