基于温度植被干旱指数的黑龙江省旱情动态研究

2015年黑龙江省发生大面积干旱,为了对此旱情进行动态监测,采用6—9月的MODIS数据,计算温度植被干旱指数(TVDI);以过去15年(2000—2014年)的全省40个旱作农业站点以旬为单位的TVDI为研究对象,根据土壤相对湿度的农业干旱等级划分标准,制定TVDI的干旱监测等级,利用2011年实地测取土壤相对湿度数据对该等级进行验证,结果表明,验证结果准确度达到83%。结果显示:TVDI被分为5个等级,TVDI0.46为无旱,TVDI在0.46~0.57之间为轻旱,TVDI在0.57~0.76之间为中旱,TVDI在0.76~0.86之间为重旱,TVDI0.86为特旱,用此标准对黑龙江省2015年的旱情进行分析,能够较好地反映出黑龙江省整体的实际旱情。在监测中2015年7月份全省旱情最为严重,持续到8月中旬,到8月下旬省内各地陆续降雨,重旱区域减少,整体旱情减轻。

Investigation on dynamic changes of drought in Heilongjiang Province based on temperature vegetation drought index

To carry out dynamic monitoring of the drought in Heilongjiang Province in 2015,MODIS data from June to September were used to calculate temperature vegetation drought index (TVDI).Baesd on the agricultural drought grade division standard of soil relative humidity and TVDI data of ten days as a unit over the past 15 years from 40 dry farming site,TVDI drought monitoring level was set.The agricultural drought grade division standard were verified by the soil relative humidity data of field survey in 2011,and the accuracy of the verified results reached 83％.The results showed there were five levels of TVDI value:no drought (TVDI ＜ 0.46),light drought (0.46 ＜ TVDI ＜ 0.57),medium drought(0.57 ＜ TVDI ＜ 0.76),severe drought(0.76 ＜ TVDI ＜ 0.86),critical drought (0.86 ＜ TVDI).The drought in Heilongjiang province in 2015 was analyzed according to the level standard.The most serious drought took place in July,and it lasted until mid August.Thereafter,areas suffered from heavy drought diminished and the overall drought was relieved because of succession of rain throughout the province.