Identification and Regulation of Critical Source Areas of Non-Point Source Pollution in Medium and Small Watersheds Based on Source-Sink Theory
Open Access
- 24 June 2021
- Vol. 10 (7), 668
- https://doi.org/10.3390/land10070668
Abstract
The identification and regulation of the critical source areas (CSAs) of non-point source (NPS) pollution have been proven as economical and effective ways to control such pollution in watersheds. However, the traditional models for the identification of CSAs have complex operation processes, and comprehensive systematic methods for the regulation of CSAs are still lacking. This study systematically developed a new methodological framework for the identification and regulation of CSAs in medium and small watersheds based on source-sink theory, which included the following: (1) a grid-based CSAs identification model involving the evaluation of the rationality of the source-sink landscape pattern and three geographical factors (landscape slope, relative elevation, and the distance from the river), and identifying CSAs by the calculation and division of the integrated grid pollution index (IGPI); (2) a comprehensive CSAs regulation strategy that was formulated based on three landscape levels/regulation intensities—including the optimization of the overall source-sink landscape pattern, the conversion of the landscape type or landscape combination, and local optimization for single source landscape—to meet various regulatory intensity requirements in watersheds. The Jiulong River watershed in Fujian Province of China was taken as a case study. The results indicate that: (1) the identified CSAs of the Jiulong River watershed covered 656.91 km2, equivalent to 4.44% of the watershed, and through adopting multiple-intensity regulation measures for 10 key control zones that had spatially concentrated high values of the IGPI among the CSAs, the watershed IGPIs were predicted to be generally reduced and the area of CSAs was predicted to decrease by 23.84% (31.43% in Zhangzhou, the major city in the watershed); (2) the identification model can identify the CSAs with easy data access and simple operation, and the utilization of neighborhood impact analysis makes the grid-based research more scientific in the evaluation of the rationality of the source-sink landscape pattern; (3) the application of multi-scale landscape planning framework and the principle of source-sink landscape pattern regulation make the CSAs regulation strategy systematic and cost-effective, and the provision of different intensity regulation strategies makes the regulation strategy easy to implement and relatively lower cost. The proposed methodological framework can provide technical support for governments to quickly and accurately identify the CSAs of NPS pollution and effectively control such CSAs in medium and small watersheds.Keywords
Funding Information
- National Key Research and Development Program of China (2016YFC0502902)
- Natural Science Foundation of Fujian Province (2015J01168)
This publication has 50 references indexed in Scilit:
- Catchment Phosphorous Losses: An Export Coefficient Modelling Approach with Scenario Analysis for Water ManagementWater Resources Management, 2011
- Surface-Flow Constructed Treatment Wetlands for Pollutant Removal: Applications and PerspectivesWetlands, 2011
- Assessment of non-point source pollution using a spatial multicriteria analysis approachEcological Modelling, 2011
- Landscape ecological approach to the relationships of land use patterns in watersheds to water quality characteristicsLandscape and Urban Planning, 2009
- Development of a new index for integrating landscape patterns with ecological processes at watershed scaleChinese Geographical Science, 2009
- Landscape Planning for Agricultural Nonpoint Source Pollution Reduction I: A Geographical Allocation FrameworkEnvironmental Management, 2008
- Source-sink landscape theory and its ecological significanceFrontiers of Biology in China, 2008
- Development of the HSPF-Paddy model to estimate watershed pollutant loads in paddy farming regionsAgricultural Water Management, 2007
- Relationships Between Landscape Characteristics and Nonpoint Source Pollution Inputs to Coastal EstuariesEnvironmental Management, 1999
- Hydrologic Controls on Phosphorus Loss from Upland Agricultural WatershedsJournal of Environmental Quality, 1998