近20年内蒙古干旱时空动态及其对气候、蒸散发变化的响应

Spatial and Temporal Dynamics of Drought in Inner Mongolia in Recent 20 Years and Its Response to Seasonal Climate and Evapotranspiration

为实现对内蒙古旱情的动态连续监测,基于温度植被干旱指数(Temperature Vegetation Dryness Index,TVDI),采用趋势分析、R/S分析方法,探究了内蒙古2001—2020年TVDI时空变化特征及降水、气温、蒸散发对TVDI的影响。结果表明:(1)20 a间内蒙古TVDI以每年0.0009速率减小,且在2007年、2010年和2013年大范围出现重旱。春、夏、秋、冬季TVDI分别以每年0.0005,0.0018,0.0013,0.00007速率减小。(2)春、夏、冬季未来一段时间大部分区域TVDI将呈增加趋势,秋季大部分区域将呈减小趋势。(3)春、夏、秋季TVDI与降水和气温均以负相关为主;冬季TVDI与气温、降水均以正相关为主。春、冬季ET与TVDI为正相关性;夏季TVDI与ET从西南向东北相关性从正逐渐过渡为负;秋季TVDI与ET以负相关为主。研究表明近20 a内蒙古干旱程度有所缓解,但未来干旱程度减缓趋势变小或增加。因此,后期研究应进一步分析月尺度干旱、蒸散发的时空动态,对进一步测量和预测季节性蒸散发和干旱如何联合影响内蒙古生态环境和经济发展具有重要意义。

In order to realize the dynamic and continuous monitoring of drought in Inner Mongolia,based on the temperature vegetation drought index(TVDI),trend analysis and R/S analysis methods were used to explore the spatiotemporal distribution characteristics of TVDI in Inner Mongolia from 2001 to 2020,and the influence of precipitation,temperature and evapotranspiration on the change of TVDI.The results show that:(1)TVDI decreased at a rate of 0.0009 per year,and severe drought occurred on a large scale in 2007,2010 and 2013;TVDI decreased at the rate of 0.0005,0.0018,0.0013 and 0.00007 per year in spring,summer,autumn and winter,respectively;(2)in spring and summer,TVDI will increase in most areas of Inner Mongolia in the future;in autumn,TVDI will decrease in most pixels in a period of time;in winter,TVDI will increase in the future;(3)in spring,summer and autumn,TVDI was negatively correlated with precipitation and temperature,while in winter,TVDI was positively correlated with precipitation and precipitation;in spring and winter,the correlation between ET and TVDI was significantly positive;in summer,the correlation between ET and TVDI gradually transited from positive correlation to negative correlation from southwest to northeast;in autumn,the correlation between ET and TVDI was consistent in spatial distribution,with negative correlation as the main correlation.These research results indicate that the drought degree in Inner Mongolia has eased in recent 20 years,but the trend of drought degree slowing down will become smaller or increase in the future.Therefore,the upcoming research should further analyze the temporal and spatial dynamics of monthly drought and evapotranspiration,which is of great significance for further measuring and predicting how seasonal evapotranspiration and drought jointly affect the ecological environment and economic development of Inner Mongolia.