Water quality improvement measures of the Yagang cross-section in the Peral River Delta based on the calculation of excessive pollutant fluxes

The aim of this study is to quantify the sources of pollution in the Yagang River Basin. The 1-D hydrodynamic model and the 1-D water quality model are combined with the excessive pollutant flux analysis method to calculate pollution data of the Yagang area. The results showed the following. (1) Upstream pollution was the primary cause of water quality degradation for the Yagang Basin, exceeding the water quality standards. In addition, the pollution problem ranking of the entire basin was the following: the Yagang area (30.4%) > the Foshan area (23.2%) > the Baini River Basin (13.1%) > the Liuxi River Basin (0.6%). In addition, the rainy season had the greatest influence on pollution concentrations. (2) It was also concluded that if the boundary water quality could meet the inspection requirements (class IV water), the internal research area sewage collection rate would reach 60%, and the ammonia in the river discharge would reach 35.7%. This would allow the water quality reach standard class IV.

Quantification of eco-compensations based on a bidirectional compensation scheme in a water environment: a case study in the Jiangsu Province, China

This study delineates adjustments to the eco-compensation pilot work of the Taihu Lake Basin and the Huaihe River Basin. The number and location of original compensation sites were adjusted based on the characteristics of the river network and of the water pollution status. A bidirectional eco-compensation system based on water quality exceeding multiple was then implemented. Under this scheme, the eco-compensation payments of each city under three different compensation standards were calculated. A suitable unified short-term compensation standard for the whole province is determined among several compensation payment schemes. The results obtained after implementing the most relevant scheme reveal that (1) the bidirectional eco-compensation system is highly flexible and is viable economically, as the payment of fiscal expenditures used to pay eco-compensation is reasonable. (2) In the southern Jiangsu Province, the ratio of pollutant flux at each compensation site to the total regional flux is relatively high and may, therefore, accurately reflect the water quality condition of the main rivers flowing into the Taihu Lake. (3) The ratio of pollutant flux in the northern Jiangsu Province is low, which highlights the need for further improving the number and location of eco-compensation sites, as well as the compensation methods and standards.