2000年-2015年长江流域植被GPP时空变化特征及其驱动因子

长江流域生态系统环境脆弱敏感，该区域植被变化受到气候变化以及人类活动等多种因素的影响.基于MODIS GPP数据，运用一元线性回归趋势分析方法对2000年—2015年长江流域植被GPP时空变化趋势进行了研究，并结合气象数据、土地利用变化数据等探讨了其驱动因素.结果表明：1) 长江流域GPP整体呈现西低东高的空间分布格局.2000年—2015年长江流域GPP在整体上呈波动增加趋势，年际变化介于919.90～ 1 051.48 g C·m－2·a－1之间，多年均值为985.11 g C·m－2·a－1.2) GPP增加区占流域总面积的4.69%，主要集中分布在甘肃省南部、陕西省南部、河南省西南部、湖北省西北部、云南省和贵州省交界地带等；GPP减少区占流域总面积的1.28%，主要集中分布在长江入海口周围的苏南地区及上海市，长江沿线的大城市，如重庆市、武汉市及周围地区，GPP退化较显著；汉江、金沙江石鼓以下、嘉陵江3个二级流域的GPP增加明显，太湖水系和湖口以下干流区域GPP则降低明显.3) 耕地转化为建筑用地是GPP损失的主要土地利用转移方式，草地转化为林地则是GPP增加的主要土地利用转移方式.该研究将对长江流域生态环境建设和可持续发展起到一定指导作用.

Spatio-temporal variation characteristics of vegetation GPP and underlying drivers over the Yangtze River Basin from 2000 to 2015

The ecosystem environment of the Yangtze River Basin is fragile and sensitive， and the vegetation change in this region is affected by many factors such as climate change and human activities.Based on MODIS GPP data，the spatiotemporal variation trend of vegetation GPP over the Yangtze River Basin from 2000 to 2015 was studied by using univariate linear regression trend analysis method， and its driving factors were discussed combined with meteorological data and land use type data.The results are shownas follows.1) The GPP over the Yangtze River Basin presents a spatial distribution pattern of low in the west and high in the east.The annual variation ranges from 919.90 to 1 051.48 g C·m-2·a－1， and the perennial average was 985.11 g C·m－2·a－1.2) The areas with increased GPP accounted for 4.69% of the total watershed area， which were mainly distributed inregions such as South Gansu Province， South Shaanxi Province， Southwest Henan Province， Northwest Hubei Province and the border of Yunnan Province and Guizhou Province.The areas of GPP reduction accounted for 1.28% of the total basin area， mainly distributed in Southern Jiangsu and Shanghai around the Yangtze River Estuary. The degradation of GPP was significant in large cities along the Yangtze River， such as Chongqing， Wuhan and surrounding areas.The GPP over Hanjiang River， Jinshajiang River below Shigu and Jialing River increased significantly， while that of Taihu Lake system and the main stream area below the Hukou decreased significantly.3) The conversion of cultivated land to construction land was the main land use transfer mode of GPP loose， while grassland conversion to forest land was the main land use transfer mode of GPP increased.This work wouldprovide references for ecological environment construction and sustainable development of the Yangtze River Basin.