Changing Tendencies and Utilizations of Water Resources in the Typical Sand Regions around Beijing
首都圈典型沙区水分资源的变化趋势及其利用

The surveys of agricultural geography in the typical sand regions around Beijing are briefly indroduced in this paper. The regional differences of water condition in the typical sand regions are analyzed from the aspects of the time space change and the frequency calculation of annual precipitation. The Pealson Type-III Model and Wakeby Distribution are used to simulate the frequency distribution of annual precipitation, and the results that accord with the demands of the precision are obtained. According to the annual area precipitation series of Fengning County, the periodicities with the annual area precipitation are determined by the autoregression analysis, the variance analysis and the spectrom analysis. The agrometeorology indexes and the water yield functions of the main crops are analyzed in water condition utilization. That also suggested in the part are the comprehensive yield increasing techniques of the main crops, shch as naked oats, potato and pea, and the effective measures for improving the condition of agricultural water supply, including the natural protective system of farmland in the rain fed agriculture regions and water saving agriculture in the irrigated agriculture regions.