北京林业大学学报2016，Vol.38Issue(3)：1-10,10.DOI:10.13332/j.1000-1522.20150360
元江干热河谷太阳辐射各分量及反照率变化特征
Characteristics of solar radiation distribution and albedo in Yuanjiang dry-hot valley, Southwest China
摘要
Abstract
Based on the continuous observation data of solar radiation ( SR) through two years( from May 2013 to April 2015)in a dry-hot valley in southwest China’s Yuanjiang, daily, seasonal and annual variations of SR components above the canopy of open shrubland were addressed. Meantime, values of SR components, e. g. , total global radiation ( Q) , reflective radiation ( Qα) , effective radiation ( I) and net radiation (Rn) related to global radiation and variations of albedo (α) as well as its driving factor were investigated. The results showed that yearly average of Q, Qα, I and Rn were 6 210. 2, 807. 9, 1 822. 9, 3 578. 7 MJ/( m2·yr) , respectively, and the ratios of Q, Qα, I, Rn in rainy season to yearly average value were 52. 9%, 56. 3%, 39. 1%, 59. 2% separately. Except for the seasonal variations of I appearing higher value in rainy season than that in dry season, Q, Qαand Rn in rainy season were higher than those in dry season. Albedo (α) in dry season was lower than that in rainy season because of the increasing leaf area index ( LAI) and canopy closure extent in rainy season, and this is also the result of long-term evolution ecological strategy of local ecosystem to reduce evaportranspiration ( ET) and increase net primary production. The annual distribution ratios of Qα, I and Rn were 13. 0%, 29. 8% and 56. 9%separately. The seasonal variations in the distribution ratios of Qαand Rn were both higher in rainy season than those in dry season; however, the distribution ratios of I showed an opposite seasonal variations pattern. The increasing distribution ratios of I in dry season decreased land surface and canopy temperatures, reduced ET of ecosystem, weakened drought stress of ecosystem in dry season and avoided vegetation death due to the damage of hydraulic architecture inducing carbohydrate starvation, which is beneficial to vegetation survival in dry season and maintain the ecosystem balance in Yuanjiang dry-hot valley. As Q and Rn of Yuanjiang hot-dry valley vegetation were higher and considering the precipitation in this region was just about 700 mm, thus human activities and climate change are more likely to affect this ecosystem balance.关键词
太阳辐射/反照率/干热河谷植被Key words
solar radiation/albedo/hot-dry valley vegetation分类
农业科技引用本文复制引用
费学海,张一平,宋清海,李培广,刘运通,金艳强,李敬,林友兴,张树斌..元江干热河谷太阳辐射各分量及反照率变化特征[J].北京林业大学学报,2016,38(3):1-10,10.基金项目
国家自然科学基金与云南省联合项目( U1202234)、国家基金重大项目(31290221)、国家基金青年项目(41405143)、碳专项(XDA05020303 （ U1202234）
XDA05050206)和中国科学院“一三五”专项(方向一:XTBG-F01)。 （方向一:XTBG-F01）
