基于遥感数据的若尔盖地区2001-2015年植被生育期特征及其对气候变化的响应分析
Characteristics of Vegetation Growth Period and Its Response to Climate Change in Zoigê Area from 2001 to 2015 Based on Remote Sensing Data
作者：李丹利(四川大学 水力学与山区河流开发保护国家重点实验室 水利水电学院, 四川 成都 610065)；李龙国(四川大学 水力学与山区河流开发保护国家重点实验室 水利水电学院, 四川 成都 610065)；贺宇欣(四川大学 水力学与山区河流开发保护国家重点实验室 水利水电学院, 四川 成都 610065)；苟思(四川大学 水力学与山区河流开发保护国家重点实验室 水利水电学院, 四川 成都 610065)；赵娜娜(中国林业科学研究院 湿地研究所, 北京 100091;中国水利水电科学研究院 流域水循环模拟与调控国家重点实验室, 北京 100038)
Author：LI Danli(State Key Lab. of Hydraulic and Mountain River Eng., College of Water Resource & Hydropower, Sichuan Univ., Chengdu 610065, China)；LI Longguo(State Key Lab. of Hydraulic and Mountain River Eng., College of Water Resource & Hydropower, Sichuan Univ., Chengdu 610065, China)；HE Yuxin(State Key Lab. of Hydraulic and Mountain River Eng., College of Water Resource & Hydropower, Sichuan Univ., Chengdu 610065, China)；GOU Si(State Key Lab. of Hydraulic and Mountain River Eng., College of Water Resource & Hydropower, Sichuan Univ., Chengdu 610065, China)；ZHAO Nana(Inst. of Wetland Research, Chinese Academy of Forestry, Beijing 100091, China;State Key Lab. of Simulation and Regulation of Water Cycle in River Basin, China Inst. of Water Resources and Hydropower Research, Beijing 100038, China)
收稿日期：2018-01-25 年卷（期）页码：2019,51(1):165-172
期刊名称：工程科学与技术
Journal Name：Advanced Engineering Sciences
关键字：遥感;归一化植被指数（NDVI）;生育期;积温;标准化降水指数（SPI）
Key words：remote sensing;normalized difference vegetation index(NDVI);vegetation growth period;accumulated temperature;standardized precipitation index(SPI)
基金项目：国家自然科学基金青年科学基金资助项目（51509170）；中央级公益性科研院所基本科研业务费专项资金资助（CAFINT2015K06）；国家重点基础研究发展计划资助项目（2015CB452701）；国家自然科学基金资助项目（51609243）；中国水利水电科学研究院流域水循环模拟与调控国家重点实验室开放研究基金资助项目（IWHR-SKL-201612p）；国家自然科学基金青年科学基金项目资助（51709190）；四川大学2016校青年启动基金资助（20826041A4222）
中文摘要
遥感NDVI（归一化植被指数）数据能较好地反映植被生长变化情况，已广泛应用于多尺度植被物候监测。基于MODIS卫星每16 d的NDVI遥感数据，通过时间序列滤波软件TIMESAT重建了若尔盖地区2001-2015年NDVI时间序列，提取出植被3个关键生育期信息-植被生育期起始时间、植被生育期长度和生育期内NDVI峰值；分析了影响植被生育期的关键气候因子。结果表明：1）2001-2015若尔盖地区植被平均生育期起始时间提前，生育期长度延长，NDVI峰值无明显变化。2）植被平均生育期在空间分布上无明显递变规律；随海拔梯度升高，植被生育期起始时间推迟，生育期长度缩短，NDVI峰值减小。3）温度是影响若尔盖地区植被生育期的主要气候因素，4、5月积温升高促进植被生育期起始时间提前（相关系数|R|=0.79）；9、10月积温升高有利于植被生育期结束时间推后，使得生植被育期长度延长（相关系数|R|=0.73）；从植被生育期起始至NDVI峰值出现时间段内积温的升高也使得植被NDVI峰值升高（相关系数|R|=0.68）。4）植被NDVI与SPI（标准化降水指数）相关性不高，若尔盖地区植被生长对降水变化不敏感。研究结果较为真实地反映了2001-2015年若尔盖区域植被的生育期特征及其对气候变化的响应，其方法可应用于遥感监测区域范围内植被变化特征。
英文摘要
NDVI (normalized difference vegetation index) can reflect the changes of vegetation growth. It has been widely used to monitor multi-scale vegetation growth conditions. Based on MODIS remote sensing data, the time series ofNDVIfrom 2001 to 2015 in Zoigê area were reconstructed by filtering software TIMESAT, and three key vegetation growth properties were extracted:The start of vegetation growth period, the length of vegetation growth period and the maximumNDVIvalue. The key climatic factors affecting the vegetation growth period were analyzed. The results showed that:1) The average start time of vegetation growth period increased, and the average length of vegetation growth period prolonged, while and the maximumNDVIvalues had no significant changes from 2001 to 2015. 2) The average vegetation growth properties had no obvious regular pattern of change in spatial distribution.As the elevation increased, the start of vegetation growth period postponed, the length of vegetation growth period shortened visibly, and the maximum ofNDVIdid not change obviously. 3) Temperature is the main factor that impacted vegetation growth period in Zoigê area. Increasing accumulated temperature in April and May could advance the start time of vegetation growth period. The average length of vegetation growth period would be longer with the higher accumulated temperature in September and October. The increase of accumulated temperature from the start time of growth period to the time of the maximumNDVIalso increased the maximum value ofNDVI. 4) The correlation betweenNDVIandSPIwas not significant. Therefore, the vegetation in Zoigê area had low dependence on precipitation. The findings showed the changes of vegetation growth period in Zoigê area and their response to climate over the past 15 years. The methods used in this paper can provided a useful tool for remote sensing monitoring of vegetation characteristics at large scales.
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