Response of Soil Moisture under Different Vegetation Coverage to Precipitation in the Headwaters of the Yangtze River
Soil moisture is the key factor which connects climate change and vegetation coverage dynamic. In this paper, the typical catchment of Zuomaoxikongqu in the headwaters of the Yangtze River was taken as an example. Based on the observations of precipitation, vegetation coverage, soil moisture,infiltration, evapotranspiration and condensation, the relationship is analyzed between soil moisture and precipitation under different vegetation coverage conditions. The study indicates that there is a significant delayed response of soil moisture to precipitation under different vegetation coverage, with a long lag time. When the vegetation degradation is seriously, soil moisture within the depth of 20 cm responds to precipitation to a certain extent,while in the deeper soil layer, which is rather dry, the response is insignificant. When the original plant community is kept with a higher coverage, the water retention ability would be enhanced, and the soil moisture content in deeper layers has been greatly improved. The depth, at which the change of soil moisture is distinct with soil moisture response to precipitation, is deeper than 40 cm. Higher vegetation coverage can improve the physical and chemical characteristics of soil, with an accelerated water infiltration. The plant roots influence the response of soil moisture to precipitation, because of preferential flow and water-absorption caused by plant roots. There exists a big difference in surface evapotranspiration and condensation under different vegetation coverage. Alpine meadow with high vegetation coverage has an apparent effect of reducing evapotranspiration and increasing condensate water.
headwaters of the Yangtze Rivervegetation coverageprecipitationsoil moistureresponse
NETL
NSTL
万方数据
维普
