PROGRESS IN GEOGRAPHY ›› 2021, Vol. 40 ›› Issue (12): 2086-2100.doi: 10.18306/dlkxjz.2021.12.009

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Effect of underlying surface factors on water use efficiency in the karst area

PENG Dawei1(), ZHOU Qiuwen1,*(), XIE Xuemei2, WEI Xiaocha1, TANG Xin1, YAN Weihong1   

  1. 1. School of Geography and Environment Science, Guizhou Normal University, Guiyang 550025, China
    2. Department of Management Engineering, Guizhou Communications Polytechnic, Guiyang 550001, China
  • Received:2021-01-20 Revised:2021-07-17 Online:2021-12-28 Published:2021-12-24
  • Contact: ZHOU Qiuwen E-mail:peng_dawei@163.com;zouqiuwen@163.com
  • Supported by:
    Basic Research Program of Guizhou Province, No. Qiankehe Jichu 〔2019〕1433;National Natural Science Foundation of China(41761003);The Science and Technology Plan Project of Guizhou Province, No. Qiankehe Pingtai Rencai 〔2017〕5726.

Abstract:

Water use efficiency (WUE) is an important indicator of terrestrial ecosystem response to climate change, and underlying surface factors affect WUE by influencing local climate. Ecological water shortage in the karst area is serious and the underlying surface is complex, but the comprehensive influence of multiple underlying surface factors on WUE is still unclear. In this study, MODIS gross primary productivity (GPP) and evapotranspiration (ET) data sets were used to calculate WUE in the karst area of Southwest China. Coupled with lithology combination, soil type, land use type, and surface roughness, the generalized linear model was used to reveal the comprehensive influence of underlying surface factors on WUE. The results show that: the WUE of the study area is affected by altitude and karst development degree, and increases from southeast to northwest. Among the underlying surface factors, the impact of lithology combination on WUE shows a difference between karst and non-karst areas. The lithology combination of carbonate rock in the karst area has a negative impact on WUE, and the negative impact of pure karst lithology combination is stronger than that of non-pure karst lithology combination; the impact of soil type on WUE is affected by the difference of distribution altitude, soil organic matter difference, and karst and non-karst landform difference; the impact of land use types generally shows a trend that more densely vegetated land use types have a stronger positive impact on the WUE; the increase of surface roughness first has a positive impact on the WUE, and then tends to have a negative impact. Carbonate rocks affect soil properties, and soil properties and surface roughness jointly affect vegetation.

Key words: water use efficiency, underlying surface factors, karst, MODIS