Derivation of a fuzzy national phosphorus export model using 84 Irish catchments

Nasr, Ahmed Elssidig; Bruen, Michael

doi:10.1016/j.scitotenv.2012.10.063

Cited by 3 publications

(1 citation statement)

References 22 publications

(24 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous studies have suggested that, due to the lack of consideration of the mechanism and process of NPS pollution, Johnes' classical ECM is insensitive to changes in rainfall, topography, land use, land management, and other factors, and is thus only applicable to regions with a uniform distribution of rainfall, at terrain, and steady land use and management. 25,26 Given the spatially varying topography, climate, vegetation and other conditions of the TGRR, pollutant load simulations using the classical ECM usually fail to produce accurate results. The development process of NPS pollution could be simplied to the process of surface production and interception pollution.…”

Section: Modication Of the Export Coefficient Modelmentioning

confidence: 99%

Simulation of the dissolved nitrogen and phosphorus loads in different land uses in the Three Gorges Reservoir Region—based on the improved export coefficient model

Wang

Shao

Wang

et al. 2015

Environ. Sci.: Processes Impacts

View full text Add to dashboard Cite

Nonpoint source pollution is one of the primary causes of eutrophication of water bodies. The concentrations and loads of dissolved pollutants have a direct bearing on the environmental quality of receiving water bodies. Based on the Johnes export coefficient model, a pollutant production coefficient was established by introducing the topographical index and measurements of annual rainfall. A pollutant interception coefficient was constructed by considering the width and slope of present vegetation. These two coefficients were then used as the weighting factors to modify the existing export coefficients of various land uses. A modified export coefficient model was created to estimate the dissolved nitrogen and phosphorus loads in different land uses in the Three Gorges Reservoir Region (TGRR) in 1990, 1995, 2000, 2005, and 2010. The results show that the new land use export coefficient was established by the modification of the production pollution coefficient and interception pollution coefficient. This modification changed the single numerical structure of the original land use export coefficient and takes into consideration temporal and spatial differentiation features. The modified export coefficient retained the change structure of the original single land use export coefficient, and also demonstrated that the land use export coefficient was not only impacted by the change of land use itself, but was also influenced by other objective conditions, such as the characteristics of the underlying surface, amount of rainfall, and the overall presence of vegetation. In the five analyzed years, the simulation values of the dissolved nitrogen and phosphorus loads in paddy fields increased after applying the modification in calculation. The dissolved nitrogen and phosphorus loads in dry land comprised the largest proportions of the TGRR's totals. After modification, the dry land values showed an initial increase and then a decrease over time, but the increments were much smaller than those of the paddy field. The dissolved nitrogen and phosphorus loads in the woodland and meadow decreased after modification. The dissolved nitrogen and phosphorus loads in the building lot were the lowest but showed an increase with the progression of time. These results demonstrate that the modified export coefficient model significantly improves the accuracy of dissolved pollutant load simulation for different land uses in the TGRR, especially the accuracy of dissolved nitrogen load simulation.

show abstract

Section: Modication Of the Export Coefficient Modelmentioning

confidence: 99%