Research On Drought Monitoring Method With Multi-sources Data

Drought is a phenomenon of natural disasters and has brought great impact to the society, economy and environment. China is located in the East Asian monsoon climate area. Monsoon instability caused the frequent occurrence of drought year by year. Especially in recent years, the drought has produced important influence on agricultural production and economic development in china. The phenomenon of global climate change and water shortages have exacerbated the occurrence of drought and expanded the scope of the effects of drought.Henan is a major agricultural province in China and an important grain production base. At the same time, it is one of the areas which are severely affected by the drought. In recent years, Henan drought disaster has a trend of aggravation, seriously impaction and frequent occurrence. The frequent occurrence of disasters has also had a major impact on agricultural production in Henan Province. Therefore, Research on adaptive drought monitoring methods and taking appropriate drought monitoring not only contribute to the disaster prevention and mitigation but also have great significance for agricultural production and people’s quality of life.This paper has reviewed and summarized the drought monitoring methods at home and abroad. Making full use of meteorological stations data, soil moisture and remote sensing data, we can mine different types Drought Monitoring Information, and carry out the research of common drought index calculation methods. Through the temporal and spatial comparison analysis of the various types of drought index, the relationship between each index in the region, and the instructions on the drought are revealed. On this basis, by the time series analysis, we reveal the response of the meteorological, agricultural and remote sensing indicators at the process of demonstration area drought occurrence and development. We can build a multi-index drought monitoring model and take Henan demonstration area as an example.The contents and conclusions of this paper are as follows:1. This paper calculated the meteorological drought index by monthly precipitation products getting from the meteorological site. Through the comparative analysis with historical drought information, we found that standard precipitation index (SPI3) can well reflect the meteorological drought. 2. This paper calculated the six commonly used remote sensing drought monitoring indices with the EOS/MODIS satellite remote sensing data. The procedure from data preprocessing to index calculating is programed by IDL. The paper monitors the drought of Henan province by using these indices and reveals the distribution pattern of drought in the study area. The result shows that different remote sensing drought indices of drought have different levels of response. According to the analysis, we found that drought conditions retrieved by the indicators of VSWI, VHI, TCI, NDWI have a better spatial and temporal consistency with historical drought data. But the VCI, AVI influenced by Crop non-growing season of the monitoring have a result of mutation. Based on this, this paper proposed the vegetation index improved method by the crop distribution mask to make the situation improved significantly.3. This paper monitors the drought of Henan province with the soil relative humidity indicators calculated from the soil moisture data. Monitoring results show that there are some problems in large-scale drought monitoring because of the limited number of stations. But this index well reflects the drought situation around the site and the adjacent area.4. This article reveals the relationship among the indicators through the correlation analysis on each drought index. This provides a reference for understanding the significance of each index, and also priori knowledge for the results of the drought monitoring analysis and diagnosis.5. The paper selects the drought monitoring indicators which have a good correlation with measured data of soil moisture point, and develops the drought monitoring model driven by the remote sensing and meteorological data. The paper monitors the drought of the demonstration area using the soil relative humidity which is reversed by drought model. The simulation of the model has achieved good results at Henan plain area in spring.