内蒙古荒漠草原区气候变化及干旱趋势分析

Analysis of Climate Change and Drought Trend in Desert Steppe of Inner Mongolia

【目的】分析荒漠草原区气候变化和干旱发生的特征及趋势。【方法】基于1970—2017年荒漠草原4个气象站资料对该区域气象要素(降水、气温、潜在蒸散量)和干旱指标(标准化降水蒸散指数,SPEI)进行分析。【结果】①温度在不同时间尺度上(月、季、年),均呈增加的趋势,其中秋、冬增温趋势要高于春、夏季。②降水在春、秋及冬季(1—6、9—12月)呈增加趋势,夏季(7、8月)呈减小的趋势,在年时间尺度上呈减小的趋势,但减小趋势不显著。③潜在蒸发量在春、夏季(2—7月)呈减小的趋势,秋、冬季(8—12月和1月)呈增加趋势,在年尺度上呈显著增加的趋势。④荒漠草原区在冬季(1、2、12月)有变湿的趋势外,其他季节(月)及年时间尺度上均有变干的趋势。⑤小波周期分析发现SPEI的主震荡周期为5~7 a,为此该区域在5~7 a尺度上呈现旱-湿交替的可能性较大。【结论】气象要素和干旱程度在年、季、月上变化具有差异性,合理的在不同时间尺度上进行生态建设和农业发展具有重要意义。

【Background】Inner Mongolia grassland is not only an important part of agricultural basic resources in China,but also an important natural resource and natural ecological barrier in northern China.The purpose of this paper To analyze the characteristics and trends of climate change and drought in desert steppe area.【Method】Based on the data of four meteorological stations in the desert steppe from 1970 to 2017,the meteorological elements and drought index were analyzed.【Result】①In the annual,seasonal and monthly scales,the temperature showed an increasing trend,and the annual scale temperature increased significantly.The increasing trend in February and March and spring was higher than that in other months and seasons.On the annual scale of precipitation and potential evaporation,the trend of potential evapotranspiration decreased significantly,and the trend changes were different in different months and seasons.②On an annual scale,the region may have a tendency to dry out,with the months and seasons likely to be July-August and summer.③Region was more likely to show the periodicity of drought and humidity alternations on the scale of 5~7 years.【Conclusion】Meteorological elements and drought degree are different in year,season and month.It is of great significance to carry out ecological construction and agricultural development in different time scales.