Emerging conflict between agriculture extension and physical existence of wetland in post-dam period in Atreyee River basin of Indo-Bangladesh

摘要

Alarming wetland loss and modification of wetland landscape in the Atreyee floodplain is an ensuing concern in post-dam condition (after the construction of a dam over Atreyee river in 2012). The nature of the conflict between the changing wetland and agriculture landscape in the altered hydrological state in post-dam period is investigated and illustrated. Agriculture and wetland maps are prepared from multi-temporal satellite images using frequency approach. The result clearly exhibited that agriculture land is increased substantially (4316.95-8047.53km(2)) and wetland is declined (1098.25-592.88km(2)) in the post-dam state. Out of the lost, 268.33km(2) of wetland area is transformed into agricultural land and the transformation rate is high from low-frequency water presence (wetland with irregular water appearance) wetland to agricultural land. The consistency and stability of agriculture land are gradually increased over time when it is decreased in case of wetland. Extension and perforation of agricultural practices toward wetland areas are caused for wetland loss and fragmentation of wetland. It causes physical and ecological vulnerability of the same. Increasing number of wetland patches (25,839-31,769), decreasing frequency of agriculture patches (94,280-16,296), dwindling of large core wetland area (656.10-212.04km(2)), doubling of large core agriculture land (2270.87-3822.88km(2)), etc., are some of the evidences signifying growing conflict between wetland and agriculture land. Aggressive growth in agriculture land has been emerging as a strong reason for wetland loss and transformation.