基于温度植被干旱指数的黑龙江省20年干旱时空特征研究

Research of Drought Characteristics in Heilongjiang Province Nearly 20 years Based on Temperature Vegetation Dryness Index by Remote Sensing

为了探讨2000-2019年黑龙江省的干旱时空变化特征,通过利用MODIS的归一化植被指数和地表温度产品计算温度植被干旱指数(TVDI),对20 a的5-9月农业干旱进行了监测。结果表明:(1)从时间上来看,2000-2006年干旱较严重、2007-2013年干旱减弱、2014-2019年干旱震荡减弱,其中2006年、2009年和2015年极端干旱情况最重,年平均干旱有显著减弱趋势而极端干旱未通过显著性检验分析。年内5月是全省干旱最严重时期,6月和9月干旱次之,7月和8月干旱较弱。(2)从空间上来看,根据干旱频率高低强度大小将全省划分为重风险区、中风险区和低风险区,年干旱特征为讷河市、甘南县、齐齐哈尔市、龙江县、林甸县、泰来县、大庆市、肇源县和杜尔伯特县属重风险区,西部地区和宝清县、富锦市、友谊县、集贤县、勃利县和宁安市属中风险区,北部、中部和东北部地区属低风险区。(3)逐月干旱空间特征表现为西部地区、宁安市、勃利县、鸡东县、友谊县、宝清县和集贤县等地区5月干旱发生频率高、强度大,西部部分地区6月持续高频率高强度干旱,大庆市周边及泰来县、龙江县、甘南县、齐齐哈尔市、讷河市等地区9月干旱发生频率高、强度大。研究结果可为黑龙江省抗旱减灾部门提供数据参考,指导高标准农田的有效灌溉。

In order to monitor drought time series and regional characteristics in Heilongjiang,based on the temperature of the moderate resolution imaging spectroradiometer(MODIS)and normalized differential vegetation index(NDVI)data,the monthly temperature vegetation dryness index(TVDI)in Heilongjiang from 2000 to 2019 was produced.The time series TVDI data were used to monitor the drought characteristics in Heilongjiang during the past 20 years from May to September.The results showed that:the time series TVDI indicated that the drought intensity was severe from 2000 to 2006,weakening from 2007 to 2013 and shock weakening from 2014 to 2019;from the perspective of whole Heilongjiang,the monthly extreme drought was the highest in 2006,2005 and 2009,respectively,the annual mean drought intensity and the monthly extreme drought event of each year were weakening from 2000 to 2019;the mostest severe drought period in the monthly mean drought intensity from 2000 to 2019 was May,drought periods in June and September were weakening,droughts in July and August were the lightest;according to the drought of intensity and frequency,the whole province could be divided into three regions:regional severe drought with the most frequency and high intensity named severe drought risk region,regional moderate drought with lower frequency and intensity named moderate drought risk region,regional light drought with slightly frequency and intensity named slight drought risk region:the severe drought risk region occurred in Nehe,Gannan,Qiqihar,Longjiang,Lindian,Tailai,Daqing,Zhaoyuan and Du′erbote,moderate drought risk region occurred in western area,Baoqing,Fujin,Youyi,Jixian,Boli and Ning′an,slight drought risk region occurred in northern,central and northeastern regions.The regional drought by the month was that:droughts in May were severe in the western regions,Ning′an,Boli,Jidong,Youyi County,Baoqing County and Jixian etc,droughts in June were continuous in the western regions,droughts in September were severe in Tailai County,other areas around Daqing and Longjiang,Gannan,Qiqihar,Nehe,etc.This study can provide certain reference for local governments to formulate drought relief and agricultural production policies.In summary,the above research results can provide data reference for drought resistance and disaster reduction departments in Heilongjiang Province,and guide the effective irrigation of high-standard farmland.