Research On The Laws Of Soil Water Infiltration And Redisribution On Red Soil Slopes

Red soil regions of the South China,because water and hot resource is rich ,and become important grain in the country and industrial crops base.But for a quality of inequality in rainfall distributed and the influencing by the seasonal high temperature, often cause the dog days, drought in autumn, bring serious influence to local agriculture. Therefore how to utilize soil water resource rationally and effectively become the keys to guarantee physiological water requirements of vegetation and improve eco-environment. In the dissertation, soil water that restricts vegetation construction primarily is focused on.By the ECHO and Neutron Probe, and the experiment of infiltration natural condition,the laws of soil moisture dynamic state during infiltration period and soil water redistribution after infiltration under different slope vegetation types have been analysed . The main results are as follows:1) Pine forest land soil moisture permeate speed decreased is the fastest with time increased, natural hillside fields most slow,it proves the infiltration capacity of natural hillside fields soils is the best, pine forest land soil upper layer better;The main factors soil infiltration rate approached are soil natural structure,initial water content and graphic condition;The Kocrakob equation of three infiltration equation match best with survey .2) The dynamic change of the soil moisture can be divided into 3 stages, the time of the first stage is relatively short, generally about lOmin, it is the stage that the soil moisture content does not change basically; Increase sharply stage for the soil moisture content about 10-30min is the second stage; The third stage increases stage slowly for the soil moisture content . It is a largest influence on upper layer soil moisture dynamic state during infiltration, 10cm depth moisture changes most violent, it is shortest to reach steady time, and the water content of soil layer changesrelatively gentlely under 50cm.3) The law of soil moisture redistribute after infiltration as follows. The extension of time with supplying water of stopping, the soil moisture content is reduced sharply in top layer 10cm, the moisture content of 20-50cm soil layer begins to have the tendency to increase, then reduce gradually. The moisture content of the soil layer slightly changes under 60cm; Different vegetation types change the range are that the natural hillside fields is the greatest,and pine forest land smallest. Compare to the condition of evaporation isolated , the range is larger for soil water content to reduce in evaporation condition...