黄土丘陵区水土保持措施配置与土壤水分的关系

SOIL WATER AND THE DISPOSITION FOR MEASURES OF SOIL AND WATER CONSERVATION IN LOESS HILLY REGION

土壤水分与水土保持措施配置间存在密切关系,从空间结构看,地形起伏引起降水再分配,而工程措施可使降水形成有益的再分配,由此产生土壤水分的微域分异。这种分异制约影响着生物措施的空间配置;从时间过程看,为防止某些植物过度的水分消耗而致土壤干燥化,需采取循环轮作配置。在黄土丘陵区要求林草与农作物地在轮作周期内的总耗水量与有效雨量(降雨量与径流深之差)持平。

There is a close relationship between soil water and the disposition for measures of soil and water conservation.In space structure,undulate terrain results in the rain redistribution and the mechanical measures make the redis- tribution be useful so soil water differences in a micro-region take place.The differences restrict and affect the space disposition of the biological measures. From time angle,the rotations of grasses,forests and crops should be taken so as to prevent the soil from drying which results from the excessive water consumption of some plants.It is necessery that the total consumptive use of water in the rotation period is equal to the total effective precipitation(pre- cipitation minus runoff depth)in the loess hilly region.