Abstract
This study aims at assessing the applicability of GIS and remote sensing as time-, cost- and labor-efficient tools in evaluating land characteristics and water balance inputs needed for efficient water management in irrigation schemes aimed at double rice cropping. The Ngamoeyeik Irrigation System in Lower Myanmar is our case study. Two scenes of LANDSAT 7 ETM+ data acquired at the beginning (January) and the end (April) of the irrigation season are used for land cover classification. Five categories of land use and land covers are identified for the January and the April classifications, showing high similarity with the ground data with an overall accuracy of 80 %. This is especially true for the rice paddy field category (96 %). From these land cover maps, the irrigated rice field category's distributions at the two different periods of the irrigation season were detected and rice field acreages accurately estimated. It is shown that using two land cover maps leads to more accurate and up-to-date information on land use and land cover conditions as well as on the rice field distributions and their temporal changes, and to more consistent rice field acreages than using a single land cover map. Irrigation water requirements and irrigation efficiencies are calculated and discussed in conjunction with water supply records in order to improve water management performances from the onfarm level to the overall irrigation system level.
