Researches On Spatio-temporal Variation And Difference Of Soil Moisture In Poyang Lake Basin

As one of the typical wet areas,the hydrological process changes in the Poyang Lake Basin have attracted extensive attention and research from academia.Soil moisture is one of the main sources of uncertainty in watershed hydrological process research.At present,there are few studies on soil moisture in the Poyang Lake Basin.There are few systematic literatures to analyze the temporal and spatial distribution characteristics of soil moisture and related factors in the Poyang Lake Basin.The research on soil moisture distribution in the Poyang Lake Basin is conducive to improving the reliability and accuracy of water balance research in the basin.In this study,the Poyang Lake Basin was taken as the research area.Using multi-source remote sensing data,the spatial and temporal characteristics and trends of soil moisture in the Poyang Lake Basin at different scales were analyzed by constructing soil moisture data sets at different time scales.The spatial and temporal distribution of soil moisture in the basin was discussed by combining the soil cover in the Poyang Lake Basin.Ring.The main research results of this paper are as follows:(1)A long-term time series data set of soil moisture in Poyang Lake basin was constructed by using the data of soil moisture from 2001 to 2013 of the Global Climate Change Initiative project.On this basis,the constructed data sets are re-fused with the soil moisture data sets of adult and monthly time scales.Through the analysis of soil moisture data sets of different time scales,it is found that the soil distribution in the Poyang Lake Basin is generally high in the north and low in the South and low around the lake area.In addition,the soil moisture in the Poyang Lake Basin shows a significant downward trend from 2003 to 2009.In addition,the soil moisture in the Poyang Lake Basin changes with the month,and its value is usually larger in the first half of the year,while September and October are usually the months with the lowest soil moisture content in the whole year.(2)Based on the data set of soil moisture from 2001 to 2013,the spatial and temporal correlation between vegetation cover and soil moisture in Poyang Lake basin was studied by regression analysis,and the effects of vegetation cover in different periods on the spatial difference of soil moisture were studied.The results showed that the soil moisture of different surface covers had similar change trend in the year;the soil moisture of different surface covers had different change trend;the change trend of soil moisture of sub-basin was different from that of the whole basin.Based on the multi-time scale analysis of remote sensing data of soil moisture in Poyang Lake Basin,the spatial and temporal distribution of soil moisture in the study area was revealed.Based on the remote sensing image data of soil cover in the same time period of the basin,the spatial and temporal variation characteristics of soil moisture in the Poyang Lake basin and the influence of different vegetation cover on the spatial and temporal variation trend of soil were found.The results of this study are helpful to understand the mechanism of soil moisture change in Poyang Lake basin,identify the influencing factors of soil moisture change,and provide decision-making basis and information for soil protection and water resources management in the basin area.