摘要
针对塔里木河下游生态输水的绩效评估和环境效益问题,本文采用2000—2017年的16天合成的MOD13Q1密集时序NDVI数据,辅助以GF-2数据,反演和监测塔里木河下游植被覆盖度(FVC)变化;进而通过最大和平均植被覆盖度指标,探讨了塔里木河下游植被在生态输水条件下的生长和恢复情况。结果表明:总体上,近20年来随着塔河的综合治理工程和人工生态调水工程的推进,塔河下游植被恢复明显,最大植被覆盖度和平均植被覆盖度均呈现显著增加的趋势(P<0.01),高植被覆盖区从2000年的3425.95 km^2增加到2017年5486.52 km^2,中植被覆盖区从2000年的6508.18 km^2增加到2015年的7131.23 km^2。在时间演化过程上,区域植被覆盖度上升变化过程中存在波动性和不稳定性,整个过程可分为3个阶段(2000—2005年快速上升,2006—2009年波动下降,和2010—2017年稳步上升)。在空间格局上,2000—2017年间FVC增加区域主要分布在河道两旁和河流的尾闾湿地,距离河道越近植被恢复越好,远离河道10 km FVC变化特征不显著(P>0.05)。结合下游生态输水数据分析表明,塔河下游植被恢复与输水量之间存在强依赖关系,且对生态输水的响应存在时间滞后性。
For the assessment of environmental benefits and performance of ecological water conveyance in the lower reaches of the Tarim River, this study detected and assessed riparian vegetation restoration by the MODIS 250 m 16-day synthetic product of MOD13 Q1 from 2000 to2017. Fractional vegetation cover(FVC) was used as the main ecological index that was estimated by a pixel dichotomy mode based on MOD13 Q1 Normalized Difference Vegetation Index(NDVI)and GF-2 data. Annual maximum and average vegetation coverages were used for comprehensively exploring the vegetation growth and recovery in the lower reach of the Tarim River basin. The results show that: vegetation activities in the basin enhanced in the past decades after the ecological water transfer. Regional maximum and average FVC increased significantly(P<0.01). The high vegetation coverage area increased from 3425.95 km^2 in 2000 to 5486.52 km^2 in 2017, and the medium vegetation coverage area increased from 6508.18 km^2 in 2000 to 7131.23 km^2 in 2015.Temporally, fluctuations were observed in the process of regional vegetation coverage increase.The process can be divided into three stages:(1) the rapid increase stage from 2000 to 2005;(2)fluctuations in 2006-2009;and(3) steady rising in 2010-2017. Spatially, the areas of vegetation increase are mainly distributed on both sides of the river and the river’s tail wetland between 2000 and 2017. The closer to the river, the better the vegetation was restored. At more than 10 km away from the river, the FVC change characteristics are not significant(P>0.05). Combined with the analysis of downstream ecological water transfer data, there is a strong dependence between vegetation restoration and the volume of water transfer in the lower reach of the Tarim River.Moreover, there is a time lag in the response of vegetation restoration to ecological water transfer.
作者
朱长明
李均力
沈占锋
沈谦
ZHU Changming;LI Junli;SHEN Zhanfeng;SHEN Qian(Department of Geography and Environment,Jiangsu Normal University,Xuzhou 221116,China;Xinjiang Institute of Ecology and Geography,CAS,Urimuq 830011,China;Institute of Remote Sensing and Digital Earth,CAS,Beijing 100101,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《资源科学》
CSSCI
CSCD
北大核心
2019年第3期591-600,共10页
Resources Science
基金
国家重点研发计划项目(2017YFB0504204)
国家自然科学基金项目(41671034
41201460
U1178302)
关键词
植被覆盖度
MODIS
塔里木河
遥感监测
生态输水
fractional vegetation cover(FVC)
MODIS
Tarim River
remote sensing monitoring
econological water conveyance
