基于土壤墒情的云南干旱分析

根据2008—2012年云南省23个土壤墒情站点土壤含水量和日降水数据,研究土壤墒情与降水、温度的关系,并基于土壤相对含水量分析云南省干旱的时空分布特征。结果表明,不同深度土壤平均相对含水量的最大值与降水关系显著,均出现在6—8月,且基本滞后降水最多月份1个月,其出现时间呈现出由东南向西北推迟的变化趋势;而不同深度土壤平均相对含水量的最小值与气温关系显著,均出现在3或4月,其出现的时间大致与旱季(11月—次年4月)最高气温出现的时间一致。云南省干旱主要发生在1、3、11和12月,其中11和12月旱情最为严重;在空间分布上,1和3月干旱主要分布在云南西部,尤其是滇西南、滇西北和滇中,11和12月干旱主要分布在云南东部,尤其是滇中和滇东南。

Analysis of Drought in Yunnan Province Based on Soil Moisture

Based on the soil water content and daily precipitation data of 23 soil moisture stations in Yunnan Province from 2008 to 2012, the re-lationship between soil moisture and precipitation and temperature were studied , and the spatial and temporal distribution of drought in Yunnan Province was analyzed based on soil relative water content .The results showed that the maximum value of mean relative soil water content in dif-ferent depths had a significant relationship with precipitation , which appeared in June to August , and the month lagging behind most of the pre-cipitation.The emergence time showed a trend of delaying from southeast to northwest .The minimum value of mean relative water content in dif-ferent depths was significantly related to air temperature , which appeared in March or April , and the time of emergence was roughly in accord-ance with the maximum temperature in the dry season (from November to next April).The main drought occurred in January, March, November and December, of which the most severe drought occurred in November and December .In the spatial distribution,the drought in January and March was mainly distributed in western Yunnan, especially in southwest Yunnan, northwest Yunnan and central Yunnan,the drought in Novem-ber and December was mainly distributed in eastern Yunnan , especially in central Yunnan and southeast Yunnan.