Assessment of wetlands to evaluate aquatic environment: a case study in Floodplain of Himalayan foothill region

Abstract

In floodplain wetland the evaluation of aquatic environment has been implemented as an effective tool for the rapid assessment. Ox-bow lakes i.e. natural wetlands are the abandoned part of the former meander are common features developed in floodplain. The northern portion of Coochbehar district is under the Tarai belt and the southern portion lies under the alluvial plain physiographic region. The Tarai zone is composed of alternate layers of clay and sand, with a high water table that creates many wetlands. Many natural wetlands in the form of ox-bow lakes have been formed in Tufanganj C.D. Blocks which are locally known as beel or baor. These beels are the abandoned channels of Raidak I, Gadadhar, Kaljani, and Mora Raidak River. Due to the geological and geomorphological set up of this region the rivers mentioned above frequently change their course. Topographical, Geomorphological and Geohydrological maps have been used to know the spatial distribution of wetlands and physiographic set up of the region. Many beels have evolved which are ecologically very much productive. With the help of the Oakton multi parameter and WTW DO meter wetland index has been prepared in some of the beels to analyze the physico-chemical properties of wetlands and to assess the ecological importance as well as human intervention. Thermal bands of Landsat image (OLI/TIRS) have also been used to assess the temperature distribution of the land and wetlands. This paper investigates the role of wetland hydrology to evaluate aquatic environment for the wetland assessment in the floodplain regime.