ESTIMATION OF AGRICULTURAL TYPE IN THE HUAIHE RIVER BASIN CHINA AND APPLIED TO THE LAND-SURFACE SCHEME

Abstract

In this study, agricultural cycle was estimated from satellite data for the evaluation of agricultural water use in the Huaihe river basin, China. Using SPOT-NDVI data from April 1998 to March 1999, all cropland are categorized into four classes (wheat+soybean, wheat+maize, rape+rice, wheat+rice). Then the harvesting time of summer harvesting crop, the planting and harvesting time of autmun harvesting crop are estimated from the time series of NDVI data at each mesh. Based on these results and water requirement data, appropriate water level and soil moisture condition is defined depending on the growing stage. In the numerical simulation, irrigation water is supplied or drained to meet this appropriate condition. Due to this method, water use of this basin is faithfully reflected in the land sueface scheme.