Research On Remote Sensing Monitoring Of Drought In Haihe River Valley Based On MODIS Data

Drought is one of the major natural disasters frequently occurred in the world, it is mostwidely distributed and causes the largest economic loss. It threatens people's livingenvironment, especially it has a very significant impact on the industrial and agriculturalproduction. Monitoring of the occurrence and dynamic changes of drought is the researchfocus in meteorology, geography, ecology and other areas.Remote sensing technology, which is fast, efficient and accurate, can be used to monitordrought and can reflect timely a wide range of drought conditions of surface vegetation.Compared to traditional ground survey method, it has great potential and unparalleledadvantages. With the development of satellite remote sensing technology and theimprovement of sensor performance, remote sensing technology can achieve high resolution,multitemporal, macro-scale drought monitoring. Researchers have established many remotesensing monitoring model and method of drought. In this paper, we used many remotesensing indices to monitor drought in Haihe River Valley from 2000 to 2009. The specificcontents and conclusions are as follows:(1) This article compares different remote sensing indices for drought monitoring. Thenthe advantages of these models and applicability in different regional types are compared.These indices are Vegetation Condition Index (VCI), Temperature Condition Index (TCI) andVegetation Supply Water Index (VSWI).(2) MODIS data are used as the primary data source according to its spatial resolution,observation period and other factors. Main preprocessing includes geometric correction,atmospheric correction, cloud detection, and re-projection. Standard Vegetation index wasextracted using infrared and thermal infrared bands while LST retrieval using split windowalgorithm. Compared with synthetic product data, 1B-level data used in this paper can reflectthe extreme parameters better, and can improve the accuracy.(3) Cloud in the vegetation index and surface temperature data is removed by IDLprogram platform. A variety of drought monitoring indices are calculated according toformula. After index standardized treatment, we can determine the level of drought andcalculate soil moisture map of Haihe River valley.(4) Remote sensing index is fitted by soil relative humidity 10cm below land surface,which is acquired from 142 stations in Haihe River Valley. According to different fittingparameters and correlation coefficients within ten days, relative humidity map of soil can beinversed, which is beneficial for analyzing inversion accuracy of various indices.(5) With MODIS data and administrative division file of Hebei province, this paperestablished Drought Monitoring System of Hebei Province. The drought in province, city andcounty level can be monitored in real time. It provides technical support and reference fordrought relief work.