起伏地形下黄河流域太阳直接辐射分布式模式

基于数字高程模型(DEM)数据和气象站观测资料建立了起伏地形下太阳直接辐射分布式计算模型,模型充分考虑了地形因子(坡向、坡度、地形相互遮蔽)对起伏地形下太阳直接辐射空间分布的影响;以1km×1km分辨率的DEM数据作为地形的综合反映,计算了起伏地形下黄河流域1km×1km分辨率太阳直接辐射的空间分布;深入分析了起伏地形下太阳直接辐射受地理、地形因子影响的变化规律.结果表明受地形起伏和坡向、坡度等局地地形因子的影响,山区年太阳直接辐射量的空间差异比较明显,向阳山坡(偏南坡)的年直接辐射量明显高于背阴山坡(偏北坡).     

基于DEM的黄河流域天文辐射空间分布

基于1 km×1 km分辨率的数字高程模型(DEM) 数据,利用建立的起伏地形下天文辐射分布式计算模型,计算了黄河流域1 km×1 km分辨率各月天文辐射的空间分布。结果表明:局部地形对黄河流域年和四季天文辐射的空间分布影响明显;在太阳高度角较低的冬季,地理和地形因子对天文辐射的影响相当强烈,山区天文辐射的空间差异大,1月份向阳山坡(偏南坡) 天文辐射可为背阴山坡(偏北坡) 的2~3倍,极端天文辐射的差异可达10倍以上;而在太阳高度角较高的夏季,天文辐射空间差异较小,7月份不同地形极端天文辐射的差异仅在16%左右;四季中,地形对天文辐射影响的程度为冬季>秋季>春季>夏季。     

复杂地形下长江流域太阳总辐射的分布式模拟

利用长江流域气象站1960-2005年的观测资料(包括常规气象站点资料和辐射站点资料)、NOAA-AVHRR遥感数据(反演地表反照率),以1km×1km的数字高程模型(DEM)反映地形状况的主要数据,通过基于DEM数据的起伏地形下天文辐射模型和地形开阔度模型,分别建立了长江流域太阳直接辐射、散射辐射和地形反射辐射分布式模型,实现了长江流域太阳总辐射模拟,并对总辐射模拟结果进行了时空分布规律分析和对其受季节、纬度、地形因子(高度、坡度和坡向等)影响的局部规律分析,以及模拟结果的误差分析和站点验证分析。结果显示:太阳总辐射在季节上受影响的程度依次是春季>冬季>夏季>秋季;随着高度、坡度、纬度的增加,太阳总辐射受坡向影响的程度呈增强趋势,从坡向上看,向阳山坡(偏南坡)对太阳总辐射量明显高于背阴坡(偏北坡)。模拟的平均绝对误差为13.04177MJm^-2,相对误差平均值3.655%,用站点验证方法显示:模拟绝对误差为22.667MJm^-2,相对误差为4.867%。     

基于GIS的起伏地形下天文辐射分布式模型——以贵州高原为例

天文辐射是辐射计算、太阳能资源评估及其他相关研究领域重要的起始参量,由于坡度、坡向和地形之间相互遮蔽等局地地形因子的影响,使实际起伏地形下获得的天文辐射与水平面上获得的天文辐射有一定差异。确定实际起伏地形下天文辐射是比较困难的。应用数字高程模型(DEM)数据和地理信息系统(G IS),建立起伏地形下天文辐射分布式计算模型,计算了起伏地形下贵州高原100 m×100 m分辨率天文辐射精细空间分布,分析了局地地形因子对起伏地形下天文辐射的影响。结果表明:(1)贵州高原起伏地形下天文辐射的空间分布具有明显的地域分布特征。(2)贵州高原起伏地形下天文辐射年总量平均为481.7~13 041.8 M J/m2,1月、7月天文辐射分别为0.0~1 244.7 M J/m2、0.0~1 264.8 M J/m2。(3)局地地形因子对起伏地形下天文辐射空间分布的影响随季节和纬度变化,虽然坡度、坡向和地形遮蔽对天文辐射的影响,在太阳高度角较低的1月比太阳高度角较高的7月相对较大,但因为7月水平面获得的天文辐射的强度相对较大,7月局地地形对天文辐射的影响依然显著。因此,贵州高原起伏地形对天文辐射的影响是不容忽视的。     

山区地形开阔度的分布式模型

 地形开阔度是影响山地辐射平衡及其分量的重要地形因子,是山区散射辐射、地形反射辐射等计算的重要参数。在复杂的地形条件下,地形开阔度的计算很难用数学公式描述。 利用数字高程模型（DEM）,全面考虑了坡地自身遮蔽和周围地形相互遮蔽的影响,提出了山区地形开阔度的分布式模型和算法。以1 km×1 km分辨率的DEM数据作为地形的综合反映,计算了起伏地形下中国地形开阔度的空间分布。同时,利用100 m和1 km两个分辨率的DEM数据,从不同DEM分辨率和不同地貌类型两个方面探讨了地形开阔度的空间尺度效应,阐明了区域地形开阔度随地形地貌和空间分辨率的变化规律。所提供的山地开阔度的数据可作为基础地理数据供相关研究应用。     

中国三种太阳辐射起始数据分布式模拟

天文辐射、干洁大气总辐射和湿洁大气总辐射是太阳辐射模拟的3种重要起始数据。依托Iqbal Model C和起伏地形下干/湿洁大气总辐射模型,实现了水平面和起伏地形下干/湿洁大气总辐射分布式模拟。以DEM数据作为地形的综合反映,结合常规气象资料,计算了水平面和起伏地形下中国1 km×1 km分辨率日天文辐射量、干洁大气总辐射量、湿洁大气总辐射量的空间分布,并对3种太阳辐射起始数据的时空分布特征做了对比分析。结果表明:3种辐射量均遵循随纬向变化的宏观分布规律;水平面干/湿洁大气总辐射量的分布体现了海拔的影响,水平面湿洁大气总辐射量的分布还体现了水汽分布的影响;起伏地形下的3种辐射量能很好的体现坡度、坡向和地形之间相互遮蔽等局部地形特征对辐射量的影响;以干/湿洁大气总辐射作为起始数据,将有助于提高太阳总辐射的模拟精度。     

贵州高原复杂地形下太阳总辐射精细空间分布

海拔、坡度、坡向以及周围地形遮蔽作用,造成山区各部位接受到的太阳辐射能有很大差异. 在前人研究的基础上,对以前的模型进行了一些改进,考虑了坡度、坡向和地形相互遮蔽作用对复杂地形下天文辐射的影响,基于数字高程模型(DEM)数据,研制了以复杂地形下天文辐射为起始数据的复杂地形下太阳总辐射的分布式模型,在模型中还考虑了散射辐射的各向异性及坡地反射辐射对复杂地形下太阳总辐射的影响.应用100 m×100 m分辨率的DEM数据及气象站常规观测气象资料,计算了贵州高原复杂地形下100 m×100 m分辨率的复杂地形下太阳总辐射.结果表明:(1) 局地地形因子如坡度、坡向、地形遮蔽等对太阳总辐射影响显著,地形对复杂地形下太阳总辐射的影响是不容忽视的.(2)在缺乏复杂地形下坡面考察资料的情况下,建立以常规气象站观测资料为主的物理经验统计模型是实现细网格辐射资源计算的可行途径.     

中国三种太阳辐射起始数据分布式模拟

天文辐射、干洁大气总辐射和湿洁大气总辐射是太阳辐射模拟的3种重要起始数据。依托Iqbal Model C和起伏地形下干/湿洁大气总辐射模型,实现了水平面和起伏地形下干/湿洁大气总辐射分布式模拟。以DEM数据作为地形的综合反映,结合常规气象资料,计算了水平面和起伏地形下中国1 km×1 km分辨率日天文辐射量、干洁大气总辐射量、湿洁大气总辐射量的空间分布,并对3种太阳辐射起始数据的时空分布特征做了对比分析。结果表明：3种辐射量均遵循随纬向变化的宏观分布规律;水平面干/湿洁大气总辐射量的分布体现了海拔的影响,水平面湿洁大气总辐射量的分布还体现了水汽分布的影响;起伏地形下的3种辐射量能很好的体现坡度、坡向和地形之间相互遮蔽等局部地形特征对辐射量的影响;以干/湿洁大气总辐射作为起始数据,将有助于提高太阳总辐射的模拟精度。     

贵州高原复杂地形下月平均日最高气温分布式模拟

在前人研究的基础上,对以前的模型进行改进,考虑了坡度、坡向和地形相互遮蔽作用对复杂地形下天文辐射的影响,基于数字高程模型(DEM)数据,建立以天文辐射为起始数据的复杂地形下月平均日最高气温的分布式模型,在模型中考虑了海拔高度、复杂地形下太阳总辐射、日照百分率对月平均日最高气温的影响.以贵州高原为例.应用100m×100m分辨率的DEM数据.1960-2000年贵州省及周边102个气象站常规气象要素观测资料以及NOAA-AVHRR观测资料,10个气象站的太阳辐射量资料,计算了贵州高原各月及年平均日最高气温精细空间分布.结果表明:(1)坡度、坡向、地形遮蔽对月平均日最高气温的影响较大,由于局地地形因子的影响,复杂地形下月平均日最高气温的空间分布具有明显的地域分布特征,局地地形对月平均日最高气温的影响是不容忽视的.(2)季节不同,局地地形因子对复杂地形下月平均日最高气温空间分布的影响不同,冬半年大于夏半年.月平均日最高气温随海拔高度的增加而降低.南坡随坡度的增大而升高:北坡随坡度的增大而降低.在坡向影响上,1-5月、10-12月偏北坡月平均日最高气温偏低,偏南坡月平均日最高气温偏高;7-8月因太阳高度较高,因此出现相反的情况.北坡高于南坡.     

DEM结构特征对坡度坡向的影响分析

数字高程模型已严格定义为按规则格网阵列记录的地形高程数据,其固有的结构特征(如格网分辨率、格网方向、高程数据准确度等)直接影响DEM对地形表达和坡度、坡向的计算精度。该文通过理论和数据独立的DEM实验分析方法,研究了DEM结构特征对坡度、坡向的影响,得出如下结论:1)高分辨率的DEM并不一定能给出高精度的坡度、坡向计算结果;2)可通过g=bm/ms×180/π×cos2S来选择合适的DEM分辨率;3)三阶不带权差分算法的坡度、坡向计算结果对DEM方向有较强的依赖性。     

起伏地形下黄河流域太阳直接辐射分布式模拟

1 Introduction Directsolarradiation (DSR)isthe key com ponentofthe globalradiation reaching the Earth.For the influence of terrain factors,calculation of DSR quantity of rugged terrain is considerably com plex (Oliphantetal.,2003). The solarradiation quan…     

Influence of complex topography on global solar radiation in the Yangtze River Basin

Global solar radiation（GSR） is the most direct source and form of global energy, and calculation of its quantity is highly complex due to influences of local topography and terrain inter-shielding. Digital elevation model（DEM） data as a representation of the complex terrain and multiplicity condition produces a series of topographic factors（e.g. slope, aspect, etc.）. Based on 1 km resolution DEM data, meteorological observations and NOAA-AVHRR remote sensing data, a distributed model for the calculation of GSR over rugged terrain within the Yangtze River Basin has been developed. The overarching model permits calculation of astronomical solar radiation for rugged topography and comprises a distributed direct solar radiation model, a distributed diffuse radiation model and a distributed terrain reflectance radiation model. Using the developed model, a quantitative simulation of the GSR space distribution and visualization has been undertaken, with results subsequently analyzed with respect to locality and terrain. Analyses suggest that GSR magnitude is seasonally affected, while the degree of influence was found to increase in concurrence with increasing altitude. Moreover, GSR magnitude exhibited clear spatial variation with respect to the dominant local aspect; GSR values associated with the sunny southern slopes were significantly greater than those associated with shaded slopes. Error analysis indicates a mean absolute error of 12.983 MJm-2 and a mean relative error of 3.608%, while the results based on a site authentication procedure display an absolute error of 22.621 MJm-2 and a relative error of 4.626%.     

复杂地形对长江流域太阳总辐射的影响(英文)

Global solar radiation(GSR) is the most direct source and form of global energy, and calculation of its quantity is highly complex due to influences of local topography and terrain inter-shielding. Digital elevation model(DEM) data as a representation of the complex terrain and multiplicity condition produces a series of topographic factors(e.g. slope, aspect, etc.). Based on 1 km resolution DEM data, meteorological observations and NOAA-AVHRR remote sensing data, a distributed model for the calculation of GSR over rugged terrain within the Yangtze River Basin has been developed. The overarching model permits calculation of astronomical solar radiation for rugged topography and comprises a distributed direct solar radiation model, a distributed diffuse radiation model and a distributed terrain reflectance radiation model. Using the developed model, a quantitative simulation of the GSR space distribution and visualization has been undertaken, with results subsequently analyzed with respect to locality and terrain. Analyses suggest that GSR magnitude is seasonally affected, while the degree of influence was found to increase in concurrence with increasing altitude. Moreover, GSR magnitude exhibited clear spatial variation with respect to the dominant local aspect; GSR values associated with the sunny southern slopes were significantly greater than those associated with shaded slopes. Error analysis indicates a mean absolute error of 12.983 MJm-2 and a mean relative error of 3.608%, while the results based on a site authentication procedure display an absolute error of 22.621 MJm-2 and a relative error of 4.626%.     

Simulation of astronomical solar radiation over Yellow River Basin based on DEM

1IntroductionDistributed watershed hydrological model has become one of the hot topics in hydrology for its predominance in reflecting the influence of the spatial distributed features of terrains on hydrological processes (Wan etal., 2001; Abbott etal., 1986; Beven etal., 1992). However its demands on the spatio-temporal changeful surface elements such as solar radiation, precipitation, temperature etc. are strict. Being the limitations of observation techniques, data availability and study …     

Simulation of astronomical solar radiation over Yellow River Basin based on DEM

Based on the developed distributed model for calculating astronomical solar radiation (ASR), monthly ASR with a resolution of 1 km×1 km for the rugged terrains of Yellow River Basin was calculated, with DEM data as the general characterization of terrain. This model gives an all-sided consideration on factors that influence the ASR. Results suggest that (1) Annual ASR has a progressive decrease trend from south to north; (2) the magnitude order of seasonal ASR is: summer>spring>autumn>winter; (3) topographical factors have robust effect on the spatial distribution of ASR, particularly in winter when a lower sun elevation angle exists; (4) the ASR of slopes with a sunny exposure is generally 2 or 3 times that of slopes with a shading exposure and the extreme difference of ASR for different terrains is over 10 times in January; (5) the spatial differences of ASR are relatively small in summer when a higher sun elevation angle exists and the extreme difference of ASR for different terrains is only 16% in July; and (6) the sequence of topographical influence strength is: winter>autumn>spring>summer.     

基于DEM的黄河流域天文辐射空间分布

Based on the developed distributed model for calculating astronomical solar radiation (ASR), monthly ASR with a resolution of 1 km× 1 km for the rugged terrains of Yellow River Basin was calculated, with DEM data as the general characterization of terrain. This model gives an all-sided consideration on factors that influence the ASR. Results suggest that (1) Annual ASR has a progressive decrease trend from south to north; (2) the magnitude order of seasonal ASR is: summer＞spring＞autumn＞winter; (3) topographical factors have robust effect on the spatial distribution of ASR, particularly in winter when a lower sun elevation angle exists; (4) the ASR of slopes with a sunny exposure is generally 2 or 3 times that of slopes with a shading exposure and the extreme difference of ASR for different terrains is over 10 times in January; (5) the spatial differences of ASR are relatively small in summer when a higher sun elevation angle exists and the extremedifference of ASR for different terrains is only 16% in July; and (6) the sequence of topographical influence strength is: winter＞autumn＞spring＞summer.