摘要
利用8年的MODIS NDVI构建时序数据集,分析了延河流域2003—2010年植被覆盖度的时空格局和演变规律。借鉴时空数据分析模型,以栅格像元为分析单元,对该流域研究时段的绿度变换率进行计算分析,并利用像元二分模型对2003年和2010年地表植被覆盖度进行反演。结果表明:(1)延河流域植被生长状况总体呈改善趋势,延安南部林区、宝塔区东南部以及延长县中部植被覆盖较好且较稳定;(2)安塞县中南部、延长县大部以及杏子河中游的王瑶水库周边区域植被恢复效果显著;(3)在宝塔城区和城市重点开发区植被出现退化趋势。经分析,引起该流域局部植被退化主要是由于不合理的土地利用方式以及城市开发建设造成的植被破坏。基于像元的变化趋势分析更易于体现区域NDVI时空演变的细节信息。
Using MODIS NDVI of 8years to build time series data sets and analyze the vegetation coverage temporal pattern and evolution of Yanhe Basin from 2003 to 2010.Using spatio-temporal data model and the grid pixel as units,and calculating GRC from 2003 to 2010,the vegetation coverage about 2003 and 2010was inverted.The results showed that:(1)the vegetation growth tended to be improved in Yanhe watershed,vegetation coverage of southern Yan′an region and southeast of Baota District and county in the central extension of was better and more stable;(2)vegetation was significantly restored in South Ansai County,Yanchang County and the major part of Wangyao reservoir in middle area of Xingzihe;(3)vegetation presented the degradation trend in urban and urban key development areas.The local vegetation degradation was mainly caused by the unreasonable land use and the vegetation destruction caused by the urban development.Pixel-based analysis is more easy to reflect the spatial and temporal evolution of regional NDVI details.
出处
《水土保持研究》
CSCD
北大核心
2017年第4期6-11,共6页
Research of Soil and Water Conservation
基金
国家科技支撑计划项目(2011BAD29B09-1)
国家"973"重点基础研究项目(2007CB407201-5)
国家自然科学基金(41271288)
