Ecological Indicators (Nov 2021)
Spatiotemporal variability of water ecosystem services can be effectively quantified by a composite indicator approach
Abstract
Ecological restoration will be promoted globally as a strategic solution supporting the relevant sustainable development goals including land degradation neutrality. However, this restorative approach is facing challenges from climate change and anthropogenic land-use change. One of these acute challenges is to balance ecological restoration and water ecosystem services particularly in dryland areas that are the most vulnerable to land degradation and climate change. Therefore, it is critical to understand the spatiotemporal variability of water ecosystem services in a changing environment on a regional scale. To gain this understanding, this paper formulates a composite indicator approach by integrating gross primary productivity (GPP) and waterbodies derived from remote sensing with key soil, climate, and topographic variables. The water ecosystem service index (WESI) was quantified in 10 watersheds of the Chinese Loess Plateau (CLP) region during 2000–2018 and found to be correlated positively with the surface runoff of these watersheds at high confidence levels. Then WESI is used in the whole CLP. The results of WESI indicate that about 90% of the CLP is low in water ecosystem services and about 45% of the CLP experienced significant increases for water ecosystem services under the impacts of large scale vegetation restoration, climate change, and land-use change. The WESI approach provides an efficient alternative to the complex modelling approaches that need much more ground based monitoring data. The WESI is useful for mapping the spatial pattern and temporal trends of regional water ecosystem services that are critical for ecological restoration and land-use planning in a changing environment.
