II. FLOOD LOSS REDUCTION AND REVIEW OF PAST EXPERIENCES
C. Methodology for assessment
2. Flood depth mapping for planning of agricultural land protection
Bangladesh has 9.562 million hectares of cultivatable land which is about two-thirds of the land area of the country. The agricultural lands are prone to river flooding since they are almost entirely on the floodplain. Most of flood control and drainage projects are to provide protection to agricultural land. The depth of flooding is a key factor in the choice of rice crops to be grown in cultivatable land. The objective of protecting agricultural land against river flooding is to bring changes in the distribution of land types that are favorable to HYV rice cultivation. In planning studies, the benefit of flood control projects is assessed by the change in the spatial distribution of land types as a result of reduction in the flood depth. For projecting future agricultural damage due to floods, past damage data is linked to the timing, depth and duration of flooding in individual years in order to determine damage coefficients for each crop, land type and land development category as suggested in the Guidelines for Project Assessment by FPCO (1992).