, simulated sampling is black and the observed is red.

Supplementary files

Figure S1. Observed and simulated monthly ET

, runoff and precipitation from April to September

0 20 40

0.4 0.6 0.8 1 1.2

Precipitat ion in Apr.(mm) Runoff in Apr.(108 m3)

0.4 0.6 0.8

0.4 0.6 0.8 1 1.2

Runoff in Mar.(10⁸ m³) Runoff in Apr.(108 m3)

0 20 40

100 120 140 160

Precipit ation in Apr.(mm)

ET0 in Apr.(mm)

50 100

100 120 140 160

ET 0 in Mar.(mm)

ET0 in Apr.(mm)

0.4 0.6 0.8

0 20 40

Runoff in Mar.(10⁸ m³)

Precipitation in Apr.(mm)

50 100

0 20 40

ET 0 in Mar.(mm)

Precipitation in Apr.(mm)

0 20 40 60

0.5 1 1.5 2

Precipitation in May (mm) Runoff in May (108 m3)

0.5 1

0.5 1 1.5 2

Runoff in Apr.(10⁸ m³) Runoff in May (108 m3)

0 20 40 60

100 120 140 160 180

Precipitation in May (mm)

ET0 in May (mm)

100 150

100 120 140 160 180

ET 0 in Apr.(mm)

ET0 in May (mm)

0.5 1

0 20 40 60

Runoff in Apr.(10⁸ m³)

Precipitation in May (mm)

100 150

0 20 40 60

ET 0 in Apr.(mm)

Precipitation in May (mm)

0 50 100

1 2 3 4 5

Precipitation in Jun.(mm) Runoff in Jun.(108 m3)

0.5 1 1.5 2 1

2 3 4 5

Runoff in May (10⁸ m³) Runoff in Jun.(108 m3)

0 50 100

120 140 160 180 200

Precipitation in Jun.(mm)

ET0 in Jun.(mm)

100 120 140 160 180 120

140 160 180 200

ET0 in May (mm)

ET0 in Jun.(mm)

0.5 1 1.5 2 0

50 100

Runoff in May (10⁸ m³)

Precipitation in Jun.(mm)

100 120 140 160 180 0

50 100

ET 0 in May (mm)

Precipitation in Jun.(mm)

0 50 100

2 4 6 8 10 12

Precipitation in Jul.(mm) Runoff in Jul.(108 m3)

2 4

2 4 6 8 10 12

Runoff in Jun.(10⁸ m³) Runoff in Jul.(108 m3)

0 50 100

120 140 160 180

Precipitation in Jul.(mm)

ET0 in Jul.(mm)

150 200

120 140 160 180

ET0 in Jun.(mm)

ET0 in Jul.(mm)

2 4

0 50 100

Runoff in Jun.(10⁸ m³)

Precipitation in Jul.(mm)

150 200

0 50 100

ET 0 in Jun.(mm)

Precipitation in Jul.(mm)

0 20 40 60 80 2

4 6 8 10 12

Precipitat ion in Aug.(mm) Runoff in Aug.(108 m3)

2 4 6 8 10 12 2

4 6 8 10 12

Runoff in Jul.(10⁸ m³) Runoff in Aug.(108 m3)

0 20 40 60 80 120

140 160

Precipitation in Aug.(mm)

ET0 in Aug.(mm)

120 140 160 180 120

140 160

ET 0 in Jul.(mm)

ET0 in Aug.(mm)

2 4 6 8 10 12 0

20 40 60 80

Runoff in Jul.(10⁸ m³)

Precipitation in Aug.(mm)

120 140 160 180 0

20 40 60 80

ET 0 in Jul.(mm)

Precipitation in Aug.(mm)

0 50 100

2 4 6

Precipitation in Sep.(mm) Runoff in Sep.(108 m3)

2 4 6 8 10 12 2

4 6

Runoff in Aug.(10⁸ m³) Runoff in Sep.(108 m3)

0 50 100

80 100 120 140 160

Precipitation in Sep.(mm)

ET0 in Sep.(mm)

120 140 160 80

100 120 140 160

ET0 in Aug.(mm)

ET0 in Sep.(mm)

2 4 6 8 10 12 0

50 100

Runoff in Aug.(10⁸ m³)

Precipitation in Sep.(mm)

120 140 160 0

50 100

ET 0 in Aug.(mm)

Precipitation in Sep.(mm)

Note: For runoff, simulated sampling is blue and the observed is red; For ET

, simulated sampling is black and the observed is red.

Table S1. The crop coefficients

Crops April May June July October September

Field maize 0.20 0.44 0.53 1.46 1.14 1.22

Seed maize 0.22 0.50 1.16 1.20 1.20 0.60

Wheat 0.30 1.15 1.15 0.93 - -

Table S2. Crop-related parameters

Crops Water production function Cost Benefit per unit water of vegetables (Yuan m

)

Planting area

a b  (Yuan kg

) (ha)

Field

maize -1.22 199.83 3281.67 0.45 - 3906.384

Seed maize -1.23 179.58 3604.24 0.5 - 6403.248

Wheat -1.44 167.67 2328.55 0.45 - 1033.648

Vegetables - - - - 4.16 2080.72

Note: the water production function: ^{Y  aW}

^{ bW  } , Y is crop yield (kg/ha); W is irrigation water (cm); ^a , ^b and  denote coefficients of quadratic term, first order term and constant term of crop water production function, respectively.

Table S3. Infiltration-related coefficients

Parameters values

Utilization coefficient of canal water 0.677

Utilization coefficient of field water 0.8

Coefficient of canal system leakage loss 0.323

Coefficient of field water infiltration 0.284

Coefficient of rainfall infiltration replenishment 0.15