基于DEM的并行可照时间模型研究  

Research on Parallel Model of Insolation-Duration Based on DEM

作　　者：张刚[1] 汤国安[1] 宋效东[1] 

机构地区：[1]南京师范大学虚拟地理环境教育部重点实验室,江苏南京210023

出　　处：《地理与地理信息科学》2014年第3期11-15,F0002,共6页Geography and Geo-Information Science

基　　金：国家863计划项目(2011AA120303);江苏省高校自然科学研究重大项目(13KJA170001)

摘　　要：可照时间是影响太阳辐射计算的重要参数。随着研究区域的增大、DEM分辨率与精度的不断提高,亟须借助并行技术满足用户对可照时间模拟的时间响应需求。该文针对栅格数据提出了一种通用有效的数据划分及结果融合策略,首次提出并行可照时间计算模型。实验表明该模型具有较好的可移植性,当处理节点数为64时,最优加速比高达16,在计算时间及加速比方面体现出优势。基于黄土高原地区90m×90m分辨率SRTM数据,计算了四季及全年可照时间,分析了可照时间的空间分布特征,表现为季节不对称性及非地带性分布规律。As the study area extremely expands and the resolution of DEM constantly improves,the amount of insolation-duration analysis computations reveals exponential growth trend,which needs to meet the demand of real-time response requirement of customers by parallel computing technique.From the perspective of data parallel,this paper puts forward an effective data partition and result fusion strategy in view of raster data.In the data partition,the original datasets is divided into equal data by row,and the adjacent block data has a common buffer.After the task is fulfilled by compute nodes,the result file is fused by token-control system.And the parallel model of insolation-duration is firstly designed over rugged terrains.The practical applications show that this parallel model provides good cross-platform portability.When the processing node number is up to 64,its speedup ratio reaches up to 16,which has a good advantage in terms of computational time and speedup.So,high efficiency can be achieved.In addition,based on the SRTM data,the seasonal and annual insolation-duration of Loess Plateau is also calculated by the parallel algorithm of insolation-duration with the resolution of 90 m× 90 m,and the distribution of insolation-duration in Loess Plateau is discussed as well.Result shows that insolation-duration is influenced greatly by terrain factors,performs higher in north and lower in south.Furthermore,it presents non-zonality distribution for the contrasting insolation-duration in different land-form areas of same latitude and asymmetry distribution of seasons in different seasonal insolation-duration.This research results would be significant for agricultural divisions,environmental protection and climate resources development.

关 键 词：DEM 可照时间 并行计算 加速比 黄土高原 

分 类 号：P208[天文地球—地图制图学与地理信息工程]