Spatio-temporal dynamics of land use transitions associated with human activities over Eurasian Steppe: Evidence from improved residual analysis.

We presented a framework to evaluate the land use transformations over the Eurasian Steppe (EUS) driven by human activities from 2000 to 2020. Framework involves three main components: (1) evaluate the spatial-temporal dynamics of land use transitions by utilizing the land change modeler (LCM) and remote sensing data; (2) quantifying the individual contributions of climate change and human activities using improved residual trend analysis (IRTA) and pixel-based partial correlation coefficient (PCC); and (3) quantifying the contributions of land use transitions to Leaf Area Index Intensity (LAII) by using the linear regression. Research findings indicate an increase in cropland (+1.17 % = 104,217 km) over EUS, while a - 0.80 % reduction over Uzbekistan and - 0.16 % over Tajikistan. From 2000 to 2020 a slight increase in grassland was observed over the EUS region by 0.05 %. The detailed findings confirm an increase (0.24 % = 21,248.62 km) of grassland over the 1st half (2000-2010) and a decrease (-0.19 % = -16,490.50 km) in the 2nd period (2011-2020), with a notable decline over Kazakhstan (-0.54 % = 13,690 km), Tajikistan (-0.18 % = 1483 km), and Volgograd (-0.79 % = 4346 km). Area of surface water bodies has declined with an alarming rate over Kazakhstan (-0.40 % = 10,261 km) and Uzbekistan (-2.22 % = 8943 km). Additionally, dominant contributions of human activities to induced LULC transitions were observed over the Chinese region, Mongolia, Uzbekistan, and Volgograd regions, with approximately 87 %, 83 %, 92 %, and 47 %, respectively, causing effective transitions to 12,997 km of cropland, 24,645 km of grassland, 16,763 km of sparse vegetation in China, and 12,731.2 km to grassland and 15,356.1 km to sparse vegetation in Mongolia. Kazakhstan had mixed climate-human impact with human-driven transitions of 48,568 km of bare land to sparse vegetation, 27,741 km to grassland, and 49,789 km to cropland on the eastern sides. Southern regions near Uzbekistan had climatic dominancy, and 8472 km of water bodies turned into bare soil. LAII shows an increasing trend rate of 0.63 year, particularly over human-dominant regions. This study can guide knowledge of oscillations and reduce adverse impacts on ecosystems and their supply services.