Characteristics of Soil Water Change and Response to Rainfall of Different Land Use Types in The Dry-Hot Valley of The Jinsha River
In order to investigate the characteristics of soil moisture change and its response to rainfall in the dry and hot river valley area,grassland,Ziziphus mauritiana woodland,Leucaena leucocephala woodland and sloping cul-tivated land located in the dry and hot river valley watershed of Yuanmou were selected as the research objects,and the soil moisture content was monitored in real time by using the HOBOH21_USB soil moisture monitoring system and rainfall from January to December of 2021 was measured by using the TE525 mm bucket rainfall cylinder to i-dentify the characteristics of temporal and vertical changes of soil moisture and the response of soil moisture content of each soil layer to different levels of rainfall in this basin.The results showed that:(1)The seasonal variation of soil moisture in the four land use types in the study area can be divided into stable period(January to May),rapid growth period(June to July),steady rise period(August to September)and consumption period(October to Decem-ber).(2)The vertical variation of soil moisture content increased with the increase of soil depth but some soil layers deviated from the general trend.(3)In the case of light rain(0.1-10 mm),only 0-20 cm soil layer of the four kinds of plots showed a weak response.Under moderate rain(10.1-25 mm)conditions,rainfall had a replenishment effect on the moisture content of 0-40 cm soil layer in different regions.Under the condition of heavy rain(25.1-50 mm),the rainfall replenishment range of various areas expanded to 60 cm soil layer.In the case of torrential rain(>50 mm),all kinds of soil strata respond to the rainfall.The findings indicated that,from the perspective of spatial and temporal changes in soil moisture as well as rainfall response as a whole,it is easier to store soil moisture on sloping cropland than on afforested land in the region and the results can provide a theoretical basis for revegetation and ecological restoration in the Yuanmou dry-heat valley area,which has a hot climate with little rainfall and where evapotranspiration is much greater than rainfall.
dry-hot valleysoil moisturetemporal and spatial variationJinsha River
万方数据
维普
