Spatiotemporal response of land surface temperature to land use/cover change in Yanqi Basin, Xinjiang

Abstract: Land-use/land cover change (LUCC) at local, regional, and global scales is one of the fundamental causes of environmental change. LUCC has been of great concern because innumerable consequent changes were produced on the earth surface. Some important researches showed that human-induced LUCC was one of the key factors which influence the regional climate. Rapid population growth and continuous exploitation of natural resources during the past century have caused rapid changes of land-use/cover. This trend has produced a series of environmental impacts on biodiversity, local climate, hydrologic processes, and so forth. The land surface temperature (LST) is the radiative skin temperature of ground. It depends on the albedo, the vegetation cover and the soil moisture. In most cases, LST is a mixture of vegetation and bare soil temperatures. In turn, the LST influences the partition of energy between ground and vegetation, and determines the surface air temperature. In recent decades, geographical information systems and remote sensing techniques are widely employed to investigate the impact of land-use/cover change on land surface temperature. Understanding the interconnection of biological and climatic processes is essential for predicting the effects of climate change on the biosphere. Spatiotemporal distribution of LST is a critical factor of environmental change, and is the driving forces of the land surface processes. Study on the spatiotemporal response of LST to LUCC is an important scientific issue under the circumstances of anthropogenic pressure increasing rapidly. In the paper, characteristics of spatiotemporal distribution of LST and its response to LUCC are studied by LST data retrieved by methods of mono-window algorithm and single-channel from Landsat data of the year 2000, 2009, 2011 and 2015, observed metrological data and field sampling data in Yanqi Basin, Xinjiang, China. Results demonstrated that: 1) LST was classified as high LST, medium LST and low LST. The decreasing ratio of high LST area from the greatest to the least took place in the year of 2000, 2009 and 2015, respectively; the decreasing ratio of low LST area from the greatest to the least took place in the year of 2009, 2000 and 2015, respectively; 2) the distribution of LST had different spatial patters obviously. High LST distributed in deserts and Gobi between mountain and basin, and it had a circular pattern around the Bosten Lake. Low LST distributed in water, wetlands and oasis area; 3) the amplitude of LST change was different depending on LUCC in 2011. The ranks of different land cover types were: desert>saline area>bare land>wheat-corn>other crops>forest>cotton>reeds wetland> waters. To sum, the spatiotemporal distribution of LST is closely related to LUCC. The structure of crop planting and the area of land use type are effecting the spatiotemporal distribution of LST in recent decades in the Yanqi Basin, Xinjiang.