Natural capital accounting of land resources based on ecological footprint and ecosystem services value.

Land resources are the material basis for human survival and development. Rapid economic development in the past has resulted in the over-utilization of land, and the undervaluation of land in market transactions has further exacerbated the loss of land benefits. This calls for monitoring the quantity and quality of land and reversing the undervaluation of land to reduce the waste of land resources. Based on this, a scientific natural capital accounting system of land resources should be established to understand the quantity and value of land resources in time. In order to provide a comprehensive evaluation of land utilization, this paper introduces the idea of compiling the land resources balance sheet. First, the physical quantity of land is calculated through the ecological footprint method improved by net primary productivity. Second, the value quantity of land is calculated through the equivalent factor method which is improved by the biologically productive land area obtained above, and then using ArcGIS to further demonstrate spatial and temporal changes in land resources. Taking the relevant data of Chongqing from 2000 to 2020 as an example, the land status is comprehensively evaluated from multiple perspectives, including quantity, value and spatial distribution. The results show that: (1) Under the dual impact of changes in the physical quantity and the unit price of land, the value quantity of land assets and equity in Chongqing realized 5.9 times and 5.1 times growth respectively during the study period. (2) Grassland was the most productive land type in Chongqing. Over a long time period, Chongqing prioritized the development of animal husbandry, placing too much emphasis on the production function of grassland and neglecting ecological protection, which was caused by an imbalance in the pasture area. In 2020, grassland utilization exceeded 40.9 % of the carrying capacity. (3) The value quantity of land in Chongqing existed in a spatial distribution pattern that was high in the southeast and northeast and low in the center and west, and there was a great imbalance in its growth rate among regions. The research results are helpful to the rational utilization and standardized transaction of land resources in Chongqing, and provide references for the inclusion of land resources in the management of state-owned assets.

Development of multidimensional water poverty in the Yangtze River Economic Belt, China.

As a basic natural and strategic resource, water is of great significance to the sustainable development of economies and societies. Owing to population growth, industrialization, the acceleration of urbanization, and global warming, water poverty is gradually increasing in some parts of the world. Effectively assessing water poverty from different dimensions is still a serious challenge for global water resources planning. This paper establishes a framework of multidimensional water poverty (MWP) from six dimensions: water management, water technology, water assets, water welfare, water resources, and water environment. The measurement model of MWP is built based on the Back Propagation Neural Network (BPNN), and the Spatial Correlation Analysis tool is used to visualize the spatial effects of MWP. The Yangtze River Economic Belt (YREB) was used as a case study and the main factors affecting the MWP of the YREB were determined by the Geodetector. When analyzing the results the following observations were made: (1) In terms of time distribution, the level of MWP in the YREB has gradually increased, and the poverty gap between the upper reaches, as well as the middle and lower reaches, shows an increasing trend. (2) With respect to spatial distribution, there is a continuously increasing agglomeration effect that shows a gradient-increasing distribution pattern of "West-Central-East." (3) The MWP in the YREB is mainly affected by these indicators in the three dimensions consisting of water resources, water technology, and water management. Specifically, R&D expenditure as a percentage of GDP, the proportion of water-saving irrigation area in the cultivable land area, the urban daily wastewater treatment capacity, the land surface water resources per capita, and the groundwater resources per capita play an important role in the MWP. Based on the above findings, targeted policy recommendations are proposed to alleviate the MWP in the YREB.

CFD-assisted modeling of the hydrodynamic cavitation reactors for wastewater treatment - A review.

Hydrodynamic cavitation has been a promising method and technology in wastewater treatment, while the principles based on the design of cavitational reactors to optimize cavitation yield and performance remains lacking. Computational fluid dynamics (CFD), a supplementation of experimental optimization, has become an essential tool for this issue, owing to the merits of low investment and operating costs. Nevertheless, researchers with a non-engineering background or few CFD fundamentals used straightforward numerical strategies to treat cavitating flows, and this might result in many misinterpretations and consequently poor computations. This review paper presents the rationale behind hydrodynamic cavitation and application of cavitation modeling specific to the reactors in wastewater treatment. In particular, the mathematical models of multiphase flow simulation, including turbulence closures and cavitation models, are comprehensively described, whilst the advantages and shortcomings of each model are also identified and discussed. Examples and methods of the coupling of CFD technology, with experimental observations to investigate into the hydrodynamic behavior of cavitating devices that feature linear and swirling flows, are also critically summarized. Modeling issues, which remain unaddressed, i.e., the implementation strategies of numerical models, and the definition of cavitation numbers are identified and discussed. Finally, the advantages of CFD modeling are discussed and the future of CFD applications in this research area is also outlined. It is expected that the present paper would provide decision-making support for CFD beginners to efficiently perform CFD modeling and promote the advancement of cavitation simulation of reactors in the field of wastewater treatment.

Spatial-temporal variation and driving factors decomposition of agricultural grey water footprint in China.

The management of agricultural water pollution is crucial to alleviate the water crisis and promote regional sustainable development. Therefore, it is necessary to clarify the spatial-temporal variation characteristics of the agricultural grey water footprint (GWF) and accurately identify its main influencing factors, aiming at formulating differentiated regional management strategies. Based on this, the agricultural GWFs of 31 provincial regions in China from 2011 to 2019 were firstly calculated, and then the spatial-temporal variation characteristics of agricultural GWF were analyzed using the ArcGIS software and Standard Deviational Ellipse (SDE) method. Finally, the Generalized Divisia Index Method (GDIM) was creatively introduced to decompose the factors of agricultural GWF change and their respective contributions at the national and provincial levels. The main results are as follow: (1) Agricultural GWF in China decreased on the whole and showed significant provincial differences. Among them, the agricultural GWF of Henan Province was the largest while that of Shanghai City was the smallest. Compared with 2011, most provinces saw a decrease in agricultural GWF in 2019 while Yunnan, Tibet, Qinghai, Ningxia and Xinjiang Provinces achieved growth. (2) Areas with higher agricultural GDP generally had higher agricultural GWF. The spatial distribution of agricultural GWF and breeding GWF generally tended to be consistent, with the lower value in northwest and southeast of China and higher value in the northeast and southwest of China. Meanwhile, the mean center of SDE of agricultural GWF was located in Henan Province from 2011 to 2018, and shifted to Shaanxi Province in 2019, showing a slight northwest shift. (3) Agricultural GWF intensity and agricultural GDP had the largest restraining effect and driving effect on agricultural GWF growth, respectively. Additionally, China has achieved decoupling between agricultural GWF and agricultural GDP, reflecting that the patterns of agricultural production and consumption have become more sustainable. The findings of this study can provide important decision-making insights for agricultural water pollution management and industry adjustment.

Research on supporting mechanism of ancillary service of PV system to grid energy efficiency based on multi-time and space-time operation.

Under the background of high-energy penetration of new energy into the power grid, this paper takes the ancillary service capability of photovoltaic energy integrated into the grid as the starting point and builds a photovoltaic system reactive power service impact evaluation model on the grid energy efficiency. This is based on the multi-temporal and spatial scale operation mode, in order to study the supporting principles of photovoltaic system reactive power services on the energy efficiency of grid operation and the law of influence on system energy efficiency changes. In this way, the space for power system energy efficiency improvement and the reactive power service market value of renewable energy are explored to improve the renewable energy auxiliary services participation in the theoretical system of electric power spot market transactions. The research conclusions can provide a decision-making reference for system dynamic energy efficiency management and can assist relevant market entities to make optimal decisions in spot market transactions, and provide empirical data for improving the theory of renewable energy participation in auxiliary service market transactions.

The influence of carbon emission disclosure on enterprise value under ownership heterogeneity: evidence from the heavily polluting corporations.

Under the background that China puts forth the goals of "Emission Peak" and "Carbon Neutrality", heavily polluting corporations as the main source of carbon emissions, whether the restriction of carbon emission disclosure could promote the transformation and upgrading of heavily polluting corporations to raise their value, is a problem worthy of in-depth study. This paper selected listed companies in heavily pollution industries from 2009 to 2019 as the research samples, and analyzed the impact of carbon emission disclosure on short-term and long-term performance based on the perspective of ownership structure heterogeneity. This paper also discussed the moderating effect of carbon emission disclosure on state-owned enterprises and private enterprises taking into account government environmental regulations, media evaluation, and corporate image management based on the Gatekeeper Theory. Firstly, this paper found that in the short term, the improvement of carbon emission disclosure level will inhibit the value growth of enterprises in the initial stage, but will promote the value growth to a certain extent. In the long run, carbon emission disclosure plays a positive role in promoting enterprise value. Secondly, the government environmental regulation, media evaluation, and corporate image management produced different moderating effects under the difference in ownership structure. For state-owned enterprises, the higher the level of government environmental regulations and media evaluation, the more significant is the short-term and long-term value effect. While the higher the level of corporate image management, the more significant is the short-term value effect, however, the long-term value effect is not significant. For private enterprises, government environmental regulations, media evaluation, and corporate image management have no significant moderating effects. Based on the above findings, this paper presents countermeasures and suggestions for the high-quality development of enterprises from the perspectives of government management and enterprise operations.

Elucidating competing strategic behaviors using prospect theory, system dynamics, and evolutionary game: a case of transjurisdictional water pollution problem in China.

Water is a critical natural resource for socio-economic and environmental systems. In transjurisdictional river basins, when basin-wide water pollution management scheme is absent, stakeholders tend to adopt utility-maximizing behavior based on incomplete information. Such a scenario could lead to a free-riding problem. This paper attempts to elucidate the strategic behavior of riparian regions using prospect theory, evolutionary game, and system dynamics. The evolution of riparian regions' strategic behaviors is explained, and the impacts of different factors on their strategic selections are simulated. The results showed that the prospective value of factors and stakeholders' attitude to risk are a key for resolving transjurisdictional river water pollution problems. Improving the subjective judgment of the probability of water pollution, raising awareness, strengthening the penalties in "polluter pays" schemes, abandoning segmented river basin management, and building a basin-wide water management system are vital for maintaining the ecological integrity of any transjurisdictional river basin and accelerate the sustainable development of its riparian regions.