宁夏农业面源污染的经济驱动特征研究

Research on economic driving characteristics of agricultural non-point source pollution in Ningxia

把握农业面源污染与农业经济增长的动态演化特征及内在机制,是制定农业可持续发展政策的重要依据之一,也是目前国内外研究的热点。本研究探讨宁夏2000-2018年农业面源污染与经济增长的演化特征,在向量自回归模型的基础上,利用脉冲响应函数和方差分解方法,探究总氮、总磷和化学需氧量与农业经济增长之间的动态冲击效果和相互作用机理。结果表明:近20年来,宁夏农业面源污染与经济增长呈"N"型变化,基本符合短期环境库茨涅兹曲线的环境经济变化规律特征,即农业面源污染排放量呈现"上升-下降-再上升"的趋势;农业经济增长的动态冲击对总氮、总磷和化学需氧量的排放具有正向促进作用,反之存在负向抑制作用。其中,总氮变化对农业经济增长的带动效果较强,总磷和化学需氧量变化的带动效果较弱,分别对农业经济增长的平均解释贡献率为33.35%、18.59%和12.11%。

Understanding the dynamic evolution characteristics and internal mechanisms of agricultural non-point source pollution and agricultural economic growth is one of the important bases for formulating agricultural sustainable development policies,and it is also a hot topic of research at home and abroad.This study explored the evolution characteristics of agricultural non-point source pollution and economic growth in Ningxia from 2000 to 2018.Based on the vector autoregressive model,impulse response function and variance decomposition methods were used to explore the dynamic shock effects between TN,TP,COD and agricultural economic growth,and the interaction mechanism of economic growth.The results show that in the past 20 years,Ningxia′s agricultural non-point source pollution and economic growth had shown an"N"-shaped change,which was basically in line with the environmental and economic change characteristics of the short-term environmental Kuznets curve,that was,the agricultural non-point source pollution discharge showed an"up-down-up"trend.The dynamic impact of agricultural economic growth had a positive effect on the emission of TN,TP,COD,and on the contrary,it had a negative inhibitory effect.Among them,changes in TN had a strong driving effect on agricultural economic growth,while changes in TP and COD had a weaker effect.The average explanatory contribution rates to agricultural economic growth were 33.35%,18.59%,and 12.11%,respectively.