Acta Geographica Sinica ›› 2019, Vol. 74 ›› Issue (7): 1292-1304.doi: 10.11821/dlxb201907002

• Climate Change and Surface Processes • Previous Articles     Next Articles

Changes in land cover and evapotranspiration in the five Central Asian countries from 1992 to 2015

RUAN Hongwei1,2,YU Jingjie1,2()   

  1. 1.Key Laboratory of Water Cycle and Related Land Surface Process, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China
    2.University of Chinese Academy of Sciences, Beijing 100190, China
  • Received:2018-05-14 Revised:2019-06-07 Online:2019-07-25 Published:2019-07-23
  • Contact: YU Jingjie E-mail:yujj@igsnrr.ac.cn
  • Supported by:
    Strategic Priority Research Program of the Chinese Academy of Sciences, Grant(XDA20040302)

Abstract:

In 1991, the collapse of the Soviet Union and the independence of the five Central Asian countries led to profound changes in land cover and evapotranspiration pattern. This study used the five Central Asian countries as target areas. European Space Agency Climate Change Initiative and Global Land Data Assimilation System data were utilised to analyse the spatio-temporal variation of land cover and evapotranspiration from 1992 to 2015 and to further study the cropland evapotranspiration water consumption. This study investigated the continuous change of land cover, specified the characteristics of and differences in land cover and evapotranspiration, strengthened the understanding of land cover and evapotranspiration in the current situation, and provided data references for water and soil resource management and environmental protection. Results show that the changes in land cover in the five countries were characterised by stages, and cropland expansion modified the land cover pattern. From 1992 to 2003, cropland increased rapidly (1.1×10 4 km 2), whereas forest land and grassland decreased. From 2003 to 2015, cropland increased slowly (0.3×10 4 km 2), whereas forest land and grassland increased slightly. Bare land and water bodies continued to decrease, whereas settlements continued to increase; the annual evapotranspiration was 276.8 mm. Evapotranspiration increased rapidly from 1992 to 2003 (11.3 mm/a) and then slowly from 2003 to 2015 (2.4 mm/a). The evapotranspiration of cropland (352.2 mm) and grassland (322.1 mm) was significantly higher than that of forest land (254.7 mm) and bare land (173.2 mm). The evapotranspiration changes in the five Central Asian countries were consistent with the land cover patterns; the evapotranspiration water consumption of the five countries was affected by the cropland area. From 1992 to 2015, the water consumption of cropland evapotranspiration increased by 3.2%, and the contributions of grassland, forest land and bare land continued to decrease. The cropland of Turkmenistan accounted for only 11% of the total evapotranspiration water consumption, whereas that of the other countries accounted for more than 25%.

Key words: the five Central Asian countries, land cover, evapotranspiration, spatio-temporal variation, evapotranspiration water consumption structure