IRRIGATED AREA MAPPING TO ASSES AWD POTENTIAL OVER BANGLADESH From 2001-2017

摘要

Bangladesh is one of the countries that use 80% of groundwater withdrawal for agricultural irrigation. Due to the green revolution and irrigation technology development, the irrigated water demand increases day by day. Among the irrigation crops, rice is the highest water-consuming crops and 70% of the total cultivatable area of the country used for rice production. Excessive pumping of groundwater and climate change impacts the groundwater table gradually declined. Moreover, the traditional flooded irrigation rice production producing GHG's especially methane, which accelerated the climate changes. Alternate wetting and drying (AWD) irrigation system are a less water use and methane emission reduction techniques for a better solution to the dilemma. To better water resource management and planning in agriculture need to introduce AWD irrigation. The main objective of this study is to prepare an irrigated area map for AWD irrigation appraisal. The important things for irrigated area mapping for AWD assessment are - to monitoring the crop growth, Crop water loss and the crop water requirement. The important things for detecting the AWD irrigation is to detect the irrigated rice crop area because in rain-fed rice cultivation AWD irrigation is not applicable. In this study, the MODIS satellite images derived NDVI and ET time series data, LSWC data from AMSR/E and AMSR2, Rainfall data from GSMaP have been used for spatiotemporal analysis of irrigated area mapping. In this study, the crop evapotranspiration is higher than the effective precipitation in a region considered as irrigated area. By using atmospheric corrected MOD16A2 long time potential evapotranspiration and Effective Rainfall data from GSMaP are considered for assessment of Irrigated area. The result compared with the sub-national statistics and published data of the irrigated area of Bangladesh shows a positive co-relation and higher accuracy.