2001-2013年黄土高原植被净初级生产力时空变化及其归因

基于光能利用率模型(CASA),利用遥感数据、气象数据和基础地理数据,测算了2001-2013年黄土高原植被净初级生产力(NPP),并辅以一元线性回归、Hurst指数及相关分析等方法,分析了2001-2013年黄土高原NPP时空变化特征、未来变化趋势及其驱动因素.结果表明,2001-2013年黄土高原植被年均NPP呈显著增加趋势,年增速为4.9 g/(m2·a).黄土高原植被NPP空间分布差异显著,表现出由东南向西北递减的趋势.黄土高原植被NPP呈增加趋势和减少趋势的面积分别占78.0%和22.0%.Hurst指数表明研究区未来植被NPP变化的正向特征显著,呈持续性和反持续性的比重分别为72.1%和28.9%.黄土高原植被NPP变化与降水、气温相关性不大,人类活动是影响植被NPP变化的重要因素,且对NPP有双重影响.

Spatiotemporal Change and Associated Driving Forces of Vegetation Net Primary Productivity in the Loess Plateau during 2001-2013

Based on the Carnegie-Ames-Stanford-Approach (CASA), the Net Primary Productivity (NPP) of vegetation in the Loess Plateau during 2001-2013 was measured and calculated with the related remote sensing data, meteorological data and basic geographic data.The temporal and spatial variation characteristics of NPP in the Loess Plateau during 2001-2013, the future trend and its driving factors were analyzed.The results showed that:The average annual NPP of vegetation in the Loess Plateau increased significantly during 2001-2013, with an annual growth rate of 4.9 g/(m2·a).The spatial distribution of vegetation NPP in the Loess Plateau showed a significant trend, with a decreasing tendency from southeast to northwest.The area of improved and degraded NPP accounts for 78.0% and 22.0% of the total study area, respectively.The NPP of the vegetation in the study area was supposed to have a significant positive trend, the area of positive and reverse characteristic accounts for 72.1% and 28.9% of the total study area, respectively.There was no significant correlation between the NPP change and the precipitation as well as the air temperature in the Loess Plateau.The human activities were the core elements affecting the change of the vegetation NPP, leading to both negative effect and positive effect.