ABSTRACT
Increasing anthropogenic global warming has emerged as a significant challenge to human health in China, as extreme heat hazards increasingly threaten outdoor-exposed populations. Differences in thermal comfort, outdoor activity duration, and social vulnerability between females and males may exacerbate gender inequalities in heat-related health risks, which have been overlooked by previous studies. Here, we combine three heat hazards and outdoor activity duration to identify the spatiotemporal variation in gender-specific heat risk in China during 1991-2020. We found that females' heat risk tends to be higher than that of males. Gender disparities in heat risk decrease in southern regions, while those in northern regions remain severe. Males are prone to overheating in highly urbanized areas, while females in low urbanized areas. Males' overheating risk is mainly attributed to population clustering associated with prolonged outdoor activity time and skewed social resource allocation. In contrast, females' overheating risk is primarily affected by social inequalities. Our findings suggest that China needs to further diminish gender disparities and accelerate climate adaptation planning.
Subject(s)
Extreme Heat , Heat Stroke , Male , Female , Humans , Hot Temperature , Seasons , Socioeconomic Factors , China/epidemiologyABSTRACT
China has formulated several policies to alleviate the water pollution load, but few studies have quantitatively analyzed their impacts on future water pollution loads in China. Based on grey water footprint (GWF) assessment and scenario simulation, we analyze the water pollution (including COD, NH3-N, TN and TP) in China from 2021 to 2035 under different scenarios for three areas: consumption-side, production-side and terminal treatment. We find that under the current policy scenario, the GWF of COD, NH3-N, TN, and TP in China could be reduced by 15.0 % to 39.9 %; the most effective measures for GWF reduction are diet structure change (in the consumption-side area), and the wastewater treatment rate and livestock manure utilization improvement (in the terminal treatment area). However, the GWF will still increase in 8 provinces, indicating that the current implemented policy is not universally effective in reducing GWF across all provinces. Under the technical improvement scenario, the GWF of the four pollutants will decrease by 54.9 %-71.1 % via improvements in the current measures related to current policies and new measures in the production-side area and the terminal treatment area; thus, GWF reduction is possible in all 31 provinces. However, some policies face significant challenges in achieving full implementation, and certain policies are only applicable to a subset of provinces. Our detailed analysis of future water pollution scenarios and response options to reduce pollution loads can help to inform the protection of freshwater resources in China and quantitatively assess the effectiveness of policies in other fields.
ABSTRACT
Sustainable management of household solid waste (HSW) is an essential step in realizing the development of a circular economy (CE). However, for many developing countries, HSW sorting is evolving incrementally, and focusing on the intervention role of policy and the sorting behaviour of residents can help achieve sustainable waste management. This study aims to investigate the main determinants of residents' HSW sorting behaviour and how policy particularly contributes to it. Drawing upon the theory of planned behaviour (TPB) and incorporating experiences, a conceptual framework is tested on a sample of Chinese residents in Shanghai (n = 560, from November to December 2020) using structural equation modelling analysis. The empirical results show that experience and behavioural intention greatly influence HSW sorting behaviour. Moreover, the positive attitude of residents promotes the success of HSW sorting. Subjective norms and perceived behaviour control indirectly affect behavioural intention and behaviour via attitude. The findings of this study provide policymakers with critical factors for the successful implementation of HSW sorting. We also propose policy implications to maintain and improve sorting efficiency from the perspective of residents (education, communication and publicity), neighbourhood committees (degree and efficiency of supervision) and property management companies (good infrastructure, services and processes).
Subject(s)
Solid Waste , Waste Management , Public Opinion , China , Intention , Attitude , Surveys and Questionnaires , PolicyABSTRACT
Rainwater harvesting systems (RWHs) are vital to alleviate water shortages, especially in arid regions. However, research on the application of RWHs in humid regions is necessary because they may also face the challenges of water supply shortages, urban flooding, runoff pollution, and heat island phenomena. Public acceptance plays a key role in the reuse of water resources. This study takes Shanghai, China, as an example and explores the public intention and motivation to use RWHs in humid regions by adding six psychological factors to the technology acceptance model (TAM). The results indicate that social influence, subjective knowledge, and the technological environment are direct drivers. Other psychological factors influence the intention to use through the moderation of perceived usefulness and attitude. The total effect of social influence, subjective knowledge, and social trust are essential for RWHs implementation. However, the technical environment and perceived risk may be psychological barriers to accepting RWHs. In addition, there is no significant effect of the perceived cost. The findings provide critical insights for policymakers to understand the public's attitudes and intrinsic motivations to address the challenges of rainwater harvesting in a humid region.
Subject(s)
Hot Temperature , Rain , China , Cities , Water Supply/methodsABSTRACT
Vertical expansion makes the structure and pattern of the city more complicated. Traditional two-dimensional landscape pattern cannot completely reflect the ecological structure and functional characteristics of urban landscape. In this study, we used the three-dimensional landscape pattern metrics to quantify the regional three-dimensional landscape pattern, and used boosted regression tree (BRT) machine learning algorithms to comprehensively analyze the interaction between social-environmental factors and urban landscape patterns in the central part of Shanghai. Results showed that high building ratio, mean architecture height, and architecture height standard deviation had higher values in the surrounding area of the inner ring. The number of buildings and landscape shape index were higher in the outer ring than those in other area. Building coverage ratio, floor area ratio and Shannon's diversity index had higher values in the central part, with the metrics of Puxi being generally higher than those of Pudong. Population density and normalized vegetation index (NDVI) interacted most significantly with the three-dimensional landscape pattern, with GDP as the least influential factor. Within a certain range, the three-dimensional landscape pattern metrics increased with larger population density in the social factors, and decreased with lower rate of NDVI and water surface ratio in the environmental factors. Our results demonstrated that the BRT method was effective in quantifying the interaction between landscape pattern and social-environmental factors. Our results help improve the understanding of the relationship between ecological environment and human well-being in the central part of Shanghai and provide a scientific basis for the urban three-dimensional expansion planning.
Subject(s)
City Planning , Ecosystem , China , Cities , Humans , Population DensityABSTRACT
Understanding the complexity of catchment-scale human activities, natural factors, and stream water quality is particularly important for basin water resources management. Thorough investigations on how multiple environmental factors quantitatively and simultaneously affect water quality are limited. This study employed Spearman's correlation and ridge regression analysis (RRA) to disentangle the hydraulic geometry and land use contributions to water quality variables (WQVs). Nine and six indicators were used to describe the hydraulic geometry and land use characteristics, respectively, in the Taihu Basin. The results revealed significant correlations between the land use, hydraulic geometry, and stream water quality. Built-up land and cropland negatively impacted the stream water quality, while woodland had the opposite trend. The structure and morphological connectivity of the river network were associated with most WQVs. The hydrologic connectivity characteristics strongly influenced ammonia-nitrogen (NH3-N), permanganate index (CODMn), and dissolved oxygen (DO). Six equations that estimated the stream water quality were established through RRA. Human factors impose a greater impact on the stream water quality than natural factors in the Taihu Basin. Our findings provide quantitative insights to mitigate water pollution via reasonable management and control of the river structure and connectivity and land-use patterns.
Subject(s)
Rivers , Water Quality , China , Environmental Monitoring , Humans , Water Pollution/analysisABSTRACT
The primary pollutants and pollution levels of surface water present spatial and temporal changes. This study quantified the grey water footprint (GWF) and surface water pollution level (WPL) in China from 2003 to 2018 based on four pollutants: chemical oxygen demand (COD), ammonia nitrogen (NH3-N), total nitrogen (TN) and total phosphorus (TP). Additionally, the spatiotemporal distribution of the primary water pollutant (PWP) and driving forces of the GWF were analyzed based on the WPLs and the logarithmic mean Divisia index (LMDI) decomposition method. The results showed that the GWF in China decreased by 13% from 2003 to 2018 and the WPL decreased from 1.11 in 2003 to 0.94 in 2018. An analysis of regional GWFs with multiple pollutants could prevent the underestimation of GWFs and WPLs caused by changes in the PWPs. The GWF spatial distribution was high in the southeast and low in the northwest, while the provinces with larger WPLs were mainly concentrated in northern China. The PWP changed from COD to TN in 2007 because of the increase in nitrogen application in China, the low TN reduction capacity of wastewater treatment plants and the improved comprehensive utilization rate of livestock and poultry manure. The driving force analysis results showed that water efficiency and technological and industrial structural effects promoted the reduced GWF. Our research conclusions and policy suggestions could provide references for reducing the GWF and improving the water quality in China.
ABSTRACT
The demonstration area of ecologically friendly development in the Yangtze River Delta is a major national strategy area, and thus eco-environmental protection should be a priority for the sustainable development. Exploring the spatial-temporal variations of franctional vegetation coverage (FVC) is conducive to accurate assessing the ecological quality of environment, which is of great significance to regional sustainable development. In this study, the characteristics and trends of spatial-temporal variation of vegetation cover during 1984-2019 in the demonstration area were analyzed based on Google Earth Engine (GEE). The effects of different ecological factors on FVC were quantified by the boosted regression tree (BRT). Results showed that,the changing trend of FVC in the study area shifted from decreasing to increasing trend from 1984 to 2019. The spatial distribution of FVC in the study area varied with both stages and regions. FVC was mainly degraded. Compared with the year 1984, the area of vegetation degradation and improvement in 2019 accounted for 49.8% and 12.8%, respectively. The vegetation degradation mainly occurred in the north of Wujiang, south of Jiashan, and northeast of Qingpu. Human activities severely weakened the influence of natural factors on FVC. Our findings suggested that the GEE is an effective tool for monitoring the dynamics of vegetation coverage.
Subject(s)
Ecosystem , Rivers , China , Conservation of Natural Resources , Environmental Monitoring , HumansABSTRACT
Lakes are important fresh water resources. Accurate understanding of lake dynamic changes benefits the sustainable development of water resources and socio-economic development. Based on the Google Earth Engine (GEE), we analyzed the dynamics of Taihu Lake from 1984 to 2018 by adopting the dataset of Joint Research Centre's Global Surface Water and Landsat imagery. The modified normalized difference water index (MNDWI) was used to explore the changes in the area of Taihu Lake in recent 35 years. The results showed that the area of Taihu Lake increased during 1984-2018, with a total increase of 45.31 km2. The area in spring and winter was larger than that in summer. Eastern Taihu Lake was the main part of Taihu Lake showing area change. Compared with 1984, 88.9% of the water area of Taihu Lake in 2018 did not change, and 0.3% of the water area disappeared permanently. Lake area changes were affected by both natural and anthropogenic factors. Agricultural irrigation, fish farming, reclamation of surrounding lakes, water conservancy engineering facilities, and the transformation of land-use types caused the reduction in lake area. Increased annual precipitation and the implementation of environmental protection policies were the main factors for the increases in lake area. The results provide reference for effective sustainable water resource management and verify the feasibility of monitoring long-term surface water change based on the GEE platform.
Subject(s)
Lakes , Water Pollutants, Chemical , China , Environmental Monitoring , Water , Water Pollutants, Chemical/analysis , Water ResourcesABSTRACT
Increasing dryness conditions under global warming are posing severe threats to water resources management in China. Projecting river basin responses to dryness conditions is beneficial to effectively managing water resources. However, existing studies have seldom considered the impact of multiple dryness conditions on future river basin health under global warming. Therefore, we combine the 3- and 12-month standard precipitation evapotranspiration index (SPEI) and reliability-resilience-vulnerability framework (RRV) to map future river basin health based on the responses of basins across China to different dryness conditions from 2021 to 2050. The calculation is based on downscaled outputs of 10 models from the Coupled Model Intercomparison Project Phase 5 (CMIP5) for three future emission scenarios (i.e., RCP2.6, RCP4.5 and RCP8.5). The results show that water deficits are projected to occur in most areas of China and significantly increase in the basins located in the northern part of China in the next 30 years due to global warming effects. The conditions in parts of the basins located in the northern part of China (especially in the Northwest River basins and Yellow River basin) are projected to be unhealthy and deteriorate significantly in the future, while the basins located in the southern part of China are projected to be moderate. The health status is anticipated to be worse under the RCP8.5 scenario than the RCP2.6 and RCP4.5 scenarios. Integrated results from the three thresholds indicated that normal dryness is applicable to most areas of northeastern, northern and southern China, while abnormal dryness is applicable to the remaining areas. Our findings could help reduce the impact of future dryness conditions on water resources and provide insights into risk planning and management for river basins in China under global warming.
ABSTRACT
Under the background of rapid urbanization, the degradation of urban river water environment and ecological function in the Taihu Lake Basin has become increasingly prominent. Consequently, it is particularly important to systematically assess urban river habitat. This study referred to and corrected the British Urban River Survey evaluation system. Based on the characte-ristics of urban rivers in the Taihu Lake Basin, we established the evaluation system of stretch habitat quality index (SHQI) of urban river stretches and analyzed the urban river habitat status and spatial variation in the Taihu Lake Basin. The results showed that the SHQI values of the 50 river stretches ranged between 8 and 21, with 3 river stretches classified as "excellent" habitat level, 6 as "good", 27 as "moderate", 9 as "poor", and 5 as "very poor". The vegetation index in urban river habitats in the Taihu Lake Basin was good, whereas that of the physical habitat and material index were bad. The overall ranking of habitats was Zhenjiang: Huzhou: Hangzhou: Jiaxing: Suzhou: Wuxi: Changzhou. There were significant differences in physical habitats, material indices and pollution indices among different cities. The main stream and the tributary section significantly differed in the material index and pollution index, but not significant for SHQI. The evaluation system constructed in this study reflected the current situation of urban river habitats in the Taihu Lake Basin, and could provide guidance for ecological restoration of urban rivers.
