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根据定位点的实测资料，阐述了南亚热带丘陵赤红壤试区的降雨、蒸散、地表径流、深层贮水和土壤贮水量的动态变化在土壤水分循环中的作用。研究结果表明，在丘陵赤红壤水分循环中，降雨量多和降雨强度大起着极重要的作用，降雨量多但分配不均匀形成明显的干湿季节，降雨强度大于土壤入渗速率是产生地表径流的关键条件。由大雨而暴雨并持续１０ｈ以上的降雨过程且降雨超过５０ｍｍ，将产生深层贮水。在干旱季节（１～２月和１０～１２月），降雨量仅占年降雨量１１．６１％～１６．４６％，而蒸发量却占年总蒸发量３３．２２％～４２．０８％，尤其是每隔两年左右的１月或１１月前后，常出现持续４０多天未下雨的现象，０～１００ｃｍ土层的蒸散量大于降水渗入量、土壤贮水减量。因此，在雨季防止或减少地表径流；在旱季减缓土壤水分蒸发，提高土壤水分利用率，或以喷灌方式补充土壤水分，是丘陵区发展“三高农业”不可忽视的问题。
According to the measured data of the locating point, the effects of rainfall, evapotranspiration, surface runoff, deep water storage and the dynamic changes of soil water storage capacity on the soil moisture cycling were described. The results show that in the hilly red latitude soil water cycle, rainfall and rainfall intensity plays a very important role in large, but the distribution of uneven rainfall to form a clear wet and dry season, rainfall intensity is higher than the rate of soil infiltration rate is the surface The key conditions of runoff. Heavy rain and rain lasting more than 10 hours of rainfall and rainfall over 50 mm, will produce deep water storage. During the dry season (January to February and October to December), the rainfall only accounts for 11.61% ~ 16.46% of the annual rainfall, while the evaporation accounts for 33.22% ~ 42.08% of the total annual evaporation. In particular, the phenomenon of no rain lasting more than 40 days often occurs around January or November every two years. The evapotranspiration of 0-100 cm soil layer is larger than the infiltration of precipitation and soil water storage reduction. Therefore, in the rainy season to prevent or reduce surface runoff; in the dry season to slow down the evaporation of soil moisture to improve soil water use efficiency, or sprinkler irrigation to replenish soil moisture is the development of “three high agriculture” in hilly areas can not be ignored.