Vol.:(0123456789) 1 3 Environmental Earth Sciences (2020) 79:312 https://doi.org/10.1007/s12665-020-09007-1 ORIGINAL ARTICLE Evapotranspiration as a response to climate variability and ecosystem changes in southwest, China Ali Mokhtar 1,2,3  · Hongming He 1,2,4  · Karam Alsafadi 5  · Yu Li 6  · Hongfei Zhao 1,2  · Soksamnang Keo 1,2  · Chunyu Bai 1,2  · Mohamed Abuarab 3  · Chuangjuan Zhang 1,2  · Khaled Elbagoury 7  · Jingjing Wang 1,2  · Qilin He 1,2 Received: 7 January 2019 / Accepted: 21 May 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract The aim of our study is to quantify the relationship between ecosystem and climate variables in southwest China. We fur- ther examined spatiotemporal distribution patterns of daily reference evapotranspiration (ET 0 ) and ecosystem types through integrated approaches, including spatiotemporal interpolation, Penman–Monteith, Mann–Kendall test, statistical correlation analysis and transition matrix based on those datasets including observation climate data, satellite remote sensing images (MODIS and Landsat) and observed ecosystem data. The following results are achieved. First, changes of ET 0 were greatly infuenced by the combined efects of precipitation (with a decrease rate of −13 mm/10 years) and temperature (with a decrease rate of + 0.17 ℃/10 years). The annual average ET 0 increased by + 2.1 mm/10 years, and the increased ET 0 are more than 25% of the total area. Second, evapotranspiration was regarded as a sensitive indicator of climate and ecosystem feedbacks, and these ecosystem types have a great transformation, including forest, agriculture, and grass. Forest and grass were distributed primarily in the southern and eastern mountain areas, grass was in high mountains area while agriculture was prevalent in basin areas respond to climate changes. The area of forest converted to grass was 3670 km 2 , which was greater than transition from grass to forest (1720 km 2 ). Correlation coefcients of evapotranspiration and NDVI were posi- tive in forest and negative in agriculture. Third, the efects of these changes on climate vegetation and ecosystem process feedbacks on the quickly warming southwest China are potentially signifcant. Although the variation in ecosystem types was combined efects caused by climate variation and human activities, an efective ecological restoration program “Grain for Green” has improved the environmental conditions in southwest China. Keywords Evapotranspiration · Climate change · Ecosystem types · Ecological restoration · NDVI * Hongming He hongming.he@yahoo.com * Yu Li liyuljy@163.com 1 State Key Laboratory of Soil Erosion and Dry Land Farming on Loess Plateau, Institute of Soil and Water Conservation, Northwest University of Agriculture and Forestry, Yangling 712100, China 2 Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Northwest University of Agriculture and Forestry, Yangling 712100, China 3 Department of Agricultural Engineering, Faculty of Agriculture, Cairo University, Giza 12613, Egypt 4 School of Geographic Sciences, East China Normal University, Shanghai 210062, China 5 Department of Geography and GIS, Faculty of Arts, Alexandria University, Alexandria 25435, Egypt 6 Institute of Geographic Sciences and Natural Resources, Chinese Academy of Sciences, Beijing 101400, China 7 Department of Agricultural Engineering, Faculty of Agriculture, Ain Shams University, Cairo 11241, Egypt