Researches On Monitoring And Assessing System For Drought Disasters Based On 3S Technology

Liaoning province belongs to the semi-arid area where precipitation varies a lotevery year because of natural environment and atmosphere circumfluence.Agriculture droughty disaster often takes place in Liaoning Province. As a result,there is heavy harm to economy.Satellite remote sense can monitor the broad range and effective in a period oftime, so it is often applied to environment change and large range natural calamitiesdynamic monitoring. Geographic information system (GIS) has the function such asdistinctive space analysis, developing forecasts and providing the decision-makingsupports. Global positioning system (GPS) can be fixed position by the preciseproducing the target location and exported space data rapidly. As we can see above,the studies tried to organically combine the three methods to research the monitoringand evaluating method of arid disaster based on the surface observation data and theremote sensing data to build corresponding system and to provide the effectivemethods and tools.According to characteristics of geographical environment and climatic changeof Liaoning Province, etc., the study, on the basis of summarizing former researches,had emphases on screening out the method and building the model of monitoring andassessing arid disaster using the surface observation data and the remote sensing data.On the basis of monitoring the model in aridity, the surface observation data formattransformation(from dispersing to grid document) and the multiple source remotesensing data (NOAA/AVHRR, EOS/MODIS, FY-1C, FY-1D) grid formattransformation was implemented by calculating the meteorology surface observationdata and meteorology remote sensing data.Secondly, more accurate arid monitoring and rank classifies were plotted out base on grid formatted data by offering divisional functions of many kinds of datasources (TXT, SHP and so on) and different disaster rank indexes of different area.On the basis of the listed above, using the function of spatial analysis, the disasterregion of crops was identified by calculating the monitor data, background data andland data. Taking account of influence on crops in different development period, therelation between different crops during various development period was analyzedand the coefficient of disaster damage of different crops and the different disasterranks were calculated and crops arid disaster damage losing was assessed.Moreover, through the methods of facing the package, transferring Arc ObjectsActiveX package and customizing ActiveX package, the arid disaster monitoringsystem based on GIS platform of Liaoning Province with the characteristics ofpracticality, speed, effectiveness and easy operation has been developed. The systemhas been used in monitoring the arid disaster in Liaoning Province in June of 2004and the satisfied results have been achieved.The innovation of this thesis had more as follows:1. The system provided the function of dividing the area of arid monitoring areaagain. Different indexes in monitoring subarea had better accuracy on the monitoringof disaster,2. It achieved the translation between raster or vector file and many kinds filesuch as text file, LDF file and LD2 file on GIS platform.3. The system of monitoring and assessing arid disaster and the arid dynamicmonitoring and assessing has been developed.