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干旱区地理 ›› 2015, Vol. 38 ›› Issue (4): 743-752.

• 生物与土壤 • 上一篇    下一篇

西北内陆河流域典型生态系统通量数据空间代表性研究

张琨, 韩拓, 朱高峰, 白岩, 马婷   

  1. 兰州大学西部环境教育部重点实验室, 干旱环境与气候变化协同创新中心, 甘肃 兰州 730000
  • 收稿日期:2014-11-12 修回日期:2015-01-17 出版日期:2015-07-25
  • 通讯作者: 朱高峰(1978-),男,博士,副教授.Email:zhugf@lzu.edu.cn
  • 作者简介:张琨(1990-),男,甘肃天水人,在读硕士研究生,主要从事干旱区生态-水文过程研究.Email:zhangk12@lzu.edu.cn
  • 基金资助:

    国家重大科学研究计划(973计划)项目(2013CB956604);国家自然基金项目(31370467)

Investigation of spatial representativeness for flux data of continental river basin in arid region of northwestern China

ZHANG Kun, HAN Tuo, ZHU Gao-feng, BAI Yan, MA Ting   

  1. Key Laboratory of Western China's Environmental Systems with the Ministry of Education, Collaborative Innovation Centre for Arid Environments and Climate Change, Lanzhou University, Lanzhou 730000, Gansu, China
  • Received:2014-11-12 Revised:2015-01-17 Online:2015-07-25

摘要: 涡度通量数据的空间代表性问题是影响其数据质量不确定性的重要原因。选取了我国西北地区具有代表性的四个通量观测站生长季数据,采用FSAM模型对各站点通量贡献源区范围以及通量贡献最大值点进行了计算,给出了在不稳定与稳定两种大气层结条件下各站点源区的主要分布范围(P=80%):盈科站源区范围相对最小(90~200 m);阿柔站源区范围约为(120~140 m);关滩站源区范围约为(500~600 m);敦煌站源区范围约为(140~280 m)。同时结合各站点仪器架设高度以及不同的下垫面生态环境等因素,对通量源区的变化进行了初步分析,仪器的架设高度直接影响涡度源区范围;不同的下垫面生态环境形成不同的近地面湍流状态进而对通量源区的分布产生间接影响。结果表明各站点观测的通量信息基本均来源于所感兴趣的研究区域。

关键词: 涡度相关, 通量源区, FSAM, 西北内陆河流域

Abstract: With the increasing of global change, the change of surface heat flux is becoming more and more attention. But the quality and uncertainty of flux data is seriously affected by the spatial representativeness. Therefore, the paper selected the data during the growing season from four observation stations in northwestern China. Then, the paper calculated the flux source area and the point of maximum flux contribution for each site by FSAM model. In this paper, the main source areas(P=80%, 60%, 40%, 20%)was given for each site under the different condition of atmosphere(Stable & Unstable). It turned out that each station under the condition of stable stratification, the source area are as follows:Yingke-station(190 m, 110 m, 80 m, 60 m); Arou-station(140 m, 115 m, 85 m, 65 m); Guantan-stati-on(580 m, 320 m, 240 m, 180 m); Dunhuang-station(280 m, 140 m, 100 m, 80 m). Under the condition of unstable stratification, the source area of the four stations are as follows:Yingkestation(90 m, 55 m, 35 m, 30 m); Arou-station(120 m, 95 m, 80 m, 65 m); Guantan-station(480 m, 280 m, 200 m, 160 m); Dunhuang-station(140 m, 80 m, 60 m, 40 m). From the results, the source area of Guantan-station is the largest in these three stations, because its underlying surface is the forest ecological system and its instrument installation location also is the highest of all. The source area of Yingke-station is not only the minimum but also in a flat elliptical shape. That is the place of the station was surrounded by windbreaks and had a strong disturbance of human activity, so that the turbulence movement for atmospheric is more complex. As a consequence, the direction of the wind is not always stable but very easy to form a strong side wind, especially under the condition of instability. For Arou-station, by the reason of its lowest instrument installation location and the homogeneous underlying surface, the change of source area is more uniform than the other three stations. The source area of Dunhuang-station is between Guantan-station and Arou-station. Thus, it is concluded that the changes of the flux source area were preliminarily analyzed with the height of the instrument and the different underlying surface, etc. Obviously, the erection height of the instrument had a direct influence on the extent of the flux source and different underlying surfaces form different turbulence and thus indirectly affected the distribution of flux source area. In the present paper, we also calculated the point of maximum flux contribution under the different atmospheric stratification for each site(Yingke 20.7-39.8 m; Arou 44.8-49.6 m; Guantan 109.3-124.7 m; Dunhuang 31.7-49.3 m). Its length is consistent with its source area size. In addition, in combination with characteristics of underlying surface for each station, the major source area of the observation is located in the area where we interested and the observation data of the four stations can represent the underlaying surface properties. It is able to provide the reliable basic data for the research that the matter and energy exchange in continental river basin in northwest China. There is some errors when calculating the tall vegetation due to the model itself. Because it is a simplified analytical model, so it can not describe the turbulence conditions inside of the canopy.

Key words: eddy covariance, footprint analysis, FSAM, northwestern China

中图分类号: 

  • P41