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| DOI：10.13522/j.cnki.ggps.2019415 |
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| Temporal and Spatial Characteristics of Surface Evapotranspiration in the Ili River Basin |
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LIANG Hongshan, WANG Dan, ZHENG Jianghua
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1. College of Resources and Environmental Sciences, Xinjiang University, Urumqi 830046, China；2.Institute of Arid Ecology and Environment, Xinjiang University, Urumqi 830046, China；
3. Key Laboratory of Oasis Ecology, Xinjiang University, Urumqi 830046, China
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| Abstract: |
| 【Objective】 This paper is to explore the temporal and spatial characteristics of the evapotranspiration in the Ili River Basin from 2000 to 2014, and to provide a basis for the determination and distribution of cross-border water resources.【Method】In this paper, the temporal and spatial variation characteristics and volatility of evapotranspiration in the Ili River Basin were studied by using the methods of variation coefficient, Theil-Sen median, Mann-Kendall and Hurst index. 【Result】The result showed that: ①The annual average evapotranspiration of the Ili River Basin was 249.80 mm, and its fluctuation range was 224.03~274.10 mm. ②The average ET value of multi years had obvious difference in space, ranging from 115.6 mm to 758.79 mm, which showed the spatial pattern of decreasing from upstream to downstream. ③The annual evapotranspiration of the basin had obvious seasonal difference, and the overall trend of unimodal wave increased first and then decreased. ④The annual average evapotranspiration of land use in the basin was as follows: cultivated land (327.23 mm) > forest land (319.10 mm) > grassland (239.50 mm) > sparsely vegetation (151.67 mm). ⑤During the study period, the variation degree of annual average ET in the basin was not obvious as a whole, and the proportion of stable and stable areas in the variation degree was 85.47%. The spatial value range of variation coefficient was 0.01~0.71, and the average value was 0.097. ⑥The decreasing trend and increasing trend of ET in the whole basin account for 64.48% and 26.72% of the total area, respectively. The main trend of ET change was decreasing, with a change rate of -1.152 mm/a. The future change of ET in the basin is consistent with the past, with a continuous decrease as the main trend.【Conclusion】Using the methods of variation coefficient, Theil-Sen median, Mann-Kendall and Hurst index, the temporal and spatial variation characteristics of the Ili River basin can be found effectively. The research results can provide a basis for planning and rational distribution of water resources in the Ili River Basin. |
| Key words: evapotranspiration; MOD16; Ili River Basin; temporal and spatial characteristics; trend analys |
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