Study Of Soil Hydrology And Corrosion Resistance Characteristics Of Alpine Shrub Meadow In Western Sichuan

The shrub meadows in the alpine mountains of western Sichuan have an important role in conserving water sources and maintaining ecological balance,and are also important animal husbandry bases in China.This paper takes Kangding's mountainous soil and litter as the research object,and comprehensively evaluates the hydrology and corrosion resistance of the shrub meadow soil in the alpine region of western Sichuan by field sampling and laboratory analysis combined with principal component analysis.Provide reference for the protection and restoration of alpine meadows in the area.The main findings are as follows:(1)The litter in the study area has obvious regularity at different elevations and slopes.The accumulation of litter on the semi-north slope is higher than that on the semi-south slope.The amount of litter accumulation decreases with the increase of altitude;the effective storage capacity of litter is generally presented.The semi-north slope is larger than the semi-north slope,and decreases with the increase of altitude;the water absorption of litter is exponential with time,the water absorption rate is a power function relationship with time,and the litter at 3800 m semi-north slope The water absorption rate is the largest,indicating that the litter in this area has a strong ability to regulate external water.(2)The soil bulk density in the study area shows the law of deposited layer >leaching layer in the vertical direction.The total soil porosity decreases with the deepening of soil depth.The soil porosity of 4000 m semi-south slope is the best.At other elevations and slopes.The soil powder content of the six plots was the largest,the sand content was the second,and the clay content was the smallest.There is no obvious uniform change of structural particle index in different soil layers and elevations.The structural grain index of semi-south slope is larger than that of semi-north slope.(3)The soil water holding capacity of the study area generally showed a leaching layer larger than deposited layer.The maximum water holding capacity of the soil shows that the semi-north slope is smaller than the semi-south slope,and the variation law of the maximum water holding capacity of different soil layers is different.The effective soil storage capacity generally shows that the semi-south slope is larger than the semi-north slope,and the 4000 m semi-south slope leaching layer soil has the best effect on rainfall storage.There is a certaincorrelation between soil water holding capacity and soil physical properties.The initial infiltration rate and steady infiltration rate of the topsoil of the six plots were larger than that of the deep soil;the initial infiltration rate of the soil decreased first and then increased with the increase of altitude,and the initial infiltration rate of the soil in the upper semi-south slope was greater than that of the semi-north slope.(4)Through the principal component analysis method,18 indicators were selected to comprehensively evaluate the soil erosion resistance of the study area.The order of soil erosion resistance in the study area was: 3800 m semi-south slope> 4200 m semi-north slope> 3800 m semi-north slope> 4200 m semi-south Slope > 4000 m half south slope > 4000 m half north slope.It is indicated that the soil corrosion resistance of the 3800 m semi-south slope is better than that of other soils in the study area,while the soil erosion of the 4000 m semi-north slope is the worst,and soil erosion is highly prone to occur.The three indexes of >0.25 mm air-dried aggregate content,aggregate GMD value and aggregate fractal dimension D are the best indicators for evaluating soil corrosion resistance in this area.