CollectHomepage AdvertisementContact usMessage

Arid Land Geography ›› 2021, Vol. 44 ›› Issue (3): 796-806.doi: 10.12118/j.issn.1000–6060.2021.03.22

• Climatology and Hydrology • Previous Articles     Next Articles

Changing trend of green water and its driving factors in the gully region of the Loess Plateau

WANG Shaona1(),SONG Xiaoyu1(),LI Lanjun1,LI Huaiyou2,LI Yaolin2   

  1. 1. State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China, Xi’an University of Technology, Xi’an 710048, Shaanxi, China
    2. Xifeng Experiment Station of Soil and Water Conservation, Yellow River Conservancy Committee, Qingyang 745000, Gansu, China
  • Received:2020-04-26 Revised:2020-11-13 Online:2021-05-25 Published:2021-06-01
  • Contact: Xiaoyu SONG E-mail:1208766620@qq.com;songxy@xaut.edu.cn

Abstract:

The gully region of the Loess Plateau is the main rain-fed agricultural area in western China, which has long been considered a fragile area, and water shortage is a critical factor restricting the development of this area. Significant changes in climate characteristics and land-use status of the Loess Plateau have taken place with the proceeding of global climate fluctuation and regional implementation of soil and water conservation measures, which will have a far-reaching effect on green water. Therefore, an in-depth study on the response of green water to climate and land-use change is required, which would have remarkable theoretical and practical significance in providing useful indications for constructing an ecological environment construction and the improvement of the efficient use of green water resources in the Loess Plateau. Green water is estimated using the Budyko-based empirical model proposed by Fu Baopu, which excels at the estimation of green water at the basin scale, to better understand the response of green water to climate and land-use change from 1981 to 2016 in Yanwachuan Basin, which is a typical small basin in the Loess Plateau gully region. The trend of green water and its influencing factors were investigated using the Mann-Kendall test, F-test, and elastic coefficient method. In this study, to improve the applicability of the Fu Baopu model, the parameters of the model were calibrated and validated using the water-balance model and historical hydrometeorological data (e.g., monitored precipitation data, evaporation data, and runoff data). The simulation results show that (1) After parameter calibration, this empirical model presents a high simulation accuracy and great applicability in estimating green water over the Yanwachuan Basin. (2) The annual mean green water of the study area is 503.7 mm, showing an insignificant increase at the temporal scale, and its mutation points occurred in 2003. (3) The elastic coefficients of green water to precipitation, potential evapotranspiration, and underlying surface are 0.93, 0.07, and 0.18, respectively. It can be seen that green water is the most sensitive to precipitation, followed by the underlying surface, which is the least sensitive to potential evapotranspiration. (4) The green water increased by 38.75 mm from the base period to the change period due to climate changes, and the green water increased by 13.32 mm from the base period to the change period due to land-use changes. The contribution rates of precipitation variation, potential evapotranspiration variation, and the underlying surface change to the increase of green water were 75.63%, -1.21%, and 25.58%, respectively. It was clear that the influence of climate change on increasing green water is stronger than that of the underlying surface.

Key words: green water, climate change, land use change, Fu Baopu model, attribution analysis