摘要:区域植被恢复改变了土地利用类型，从而有效控制了水土流失，但土地利用与水土流失关系的空间分异尚未明晰。整合了黄土高原坡面径流小区试验观测研究文献59篇和1121条年径流产沙记录，以8大关键带类型作为空间分层依据，采用地理探测器分析了土地利用与年径流产沙关系的空间分异。结果显示：撂荒地的年均径流量和产沙量最高分别为35.99 mm和4208.82 g/m²，撂荒地、裸地和耕地的产流产沙能力显著高于人工草地、林地、自然草地和灌丛，灌丛和林地的年均产沙量显著低于人工和自然草地（P<0.05）；除了撂荒地的年均产沙量在山地森林关键带最高（16240.40 g/m²）外，在丘陵沟壑农林草交错关键带的撂荒地年均径流产沙显著高于丘陵农业-草地关键带，丘陵沟壑农林草交错关键带和丘陵农业-草地关键带裸地、耕地的产流产沙能力较高，人工草地和灌丛年均产沙量显著高于其他关键带类型（P<0.05）；在山地森林关键带的林地年均径流量、径流系数和产沙量最低，分别为1.56 mm、0.41%和307.36 g/m²，而自然草地在各关键带类型都有较高的年均产流量和较低的年均产沙量；坡面径流小区的局地特征（如土地利用、面积、坡度、坡长）是影响年径流产沙关键带分异的首要因素，且存在多因子互作、非线性增强的关系。这些结果表明植被恢复能有效地保持水土，但是区域植被恢复时需要选择合适的类型，黄土丘陵沟壑区应首选自然草地、灌丛和林地。研究可为黄土高原区域植被恢复的优化配置提供科学依据。



Abstract:Regional vegetation recovery can change the land use types and effectively control soil and water loss. However, the spatial variation of the relationship between land uses and soil and water loss remains unclear. In this study, we integrated 59 peer-reviewed articles and 1121 records of annual runoff and sediment yield of runoff plots at the hillslope on the Loess Plateau. And, we used geodetector to determine the spatial differentiation of the relationship between annual runoff, annual sediment yield, and land use by regarding the eight critical zones (CZs) of Loess Plateau as a basis of spatial strata, which was classified by comprehensive methods combining the theory of earth's critical zone with principal component analysis and cluster analysis. The results showed that abandoned land had the highest annual mean runoff and sediment yield at 35.99 mm and 4208.82 g/m², respectively. The abandoned land, bare land, and cropland had a higher ability to yield runoff and sediment than artificial grassland, forest, natural grassland, and shrubland. The annual mean sediment yields of shrubland and forest were significantly lower than that of artificial and natural grassland (P<0.05). Annual mean runoff and sediment yield of abandoned land in the hilly-gully agriculture-grassland-woodland transition CZ were significantly higher than that of the hilly-gully agriculture and grassland CZ in addition to abandoned land had the highest annual mean sediment yield in the mountainous forest CZ (P<0.05). Forests in the mountainous forest CZ had the lowest annual mean runoff, runoff coefficient, and sediment yield at 1.56 mm, 0.41%, and 307.36 g/m², respectively while natural grassland in all CZs had highly annual mean runoff and lowly annual mean sediment yield (P<0.05). Furthermore, site-specific characteristics of runoff plots at the hillslope such as land uses, area, slope, and slope length were the first controlling factors to affect the difference of annual runoff and sediment yield in CZs. There are interactions among these multiple factors along with nonlinear enhanced relationships. The results indicate that vegetation recovery can effectively retain soil and water, but we need to select suitable types when implementing regional vegetation restoration, and the priority is to select natural grassland, shrubland, and forest in the loess hilly and gully region. Our study can provide a scientific basis for the optimal allocation of vegetation restoration on the Loess Plateau.





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