Upstream to downstream: a multiple-assessment-point approach for targeting non-point-source priority management areas at large watershed scale

Abstract

Abstract. The identification of priority management areas (PMAs) is essential for the control of non-point source (NPS) pollution, especially for a large-scale watershed. However, previous studies have typically focused on small-scale catchments adjacent to specific assessment points; thus, the interactions between multiple river points remain poorly understood. In this study, a multiple-assessment-point PMA (MAP-PMA) framework was proposed by integrating the upstream sources and the downstream transport aspects of NPS pollution. Based on the results, the integration of the upstream input changes was vital for the final PMAs map, especially for downstream areas. Contrary to conventional wisdom, this research recommended that the NPS pollutants could be best controlled among the upstream high-level PMAs when protecting the water quality of the entire watershed. The MAP-PMA framework provided a more cost-effective tool for the establishment of conservation practices, especially for a large-scale watershed.

An auto-adaptive optimization approach for targeting nonpoint source pollution control practices

“…The final Pareto-optimality front indicated average reductions of N and P loads from 43.74%–93.38% and 49.74%–88.83%, respectively. In our previous studies 19 20 , the average concentrations of TN and TP at the Wuxi station were quantified as 0.82 and 0.13 mg/l, respectively, indicating a further requirement of 39.02% and 23.07% load reductions from the baseline. Figure 2 indicates that the optimal watershed-scale BMP configurations would be disproportionate to the intended objective of maintaining the water quality provisioning services in the TGRA.…”

A preference-based multi-objective model for the optimization of best management practices

“…According to the results from previous studies, the downstream water quality could meet the concentration standard of the corresponding water function areas if the water quality in the Wuxi hydrologic station was in a critical state of health with a 100% water quality compliance rate (Chen et al, 2014b). Thus, the Wuxi hydrologic station was chosen as the assessment point to evaluate the objective functions for the TN load, TP load and the total cost of the set of BMPs.…”

“…The preferred solution adjusts the types and number of BMPs locally. A tiny change in decision makers' preferences will influence the watershed management programs in the highly polluted areas identified by Chen et al (2014b).…”

Heavy Metal Contamination Near Industrial Estate Areas in Phra Nakhon Si Ayutthaya Province, Thailand and Human Health Risk Assessment

“…It might be explained that although the major industries of these industrial estates were similar, the level of heavy metal contamination can be different depending on numbers of factories, pollution control measures, and environmental management effectiveness. In addition, since Bangpa-in district is located downstream of Uthai District, heavy metal input from multiple sources upstream, including agriculture, factories, and communities along the river, can contribute higher heavy metal contamination to the downstream area [ 32 ].…”