The effect of urbanization on agricultural water consumption and production: the extended positive mathematical programming approach

Research on emergy evaluation method of ecological water use efficiency based on comprehensive benefits

Scientifically evaluating ecological water use efficiency (EWUE) is an effective means to regulate the level of ecological water use in a country or a region. It is also a basic work to achieve high-efficiency use of ecological water under the current situation of water shortage. However, there were few researches on EWUE, and existing studies only focus on eco-environmental benefits generated by ecological water, without considering its impact on economy and society. An emergy evaluation method for EWUE based on comprehensive benefits was proposed in this paper innovatively. Considering the impact of ecological water use on society, economy, and eco-environment, the concept of EWUE could be defined. Then, comprehensive benefits of ecological water use (CBEW) were quantified by emergy method, and EWUE was evaluated by the comprehensive benefits of unit ecological water use. Taking Zhengzhou City as an example for calculation, from 2011 to 2020, CBEW increased from 5.20 × 10¹⁹ sej to 6.72 × 10²⁰ sej, showing an overall upward trend, and EWUE rose from 2.71 × 10¹¹ sej/m³ (1.27￥/m³) to 1.32 × 10¹² sej/m³ (8.10￥/m³) with fluctuation. It showed that Zhengzhou City has paid enough attention to the allocation of ecological water and EWUE at a high level. The method proposed in this paper provides a new idea to evaluate EWUE scientifically, and the results can provide guidance to allocate ecological water resources to achieve sustainable development.

Does Rapid Urbanization Improve Green Water-Use Efficiency? Based on the Investigation of Guangdong Province, China

The green water-use efficiency considers the undesired output of water pollution discharge as well as desirable output, pursuing the unification of economic and ecological benefit. In recent years, China has been undergoing a process of rapid urbanization and a dramatic change in the water utilization pattern, while the water pollution discharge is becoming more obvious. Taking Guangdong Province as an example, the largest economy and urbanization pilot area, exploring the impact of different aspects of rapid urbanization on green water-use efficiency is of great significance for promoting new-type urbanization and green development. This study adopts the super efficiency slack-based model (SE-SBM) considering undesirable output to measure the green water-use efficiency of each city in Guangdong Province. On this basis, mixed panel, random panel, and fixed panel models are used to explore the relationship between industrial urbanization, population urbanization, land urbanization, social urbanization, and urban-rural integration on green water-use efficiency. The results reveal that Guangdong’s green water-use efficiency follows a low upward trend. The green water-use efficiency of the Pearl River Delta has improved rapidly, while other regions are maintained at a low level, so regional disparities are also widening. Industrial urbanization and land urbanization have a significant positive effect on green water-use efficiency, while social urbanization and urban-rural integration have a significant negative effect. The effect of population urbanization on the efficiency is not significant. The construction of new-type urbanization should be accelerated, the green transformation and upgrading of industries should be guided, and the urbanization of agricultural migrants should be promoted. It is necessary to rationally plan and utilize urban land resources and comprehensively improve urban functions and livability.

The Impacts of Urbanization to Improve Agriculture Water Use Efficiency—An Empirical Analysis Based on Spatial Perspective of Panel Data of 30 Provinces of China

China has witnessed accelerated urbanization since the reforms and open policies which began in 1978. This eventually resulted in increased residential water requirements and worsening water shortages, particularly in the current century. In the context of resource and environmental constraints, improving agricultural water use efficiency (AWUE) is a crucial issue to ensure food security, improve the ecological environment, and meet the needs of sustainable agricultural development. Based on the panel data of 30 provinces in China from 1999 to 2018, the article uses the Super-SBM model to measure the AWUE. Moreover, the study uses the entropy method to establish the urbanization evaluation index system from the dimensions of population, land, economy, measures the comprehensive level of urbanization development, and further constructs a dynamic spatial econometric model. We use the unconditional maximum likelihood estimation method to evaluate the impact of urbanization development on AWUE and its heterogeneity. The findings reveal that the AWUE considering undesired outcomes has generally shown a steady improvement, but there is ample space for resource conservation and environmental protection, and there are noticeable differences among regions. The decomposition of spatial effects shows that urbanization development in each region has a short-term positive effect on AWUE in the region and neighboring regions, and a long-term effect exists only in the western region. The impact of urbanization in different dimensions has been found that both land urbanization and economic urbanization contribute to the improvement of AWUE, while population urbanization helps to improve AWUE by improving the awareness level of the farmers.