摘要
山地地表接收的太阳入射辐射由于受到坡度、坡向及地形遮蔽等影响,导致其在时空分布上呈现较高的异质性。为定量分析山地地表太阳辐射的时空分布特征,本研究选择川西山区为研究对象,针对山地特殊地理环境,基于太阳直接辐射、散射辐射和周围地形反射辐射的参数化方案,采用Landsat系列卫星遥感影像数据和30m ASTER GDEM数据定量估算了研究区在不同时期的太阳辐射空间分布,并结合研究区的坡度、坡向、海拔等地形因子,选择夏、秋、冬不同季节对山地太阳辐射时空分布进行了综合分析。结果表明:(1)经过贡嘎山站观测数据的验证,本研究所采用的估算方案能够取得较高的估算精度,平均绝对误差为48.7 W·m-2,相对误差为6%;(2)山地太阳辐射分布具有很强的地形规律,总体特点是山脊大于山谷,阳坡大于阴坡;(3)随着坡度的增加,太阳辐射呈现递减的趋势;而随海拔的上升太阳辐射总体来说呈现增加趋势,只是在低海拔处由于地形遮蔽和山顶由于坡度陡峭造成坡面入射角小而略有回落;(4)在不同的季节,太阳辐射受地形因子的影响程度有所差异,这与太阳高度角的大小有着直接的关系。
Land surface incident solar radiation comes from a complex interaction of energy transfer between atmosphere and surface. Due to the influence of slope,aspect,and terrain shielding,the spatial distribution of solar radiation in the mountainous area varies significantly and its estimation is more complicated than those in the flat area. To demonstrate spatio-temporal variation of solar radiation in the mountainous area,values of the solar radiation at different seasons in Western Sichuan were collected with the aid of Landsat image and 30 m ASTER GDEM data.Considering topographical effects,the parameterization approach was improved by using sky-view factor and terrain configuration factor. Meanwhile,land surface albedo was also corrected to reduce the topographical effects in the study area. The estimated results were consistent with the in-situ observations,with a mean bias of 48. 7 W·m-2and a mean relative error of 6%. Based on our analysis,it was found that the solar radiation on the sunny slope was greater than that on the shade slope. With the increase of inclination,the amount of radiation showed a decreasing trend. The solar radiation generally increased with altitude ascent except the low elevation and peak. In addition,the topographic effects varied with seasons,because it was directly related to the solar altitude angle.
出处
《山地学报》
CSCD
北大核心
2017年第3期420-428,共9页
Mountain Research
基金
国家自然科学基金项目(41401425
41631180)
国家重点研发计划全球变化及应对专项子课题(2016YFA0600103)
中国科学院水利部成都山地灾害与环境研究所青年百人团队计划(SDSQB-2015-02)
中国科学院青年创新促进会项目(2016333)~~
关键词
太阳辐射
地形影响
时空分布
川西山区
solar radiation
topographic effect
spatial and temporal distribution characteristics
mountainous areasof western Sichuan
