Development Of Spatial Extension For Solar Radiation Resources In Chongqing Based On GIS

Solar radiation models of different temporal and spatial scales were established by using ground observed data from meteorological stations. A series of distributed models were developed based on principles of direct and diffuse radiation on tilted surfaces and integrated with GIS software. Using DEM data of Chongqing, the distributions of direct and diffuse radiation over rugged terrains were simulated. This project may provide the methodology of spatial extension both for solar radiation and other meteorological elements. The main achievements of this project were concluded as follows:1. Simulation of atmospheric attenuation to solar radiation.Date integration technique was used to analyze the relationship between monthly mean daily clearness index kt and s, the ration of monthly mean daily sunshine duration to possible sunshine duration as well as that of monthly mean daily direct transmittance kb . Based on data from 1957 to 2000, a series of kt and kb estimation models with different temporal and spatial scales were established. Furthermore, the distributions of kt and kb from January to December in Chongqing were mapped by Kriging interpolation for long-term mean.2. Development of distributed simulation models of solar radiation over rugged terrains.Based on the geometry between sunshine ray and real terrains, the distributed models were developed to simulate the extraterrestrial radiation and possible sunshine duration over rugged terrains respectively. According to the principles of direct and diffuse radiation on tilted surfaces, the distributed models to estimate the direct and diffuse radiation over rugged terrains were developed also. The proposed models wereproved to be able to treat volumes of data and are applicable to satellite image processing platforms or Geographic Information System (GIS).3. Mapping of spatially explicit distribution of solar radiation.Using the Digital Elevation Model (DEM) data as input, the distribution of extraterrestrial radiation and possible sunshine duration from January to December were mapped both for Chongqing (resolution of 100m X100m). Integrated with kt and kb , the distributions of direct and diffuse radiation were also mapped for long-term mean. The data mentioned above were provided in the same format as other kinds of spatial information and can be employed as basic geographic data for relevant studies as well.