基于BP-DEMATEL模型的农产品虚拟水流动影响因素分析

虚拟水已经成为水资源和水安全研究领域的热点之一. 如何预测和调控虚拟水流动格局成为实施具有中国特色虚拟水战略的重要前提, 识别虚拟水流动格局的关键影响因素显得尤为重要. 通过估算2008-2010年区际间主要农产品虚拟水流量关系矩阵表明, 我国主要农产品的虚拟水流动趋势仍然是由贫水的北方流向富水的南方地区. 为定量研究虚拟水流动格局的影响因素, 采用影响因素识别领域常用的决策与试验评价实验室法(DEMATEL), 并引入可代替专家打分求得直接关联矩阵的BP神经网络法, 构建BP-DEMATEL模型, 从人口、 农业资源、 农业生态环境、 经济、 技术及交通和物流6个方面对我国主要农产品虚拟水流动格局的影响因素进行分析. 结果表明: 人口、 农业资源和技术是最主要影响因素; 化肥施用量为强驱动型因素, 第一产业增加值占地区生产总值的比重为强特征型因素. 为使虚拟水流动格局持续稳定, 提出优化调整人口结构、 强化惠农政策, 转变农业发展方式、 发展循环农业, 提高农业技术水平、 发展高效农业等对策和建议.

The analysis of influencing factors of virtual water flow in major crops in China based on the BP-DEMATEL model

The virtual water has become one of the hot spots in the research field about water recourses and water safety. How to predict and control the virtual water flow pattern has become an important precondition for implementing the virtual water strategy with Chinese characteristics, so identifying the key influence factors of virtual water flow pattern is very important. Virtual water interregional flows for major crops in China were explored and virtual water flow during 2008-2010 was estimated. It is found that the virtual water flow for major crops is still from North China to South China. In order to quantificationally research the influence factors of the virtual water flow pattern, a BP-DEMATEL model is built, which is commonly used by the Decision Making Trial and Evaluation Laboratory in the field of recognizing the influential factors. And the BP-Neural Network is introduced, which can replace the expert scoring to obtain the direct correlation matrix. The method is used to analyze the main influence factors of China's virtual water flow of the major crops and to reveal the mechanisms of each influence factor. It is necessary to further divide the influence factors into four types, i.e., strongly driven, driven, strong feature type and characteristics, which provides a theoretical support for scientifically and rationally adjusting the virtual water flow pattern. The influence factors are further divided into four types, i.e., strongly driven, driven, strong feature type and characteristics, which provides a theoretical support for scientifically and rationally adjusting the virtual water flow pattern. The influence factors of the virtual water flow pattern of the major crops in China are analyzed from the following six aspects: population, agricultural resources, agricultural ecological environment, economy, technology and transportation and logistics. The results show that population factors, agricultural resources factors and technology factors are the principal influence factors; fertilizer input is the strong driving factors, the proportion of the first industry accounted for the GDP is the strong feature type factors. Finally, the following three measures are suggested to be taken: (1) optimizing and adjusting the population structure and intensifying the favorable policies; (2) transforming the mode of agricultural development and developing recycle agriculture; (3) improving the level of agricultural technology and developing high-efficiency agriculture.