scholarly journals Nationwide Assessment of Urban Surface Water Environment Status in China

2019 ◽  
Vol 81 ◽  
pp. 01003
Author(s):  
Hongjie Gao ◽  
Peng Yuan ◽  
Ruixia Liu ◽  
Lu Han ◽  
Yonghui Song
Keyword(s):  
Water Resources ◽  
Population Density ◽  
National Level ◽  
Water Environment ◽  
National Standard ◽  
Impact Factors ◽  
Urban Water ◽  
Class Iii ◽  
Negative Effect ◽  
The Impact

In this study, the assessment of nationwide urban water environment status was conducted based upon a method of integrating both 70% of objective water quality and 30% of standard compliance percent compared with national standard limit of GB3838-2002 for Class III. The impact factors on urban water environment status were discussed. The results showed that the status of urban water environment could be graded into 5 types in China. The population density, water resources, urbanized areas and so on were key impact factors on water environment. The study found that population density and urban built-up area had significantly negative effect on urban water environment status, and there was positive relationship between per capita water resources and urban water environment status. The results would provide the guidance for effective governance and management of urban water environment at national level.

scholarly journals The Impact of Health Policies and Sociodemographic Factors on Doubling Time of the COVID-19 Pandemic in Mexico

2021 ◽  
Vol 18 (5) ◽  
pp. 2354
Author(s):  
Lina Díaz-Castro ◽  
Héctor Cabello-Rangel ◽  
Kurt Hoffman
Keyword(s):  
Population Density ◽  
Doubling Time ◽  
Sociodemographic Factors ◽  
Health Policies ◽  
Government Response ◽  
University Of Oxford ◽  
Negative Effect ◽  
Population Sizes ◽  
The University ◽  
The Impact

Background. The doubling time is the best indicator of the course of the current COVID-19 pandemic. The aim of the present investigation was to determine the impact of policies and several sociodemographic factors on the COVID-19 doubling time in Mexico. Methods. A retrospective longitudinal study was carried out across March–August, 2020. Policies issued by each of the 32 Mexican states during each week of this period were classified according to the University of Oxford Coronavirus Government Response Tracker (OxCGRT), and the doubling time of COVID-19 cases was calculated. Additionally, variables such as population size and density, poverty and mobility were included. A panel data model was applied to measure the effect of these variables on doubling time. Results. States with larger population sizes issued a larger number of policies. Delay in the issuance of policies was associated with accelerated propagation. The policy index (coefficient 0.60, p < 0.01) and the income per capita (coefficient 3.36, p < 0.01) had a positive effect on doubling time; by contrast, the population density (coefficient −0.012, p < 0.05), the mobility in parks (coefficient −1.10, p < 0.01) and the residential mobility (coefficient −4.14, p < 0.01) had a negative effect. Conclusions. Health policies had an effect on slowing the pandemic’s propagation, but population density and mobility played a fundamental role. Therefore, it is necessary to implement policies that consider these variables.

Urban-Water Harmony model to evaluate the urban water management

2014 ◽  
Vol 70 (11) ◽  
pp. 1774-1781 ◽  
Author(s):  
Yifan Ding ◽  
Deshan Tang ◽  
Yuhang Wei ◽  
Sun Yin
Keyword(s):  
Water Management ◽  
Water Resources ◽  
Urban Areas ◽  
Large Scale ◽  
Rapid Development ◽  
Urban Expansion ◽  
Water Environment ◽  
Integrated Approach ◽  
Urban Water ◽  
Urban Water Management

Water resources in many urban areas are under enormous stress due to large-scale urban expansion and population explosion. The decision-makers are often faced with the dilemma of either maintaining high economic growth or protecting water resources and the environment. Simple criteria of water supply and drainage do not reflect the requirement of integrated urban water management. The Urban-Water Harmony (UWH) model is based on the concept of harmony and offers a more integrated approach to urban water management. This model calculates four dimensions, namely urban development, urban water services, water–society coordination, and water environment coordination. And the Analytic Hierarchy Process has been used to determine the indices weights. We applied the UWH model to Beijing, China for an 11-year assessment. Our findings show that, despite the severe stress inherent in rapid development and water shortage, the urban water relationship of Beijing is generally evolving in a positive way. The social–economic factors such as the water recycling technologies contribute a lot to this change. The UWH evaluation can provide a reasonable analysis approach to combine various urban and water indices to produce an integrated and comparable evaluation index. This, in turn, enables more effective water management in decision-making processes.

scholarly journals Adsorption Behaviors of Oxytetracycline onto Sediment in the Weihe River, Shaanxi, China

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Dong-Hui Cheng ◽  
Sheng-Ke Yang ◽  
Yue Zhao ◽  
Jing Chen
Keyword(s):  
Freundlich Isotherm ◽  
Entropy Change ◽  
Impact Factors ◽  
Isotherm Models ◽  
Solution Ph ◽  
Adsorption Behaviors ◽  
Adsorption Data ◽  
Negative Effect ◽  
Weihe River ◽  
The Impact

Adsorption behaviors of oxytetracycline onto sediment in the Weihe River were described. The impact factors in the processes of adsorption, such as contact time, solution pH, temperature, and ionic strength, were determined by experiments. The experimental results were analyzed by kinetic and isotherm models. The adsorption kinetics was found to follow a pseudo-first-order model. The equilibrium adsorption data fitted well with the Langmuir and Freundlich isotherm models. However, the Langmuir isotherm was more suitable to describe the adsorption. Thermodynamics parameters such as Gibbs-free energy change (ΔG°), enthalpy change (ΔH°), and entropy change (ΔS°) were calculated. Results showed that the adsorption was feasible, spontaneous, entropy increasing, and endothermic in nature, which reached equilibrium in about 24 hours. The adsorption capacity did not cause obvious change at solution pH 4.0–7.0, and both decreased in solution pH 7.0–10.0 and 4.0–2.0. The presence of electrolytes such as NaCl in aqueous solution had a significant negative effect on the adsorption. The mechanisms controlling the adsorption were supposed to be chemisorption.

STRATEGIC ENVIRONMENTAL ASSESSMENT (SEA) OF WASTEWATER REUSE POLICY: A CASE STUDY FROM TIANJIN IN CHINA

2003 ◽  
Vol 05 (04) ◽  
pp. 503-521 ◽  
Author(s):  
XU HE ◽  
ZHU TAN ◽  
DAI SHUGUI
Keyword(s):  
Water Pollution ◽  
Water Resources ◽  
Environmental Assessment ◽  
National Level ◽  
Water Environment ◽  
Wastewater Reuse ◽  
Strategic Environmental Assessment ◽  
Chinese Government ◽  
Waste Reuse

China is one of the thirteen countries in the world that lacks water. Rapid economic growth and urbanisation over the past two decades have exerted enormous pressure on China's water resources. The shortage of water resources and serious water pollution have become important factors restraining the sustainable development in the cities. Wastewater reuse has been proven to prevent water pollution and ameliorate the pressure on the water environment. Moreover, wastewater reuse can make up for the lack of funds in wastewater treatment. So, wastewater reuse is a viable choice to realise the sustainable utilisation of water resource in China. There still remain many uncertainties in wastewater reuse. It is strongly recommended that a wastewater reuse policy be pushed forward considering the necessity and the implications to society, the economy and the environment. Strategic environmental assessment (SEA) is seen as an important tool for integrating the environmental factors into decision-making. This paper illustrates a case study for SEA — aimed at Tianjin Wastewater Reuse Policy (TWRP). The process of SEA at the policy level and the related problems are presented within this case study. It provides a good framework for carrying out SEA of waste reuse at the national level. The study will support the Chinese Government in developing a national strategy on urban wastewater reuse through an investigation of the existing situations, evaluation of policy options in different areas, and offering recommendations.

scholarly journals Quantitative analysis on the environmental impact of large-scale water transfer project on water resource area in a changing environment

2012 ◽  
Vol 16 (8) ◽  
pp. 2685-2702 ◽  
Author(s):  
D. H. Yan ◽  
H. Wang ◽  
H. H. Li ◽  
G. Wang ◽  
T. L. Qin ◽  
...  
Keyword(s):  
Water Resources ◽  
Environmental Impact ◽  
Water Resource ◽  
Large Scale ◽  
Water Environment ◽  
Water Transfer ◽  
Long Distance ◽  
Changing Environment ◽  
The Impact ◽  
Natural Reserves

Abstract. The interbasin long-distance water transfer project is key support for the reasonable allocation of water resources in a large-scale area, which can optimize the spatio-temporal change of water resources to secure the amount of water available. Large-scale water transfer projects have a deep influence on ecosystems; besides, global climate change causes uncertainty and additive effect of the environmental impact of water transfer projects. Therefore, how to assess the ecological and environmental impact of megaprojects in both construction and operation phases has triggered a lot of attention. The water-output area of the western route of China's South-North Water Transfer Project was taken as the study area of the present article. According to relevant evaluation principles and on the basis of background analysis, we identified the influencing factors and established the diagnostic index system. The climate-hydrology-ecology coupled simulation model was used to simulate and predict ecological and environmental responses of the water resource area in a changing environment. The emphasis of impact evaluation was placed on the reservoir construction and operation scheduling, representative river corridors and wetlands, natural reserves and the water environment below the dam sites. In the end, an overall evaluation of the comprehensive influence of the project was conducted. The research results were as follows: the environmental impacts of the western route project in the water resource area were concentrated on two aspects: the permanent destruction of vegetation during the phase of dam construction and river impoundment, and the significant influence on the hydrological situation of natural river corridor after the implementation of water extraction. The impact on local climate, vegetation ecology, typical wetlands, natural reserves and the water environment of river basins below the dam sites was small.

A Multi-Objective Decision-Making Model for Water Demand Management Based on ET Indicator

2014 ◽  
Vol 955-959 ◽  
pp. 2955-2962
Author(s):  
Fan Lu ◽  
Ming Na Wang ◽  
Dong Dong Zhang ◽  
Zhi Guo Gan ◽  
Bai Sha Weng
Keyword(s):  
Decision Making ◽  
Water Resources ◽  
Water Demand ◽  
Demand Management ◽  
Water Environment ◽  
Social Economy ◽  
Water Demand Management ◽  
Multi Objective ◽  
The Impact ◽  
Economy System

This paper aims at comprehensively considering the mutual coupling between available water resources and water consumption in (i) a regional social economy system; (ii) a macro-economy system; and (iii) an ecological environmental system. The main focus is to investigate the impact of controlling the total amount of ET and to be able to utilize water resources efficiently. An analytic model for multi-objective decision making of water demand management based on ET indicator is developed in order to research the strategies and corresponding water demand schemes that are relevant to future objectives for economic development, agricultural development, ET regulation and control, water engineering investment, and water environment management of Beijing. Various scenarios examined in the study indicate the validity of the proposed method in analyzing water demand administrative decisions.

scholarly journals Research on the Impact Factors of Green Economy of China—From the Perspective of System and Foreign Direct Investment

2021 ◽  
Vol 13 (16) ◽  
pp. 8741
Author(s):  
Bohan Chai ◽  
Junwei Gao ◽  
Lingying Pan ◽  
Yishu Chen
Keyword(s):  
Foreign Direct Investment ◽  
Direct Investment ◽  
Global Economy ◽  
Green Economy ◽  
Impact Factors ◽  
Eastern Region ◽  
Real Economy ◽  
Green Development ◽  
Negative Effect ◽  
The Impact

The outbreak of COVID-19 has had an immeasurable impact on the global economy. It has damaged parts of the real economy, but also provided new opportunities for China’s green development. Both the system and foreign direct investment (FDI) have an important impact on China’s green recovery path. Based on the provincial panel data of China from 2007 to 2016, this paper uses a slacks-based measure (SBM) model and Malmquist–Luenberger (ML) index to measure the green total factor productivity (GTFP), and empirically analyzes the regulatory role of system in the influencing mechanism of FDI on GTFP. The results show that the overall level of FDI significantly inhibits the improvement of GTFP, and the interaction between system and FDI makes it shift from inhibition to promotion, but the promotion would be weakened with the improvement of the system. FDI in the eastern region shows a positive effect on GTFP, which will be weakened with the improvement of the system. FDI in central and western regions shows a negative effect on GTFP, and the negative effect in western regions will be increased with the improvement of the system. Then this article puts forward targeted policy suggestions for further improving the level of regional systems and introducing FDI of high quality.

scholarly journals Quantitative analysis on the ecological impact of large-scale water transfer project on water resource area in a changing environment

2011 ◽  
Vol 8 (6) ◽  
pp. 10465-10500 ◽  
Author(s):  
D. H. Yan ◽  
H. Wang ◽  
H. H. Li ◽  
G. Wang ◽  
T. L. Qin ◽  
...  
Keyword(s):  
Water Resources ◽  
Water Resource ◽  
Large Scale ◽  
Ecological Impact ◽  
Water Environment ◽  
River Basins ◽  
Water Transfer ◽  
Long Distance ◽  
The Impact ◽  
Natural Reserves

Abstract. The interbasin long-distance water transfer project is a key support for the reasonable allocation of water resources in a large-scale area, which can optimize the spatiotemporal change of water resources to reinforce the guarantee of the access of water resources. And large-scale water transfer projects have a deep influence on ecosystems; besides, global climate change causes the uncertainty and additive effect of the ecological impact of water transfer projects. Therefore, how to assess the ecological and environmental impact of large-scale water transfer projects in both construction and operation has triggered a lot of attention. The water-output area of the western route of China's South-North Water Transfer Project was taken as the study area of the present article. According to relevant evaluation principles and on the basis of background analysis on the eco-environment of the study area, the influence factors were identified and evaluation indexes were established. The climate-hydrology-ecology coupled simulation model was used to imitate the laws of ecological and environmental change of the water resource area in a changing climate. The emphasis of influence analysis and quantitative evaluation was placed on the reservoir construction and operation scheduling, representative river corridors and wetlands, natural reserves and the water environment of river basins below the dam sites. In the end, an overall influence evaluation of the impact of the project on the water circulation and ecological evolution of the water resource area was conducted. The research results were as follows: the environmental impacts of the western route project in the water resource area were concentrated on two aspects, i.e. the permanent destruction of vegetation during the phase of dam construction and river impoundment, and the significant influence on the hydrological situation of natural river corridor after the implementation of water transfer. Its impact on local climate, vegetation ecology, typical wetlands, natural reserves and the water environment of river basins below the dam sites was small.

Prediction Model on Urban Residential Water Based on Resilient BP Learning Algorithm

2014 ◽  
Vol 543-547 ◽  
pp. 4086-4089
Author(s):  
Ying Zhao ◽  
Xiao Ji Chen
Keyword(s):  
Prediction Model ◽  
Learning Algorithm ◽  
Supply And Demand ◽  
Back Propagation ◽  
Bp Algorithm ◽  
Impact Factors ◽  
Urban Residents ◽  
Urban Water ◽  
Back Propagation Algorithm ◽  
The Impact

Urban water is an important part of urban water systems, Predicting urban residents water is the important work to ensure urban people's lives and to achieve urban water resources supply and demand balance. For BP algorithm existing problems in the training process, this paper uses resilient BP algorithm to improve it. Firstly, analysis of the impact factors of urban residents water for adjusting the prediction model; Then, the study on resilient Back Propagation algorithm, to overcome the adverse effects of gradient amplitude; Finally, the study identifies number of hidden nodes, dynamically adjust related parameters, data normalization and so on predict key steps. The results show that the convergence rate of resilient BP algorithm is faster than increased the momentum item of BP learning algorithm and variable learning rate of BP algorithm , it is simple to achieve and does not consume too much memory.

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