Grassland Drought Disaster Monitoring, Evaluation Research Based On RS And GIS Technology Of Eastern Inner Mongolia

Drought has always been the main meteorological disaster which influences livestock productionof the prairie areas. Under the context of rapid development of information, using the new remotesensing and geographic information system (GIS) to profoundly study draught in grassland areas andestablishing effective monitoring and evaluation system for disaster decision-making departments canprovide richer and more powerful information support for decision-making departments. This paperadopted remote sensing and GIS techniques to monitor and assess the draught in the eastern grasslandsof Inner Mongolia. Taking MODIS 1B data as the remote sensing information sources and at the sametime combining with the ground quadrat investigation data, a long series data of meteorological stationsand economic and social statistic data, the paper took a deep analysis of the impacts of draught on thegrassland vegetation. Furthermore, it set up stable inversion model of soil moisture through thequantitative excavation of remote sensing information. On the basis of this model, the author carried outresearch in the following four aspects: The influence of drought to the prairie grassland vegetation; thedrought monitoring and early warning of grassland; the drought assessment of grassland and the droughtrisk and zoning of grassland.By employing the nearly 40 years data on the index precipitation, using the precipitation in timeseries GAMMA distribution probability function as a model, and applying the standardized rainfallindex (SPI) as the meteorological drought index, the paper analyzed the different types of grasslands onthe aspects of growth speed, plant yield and the building of the advantage degree index to the responseof the drought by the different dry degree and different growth periods. The result indicated that in thethree different types of grasslands: meadow grassland, typical grassland and desert grassland, thegrowth rate of the meadow grassland is more sensitive to the response of the drought, while the desertgrassland is slower. Different types of grassland vegetation in different growth period responsedifferently to drought. As for meadow grassland, rainfall in April and May is the most critical; fortypical grassland, rainfall in April, May, August and September is the most critical to vegetation growth;for desert grassland vegetation the precipitation in August and September is the most critical.This paper, by using LST-NDVI character space principle to dig in the feature space relativelystable Angle information, established the effective soil humidity remote sensing data model. The modelovercame the disadvantage of traditional NDVI feature space method's poor time comparability. It cansatisfy the monitoring requirements at the different years and periods.Through a ten-day remote sensing monitoring of drought index such as soil moisture, vegetationgrowth, a composite index system can be established. In the 2009 summer drought cases, the compositeindex system was used by the ten-day monitoring, which can not only reflect the current droughtconditions but also warn the drought development of the next phase is established. The result indicatedthat the compound warning index and the last-1 M index SPI similarly changed, which can not onlyreflect the current drought in the early but also warn the next time development and the affect of thedrought monitoring and warning is good. The paper established the drought disaster evaluation standard on the basis of evaluating of scope,duration and intensity of the disasters and classified the drought disaster types by applying the BP neuralnetwork. Compared to the general statistic clustering method, the BP neural network overcame therestrictions on interpretation experience of different types of drought disasters and the assumptionrestrictions on the relationship of each index of different degree of drought disaster types. It has acertain technical superiority. By using the evaluation method of prairie areas, the paper evaluated thedifferent years of droughts happened in spring, summer and autumn of the study areas. The result notonly can reflect the annual disaster degree, but also the type of drought disaster.By using meteorological disaster risk evaluation method to research area grassland drought disasterrisk assessment and divisions. The evaluation results of Eastern Inner Mongolia grassland area droughtdisaster risk level showed that: the low-risk areas include six Banners and Counties, such asXinBaErHuZuoQi, ZaLuTeQi and so on. The medium-risk areas include seven Banners and Counties,such as SuNiTeYouQi, linxi county and so on; The high- risk areas include XinBaErHuYouQi,XiWuZhuMuQinQi seven Banners and Counties.