基于MOD17A3的河南省NPP时空格局

Spatiotemporal pattern of vegetation net primary productivity in Henan Province of China based on MOD17A3

利用2000—2010年MOD17A3数据集的年NPP数据和GIS技术,定量分析了河南省植被NPP的时空变化特征。结果表明:河南省年NPP变化范围为308~430 g C·m^(-2)·a^(-1),平均值为384 g C·m^(-2)·a^(-1);年均NPP分布全省呈现北低南高趋势,NPP高值区(>500 g C·m^(-2)·a^(-1))主要分布在豫西和豫东南的林区,太行山和丹江流域的林区NPP大部在200~300 g C·m^(-2)·a^(-1),农田覆盖区年平均NPP在300~500 g C·m^(-2)·a^(-1),黄河生态涵养带年平均NPP多小于200 g C·m^(-2)·a^(-1),城市及其周边地区NPP多小于100 g C·m^(-2)·a^(-1);与2000年相比,2010年河南省年NPP大部分地区是增加的,年NPP增加的面积占总土地面积的93.8%;河南省年NPP线性变化趋势以增加为主,年NPP变化百分率增加10%以上的面积所占河南省国土面积的比例为83.7%;年NPP的变化百分率<-10%的植被主要分布在河南省西南部的丹江流域、焦作市和济源市北部以及各城市周边地区,下降的原因主要是森林的破坏及城市的扩张;植被类型分布、年均气温和年均降雨量差异导致河南省NPP南高北低的分布;不同的NPP估算模型或基于不同数据源对同一区域NPP估算存在较大差异。

By using the 2000-2010 annual net primary productivity （NPP） data from MOD17A3 dataset and the GIS technology, a quantitative analysis was made on the spatiotemporal variation of NPP in Henan Province of China. In the Province, the annual NPP ranged from 308 to 430 g C·m-2·a-1, with an average of 384 g C·m-2·a-1. The average annual NPP was higher in the south and lower in the north part of the Province. The area with high NPP （〉500 g C·m-2·a-1） was mainly distributed in the forested regions of west and southeast Henan. The forested regions of Taihang Mountains and Danjiang River Basin had an annual NPP of 200-300 g C·m-2·a-1. The farmland regions had an average annual NPP of 300-500 g C·m-2·a-1, the ecological conservation zone of Yellow River had an average annual NPP of 〈200 g C·m-2·a-1, while the cities and their surrounding areas had an average annual NPP of 〈100 g C·m-2·a-1. As compared with that in 2000, the annual NPP in most parts of the Province in 2010 had an increase, and the areas with the increased annual NPP accounted for 93.8% of the territory of the Province. The increase of the annual NPP in the Province was mainly in linear, and the areas with an increment of 〉10% occupied 83.7% of the territory of the Province. The areas with a 〈-10% decrease of annual NPP were mainly distributed in Danjiang River Baisn, northern parts of Jiaozuo City and Jiyuan City, and the areas surrounding cities, which could be induced by the destruction of forests and the expansion of cities. The distribution of vegetation types and the differences in the mean annual temperature and mean annual precipitation in the Province led to the differences in the NPP distribution, i.e., lower in north and higher in south. There existed a great difference in the estimation of the NPP among different NPP estimation models or among different data sources.