Ecological Compensation Mechanism in a Trans-Provincial River Basin: A Hydrological/Water-Quality Modeling-Based Analysis

Ecological compensation is an important economic means of water pollution control and quality management, especially for trans-regional rivers with unbalanced social development between upstream downstream. The Tangbai River Basin (TRB), a watershed crossing Henan province Hubei province, China, forms one the nation’s most productive agricultural regions. TRB has been exposed to high doses fertilizers long time. This study simulates hydrologic nutrient cycling in using Soil Water Assessment Tool (SWAT) limited data available. results indicate that dryland fields, which constitute 62% basin area, produce 80% total nitrogen (TN) 85% phosphorus (TP) yields whole river basin. sections at provincial boundary shows only 29% time from 2000 2019 met Class III standard regarding TN TP concentrations, concentrations spring flood season are approximately three times mean non-flood season. Grain Green ecological restoration measure non-flat drylands can reduce loads trans-provincial by 3.5 compared slope-independent drylands; however, compliance rate remains similar. value also vary widely depending on different quantitative criteria. SWAT-based pollutant quantification method adopted this could have implications rivers.