Seasonal Hydrological Characteristics of Langolhata Wetland of Birbhum District and its impact on Agricultural

Abstract

Wetlands are fundamental hydrologic landscape unit that generally forms on flat areas, or on shallow slopes, where perennial water lies at or near the land surface, either above or below. Wetlands tend to form where surface water and ground water accumulate within topographic depressions of different Geomorphological environment. The surface hydrological characteristics of langolhata wetland is controlled by the amount of rainfall, no of rainy days, height & width of water of Kuya river and sinuosity of the river. In this study rainfall and river water fluctuation is positively correlated with the wetland hydrology and both Kuya river and Kandar Khal have Sinuosity Index as 1.5 which indicate both the river is meandering in nature as well as narrow cross sectional width result into low water holding capacity of the channel which cause overflow towards the Langolhata wetland. The impact of wetland on agricultural pattern varies between flood year and nonflood year. During the flood year almost all the area of wetland is submerged and the standing crops are being lost. In non-flood year waterlogging also occurs due to some other hydrological parameter. It covers only part of wetland when the remaining area is used for cultivation. Moreover during post-monsoon period when the spatial extension as well as the height of the water has decreased, then the post-monsoonal crops are cultivated with the aid of surface water irrigation.