Acta Agrestia Sinica ›› 2023, Vol. 31 ›› Issue (2): 479-488.DOI: 10.11733/j.issn.1007-0435.2023.02.022

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Dynamic Monitoring of Vegetation in Tongtian River Basin and Its Responses to Climate Factors

ZHANG Xun-xun1,2, DUAN Yang-hai1,2, WU Shu-ying3,4, TAN Chang-hai1,2, ZHAO Yang-gang1,2, YANG Bin1,2, WEN Lang1, XIAO Zhi-qiang5, SUN Jian6   

  1. 1. Research Center of Applied Geology of China Geological Survey, Chengdu, Sichuan Province 610036, China;
    2. Key Laboratory of Coupling Process and Effect of Natural Resources Elements, Ministry of Natural Resources, Bejing 100055, China;
    3. Sichuan Hua Di Building Engineering Co., Ltd, Chengdu, Sichuan Province 610081, China;
    4. Chengdu center of hydrogeology and engineering geology of Sichuan provincial geology and mineral resources bureau, Chengdu, Sichuan Province 610081, China;
    5. State Key Laboratory of Remote Sensing Science, School of Geography, Beijing Normal University, Beijing 100875, China;
    6. State Key Laboratory of Tibetan Plateau earth system science, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
  • Received:2022-08-24 Revised:2022-10-11 Published:2023-02-28

通天河流域植被动态监测及其对气候因子的响应

张浔浔1,2, 段阳海1,2, 吴淑莹3,4, 谭昌海1,2, 赵阳刚1,2, 杨斌1,2, 文浪1, 肖志强5, 孙建6   

  1. 1. 中国地质调查局应用地质研究中心, 四川 成都 610036;
    2. 自然资源要素耦合过程与效应重点实验室, 北京 100055;
    3. 四川省华地建设工程有限责任公司, 四川 成都 610081;
    4. 四川省地质矿产勘查开发局成都水文地质工程地质中心, 四川 成都 610081;
    5. 北京师范大学地理学院, 遥感科学国家重点实验室, 北京 100875;
    6. 中国科学院青藏高原研究所 青藏高原地球系统科学国家重点实验室, 北京 100101
  • 通讯作者: 段阳海,E-mail:duanyanghai@163.com
  • 作者简介:张浔浔(1995-),男,汉族,工程师,主要从事自然资源调查、遥感调查和地球化学方面研究,E-mail:zhangxunxun9511@163.com
  • 基金资助:
    青藏高寒区资源与环境调查监测与评价(ZD20220138);长江源沱沱河地区生态环境调查评价(ZD20220222);气候变化背景下基于氢氧同位素和水化学方法的青藏高原沱沱河地区径流分割研究(2021490711)资助

Abstract: Tongtian River is an important main stream of the source area of the Yangtze River. It is of great significance to study the vegetation growth and its response to climate factors in the source area of the Sanjiangyuan area. This paper focused the Tongtian River Basin by using the General regression neural network (GRNN) calculation model to invert the Leaf area index (LAI) and Fractional vegetation cover (FVC) data on the variation characteristics of LAI and FVC and their responses to climate factors. The results show:the vegetation in the Tongtian River Basin showed a significant fluctuating growth trend overall,with the growth rates of LAI and FVC being (1.2×10)-3·a-1 and (0.9×10)-3·a-1respectively. The vegetation improvement areas in the basin are distributed in the valleys with lower altitude and better hydrothermal conditions,but the vegetation around Qumalai County and Zhiduo County with frequent human activities in the lower reaches of the river was degraded significantly. Vegetation in the basin mainly grew in the area above 4 000 m above sea level,and the vegetation growth was poor where the area locates at more than 5 200 m above sea level. The low vegetation coverage type existed the most area of that basin,and the medium to high coverage was concentrated in the lower reaches of the river. Compared with air temperature,precipitation was the dominant factor affecting vegetation coverage in the basin,and was significantly positively correlated with vegetation LAI and FVC.

Key words: General regression neural network, Tongtian River Basin, Sanjiangyuan national Nature Reserve, Leaf area index, Fractional vegetation cover

摘要: 通天河是长江源头重要的干流,探讨其植被生长状况及其与气候因子的响应对三江源区生态系统稳定性研究具有重要意义。本文以通天河流域为研究区,采用了广义回归神经网络(General regression neural network,GRNN)计算模型来反演叶面积指数(Leaf area index,LAI)和植被覆盖度(Fractional vegetation cover,FVC)数据,分析LAI和FVC的变化特征及其对气候因子的响应。分析结果表明:通天河流域植被总体呈显著波动增长趋势,LAI,FVC增长速率分别为(1.2×10-3)·a-1和(0.9×10-3)·a-1;流域内植被明显改善区分布在海拔较低水热条件较好的沟谷地带,但下游人类活动频繁的曲麻莱县和治多县周边地区植被退化明显;流域内植被主要生长在海拔4 000 m以上地区,超过5 200 m植被生长差,覆盖类型以低覆盖为主,中-高覆盖集中在河流下游地区;相较于气温而言,降水是影响该流域植被的主导因素,与植被LAI和FVC呈显著正相关。

关键词: 通天河流域, 三江源, 广义回归神经网络, 叶面积指数, 植被覆盖度

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