子午岭地区土壤保持服务时空变化及其影响因素

土壤保持是黄土高原首要的生态系统服务功能,对于黄土高原地区生态经济可持续发展至关重要,开展该区域的土壤保持变化和影响因素研究十分必要。基于退耕还林还草背景,综合使用InVEST泥沙输移比模块、空间自相关、地理探测器等方法模型对2000—2017年子午岭地区土壤保持服务时空变化及影响因素进行了分析。结果表明:2000—2017年,子午岭地区大量耕地转为林地和草地,土壤保持服务有所增强,其中林地的单位面积土壤保持量最高;土壤保持随海拔呈先增后减趋势,随坡度的增大而增大,区内西坡和东坡处土壤保持量最高;子午岭地区土壤保持变化的空间自相关程度高,空间聚集类型主要有高高型和低低型,高高聚集区位于东北部,低低聚集区主要分布在西北部。地理探测结果显示,因子变化对土壤保持变化均起交互增强作用,高高聚集区受NDVI变化的作用最大;低低聚集区主要受降水和土地利用强度变化的影响,不显著区域受各因子的影响微弱,整个子午岭地区土壤保持变化主要受降水、GDP密度、还有人口密度和NDVI变化的影响。

Spatiotemporal Variations and Influencing Factors of Soil Conservation Service in Ziwuling Area

Soil conservation (SC) is the primary ecological service function of the Loess Plateau, which is vital to the sustainable development of ecological economy in Loess Plateau. Therefore, it is necessary to carry out research on changes and its influencing factors of soil conservation in this area. In the context of Grain for Green Project, the spatiotemporal changes and its influencing factors of soil conservation services in Ziwuling (ZWL) from 2000 to 2017 were analyzed by using the InVEST Sediment Delivery Ratio Module, spatial autocorrelation, geographic detector and other methods. The results showed that a large amount of cultivated land in ZWL area changed into woodland and grassland from 2000 to 2017, and the soil conservation service showed an increase trend. Among them, the amount of soil conservation per unit area of woodland was the highest. The soil conservation service first increased and then decreased with altitude, and increased with the increasing of slope. The amounts of soil conservation in the west slope and east slope were the highest. The spatial autocorrelation of soil conservation variation was high in ZWL area, and the main aggregation types were high-high and low-low. The high-high concentration area located in the northeastern part of ZWL, and the low-low concentration area mainly distributed in the northwestern part. The changes of influencing factors had an interactive enhancement effect on soil conservation changes, and NDVI was the most important factor in high-high aggregation area. The low-low aggregation area was mainly affected by the changes of precipitation and land use intensity, and the insignificant area was weakly affected by each factor. The soil conservation changes of whole ZWL area were mainly affected by the changes of precipitation, GDP density, population density and NDVI.