Experimental analysis of soil moisture response to rainfall in a typical grassland hillslope under different vegetation treatments

Junyi Zhang; Limin Duan; Tingxi Liu; Zexun Chen; Yixuan Wang; Mingyang Li; Yajun Zhou

doi:10.1016/j.envres.2022.113608

Experimental analysis of soil moisture response to rainfall in a typical grassland hillslope under different vegetation treatments

Environ Res. 2022 Oct:213:113608. doi: 10.1016/j.envres.2022.113608. Epub 2022 Jun 7.

Authors

Junyi Zhang¹, Limin Duan², Tingxi Liu³, Zexun Chen¹, Yixuan Wang², Mingyang Li¹, Yajun Zhou¹

Affiliations

¹ The College of Water Conservancy and Civil Engineering Inner Mongolia Agricultural University, Hohhot, 010018, China.
² The College of Water Conservancy and Civil Engineering Inner Mongolia Agricultural University, Hohhot, 010018, China; Inner Mongolia Water Resource Protection and Utilization Key Laboratory, Hohhot, 010018, China.
³ The College of Water Conservancy and Civil Engineering Inner Mongolia Agricultural University, Hohhot, 010018, China; Inner Mongolia Water Resource Protection and Utilization Key Laboratory, Hohhot, 010018, China. Electronic address: txliu1966@163.com.

PMID: 35688223
DOI: 10.1016/j.envres.2022.113608

Abstract

The responses of soil moisture to rainfall are of great significance for watershed hydrological modeling. However, few studies have been done to investigate these responds on hillslope in a typical semi-arid grassland region. This study used high temporal resolution soil moisture data to explore the soil moisture dynamics, response conditions and its controls of 0-40 cm soil profile in the upslope (14°), midslope (9°), and downslope (4°) of a typical grassland inland river basin under bare ground (BG), stubble (SG), and natural grassland (CK) treatments. The results showed that soil water content and water storage increased in the downslope direction, and all showed as BG > SG > CK. The dry and wet changes in fast-changing layer (5 cm) and active layer (10 cm) were rapid, while soil moisture below 20 cm was relatively stable and fluctuated only in heavy or continuous rainfalls. The soil moisture response process varied greatly under different rainfall, rainfall intensity and antecedent soil moisture conditions, which explained 41.1% of the total difference. The rainfall replenishment threshold and the required initial soil profile water content of soil moisture response in 5 cm, 10 cm and 20 cm soil layers were 5.8 mm, 8.0 mm, 11.4 mm and 8.7 vol%, 9.4 vol%, 10.8 vol%, respectively. Soil properties, vegetation characteristics and topography could explain 38.8%, 14.5% and 5.6% of the soil moisture variation on the hillslope. In addition, under the comprehensive influence of environmental factors, changes in soil moisture of the upslope were significantly affected by soil sand content, the differences in the midslope were mainly due to soil clay content and belowground biomass, whereas the vegetation characteristics were the main factors in the downslope. This study can contribute to the further understanding of slope-scale ecohydrological processes and hydrological simulation of semi-arid grassland watersheds.

Keywords: Hillslope positions; Soil moisture response; Soil water content; Typical grassland hillslope; Vegetation treatments; Xilin river basin.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Biomass
China
Grassland*
Hydrology
Soil*
Water / analysis

Substances

Soil
Water