甘肃白龙江流域生态系统土壤保持功能时空变异及其影响因子

Spatiotemporal Variation of Soil Conservation Function and Its Influencing Factors in Bailongjiang Watershed in Gansu Province

土壤保持是生态系统提供的调节服务之一,在缓解区域侵蚀和维持生态安全等方面发挥着重要作用。基于InVEST模型和地理探测器等方法,开展了甘肃白龙江流域生态系统土壤保持功能时空变异及其影响因子分析。结果表明:(1)2002—2014年流域生态系统土壤保持功能不断增强,但空间格局变化不大;(2)各土地利用类型、海拔、坡度及坡向上土壤保持功能均有所提升,且保土功能增幅表现出随海拔抬升而减小,随坡度递增而增加的趋势;(3)降水量变化是流域土壤保持功能变化的主要因素,其与农作物单产变化、土地利用类型变化分别交互后的因子影响力较大。由于降水具有不可控性,因此,降低人类农业活动干扰,增加植被覆盖有利于甘肃白龙江流域土壤保持功能的提高。研究结果可为西北山地流域土壤保持和生态系统管理提供参考。

Soil conservation is one of the regulatory services provided by ecosystems,which plays an important role in mitigating regional erosion and maintaining ecological security.Based on the InVEST model and Geodetector analysis,the spatiotemporal variation of the soil conservation function and its influencing factors of the Bailongjiang Watershed in Gansu Province were analyzed in this paper.The results showed that：（1）the soil conservation function constantly increased from 2002 to 2014 at the watershed scale,and the spatial pattern change of soil conservation was not obvious;（2）from 2002 to 2014,soil conservation function increased in all land use types,elevation,slope and aspect,respectively;the growth of soil conservation function decreased with the increase of elevation,and increased with the increase of slope;（3）the change of precipitation was the main factor influencing the change of watershed soil conservation function,it influenced apparently with the interaction of the crop unit area yield change and land use type change,respectively;while precipitation was uncontrollable,to decrease the disturbance of human agricultural activities and to increase the vegetation coverage would be great beneficial for the improvement of soil conservation function in Bailongjiang Watershed in Gansu Province.The results can provide reference for the soil conservation and ecosystem management in the mountainous area in northwestern China.