The ecohydrological response to soil moisture based on the distributed hydrological assimilation model in the mountain region

Abstract

AbstractIn the mountain region, there is high spatial variability of soil moisture, which limited soil moisture sites may not express. Data assimilation methods can combine the advantages of model simulation and data observation. This study constructs the distribution of soil moisture based on the distributed hydrological assimilation model and explores the ecohydrological response to soil moisture in the mountain region. The relationship between the coefficient of variation and mean soil moisture shows a hysteresis pattern. The terrain conditions where high soil moisture occurs in the study area are an altitude of about 3500 m, a gentle slope, and a shady slope. The low value of soil moisture is characterized by banded aggregation distribution. There is an initial threshold for the contribution of soil moisture to watershed runoff, and the threshold value in the study area of this paper is 0.28 cm3/cm3. The regions with dense vegetation exhibit higher spatial variability in soil moisture. Vegetation plays a heterogeneous role in the spatial variability of soil moisture when precipitation events occur. The study contributes to a deeper understanding of ecohydrological processes by providing regional‐scale data and uncovering the relationships between soil moisture and various ecohydrological factors.