青海三江源试验区NPP时空特征及影响因素分析

青海三江源国家生态保护综合试验区是我国建立的第1个国家级生态保护综合试验区,在我国生态文明建设中有重要的地位,分析其植被净初级生产力(NPP)具有重要意义。利用三江源试验区的MODIS遥感影像等数据及其周边地区的气象资料,结合CASA模型,对三江源试验区2010~2013年的NPP进行估算,并对其时空特征及影响因素进行简要分析。结果表明:三江源试验区2010年的NPP平均值最大,2010~2013年NPP呈波动变化趋势,先减少后增加;年均NPP总量为68.46TgC/a(1Tg=1012g),年均NPP为144.29gC/m2,NPP的季节变化明显,7、8月的月NPP值最大;在空间分布上呈现出由东南向西北递减的特征,东侧出现最高值,其值为418.94gC/(m2·a);NPP值高低分布情况与植被类型、海拔、坡度、坡向有密切关系。

Analysis of spatial-temporal characterstics of NPP and Its influencing factors in Three-river Headwater Area pilot region of Qinghai

Three-river Headwater Area of Qinghai is the first nation ecological reserve pilot region.It plays an important role in the construction of ecological civilization in our country.Using the MODIS remote sensing image data and meteorological data,the Geographic Information System and CASA model were applied to esti-mate the NPP in the region during 2010~2013.The result showed that the region had the highest NPP in 2010, the value was increase and then decrease from 2010~2013.The total annual NPP was 68.46 Tg/a (1Tg = 1012 g)and the annual average of NPP was 144.29 gC/(m2 ·a).The seasonal change of NPP was obvious,the maxi-mum value appeared in July and August.The NPP gradually decreased from southeast to northwest in the re-gion,the highest NPP value was 418.94 gC/(m2 ·a)at the eastern section.The distribution of NPP had a close relation with vegetation types,elevation,slope and aspect.