| 摘要: |
| 【目的】比较4种空间插值方法的插值效果，为分析榆林市降水空间分布特征奠定基础。【方法】采用榆林市45个水文及雨量站点35年(1970-2004年)的降水量观测资料，结合GIS技术，以榆林市1 km×1 km网格DEM（Digital Elevation Model）数据为基础，建立35年各月平均、年平均降水量与站点坐标、高程之间的回归方程。选取反距离加权法、张力样条函数法、普通克里金法及协同克里金法等4种空间插值方法，对榆林市35个站点的多年平均降水量进行空间插值计算，采用10个站点的降水量数据对插值结果进行验证，并进行对比误差分析，根据插值结果，进一步分析榆林市降水空间分布特征。【结果】考虑了地形因素的协同克里金法插值效果最好，且较为真实地反映了榆林市降水空间分布特征，普通克里金法次之，反距离加权法和张力样条函数法较差。总体而言，4种插值方法均达到了较高的分析精度。插值结果表明，榆林市降水呈现明显的纬度地带性分布特征，且降水受地形、地貌以及季节因素影响较大。【结论】应用GIS空间插值技术，综合考虑地形因素，可以提高研究区域降水空间插值结果的精度，并可为分析该区域降水时空结构特征提供更为精细的数据。 |
| 关键词: 降水 DEM 空间插值 地形因素 榆林市 |
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| 基金项目:国家高技术研究发展计划(“863”计划) 项目(14110209)；国家重大科技支撑计划项目(10712)；西北农林科技大学博士科研启动基金项目(01140504)；西北农林科技大学科研专项(08080230) |
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| Analysis of spatial interpolation methods to precipitation in Yulin based on DEM |
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| Abstract: |
| 【Objective】Comparing the results of the four kinds of spatial interpolation methods,this paper makes a basis to analyze the temporal and spatial distribution of regional precipitation in Yulin.【Method】Combined with the geographic information system (GIS) technology,the annual precipitation data of 45 hydrometric and precipitation stations in Yulin from 1970 to 2004 based on the DEM(Digital Elevation Model) of 1 km×1 km spatial resolution are used to establish the regression equation among the precipitation,the coordinate and elevation of the 45 stations.Average annual precipitation (from 1970 to 2004) data of the 35 stations in Yulin are interpolated and analyzed by inverse distance weight tension (IDW),Spline with tension,Ordinary Kriging,CoKriging methods.The precipitation data of the last 10 stations are used to analyze the comparative error and validate the results of the interpolation.Based on the interpolation results,the spatial distribution of precipitation in Yulin is analyzed.【Result】The results indicate that the four interpolators have all achieved high precision in reflecting the spatial distribution of average annual precipitation in Yulin,among which CoKriging method having dealt with topography factor proves to be the most effective,followed by Ordinary Kriging,IDW and Spline with tension method.Interpolation results show that the precipitation distribution in Yulin is clearly latitude zonal,and is greatly affected by topography,physiognomy and seasonal factors.【Conclusion】Considering the topography factor in the study area,the GIS spatial interpolation techniques can improve the accuracy of interpolation of precipitation,and refine the data of analyzing the temporal and spatial distribution of regional precipitation. |
| Key words: precipitation DEM spatial interpolation topography factor Yulin |
