Urban Water Ecosystem Health Evaluation Based on the Improved Fuzzy Matter-Element Extension Assessment Model: Case Study from Zhengzhou City, China

Table 2

The grade standard of evaluation index system.

Factor	Indicators	Unit	Character	healthy	sub-healthy	unhealthy	sick	very sick
Pressure (B1)	GDP Growth Rate (P1)	%	-	≤3	(3, 5]	(5, 8]	(8, 10]	>10
	Urbanization Rate (P2)	%	-	≤30	(30, 40]	(40, 50]	(50, 60]	>60
	The Proportion of Tertiary Industry (P3)	%	-	≤30	(30, 40]	(40, 50]	(50, 60]	>60
	Water Consumption Per Unit of GDP (P4)	m^3 / 10^− 4 Yuan	-	≤100	(100, 200]	(200, 300	(300, 400]	>400
	Water Consumption of Industrial Output (P5)	m^3 / 10^− 4 Yuan	-	≤30	(30, 60]	(60, 90]	(90, 120]	>120
	Water Consumption of Eco-environment (P6)	10^9 m^3	-	≤1	(1, 2]	(2, 3]	(3, 4]	>4
	Household Water Consumption (P7)	10^9 m^3	-	≤4	(4, 6]	(6, 8]	(8, 10]	>10
	Sewage Discharge (P8)	10^9 m^3	-	≤4	(4, 6]	(6, 8]	(8, 10]	>10
State (B2)	Water Resources Amount Per Unit Area (S1)	10^4 m^3  ·  km^−2	+	≥200	[150, 200)	[100, 150)	[50, 100)	<50
	Per Capita Water Resources (S2)	m^3	+	≥1000	[750, 1000)	[500, 750)	[250, 500)	<250
	Per Capita Green Area (S3)	m^2	+	≥12	[10, 12)	[8, 10)	[5, 8)	<5
	Flood Control Rate (S4)	%	+	≥95	[95, 90)	[85, 90)	[80, 85)	<80
Response (B3)	Sewage Treatment Rate (R1)	%	+	≥80	[60, 80)	[40, 60)	[20, 40)	<20
	Green Coverage Rate (R2)	%	+	≥40	[30, 40)	[20, 30)	[10, 20)	<10
	River Water Quality Compliance Rate (R3)	%	+	≥90	[80, 90)	[70, 80)	[60, 70)	<60
	Source Water Quality Compliance Rate (R4)	%	+	≥95	[80, 95)	[65, 80)	[50, 65)	<50
	Rate of Wastewater up to Discharge Standard for Urban (R5)	%	+	≥95	[85, 95)	[75, 85)	[60, 75)	<60
	Water Functional Area Compliance Rate (R6)	%	+	≥80	[60, 80)	[40, 60)	[20, 40)	<20
	Rate of Water Ecosystem Project Investment to GDP (R7)	%	+	≥1.5	[1, 1.5)	[0.6, 1)	[0.3, 0.6)	<0.3
	Rate of Environmental Protection Investment to GDP (R8)	%	+	≥1	[0.8, 1)	[0.5, 0.8)	[0.3, 0.5)	<0.3