Spatial Variability of Soil Moisture in Relation to Land Use Types and Topographic Features on Hillslopes in the Black Soil (Mollisols) Area of Northeast China

Abstract

Soil moisture, as a crucial factor in the eco-hydrological process, is of great importance for food production, land management in response to water and soil loss, geomorphic processes, and environmental protection. Understanding the spatial variability of soil moisture induced by different land use types and topographic features is conducive to advancing the adjustment of the land use structure and preventing soil erosion on the hillslopes in the black soil (Mollisols) area of Northeast China. Classical statistical methods and Canonical Correspondence Analysis were used to analyze the spatial heterogeneity of soil moisture at 0–20, 20–40, and 40–60 cm on slopes, to identify the main controlling factors and their relative contributions. The results suggested that: the average soil moisture content followed a decreasing order of grassland > shrubland > soybean land > maize land > adzuki bean (Vigna angularis) land > forestland; the profile soil moisture content (SMC) patterns could be divided into four types, related to the comprehensive influence of vegetation types, root system characteristics, and topographic attributes; the spatial variability of soil moisture was strongly influenced by slope gradient, followed by land use types and elevation and slope position, while slope aspect had the least impact; and finally, land use type had a greater impact on the deep layer than the surface layer, while on the contrary, the influence of the topographic attributes on the deep layer was smaller than on the surface layer. Land use types and topographical elements work together on the soil moisture variability and vertical patterns at differing depths. This study provides an insight into policy making of land resource management and can be used in the modeling of hydrological processes.

Comparison of soil moisture indices and field measurements in hilly agricultural lands of SW Hungary

“…This can probably be explained with the water retention capacity of anthropogenic landscape microelements (hedgerows, tree rows) and the infiltration induced by such elements (Syrbe -Grunewald 2017). Our results are in harmony with the claim by Guo et al (2020) that land use class has a greater impact on the deeper root zone than on the surface layer. In areas where the vegetation had deeper reaching roots, we found higher SAVI values (above 1.102).…”

Spatial Heterogeneity and Driving Factors of Soil Moisture in Alpine Desert Using the Geographical Detector Method

“…This may be affected by vegetation and topographic factors, as well as extreme rainfall, sand movement, strong evaporation, and groundwater table fluctuation, which is consistent with the conclusion of Li et al [33]. Moreover, the uncertainty resulting from the random measured samples may increase such strong soil moisture variability [13,33,46]. In the geographical detector analysis, the interaction among evaluation factors had a strong effect of dual factors and a nonlinear enhancement effect on soil gravimetric water content in the 0-50 cm layer.…”

“…It was reported that the change of soil moisture in sandy soils is affected not only by topography and vegetation but also by the spatiotemporal variation of precipitation with a strong dependency. Meanwhile, the previous studies have mainly focused on the effects of different land use patterns, vegetation types, spatiotemporal factors, and soil properties on soil hydrological changes in sandy soils [7][8][9][10][11][12][13].…”

Investigating the Spatio-Temporal Variation of Soil Moisture and Agricultural Drought towards Supporting Water Resources Management in the Red River Basin of Vietnam

“…In addition to the impacts of meteorological variables, according to [4], soil moisture variation is also impacted by other factors such as (i) land cover type and vegetation, which affect the runoff, infiltration, and evapotranspiration through root water uptake [4,[29][30][31]; (ii) topography, which influences the runoff and infiltration [32,33]; and (iii) soil type, which impacts the water-holding capacity [34,35]. Vegetation type, density, and uniformity are key characteristics that contribute to soil moisture changes at different spatial and temporal scales.…”

“…In addition to the impacts of meteorological variables, according to [4], soil moisture variation is also impacted by other factors such as (i) land cover type and vegetation, which affect the runoff, infiltration, and evapotranspiration through root water uptake [4,[29][30][31]; (ii) topography, which influences the runoff and infiltration [32,33]; and (iii) soil With respect to land cover and topography, the northeast region has the most dominant land cover and vegetation type is the mixed forest, followed by the cropland/grassland mosaic (Figure 4a) and the elevation decreasing from north to south (Figure 4b). The uppermost areas near the border with China are mainly covered by the cropland/grassland mosaic and have the mountainous and steep landform with an average elevation of 1000-1200 m. The cropland/grassland mosaic could favor soil evaporation and has the weak effect of slowing down the runoff [17,43] while the mountainous landform could facilitate the surface runoff and reduce the infiltration, which resulted in the low soil moisture in these areas for all three seasons (Figure 2).…”