Evaluating the Impacts of Climate Change and Vegetation Restoration on the Hydrological Cycle over the Loess Plateau, China

Abstract

In recent decades, both observation and simulation data have demonstrated an obvious decrease in runoff and soil moisture, with increasing evapotranspiration, over the Loess Plateau. In this study, we employed a Variable Infiltration Capacity model coupled with scenario simulation to explore the impact of change in climate and land cover on four hydrological variables (HVs) over the Loess Plateau, i.e., evapotranspiration (ET), runoff (Runoff), shallow soil moisture (SM1), and deep soil moisture (SM2). Results showed precipitation, rather than temperature, had the closest relationship with the four HVs, with r ranging from 0.76 to 0.97 (p < 0.01), and this was therefore presumed to be the dominant climate-based driving factor in the variation of hydrological regimes. Vegetation conversion, from cropland and grassland to woodland, significantly reduced runoff and increased soil moisture consumption, to sustain an increased ET, and, assuming that the reduction of SM2 is entirely evaporated, we can attribute 71.28% ± 18.64%, 65.89% ± 24.14% of the ET increase to the water loss of SM2 in the two conversion modes, respectively. The variation in HVs, induced by land cover change, were higher than the expected climate change with respect to SM1, while different factors were selected to determine HVs variation in six catchments, due to differences in the mode and intensity of vegetation conversion, and the degree of climate change. Our findings are critical for understanding and quantifying the impact of climate change and vegetation conversions, and provide a further basis for the design of water resources and land-use management strategies with respect to climate change, especially in the water-limited Loess Plateau.

Attributing trend in naturalized streamflow to temporally explicit vegetation change and climate variation in the Yellow River Basin of China

“…To balance the high cost of computation and the characterization of heterogeneous underlying surface, we performed simulations using the VIC model on a 0. on hydrological processes rarely be discussed in previous studies (Xie et al, 2015;Yang et al, 2019;Zhai et al, 2021). In this study, the VIC model simulation scheme considering time-variant LAI was designed as the following two steps:…”

“…Therefore, traditional configuration in land cover and vegetation parameters of VIC model probably underestimate the cumulative contribution of interannual vegetation change to the hydrological cycle (Xie et al, 2015). Improvement of the VIC model by coupling yearly land cover and continuously dynamic vegetation parameters that can be retrieved from remote sensing data sets would be favorable to remedy this issue (Tang et al, 2008, Xie et al, 2015Yang et al, 2019). Table 1 summarizes some typical studies about the attribution of annual runoff change in YRB and in China.…”

Attributing trend in naturalized streamflow to temporally explicit vegetation change and climate variation in the Yellow River basin of China

“…The default setting of the VIC model only considers the climatology of vegetation (e.g., 12-month LAI), and the monthly LAI and land cover are stationary in each year during the simulation period. Therefore, the impacts of continuous interannual change of LAI and land cover types on hydrological processes have rarely been discussed in previous studies using the VIC model (Xie et al, 2015;Yang et al, 2019;Zhai and Tao, 2021). In this study, the simulation scheme of the VIC model (version 4.1.2.a) considering time-variant LAI was designed as the following two steps:…”

“…Therefore, traditional configuration in land cover and vegetation parameters of the VIC model probably underestimate the cumulative contribution of interannual vegetation change to the hydrological cycle (Xie et al, 2015). Improvement of the VIC model by coupling yearly land cover and continuously dynamic vegetation parameters that can be retrieved from remote-sensing datasets would be favorable to remedy this issue (Tang et al, 2008;Xie et al, 2015;Yang et al, 2019).…”

Exploring the Dominant Runoff Processes in Two Typical Basins of the Yellow River, China

“…This threatens socio-economic development and the natural environment [2][3][4]. The runoff in the Yellow River has significantly reduced, with sudden changes occurring after the 1980s [5][6][7]. Human activities (e.g., Grain for Green Project) and climate change (e.g., changes to rainfall and temperature) are considered to be the key factors causing dramatic reductions in the runoff in the middle reaches of the Yellow River [8].…”