Design And Application Of Lightning Parameters Inquiry System

To assist daily work and scientific research as needed, in the use of GIS componentbased development technology and database application and development technology, a software named lightning parameters inquiry system has been developed in dotNET4.0development environment. By analyzing the characteristics of data from Lightning Detection and Location System, a new pattern matching algorithm based on the Regular Expression was proposed in this paper. And on that basis, a function about lightning data warehousing has been developed. This software has also realized the following functions:map import and export, data management, layer control, Eagle eye view, View control, area and distance measurement, Simple inquires of lightning data, inquires of lightning location and peak current, thematic map drawing, etc.First, use lightning data warehousing function of lightning parameters inquiry system to make sure that the lightning data from ADTD Lightning Detection and Location System in five provinces in central China (Hubei, Anhui, Hunan, Jiangxi, Henan) has been put in storage. Then, for the sake of discussing the characteristics and distribution of cloud-to-ground lightning in central China, use lightning parameters inquiry system to analyze the parameters of cloud-to-ground lightning, including the total cloud-to-ground flash density, the positive flash density, the percentage of positive and negative flashes, the first stroke negative and positive peak currents, and the multiplicity for negative and positive flashes. Statistics Indicates:The percentage of negative lightning is far more greater than the positive one. The curve of mean diurnal flash count has one peak and one valley. The mean monthly flash count increases at February, peaks at August and decreases at September. The percentage of positive and negative flashes in the south differ from the ones in the north, the percentage of negative flashes in the south is much greater than the one in the north. The mean flash density maxima occur throughout central hubei province, jiangxi province and southern anhui province. The region of relatively high flash density moves with the direct sunlight point, first to the north and then to the south in a year.Use the simple query function of lightning parameters inquiry system to analyze the characteristics of lightning parameters in detial in each latitude, and combine with the analysis results of thunderstorm day of the five provinces, we get a conclusion that lightning parameters show different distribution characteristics in the north and south of30.8°.Use lightning parameters inquiry system, ArcGIS, MaoInfo, data of lightning, soil type, physiognomy, land resources and surface temperature to research the relationship of flash density and underlying surface properties. The results show that:the density is relatively high when the underlying surface is river, lake or reservoir. When the Soil texture is heavy clay and rich in Metal elements and water, it’s flash density is high. The junction of different soils has a high flash density. The border of land and water with low altitude and the junction of various topographies have high flash densities. The junction of tectonic geomorphologies in different ages or in different types has a high flash density. When the topographic slope is3-7degrees, the effective thickness of soil layer is49(59)-20cm, the percentage of bedrock is21%-50%or the soil is clay or sandy loam, the flash density is relatively high. The low annual average surface temperature (less than about11℃) differs from the high one (more than about11℃) in flash density.