塔里木河下游荒漠河岸林带辐射平衡特征  

Radiation Balance over Riparian Forest Belt in the Lower Reaches of the Tarim River

作　　者：薛沙沙[1,2] 袁国富[1,3] 罗毅[1,3] 

机构地区：[1]中国科学院地理科学与资源研究所,北京100101 [2]中国科学院大学,北京100049 [3]中国科学院生态系统网络观测与模拟重点实验室,北京100101

出　　处：《干旱区研究》2014年第1期65-73,共9页Arid Zone Research

基　　金：全球变化研究重大科学研究计划项目(2010CB951002);自然科学基金面上项目(41271050)

摘　　要：利用新疆塔里木河下游河岸林带观测的太阳辐射数据，结合下垫面和天气变化状况，分析该区太阳辐射变化特征，同时评价FAO56辐射估算方法模拟该区域太阳辐射的效果。结果表明：净辐射和辐射四分量的年均日变化，除大气逆辐射在300 W·m^-2左右波动外，均呈现出典型的单峰趋势。其中，总辐射平均极大值为629.96 W·m^-2，净辐射平均极大值为520.76 W·m^-2，净辐射日积分值在一年内呈现单峰对称型趋势，年平均值为7.81 MJ·m^-2·d^-1，地表长波辐射的峰值在中午前后滞后于总辐射峰值约2 h。较之晴天而言，阴天和风沙天气太阳辐射波动较大，总辐射和净辐射均明显降低。地表反照率的变化与下垫面植被覆盖度密切相关，生长季节为0.18左右，非生长季节为0.20左右，年均值为0.19。FAO56方法模拟日尺度辐射结果表明：总辐射、净短波辐射和净辐射模拟效率分别为0.94、0.87、0.80，而有效辐射模拟效率仅为0.19；各辐射通量均方根误差均在1.67-1.98，平均偏差值均较小。有效辐射量在总辐射中所占比例较小，虽模拟效率较低，但其对净辐射的贡献较小，使得净辐射模拟误差在合理的范围内，故认为FAO56辐射模拟方法经验系数可用于计算该地区日尺度净辐射值。Solar radiation plays a critical role in the process of energy and material exchange over land surface. It is not only the drive force of land surface physical process, but also the input parameter of Land Surface Model and Remote Sensing Model. Researchers focused on the semiarid and arid regions because of its special geographic en- vironment. Therefore this paper took a typical arid area in the lower reaches of the Tarim River as a case to discuss the radiation balance over riparian forest belt and the measured radiation data, and to evaluate the applicability of FAO56 method used to calculate the net radiation in arid region. FAO56 method is used to calculate shortwave ra- diation through sunshine duration and long-wave radiation Accuracy was evaluated by Model Efficiency （ME）, Root （MBE）. Statistical results of measured values showed that through air temperature, humidity and cloud amount. Mean Square Difference （RMSD） and Mean Bias Error the daily variation of radiation flux was in a typical nor- mal distribution trend. The maximal values of solar radiation, reflected radiation and net radiation occurred at Bei- jing time 14：00 o＇ clock and were 629.96 W ·m^-2, 106.51 W·m^-2 and 520.76 W·m^-2 respectively. Maximal was highly related to zenith angle and albedo. Annual variation of net radiation was unimodal with a slight inter-an- nual fluctuation, the net radiation increased gradually from January to June, reached its maximum in June, and de- creased gradually from June to December. Daily total value of net radiation fluctuated between 0. 5 MJ·m^-2·d^-1 and 18 MJ·m^-2·d^-1 , and its average in full year was 7.81 MJ·m^-2·d^-1. Weather conditions, such as windy or cloudy weather, affected significantly the radiation flux. Wind and cloud could reduce solar radiation and corre- spondingly reflected radiation. Effective radiation was slightly affected, thus net radiation dropped to some extent compared with that on sunny day. The curve of daily albedo was U-shaped, it was high at sunrise

关 键 词：辐射平衡 荒漠河岸林带 FAO56辐射模拟方法 塔里木河下游 

分 类 号：S718.5[农业科学—林学]