A GIS-aided two-phase grey fuzzy optimization model for nonpoint source pollution control in a small watershed

作者：Maeda Shigeya^*; Kuroda Hisao; Yoshida Koshi; Tanaka Kenji

来源：Paddy and Water Environment, 2017, 15(2): 263-276.

DOI：10.1007/s10333-016-0545-z

• Water quality
• Nonpoint source
• Watershed
• Mathematical programming
• Fuzzy
• Uncertainty

A method for allocating allowable ranges of total nitrogen (TN) load to nonpoint (diffuse pollution) sources in a watershed has been developed by adopting the two-phase grey fuzzy optimization approach. Competing goals of water quality management authorities and TN load dischargers at nonpoint sources such as paddy field, upland crop field, and residential area are described with linear imprecise membership functions including interval numbers. TN load discharged from each cell of the nonpoint sources is assumed to be transported along with surface, subsurface, and river flow under the conventional first-order kinetic removal with respect to distance. The travel length of the load is estimated with a digital elevation model in a geographic information system (GIS). Uncertainty of river discharge and self-purification coefficients appearing in the TN transport model is also expressed with interval numbers. The GIS-aided grey fuzzy optimization model developed here is applied to the Seimei River watershed, Japan. By solving the optimization model, the allowable load represented by an interval number at each cell is procured, which would be a scientific base for effluent control regarding nonpoint sources in the area.

• 出版日期2017-3