Based On SWAT Models Drought Index Of Different Types Relationship Analysis And Forecast

Drought occurs high-frequently, long lastingly and broad in scale. Drought index,which is an important method in drought research, has been a hottopic in these years.At the same time, drought forecast can provide technology support fordrought-resisting rescue.The study went on smoothly based on the national natural science foundation ofChina (51079131) and the China meteorological administration open fund "typicalriver basin in Henan province building of different kinds of drought indexes andassessment". Considering the characteristics of the mechanism of drought anddrought index, and combining with the practical situation of muddy reservoir controlriver basin, it chose different drought indexes, including standardized precipitationindex (SPI), detecting drought index (RDI), soil moisture content index (SW), meltflow index (SRI) and so on, to analyse the change of different types of relationshipbetween the drought indexes. In the next step, it made a research on the variationtendency, the hysteretic quantitatively, qualitatively on the basic of SWAT modeland gray relation. Furthermore, the spatial distribution of different types of droughtwas obtained by ArcGIS software. Under the A1B scenario, the growing trend ofdifferent kinds of droughts in the next50years was predicted and the correspondingsolution measures were proposed.(1) In order to get out the judgement of the relation between different types ofdrought indexes, the study selected standardized precipitation index (SPI),reconnaissance drought index (RDI), soil moisture content index (SW), andstandardized runoff index (SRI) as basic indexes. What is more, it analyzeddifferent drought indexes and the definition of different types of drought, as well asmade a combination with the physical situation and the data of the studied area.(2) It adopted DEM data, land use, soil style and meteorological data, to buildSWAT model and analyze the change features of the drought indexes in Lunhunreservoir. The study indicates that meteorological drought, agriculture drought andhydrologic drought increased obviously. Especially in the21st century, drought occurred in high-frequency in spring and autumn. By analyzing the drought controllevel, it can determine the drought control level of Luhun reservoir to be305.5m. Itdraw the conclusion that the hysteretic time of SPI and SW is26days; SPI and SRIhysteretic time is79days; and SW and SRI lag time is23days.(3) As the study shows, drought disaster in different degrees concentratedobviously in space, mainly distributed in the central and southern. Meanwhile,drought degree increased from north to south without visible diversity.（4）There would be a good coherence in change trend and change regular inA1B scenario for the next50years. At the same time, the frequency would increasedsignificantly, and drought might occur mainly in winter.