Land-use-mediated inconsistency of changes in the provision and delivery of soil erosion control servicesat the watershed scale.

Abstract

Soil erosion control services (SECSs) are the benefits deliveredto people derived from preventing the negative impacts of soil erosion, such as avoiding the loss in soil productivity and preventing the damage to infrastructures such as dams and roads. SECS is derived from the functions of the ecosystems and isdeliveredto people through physical processes and social activities. The land-use change (LUC) reshapes the SECSs supply capacity, the SECS flow over the landscape, and the related benefit people received. Numerous studies have revealed how LUC shapes the SECSs supply capacity. However, the SECSs flow to local communities, and the LUC-derived SECS flowdynamics remain unclear. This study quantified the SECSs delivered to local communities following a land-use-specific cascade mechanism and using the WATEM/SEDEM framework. The effects of on-site soil erosion and sediment delivery over the watershed were combined. The cultivated lands were considered as the conveyers of SECSs. The study revealed the inconsistency of temporal change in SECS provision and the actual SECSs delivery to local communities. The results illustrated the increased capacity for soil erosion prevention and sediment flow reduction and a consequent increase in SECS supply capacity. However, the total amount of actual SECSs delivered to the local communities was declined due to the land-use change featured in reduced cropland area. The results imply that changes in SECS provision capacity cannot directly indicate the changes in SECS delivery to local communities. Though the modeled SECSs did not cover all SECSs in this region, this study highlights the effectiveness of the land-use-specific cascade framework in describing the delivery of SECSs and the importance of addressing the delivery processes of ecosystem servicesfrom ecosystem to people.