The Study In The Infiltration Process And The Factors Of The Soil Moisture In The Permafrost Alpine Meadow

Infiltration is an important process in hydrologic cycle,in the source region of Yangtze River,infiltration of soil moisture has impact in runoff and plateau ecology. Basing on the measured data in infiltration,ground temperature and vegetation during three years,we studied the main facts on infiltration in the area of alpine ecological system:soil temperature,depth,vegetation type and cover degree,original soil water concentration,and soil crustation.The main conclusions are as follows:(1)The correlation coefficient between saturation conductivity and soil temperature is high as ST＞4℃under the same vegetation cover degree and soil construction.(2)We simulate the infiltration process using Kostiakov and Horton model,and find that Kostiakov infiltration model is better for meadow grassland in cold region.The infiltration rate is higher at the beginning of infiltration,and the infiltration rate has a timly decreasing trend..The infiltration rate of swamp is higher than the infiltration rate of meadow.(3)In profile,the sequence of saturation conductivity coefficient was soil layers 0～10cm,20～30cm,10～20cm and 30～40cm below the surface from max.to min. In vegetation cover less than 70 percent of cases,the impact of vegetation it is very difficult to 30 cm below the soil saturated hydraulic conductivity.When the vegetation cover more than 70%,30 cm below the soil saturated hydraulic conductivity and vegetation There is a certain correlation.(4)Through analysis,0～10 cm,10～20cm,20～30cm of soil in the three-tier, with the increase of vegetation cover,soil saturated hydraulic conductivity increased, saturated hydraulic conductivity and vegetation cover in a significant correlation(R~2≥0.6).Soil moisture infiltration process simulation results showed that:Kostiakov infiltration model is better for meadow grassland in cold region.The greater vegetation cover,Kostiakov a simulation model The better.(5)The initial soil moisture content of soil moisture affects only the infiltration process,will not affect the results of soil water infiltration.Initial high moisture content of the soil,the initial rate of infiltration of small,fast and stability;initial low moisture content of the soil,the initial infiltration rate,slower stability.(6)Soil encrustation greatly weakened the capacity of the soil infiltration, reducing the efficiency of water infiltration,the infiltration of water conservation and the existence of adverse effects.Guitar cortex soil water infiltration rate trends for small - big - small,finally stabilizing.