近十年长三角地区陆地净第一性生产力时空变化

陆地净第一性生产力（NPP）是陆地生态系统的一项重要指示性指标，与碳循环过程和全球气候变化密切相关，不仅已成为地学研究的热点问题，更受到各国政府的高度重视。长三角地区是我国经济最发达、最具综合竞争力的地区之一，该地区的陆地生态系统同时承受着自然因素及高强度人为活动的双重影响。因此，利用CASA模型，在RS和GIS技术支撑下，探讨近十年来长三角地区陆地NPP的时空演变规律及控制因子，以期为进一步开展高强度人为活动对陆地系统碳循环过程的影响研究提供基础参数。主要结论如下：（1）在时间上呈下降趋势：近十年长三角地区陆地NPP呈现3 a周期式波动下降；（2）在空间上分异规律明显：陆地NPP分布为浙江＞江苏＞上海，呈现南北高中间低的凹槽状；（3）控制NPP的自然要素是NDVI和太阳辐射，而城市化是NPP变化的主要社会经济要素

TEMPORAL-SPATIAL VARIATION OF TERRESTRIAL NET PRIMARY PRODUCTIVITY IN THE YANGTZE RIVER DELTA OVER THE PAST DECADE

The Terrestrial net primary productivity (NPP) is a crucial indicator of terrestrial ecosystem,and is closely related to the carbon cycle and global climate change.Nowadays it’s not only a hot issue in the field of geography,but also attached great importance by all the governments.Yangtze River Delta region is one of China′s most economically developed and most cost effective,most comprehensive regions,whose terrestrial ecosystem withstands dual impacts from the natural elements and human activities of high strength.Hence,in support of RS and GIS technology,we used CASA model to investigate the temporal spatial variation discipline of terrestrial net primary productivity in the Yangtze River Delta region over the past decade and figured out the main control factors of,it in order to provide the basis of the process parameters for further research on impact of high intensive human activities on terrestrial carbon cycle.The main conclusions of this study were as follows.(1) From 1999 to 2009,the net primary productivity of the Yangtze River Delta decreased from 283094 gC/(m2·a) to 223521 gC/(m2·a) with an average annual reduction of 234%.The Yangtze River Delta terrestrial net primary productivity showed a three year cycle type of wave decline over the past decade.(2) In terms of Jiangsu,Zhejiang and Shanghai,the sort of NPP value was Zhejiang,Jiangsu and Shanghai,showing the spatial distribution of high middle and low north and south groove shape.(3) The correlation coefficient of reduction in NPP and increase in urban construction land and non agricultural population was respectively 0553 and 0447,indicating that urbanization was an important factor to NPP variation.The main natural factors controlling NPP variation were NDVI and solar radiation,whose correlation coefficient with NPP was 0750 and 0739;while precipitation and temperature had a relatively weak impact on NPP,with the correlation coefficient of 0235 and 0159 respectively.NPP was the accumulation result of vegetation and heat.