科尔沁沙地乌兰敖都地区气温变化趋势分析

Analysis on the Change Trend of Air Temperature in the Ulan'aodu Region in the Horqin Sandland

通过对乌兰敖都气象观测站23 a的观测资料分析表明,在全球气候逐渐变暖的背景下,科尔沁沙地乌兰敖都地区气候发生了显著的变化,气温的季节变化明显,春季、冬季温度有逐渐回升的趋势,冬季升温明显大于春季,作物生长期的温度也呈升高趋势;偏暖温和高温的年份出现频率较多,且这一趋势在近3 a表现明显。科尔沁沙地西部乌兰敖都地区在近15 a内正向暖温化方向发展,且以冬季变暖的趋势最为明显。

The study area （43°02′N, 119°39′E）, the Ulan＇aodu region, is located in the west Horqin Sandland, the landforrns are dominated by mobile dunes and semi-mobile dunes, and the region is the drought center in the upper and middle reaches of the west Liaohe River Watershed. It belongs to the temperate monsoon climate, and its continental characteristics are significant. According to the climatic divisions of Inner Mongolia Autonomous Region, the region belongs to a semi-arid climatic zone, is characterized by the arid climate, less precipitation, frequent occurrence of strong winds and sand drift disasters, mobile and semi-mobile dunes, sparse vegetation, etc. The annual precipitation is 310 mm, the aridity index varies in a range of 1.0～1.8, the relative humidity varies in a range of 50% ～55%, and drought is serious in spring. Under the background of global warming, the climate in the Ulan＇ aodu region in Horqin Sandland is significantly changed, such as the air temperature increase, precipitation reduction and more serious droughts and sand drift disasters. In this paper, the 23-year （1981 -2003） observation data observed by the meteorological stations in the Ulan＇aodu region are analyzed. The results show that the change of air temperature in the Ulan＇ aodu region has experienced the processes of normal temperature → low temperature → high temperature → normal temperature → temperature increase since 1981. The monthly maximum and minimum temperatures are increased to a certain extent, especially the monthly minimum temperature. The change of seasonal temperature is significant, the temperature increase in spring and winter is significant, especially in winter, but it is not so obvious in summer and autumn. The occurring frequency of warm years and high-temperature years is high, especially in recent years. To sum up, the climate warming in the Ulan＇aodu region in Horqin Sandland is significant, especially in winter since recent years. Thus, the ecological environment in the region will be further degenerated because the strong winds occur frequently in winter and spring, and the vegetation coverage is low.