| In this paper, Fenghuoshan watershed in Yangtze River valley of Qinghai-Tibet Plateau permafrost region had been selected as the study area. For the Alpine meadow and swamp meadow, the coverage of the vegetation cover is a basis for distinguishing the extent of ecological degradation. The changes of vegetation coverage, slope, aspect convergence had been as the research objection Rainfall interception, soil water infiltration, soil evaporation and dew process were the research contents. Through analysis basin meteorological factors of different cover of Alpine meadow vegetation, rainfall interception, soil water infiltration, soil evaporation and condensation processes, and soil temperature and moisture distribution and other factors, the results were analyzed between the changes in vegetation cover. The vegetation-soil and surface water cycle relationship between the factors indicated the extent and mechanism of interaction. The results of the study showed that:1.(1) The maximum interception and retention rates of Alpine and swamp meadow vegetation varyed widely, the maximum interception of Alpine meadow was significantly greater than the maximum interception of swamp meadow. swamp meadow maximum interception capacity was 0.18mm, the maximum interception rate was 3.8%; The largest Alpine meadow interception was 0.61mm, the maximum retention rate was 12.4%. Alpine meadow and swamp of interception and retention rates and rainfall, rainfall intensity, rainfall duration, and factors such as vegetation cover is closely related to, and Alpine meadow and swamp in the strong correlation between the factors. (2) Alpine meadow and swamp interception and retention function between the power function correlation between interception and rainfall intensity also had a better power function relationship. Alpine meadow interception and rainfall correlated the power function, swamp meadow between interception and rainfall had quadratic relationship. (3) Rainfall interception was significant increasing with the vegetation coverage of Alpine meadow and swamp. Also, the rainfall intensity had increased interception. With the increase of vegetation cover, rainfall interception in Alpine meadow were improved the swamp meadow of interception, but the rainfall interception of the Alpine meadow and swamp cover increased with the magnitude of differences, Alpine meadow vegetation with the different of vegetation coverage. (4) In order to more in-depth understanding of the Alpine cold meadow and swamp meadow vegetation, rainfall interception characteristics, and the relationship between the various influencing factors. The influence of Alpine meadow and swamp vegetation between the each factor can be multiple by nonlinear regression analysis. The statistical regression analysis showed that the interception of Alpine meadow had the relationship:I= 0.0025C·Ri0.34·T0.19 multi-function to vegetation cover, rainfall intensity and duration of rainfall; and the swamp meadow had the relationship:I= 0.00073C·Ri0.18·T0.33 multi-function.2. (1) With the increase of Alpine meadow vegetation cover, soil physical and chemical properties of Alpine meadow can be improved, soil bulk density decreased significantly, clay content, total N, organic matter content showed an increasing trend, and the infiltration rate and saturated hydraulic conductivity was significantly increased. The soil of high Alpine meadow vegetation cover, Alpine meadow as well-developed root system, made the structure of the soil relatively loose. so the formation of preferential flow was more easily, higher saturated hydraulic conductivity. (2) The initial water content of Alpine meadow soil would affect the infiltration process, the results of soil water infiltration would not have a significant impact of soil initial water content. With the Alpine meadow soil temperature increased from 0℃, saturated hydraulic conductivity began 0℃first by a slow downward trend, when the Alpine meadow soil temperature was higher than 5℃, the saturated hydraulic conductivity showed an increasing trend. Soil saturated hydraulic conductivity increased with the increasing of soil temperature were related. When the initial soil moisture content was low, the soil's initial infiltration rate of infiltration reaching a relatively state would have much longger time. (3) The results showed that the main factors affecting soil infiltration can be concluded in physical and chemical properties of soil texture, the degree of soil loose aggregate factor and hydrophilic organic colloid three main components.3. (1) Dew water of Alpine meadow in Fenghuoshan mountain watershed mainly origined from two aspects:one is condensation water vapor of the free air; for the vadose geothermal gradient with water vapor in the upward flow of condensation under the effect of condensate formation. Non-degraded, moderately degraded and severely degraded meadow air, water vapor condensate formed by condensation of water in the proportion of the total, respectively:67.3%, 73.2% and 85.3%; vadose zone water vapor condensate formed on the shift of the total condensate proportion were:32.7%,26.8% and 14.7%. And air vapor condensate formed package to be significantly greater than the upward flow of air with water vapor condensate formed. (2) By observations of dew water in Alpine meadow showed that:the occurrence of dew water was in the night 20:00 to 8:00 hours, the largest dew amount was in the 6:00 to 8:00. Dew amount was changed with the degradation of Alpine meadow, the dew of Alpine meadow ecosystem was important to maintain balance of ecology. (3) High vegetation cover was conducive to the retention of dew in the air. The soil the night 0-5cm soil layer to the amount of dew will increase with the greater of Alpine meadow vegetation cover. while the 5cm soil layer the following night evaporation will decrease accordingly. The higher vegetation cover enhanced the efficiency of soil formation of dew water. (4) Meteorological factors in Alpine meadow had an great influence on the amount of the the dew. The greater the magnitude of changes in temperature, the more conducive to the formation of dew water. The highernear-surface air humidity, the more conducive to the formation of dew. Rainfall and wind speed had a negative effect on the occurrence of dew.
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