基于GIS和RS的区域陆地植被NPP估算——以中国内蒙古为例

Estimating Net Primary Productivity of Terrestrial Vegetation Based on GIS and RS:A Case Study in Inner Mongolia,China

在GIS的支持下,利用地面气象数据和MODIS数据,考虑到最大光利用率在不同植被类型中的差异,构建了一个区域陆地植被NPP估算模型,并以2002年的内蒙古植被为例,研究了植被净初级生产力及其时空分布。结果表明:(1)该模型在数据获取了上比较容易,仅利用地面气象数据和遥感数据就可以对陆地植被NPP进行估算,使其实际的可操作性得到加强。(2)通过与NPP的实测资料及其他模型的对比研究表明:该模型对区域陆地值被NPP的模拟效果较好,与Chikugo模型相比,它更能反应森林NPP的实际情况。(3)2002年内蒙古植被净初级生产力为390.8MtC/a,总体分布趋势是由东北向西南递减,其季节变化也非常明显,在6月中旬至9月中旬的3个月时间里,NPP占了全年的72.7%,而1—2月份植物基本停止生长,净初级生产力极低,每月仅为3.59MtC。

According to recent studies that there are important differences in maximum light utiliazion efficiency(ε max )among vegetation types,an estimation model of net primary productivity(NPP),based on geographic information system(GIS)and remote sensing(RS)technology,is presented.This model has two significant characteristics;(1)NPP can be estimated just using ground meteorological data and remote sensing data.It is relatively easier to acquire data and its application can be enhanced.(2)After the validation with observed data and the comparison with other NPP models,the results showed that the predicted NPP was consistent with observed values,and it can more actually reflect the forest NPP than Chikugo model.In order to validate the NPP model,a case study in Inner Mongolia,China,was carried out.The results showed that the total annual NPP in Inner Mongolia in2002was390.8Mt C.The spatial changes of NPPwere remarkable,and it decreased from northeast toward southwest.Moreover,seasonal variations of NPP were also large.It was about72.7%of the total annual NPP in the three month of June,July and August,and the NPP values was very low(3.59Mt C per month)in January and February.