Dynamic response patterns of profile soil moisture wetting events under different land covers in the Mountainous area of the Heihe River Watershed, Northwest China

被引：61

作者：

Tian, Jie ^{[1
]}

Zhang, Baoqing ^{[1
]}

He, Chansheng ^{[1
,2
]}

Han, Zhibo ^{[1
]}

Bogena, Heye Reemt ^{[3
]}

Huisman, Johan Alexander ^{[3
]}

机构：

[1] Lanzhou Univ, Coll Earth & Environm Sci, Minist Educ, Key Lab Western Chinas Environm Syst, Lanzhou 730000, Gansu, Peoples R China

[2] Western Michigan Univ, Dept Geog, Kalamazoo, MI 49008 USA

[3] Forschungszentrum Julich, Agrosphere Inst IBG 3, D-52425 Julich, Germany

来源：

AGRICULTURAL AND FOREST METEOROLOGY | 2019年 / 271卷

基金：

中国国家自然科学基金;

关键词：

Soil moisture response pattern; Land cover; Heihe River Watershed; High-altitude mountainous area; PREFERENTIAL FLOW; CLIMATE-CHANGE; LOESS PLATEAU; VEGETATION RESTORATION; HYDRAULIC CONDUCTIVITY; RAINFALL; VARIABILITY; MODEL; EVAPOTRANSPIRATION; PRECIPITATION;

D O I：

10.1016/j.agrformet.2019.03.006

中图分类号：

S3 [农学（农艺学）];

学科分类号：

0901 ;

摘要：

Understanding the dynamic response of soil moisture to rainfall is critical for hydrological modelling in arid and semi-arid basins. However, little is known about rainfall-related soil moisture dynamics in arid high-altitude mountainous areas due to the absence of long-term high-resolution soil moisture observations. In this study, we investigated the dynamic response processes of profile soil moisture using data from a soil moisture monitoring network in the Qilian Mountains established in 2013 covering altitudes from 2,000-5,000 m a.s.l. To investigate the effects of different land covers on soil moisture response, we selected data from eight soil moisture stations with the same soil textural class and slope, but different land covers (scrubland, meadow, high coverage grassland (HCG), medium coverage grassland (MCG) and barren land). Several indices were evaluated to quantitatively describe soil moisture dynamics during the growing seasons of 2014-2016 based on soil wetting events. In addition, HYDRUS-1D simulations were used to further analyze the effect of land cover on soil moisture dynamics. Our results showed that soil moisture response amplitudes along profile are similar under MCG and barren land, but significantly different under scrubland, meadow and HCG. The rate of soil moisture increment decreased significantly with depth for all land covers, except for the HCG. The temporal pattern of soil moisture increase was highly variable along the soil profiles depending on land cover type. In particular, the difference of response time between the adjacent layers varied from negative values to 280 h with depth. Preferential flow occurred mostly in soils covered by scrubland. Water transferability was higher in deeply rooted soil. Furthermore, sensitivity analysis indicated that soil hydraulic properties are key factors in regulating profile soil wetting events. Our results show that the soil moisture response indices are useful to quantitatively characterize patterns in profile soil moisture dynamics, and provide new insights into the soil moisture profile wetting process (e.g. occurrence of preferential flow etc.), which helps for effective model parameterization and validation, in turn improving hydrological modelling in arid high-altitude mountainous areas.

引用

页码：225 / 239

页数：15