# Changes in Meteorological Elements and Its Impacts on Yunnan Plateau Lakes
###### Abstract  
In this study, we analyzed the main climatic factors influencing nine plateau lakes in Yunnan Province over the past 40 years (from 1980 to 2019) based on trend and mutation analyses. The results revealed that the air temperatures of these plateau lakes have increased, with an annual average air temperature increase of 0.18 \({}^{\circ}\)C per decade, during this 40-year period. From 2000 to 2005, there was an abrupt change in the air temperature increase, the rate of which was 0.20 \({}^{\circ}\)C per decade, and there were reductions in long-wave radiation, relative humidity, wind speed, precipitation, and snowfall. In addition, the rising trend in the air temperature of these lakes located in northwest Yunnan (temperate climate, higher elevation) was found to be significantly higher than that of the lakes in central Yunnan (subtropical climate, lower elevation), whereas in contrast, the declining trends in long-wave radiation, relative humidity, wind speed, and precipitation were more pronounced in central than in northwestern Yunnan. warming of large inland waters is much greater in the northern hemisphere at middle and high latitudes than in the lower latitudes and southern hemisphere [19]. Previous studies have shown that climate change will have more severe impacts at higher elevations [20]. In this respect, although analysis based on global coarse-grain data can provide insights regarding global trends and geographical heterogeneity as a whole, it may fail to accurately predict changes at a more local scale. The average air temperature of the six lakes in Northern Poland increased from 0.02 \({}^{\circ}\)C to 0.025 \({}^{\circ}\)C per year, while the temperature of the lake water varies more, from 0.005 \({}^{\circ}\)C to 0.028 \({}^{\circ}\)C per year [21]. These values are considerably larger than estimates based on global data [8]. In addition, due to the extremely rich diversity of morphological characteristics, such as lake area and water depth, the responses of different lakes to climate change also differ to a considerable extent [22; 23]. Consequently, a larger number of regional case studies are necessary to gain a more detailed understanding of climate change processes, and thereby provide a basis for clarifying the responses of lakes to such changes. The Yunnan Plateau lakes form one of the five major lakes in China, with nine major lakes including Dianchi, Yangzonghai, Fuxian Lake, Xinyun Lake, Qilu Lake, Erhai, Lugu Lake, Chenghai, and Yilong Lake. These plateau lakes are semi-enclosed fault lakes, located in regions at high elevations that are exposed to high levels of radiation and are characterized by a shortage of natural water resources and long water exchange cycles. The climate and morphological characteristics of the plateau lakes in Yunnan Province are conducive to the growth of algae and the accumulation of organic materials, which may render these water bodies more sensitive to climate change. In addition, these lakes are notably diverse, particularly with respect to the influence of differences in elevation and climate type. For example, whereas the highest lake, Lake Lugu, is located at an elevation of 2690 m, the lowest, Lake Chenghai, lies at the elevation of 1501 m. With respect to climate, Lake Lugu lies within a temperate climatic zone, whereas lakes Dianchi, Fuxian, Yangzonghai, Yilong, Xingyun, and Qilu lie within a subtropical climate zone, and lakes Chenghai and Erhai Lake are located in two transitional zones. Given the diversity and typicality of the Yunnan Plateau lakes, we selected these lakes to undertake a case study, with the aim of gaining a further understanding of the change trends in key climate factors over the past 40 years in a plateau region characterized by a concentrated distribution of fault-depressed lakes.