Table 3: The estimated values of membership degree for evaluation indicator of the Weihe River in Shaanxi Province.

ReachCriterion layer Indicator layerValue of membership degree
ExcellentGoodModeratePoorSick

LWWater qualityCOD (mg/L)0.070.930.000.000.00
NH3-N (mg/L)0.000.680.320.000.00
Ecological functionRatio of wetland area (%)0.000.000.000.140.86
Riparian vegetation coverage ratio (%)0.000.490.510.000.00
Guaranteed rate of discharge in dry flow season (%)0.000.100.900.000.00
Recreation function Recreation value index0.000.000.500.500.00

WXWater qualityCOD (mg/L)0.000.000.000.001.00
NH3-N (mg/L)0.000.000.000.001.00
Ecological functionRiparian vegetation coverage ratio (%)0.000.580.420.000.00
Proportion of fish species (%)0.000.000.850.150.00
Guaranteed rate of discharge in dry flow season (%)0.000.001.000.000.00
Recreation functionRecreation value index0.000.000.210.790.00

XLWater qualityCOD (mg/L)0.000.000.000.001.00
NH3-N (mg/L)0.000.000.000.001.00
Ecological functionRatio of wetland area (%)1.000.000.000.000.00
Riparian vegetation coverage ratio (%)0.000.530.470.000.00
Guaranteed rate of discharge in dry flow season (%)0.000.020.980.000.00
Flood controlVariation rate of streambed gradient (%)0.000.790.210.000.00
Capacity of flood discharge (%)0.000.000.000.830.17

LHWater qualityCOD (mg/L)0.000.000.000.950.05
NH3-N (mg/L)0.000.000.000.001.00
Ecological functionRiparian vegetation coverage ratio (%)0.000.860.140.000.00
Guaranteed rate of discharge in dry flow season (%)0.000.580.420.000.00
Flood controlVariation rate of streambed gradient (%)0.000.000.000.100.90
Requirement rate of bankfull discharge (%)0.000.000.000.990.01

DHWater qualityCOD (mg/L)0.000.000.170.830.00
NH3-N (mg/L)0.000.000.000.001.00
Ecological functionRatio of wetland area (%)0.000.000.000.710.29
Guaranteed rate of discharge in dry flow season (%)0.000.000.960.040.00
Flood controlVariation rate of streambed gradient (%)0.000.000.020.980.00
Requirement rate of bankfull discharge (%)0.000.040.960.000.00