土地利用方式对红壤坡地雨水利用和水量平衡的影响研究

通过红壤坡地5种典型土地利用方式的长期定位观测研究,剖析了不同利用方式对雨水利用和水量平衡的影响.(1)荒草区常年水分消耗稳定茶园区和恢复区对土壤深层贮水利用能力强,表明不同的土地利用类型对土壤水分利用特征随季节和深度不同而不同;(2)土壤蒸散是各区100 cm耕作层中水量平衡最主要的支出项(83%以上),农作区蒸散量最小,地表径流量最大,恢复区则相反;(3)从减少水土流失和提高水分利用率两者结合考虑,构建农林复合系统以及间作、套作、撩壕等耕作方式为红壤坡地最优的雨水资源利用模式.

Impacts of Different Landuse Patterns on Rainfall Utilization and Water Budget of Sloping Land in Red Soil Region

Based on fixed field observation for five typical landuse modes,this paper analyzed the effects of different landuses on its rainfall utilization and water balance.The main results were reported as follows.(1)The difference laws of steady soil water consumption in grassland and a higher ability in sufficient use of water stored in deep soil layer in tea garden and the restoration area showed that the characteristics of soil water utilization in different landuse patterns were different with different seasons and soil layers.(2)Evapotranspiration hold more than 83%of input(rainfall),which was the most important output part of water balance in 100 cm plough layer.Evapotranspiration on cropland was the lowest and runoff on it was the highest,but those in the restoration area were reverse.(3)An optimal model of rainfall utilization on sloping land in red soil region must be constructed for reducing surface runoff and improving the utilization rate of rainfall,so the compound management of cropping forestryher bage and the tillage methods of broad base terracing would be the best choice.