Research On Climatic Factors Simulation In Shandong Tea-tree High-quality Area Based On DEM

Based on Geographical Information System, this paper studied the spatial distribution of climatic factors(solar radiation,air temperature,wind speed) in Rizhao city using grid-based DEM data derived from 1:50000 topographic maps and 30-years (1970-2000) observed data of meteorological stations in Rizhao and its surrounding areas, and a case of suitability evaluation for tea-tree in Rizhao city was carried out for the application research.DEM is the three dimension stereo describe to the surface configuration, it has the basic information of climate resources simulation such as geographical position and altitude, and the topographic factors such as slope gradient, orientation of slope (aspect) and terrain shading can be abstracted conveniently, and DEM has high spatial resolution, so the simulation of climate resources is more convenient and the result of simulation is more accuracy and particularity.Through calculating necessary topographic factors such as slope gradient, orientation of slope (aspect) and terrain shading, assisted by geographic information system (GIS) mufti-layer composite analysis, this paper calculates the solar radiation grid by grid, whilst, analyses the spa-temporal distribution law of solar radiation.The air temperature distribution is affected by many factors in actual landform, altitude and topography are the major factors. Based on the spatial interpolation technique served by ARC/INFO software and considered the effect of altitude, slope degree and slope aspect to the air temperature by the method of air temperature lapse rate and the correlation between solar radiation and air temperature, this paper studied the spatial distribution of air temperature in Rizhao city using grid-based DEM data derived from 1:50000 topographic maps and 30-years (1970-2000) air temperature data of meteorological stations in Rizhao and its surrounding areas. After calibrating, the simulation result have more efficient.The wind speed distribution is affected by many factors in hilly area. In previous researches, although some methods were put forward on interpolating station data of wind speed, however, only the altitude factor was discussed on research of wind speed simulation. In this paper, taking Rizhao city as an example, considering such topographic factors as the altitude, slope degree, slope aspect and slope position, by support of ARC/INFO software, an AML program was designed to simulate the distribution of wind speed using grid-based DEM data derived from 1:50000 topographic maps and 30-years (1970-2000) wind speed data of meteorological stations in Rizhao and its surrounding areas. The simulation result will provide an important data to evaluate the suitability of tea tree living environment.The date base of evaluation factors was build with the spatial distribution of climatic factors and the soil Ph, soil texture and slope etc, then get the distribution of tea-tree high-quality area in study area with assessment and classification. After calibrating, the result of evaluation have more efficient.This paper makes a general research on the distribution of solar radiation,air temperature, wind speed etc, and the simulation result of climatic factors is of great significance in practical application. The simulation result will provide an important data to survey of climate resources,agricultural division, precision agriculture and ecology environment construction. It will increase the work efficiency and save much time and manpower.