基于VAR模型的水土保持技术与农业产业、资源的互馈效应

Mutual Effect Among Soil and Water Conservation Technology,Agricultural Industry and Resources Based on VAR Model

选取县南沟流域2000—2016年的时间序列数据,通过构建水土保持技术、农业产业、农业资源三者间的向量自回归模型,运用格兰杰因果关系检验、脉冲响应函数和方差分解对三者间的关系进行了实证分析。结果表明:水土保持技术与农业产业、资源三者之间相互构成双向因果关系。三者之间的关系在初期波动幅度比较明显,并产生负向效应,但随着滞后期数的增加,负向效应逐渐减弱呈现出向0收敛的迹象;原因主要是水土保持技术实施初期对农业产业、资源产生了阻挠作用,随着水土保持技术的应用和实施、技术效益的显化、农民思想意识的提高,这种负向作用逐渐减弱。其中水土保持技术的最大影响因素是技术本身;农业产业的最大影响因素是水土保持技术的应用;农业资源前期最大影响因素是水土保持技术的应用,后期最大影响因素是农业产业的发展;说明了农业产业的发展、资源的利用都离不开水土保持技术的应用。因此,未来水土保持技术更新、优化在优先考虑技术相宜性的基础上,还需要考虑经济发展、社会需求以及生态环境条件等。

Based on the time series data from 2000 to 2016 in Xiannangou watershed,we constructed a VAR model among soil and water conservation technology,agricultural industry and resources.Granger causality test,impulse response function and variance decomposition were used to analyze the relationship between them.The results showed that:soil and water conservation technology,agricultural industry and resources constituted a two-way causal relationship;the relationship between the three was more obvious at the initial stage and produced negative effect;however,with the increase of lag period,the negative effect gradually weakened and showed signs of convergence towards 0;the main reason was that soil and water conservation technology obstructed agricultural industry and resources in the early stage of implementation;with the application of the technology,the manifestation of technical benefits,and the improvement of farmers′awareness,this negative effect was gradually weakened;the biggest influence factor of soil and water conservation technology was technology itself;the biggest influence factor of agricultural industry was the application of soil and water conservation technology;the application of soil and water conservation technology was the biggest influencing factor in the early stage of agricultural resources,and the development of agricultural industry was the biggest influencing factor in the later stage,indicating that the development of agricultural industry and the utilization of resources were inseparable from the use of soil and water conservation technology.Therefore,in the future,technological suitability should be given priority in the renewal and optimization of soil and water conservation technology,followed by economic development,social demands and ecological environment conditions.