西安市植被碳汇时空演变特征及影响因素解析

Spatio-temporal Evolution Characteristics of Vegetation Carbon Sink in Xi’an City and Its Influence Factors

基于2001-2015年MOD17A3 NPP数据,运用土壤呼吸模型,计算出植被NEP值,以植被NEP值作为估算碳汇的重要指标,借助GIS空间分析、相关性分析,研究了2001-2015年西安市碳汇时空格局及演变特征,分析了气温、降水、高程、坡度对植被碳汇变化的影响,为西安市生态环境调控提供了一定参考。研究结果表明:如果不考虑人为干扰条件影响,西安市除建设用地之外均属于碳汇用地。2001-2015年西安市植被碳汇整体呈上升趋势,显著增加区域面积占比达44.49%;植被NEP与高程、坡度间存在阶段性变化特征,且高程影响幅度较大;植被碳汇与降水呈正相关,与气温呈负相关关系,但局部存在较大差异。

Based on the MOD17A3 NPP data from 2001 to 2015,we used the soil respiration model to calculate NEP value of vegetation.Taking NEP value of vegetation as an important index for estimating carbon sink,with the help of GIS spatial analysis and correlation analysis,we stud-ied the spatio-temporal pattern and evolution characteristics of carbon sink in Xi’an from 2001 to 2015,and analyzed the effects of temperature,precipitation,elevation,slope and NDVI on the change of vegetation carbon sink,which could provide a certain reference for the regulation of ecological environment in Xi’an.The results show that if the influence of human interference conditions is not considered,Xi’an belongs to car-bon sink land except for construction land.From 2001 to 2015,the vegetation carbon sink in Xi’an showed an overall upward trend,with a signif-icant increase in the area accounting for 44.49%.There are periodic changes between vegetation NEP and elevation and slope,and the influence of elevation is large.Vegetation carbon sink is positively correlated with precipitation and negatively correlated with temperature,but there are great differences in some parts.