鉴于我国东北地区是全球变化最敏感的区域之一,以东北地区植被净初级生产力(Net Primary Productivity,NPP)为指标,监测该地区的生态环境状态变化。在东北三省选取了东、中、西3个研究区,基于CASA(Carnegie-Ames-Stanford Approach)模型,利用2007年和2010年两个时相的美国陆地卫星多光谱扫描仪(Landsat TM)遥感数据和气象观测数据实现了NPP估算,并对其空间分布进行了分析。结果表明:3个研究区在2个时相NPP的数值有一定的波动,农田、草地面积较大的中、西部2个研究区,NPP受到季节条件以及人为因素的影响较显著;森林面积较大的东部研究区,NPP主要受季节、水热条件影响;相对于中、西部研究区,东部研究区的NPP最大。该文以东北地区3个研究区为例,为利用多时相遥感与模型相结合的方式,开展区域NPP估算和研究碳储量动态变化提供了科学依据和方法借鉴。
Northeast China is one of the regions most sensitive to global changes.This paper uses Net Primary Productivity(NPP)to monitor environment changes of this area.Three typical study areas located in east,middle and west of the Northeast China were chosen.Based on the Carnegie-Ames-Stanford Approach(CASA)model,the Landsat TM data in two phases(2007and 2010)and the meteorological observation data were employed to retrieve NPP.Consequently,the spatial distribution of NPP was analyzed.The results show that the NPP of three study areas fluctuates in two phases.As farmland and meadow area are larger in the western and central regions,NPP is significantly affected by seasons and human activities.On the other hand,as forests in the eastern area have a wide coverage,NPP is mainly influenced by seasons and hydrothermal conditions.Compare to the central and southern,the NPP of eastern area is higher.This paper combined multi-temporal remote sensing data with models,providing scientific bases for estimating regional NPP and researches on the dynamic changes of carbon storage.