The Research Of Drought Monitoring In Heilongjiang Province Based On Satellite Remote Sensing

Drought had not only affected the balance of natural ecological environment,but also had a serious impact on China's agricultural production,which was one of the factors restricting the development of agriculture in China.Although the traditional method of drought monitoring was a high degree of authenticity,it had regional limitations,which couldn't accurately reflect the regional drought condition of large spatial continuity.Remote sensing technology had many characteristics,such as timely,economical,wide coverage,continuity and so on,which provided a new way for drought monitoring,and had become an important means of regional drought monitoring research.Therefore,it was of practical significance to study the regional drought by using the advantages of remote sensing technology.In this paper,Heilongjiang Province as the study area,using MODIS and FY-3A satellite remote sensing data for drought monitoring technology research,specific conclusions were as follows:(1)Using the MODIS data to extract the dry and wet side surface temperatures of the single-period Ts-NDVI feature space of May 25 to June 9 from 2000 to 2008 respectively,the dry and wet side surface temperatures of general Ts-NDVI feature space was synthesized.The results showed that the general Ts-NDVI feature space was a typical triangular distribution,and the boundaries of dry and wet edges were relatively clear.The general Ts-NDVI feature space improved the instability of the dry and wet edges of the traditional Ts-NDVI feature space based on single-period satellite observation data.Compared with the single-period Ts-NDVI feature space,the monitoring results of the general Ts-NDVI feature space were more accurate.(2)The correlation analysis between VTCI value and soil relative humidity of 10 cm and 20 cm was carried out in two kinds of feature space.The results showed that there was a positive correlation between the VTCI value of the two feature spaces and the soil relative humidity of 10 cm and 20 cm.The correlation coefficient in most years was between 0.05 and 0.001,and the correlation with 10 cm soil relative humidity was better,indicating that the VTCI of Ts-NDVI feature space could reflect the relative humidity of the soil objectively and more sensitive to shallow soil relative humidity.Meanwhile,the correlation between the general Ts-NDVI feature space and 10 cm,20cm soil relative humidity was better than that of the single-period Ts-NDVI feature space,and the monitoring results of the general Ts-NDVI feature space were closer to the monitoring results of 10 cm soil relative humidity.(3)In this paper,the general Ts-NDVI feature space based on FY-3A/VIRR data was realized,and the monitoring results were evaluated and tested.The results showed that the correlation coefficient of 10 cm soil relative humidity and the general Ts-NDVI feature space and single-period Ts-NDVI feature space was 0.294 and 0.136 respectively,the former had passed the significance test of 0.1,the latter had not passed the significance test;the correlation coefficient of precipitation and the general Ts-NDVI feature space and single-period Ts-NDVI feature space was 0.252 and 0.151 respectively,the former had passed the significance test of 0.05,the latter had not passed the significance test.It sould be seen that the general Ts-NDVI feature space monitoring results based on FY-3A/VIRR data were better than that of the single-period Ts-NDVI feature space,indicating that the general Ts-NDVI feature space method based on FY-3A / VIRR data could be used for drought monitoring in Heilongjiang Province.