Implications of climate change for water management of an arid inland lake in Northwest China

Figures & data

Figure 1 Sketch map of the study area (the photo is a Landsat TM5 image).

Table 1 Mann-Kendall (MK) trend tests of annual water surface evaporation capacity, water surface area and actual evaporation loss in Bosten Lake, and annual temperature and precipitation in Bosten Lake Basin from 1980 to 2011.

			MK trend test
Items	Mean value	Trend rate	Z	Significance level
Annual evaporation capacity (mm/yr)	896.1	0.001	0.73	P > 0.1
Surface area (km^2/yr)	975.1	4.16	3.07	P < 0.01
Annual actual evaporation loss (m^3/yr)	8.8	0.05	2.45	P < 0.01
Temperature (C)	8.9	0.39	3.67	P < 0.01
Temperature at alpine mountain station (C)	4.2	0.33	3.58	P < 0.01
Precipitation (mm)	152.3	1.94	1.57	P > 0.1
Precipitation at alpine mountain station (mm)	273.0	22.50	2.07	P < 0.05

Figure 2 Annual evaporation capacity of Bosten Lake from 1980 to 2011: (A) temporal trend and (B) Mann-Kendall–Sneyers test (P > 0.05).

Figure 3 Water surface area of Bosten Lake from 1980 to 2011: (A) temporal trend and (B) Mann-Kendall–Sneyers test (P < 0.05).

Figure 4 Annual actual evaporation loss of Bosten Lake from 1980 to 2011: (A) temporal trend and (B) Mann-Kendall–Sneyers test (P < 0.05).

Figure 5 (A) Temporal trends in the TDS of Bosten Lake water from 1958-2011 and (B) regression analyses of TDS and both water surface area and actual evaporation loss of Bosten Lake from 1980 to 2011 (P < 0.05).

Figure 6 Mann-Kendall–Sneyers tests of annual temperature (A; P < 0.05) and precipitation (B; P > 0.05) in Bosten Lake Basin from 1980 to 2011.

Table 2 Pearson correlation coefficients for correlations between Bosten Lake hydrologic variables and Bosten Lake Basin climatic variables.

Items	Temperature	Precipitation	Precipitation in mountains	Precipitation on plains
Evaporation capacity	0.101	−0.228	0.037	0.023
Surface water area	0.649**	0.002	0.519*	0.142
Evaporation loss	0.641**	-0.105	0.503*	0.123

**P < 0.01, *P < 0.05.

Figure 7 (A) Linear regression analysis of Kaidu River annual runoff and Bosten Lake water surface area and (B) temporal trends in net inflow and outflow of Bosten Lake and Kaidu River annual runoff from 1980 to 2011.

Table 3 Water balance of Bosten Lake in 1996.

Water balance	Item	Quantity (× 10^8 m^3)	Percentage (%)
Inflow sources	Kaidu River	22.7	84.4
	Huangshuigou River	1.8	4.0
	Qingshui River	0.3	1.1
	Farmland drainage	0.8	3.1
	Confined aquifer replenishment	0.5	2.0
	Precipitation	1.5	5.4
Outflow sources	Konqi River	11.3	55.3
	Evaporation loss	8.6	41.8
	Seepage flow	0.6	2.8
Budget deficit		1.9

Note: data were obtained from Sun and Wang (2006), except for evaporation loss, which was estimated using the formulas in this study.