Supply-demand Ratio Research Articles

Impact of Variations in the Nursing Care Supply-Demand Ratio on Postoperative Outcomes and Costs

Improving surgical outcomes is a priority during the last decades because of the rising economic health care burden. The adoption of enhanced recovery programs has been proven to be part of the solution. In this context, the impact of variations in the nursing care supply-demand ratio on postoperative complications and its economic consequences is still not well elucidated. Because patients require different amounts of care, the present study focused on the more accurate relationship between demand and supply of nursing care rather than the nurse-to-patient ratio. Through a 3-year period, 838 patients undergoing elective and emergent colorectal and pancreatic surgery within the institutional enhanced recovery after surgery (ERAS) protocol were retrospectively investigated. Nursing demand and supply estimations were calculated using a validated program called the Projet de Recherche en Nursing (PRN), which assigns points to each patient according to the nursing care they need ( estimated PRN) and the actual care they received ( real PRN), respectively. The real/estimated PRN ratio was used to create 2 patient groups: one with a PRN ratio higher than the mean (PRN+) and a second with a PRN ratio below the mean (PRN-). These 2 groups were compared regarding their postoperative complication rates and cost-revenue characteristics. The mean PRN ratio was 0.81. A total of 710 patients (84.7%) had a PRN+ ratio, and 128 (15.3%) had a PRN- ratio. Multivariable analysis focusing on overall complications, severe complications, and prolonged length of stay revealed no significant impact of the PRN ratio for all outcomes ( P > 0.2). The group PRN- had a mean margin per patient of U.S. dollars 1426 (95% confidence interval, 3 to 2903) compared with a margin of U.S. dollars 676 (95% confidence interval, -2213 to 3550) in the PRN+ group ( P = 0.633). A PRN ratio of 0.8 may be sufficient for patients treated following enhanced recovery after surgery guidelines, pending the adoption of an accurate nursing planning system. This may contribute to better allocation of nursing resources and optimization of expenses on the long run.

Impact of urban expansion on the supply-demand balance of ecosystem services: An analysis of prefecture-level cities in China

The coercive impact of urban expansion on ecosystems is becoming increasingly severe. Understanding the impact of urban expansion on the supply and demand (S&D) balance of ecosystem services (ESs) across regions with various ecological backgrounds and developmental levels is imperative for regional ecological management. However, few studies have explored the spatial dependence and spatial heterogeneity of the impact of urban expansion on the S&D balance of ESs and the differences across regions with different natural geographical environments and degree of social-economic development, especially on a large scale. We selected the urban expansion proportion index, urban expansion rate index, urban expansion degree index, and ecosystem services supply-demand ratio to reflect the urban expansion and S&D balance of different prefecture-level cities in China, and discussed the impact of urban expansion on the S&D balance of different regions. From 2000 to 2020, the area of deficit zones increased while the area of surplus zones decreased, aggravating the S&D imbalance of ESs. The impact of urban expansion on ESs S&D displayed significant spatial dependence. There was an inverse correlation of urban expansion on S&D balance, showing significant inter-regional heterogeneity. Hence, regional differences and linkages should be comprehensively considered in urban planning and decision-making related to development and ESs.

The spatial-temporal changes of supply-demand of ecosystem services and ecological compensation: A case study of Hexi Corridor, Northwest China

Understanding the relationship between supply and demand of ecosystem services (ES) is important to achieve sustainable use of natural capital and keep coordination of supply and demand. This paper used spatial analysis of the Geographic Information Science (GIS) method to quantify ecosystem service supply (ESS) and ecosystem service demand (ESD) by constructing the ecosystem services provision index and land development index respectively. Then the spatial-temporal characteristics of ES's supply and demand situation in Hexi Corridor (HC) were analyzed. In addition, the ecosystem service flow (ESF) and the corresponding ecological compensation (EC) for the ecosystem services supply areas (ESSA) and ecosystem services demand areas (ESDA) were quantified. The results showed that the regions with medium and high ESS showed significant growth, and regions with high ESD increase significantly. Besides, the distribution pattern of the ecosystem services supply-demand ratio (ESSDR) was high in the northwest and low in the southeast, which was mainly dominated by ES surplus, and the ESSDR always has spatial autocorrelation and spatial heterogeneity, forming a relatively stable spatial pattern. The High-High cluster areas of ESSDR were mainly distributed in the better ecological area, while the Low-Low cluster was mainly distributed in the economic development area. The supply-demand coordination displayed a balanced trend, and the changing area of supply-demand was mainly concentrated in the population aggregation region in the south of HC. The EC amount paid by ESDA decreased from 2000 to 2020, indicating that the supply capacity of ES was increased. This paper can provide references for regional ecosystem management and restoration.

A novel approach to identify crop irrigation priority

It is urgent to determine the crop critical irrigation period and the priority of crop water irrigation in arid and semi-arid regions to cope with agricultural water shortage. In this study, a method combining Agricultural Production Systems Simulator (APSIM) crop model with grey relational analysis was proposed to determine the irrigation priority of wheat, maize, and sunflower in the irrigation water distribution to ensure food security, and applied to the Hetao Irrigation District (HID) in China. Crop irrigation priority was determined by crop yield, water supply demand ratio (SDR), and water productivity (WP). The maximum yield, maximum water productivity and minimum water stress (crop growth stage) were evaluated. The obtained results indicate that: (1) When the irrigation scenario was 100%, the critical irrigation period for wheat was the first 10 days after sowing and 40–61 days after sowing; The critical irrigation priority for maize was 20–30 days after sowing and 61–81 days after sowing; And the critical irrigation priority for sunflower was 30–61 days after sowing. (2) In early May, irrigation priority was wheat priority to maize, while maize was a priority to wheat in mid to late May. In June, sunflower priority to wheat and maize irrigation. From early to middle July, irrigation priority to maize, and from late July to late August, sunflower water irrigation priority to maize. The method of to identify irrigation priority and crop priority to provide irrigation decision for allocating agriculture water resources.

Estimation of Disaster Evacuation Shelter Capacity of Hitoyoshi City, Japan

Heavy rains since early July 2020 have caused flooding in the Kyushu area. The Kuma River overflowed due to heavy rain. The river itself located in Kumamoto Prefecture right in the Hitoyoshi city. Disaster shelter is one of the most important requirements for those evacuated in the event of a disaster. It is used to analyze the supply and demand of the shelter based on the distance from the point of application to the disaster evacuation shelter, using the P-median model. As a result, the demand for evacuation shelters in the city of Hitoyoshi is 48%, which indicates that the demand for evacuation centers in case of disaster is about half. In this study, the location-allocation method was used in ArcGis 10.6 to determine the supply-demand ratio for Hitoyoshi. These data are expected to be used to optimize the operation of shelters in the Hitoyoshi area, an area prone to disasters for future urban development. This allows evacuation or disaster safety planners to develop tools for their area during floods and provides a way to predict when an event will occur and when roads will become unsafe for the residents during the future evacuation process. When a natural disaster happens again in the future, the demand and supply of disaster evacuation shelters should be assessed to determine their total capacity.

Peer-to-Peer trading with Demand Response using proposed smart bidding strategy

The electricity demand is increasing rapidly among residential consumers due to the utilization of many smart appliances. The renewable-based Distributed Generation (DGs) and Electric Vehicles (EV) investment is also rising among residential consumers. Consumers with renewable-based DGs and smart appliances are considered prosumers in this work. The main objective of this work is to reduce the electricity cost of the smart home by scheduling the smart appliances with Demand Response (DR) using Binary Particle Swarm Optimization (BPSO) algorithm and Peer-to-Peer (P2P) trading using a smart bidding strategy. The smart home consists of two prosumers and two consumers with different Distributed Generation (DG) availability, battery, EV, and smart appliances (thermal and electrical loads). The smart appliances are scheduled based on Real-Time Pricing (RTP), DGs and storage devices availability. The available excess power in the prosumers after self-consumption is traded to the neighbouring consumers to reduce the grid dependency. The novelty of this article lies in the trading decision and trading cost determination for P2P trading, which is called the proposed smart bidding strategy in this work. The proposed smart P2P trading algorithm involves the double auction mechanism, where the bidding occurs between the prosumers and consumers based on the supply–demand ratio (SDR) and RTP. The trading cost calculated is beneficial for both prosumers and consumers in reducing their electricity costs. The electricity cost of consumer 1, consumer 2, prosumer 1, and prosumer 2 is reduced by ₹58.073, ₹20.37, ₹51.656, and ₹20.37, respectively, as compared with grid tariff under the category of normal condition. Similarly, the electricity cost of consumer 1, consumer 2, prosumer 1, and prosumer 2 is reduced by ₹63.514, ₹3.208, ₹98.155, and ₹34.049, respectively, as compared with grid tariff under the category of EV uncertainty in both consumer & prosumer premises. The simulation results proved that the proposed smart bidding strategy effectively reduced the electricity cost of the prosumers and consumers under normal and uncertain conditions compared to the grid tariff.

Spatial-temporal pattern of ecosystem service supply-demand and coordination in the Ulansuhai Basin, China

• Ecosystem services supply, demand, match degree and coordination dynamics were assessed at basin scale and county scale. • Spatially correlations between influencing factors and coupling coordination degree were investigated by mixed effects model. • Different development policies at county scale according to local dynamic of coupling coordination degree and total ES supply-demand match degree were formulated. Accurately quantifying the spatiotemporal patterns in ecosystem service (ES) 1 1 ES-Ecosystem service. supply and demand and their coupling coordination dynamics, as well as identifying the spatial heterogeneity of the influencing factors for coupling coordination degree are necessary for regional sustainable development. This study used the Ulansuhai Basin in Inner Mongolia Province of China as a case to quantify the supply, demand, and supply-demand ratio of ES (meat production, grain production, carbon storage, water yield, nitrogen purification, and phosphorus purification) from 2000 to 2020. The synthesized coefficient of ES supply (ESCI) 2 2 ESCI-Synthesized coefficient of ES supply. and demand (ESDI), 3 3 ESDI-Synthesized coefficient of ES demand. the match degree of total supply and demand (MD), 4 4 MD-Match degree of total ES supply and demand. and the coupling coordination degree (CD) 5 5 CD-Coupling coordination degree between total ES supply and demand. were taken as indices to explore the relationship between the ESCI and ESDI and the coordination relationships. A mixed effects model was used to determine the spatial heterogeneity response of CD to different influencing factors. The results showed that the total ES supply in the Ulansuhai Basin always met the demand. The area with the highest ESCI was always observed in the Urad Front Banner, while Linhe district had the highest ESDI. Although incoordination improved from mild to superior from 2000 to 2020 at the basin scale, significant spatial variations were observed at the county scale. In addition, the variation in CD was significantly correlated with population, followed by precipitation, and cropland area. The findings comprehensively explore the match and coordination between ES supply and demand, and the spatial heterogeneity of the effects of the influencing factors on CD. Our study can contribute to the formulation of future policies for regional ecological restoration and sustainable development.

Excavating the social representations and perceived barriers of organ donation in China over the past decade: A hybrid text analysis approach.

BackgroundOrgan donation has been claimed as a prosocial behavior to prolong the recipient's life and deliver great love. However, the supply-demand ratio of organs in China is highly unbalanced. Being entangled with multiple factors derived from individual and supra-individual levels, organ donation in China is important but sensitive. Previous scholars usually depended on obtrusive approaches to explore the facilitators and hindrances of organ donation, which is hard to discover genuine perceptions toward organ donation. Besides, relatively limited scholarly attention has been paid to what hampers organ donation in China.ObjectiveWe intended to excavate the diversified social representations and perceived barriers to organ donation in China over the past decade.MethodTwo kinds of text analysis methods—semantic network analysis and conventional content analysis, were applied to 120,172 posts from ordinary users on the Sina Weibo platform to address the research questions.ResultsRegarding social representations, the “hope, understanding, and acceptance” of organ donation was the most pronounced one (34% of the whole semantic network), followed by “family story” (26%), “the procedure of organ donation in NGOs” (15%), “the practical value of organ donation” (14%), and “organ donation in the medical context” (11%). Regarding perceived barriers, a four-layer framework was constructed, including (1) the individual level, mainly about the fear of death and postmortem autopsy; (2) the familial level, which refers to the opposition from family members; (3) the societal level, which alludes to distrust toward medical institutions and the general society; (4) the cultural level, which covers religious-cultural concerns about fatalism.ConclusionIn concordance with prior works on social representations regarding organ donation, the current study also uncovered the coexistence of antithetical representations about organ donation—the longing for survival and the fear of death. This representation pair serves as the foundation of Chinese people's ambivalence. Besides, family-related narratives were dispersed over various representations, demonstrating the critical position of family support in organ donation. Moreover, the four-layer framework concerning donation barriers affords a reference for future empirical studies. The practical implications of this work are further discussed.

Ride-pooling services with differentiated pooling sizes under endogenous congestion effect

This paper analytically examines the ride-pooling market equilibrium under a single or multiple ride-pooling service(s) considering different pooling sizes (number of riders sharing the same vehicle) and endogenous congestion effect of the ride-pooling fleet, and investigates the optimal operation decisions of the service operator(s) regarding the pricing, fleet size, and pooling size in different administrative and market regimes. We firstly examine the scenario with a single ride-pooling service platform given a specific vehicle type for either profit-maximization or social welfare-maximization (different administrative regimes), and then extend the model to the scenario with two differentiated ride-pooling services (given different vehicle types), where the platforms may either compete or cooperate (different market regimes). We have the following major findings. First, the pooling size should be optimized to accommodate the congestion effect and thus simultaneously increase operator’s profit and social welfare. The optimal pooling size balances the marginal pickup time, crowding cost and waiting time cost, and the optimal value is different in different market regimes. Second, the ride-pooling service operator will internalize the congestion effect of providing more vehicles to serve customers, which yields a larger ratio of waiting customers to vacant vehicles (larger demand–supply ratio). Under two differentiated ride-pooling services, in addition to the direct congestion effect of providing more vehicles, its effect on the other operator’s decision will also be internalized by the service operator in concern. Our results also suggest that the competition between platforms tends to reduce the waiting customers-vacant vehicles ratio (demand–supply ratio), while the cooperation between or integration of two operators might yield a large ratio. Third, when the endogenous congestion effect of fleet size is zero, the operator’s profit at social optimum will always be negative when the matching function exhibits increasing return to scale and the marginal operation cost is less than the average operation cost, which means that the social welfare seeking operator has to be subsidized. When the endogenous congestion effect of the fleet size is positive, the ride-pooling service operator may earn a positive profit at social optimum under certain conditions. This study enhances the understanding in relation to users’ reactions to differentiated ride-pooling services, how such services interact with congestion, and how such services can be optimized in different market regimes.

Constructing an ecological security pattern in Shenzhen, China, by matching the supply and demand of ecosystem services

Constructing an ecological security pattern by matching the supply and demand of ecosystem services is of great significance for Shenzhen, China. To determine the strategic positioning of sustainable development pioneers and benchmarks for human well-being in a pilot demonstration area of socialism with Chinese characteristics, we selected water yield, carbon sequestration, and recreational services to identifiy the integrated supply and demand status of ecosystem services in Shenzhen using the InVEST model, ecological supply-demand ratio, cell phone signalling data analysis, and circuit theory. An ecological security pattern based on the matching of supply and demand of ecosystem services was constructed. We further examined the impacts of different delimitation boundaries on the area and number of ecological sources. The results showed that the comprehensive ecological supply-demand ratio in Shenzhen generally showed a distribution pattern of abundant in the east and scarce in the west. Among them, water yield services met the demand in terms of quantity and spatial distribution, but carbon sequestration services can not. Recreational services met the demand in terms of quantity, but their spatial distribution was extremely uneven. We identified 25 ecological sources covering a total area of 347.62 km2 and 34 ecological corridors with a total length of 346.06 km. The ecological source area was large in the east and small in the west, while the length of the corridors showed the opposite distribution pattern. Different delineation boundaries had different effects on the area and number of ecological sources. Primary, secondary, and tertiary ecological source areas cover 347.62, 520.84, and 557.58 km2, respectively, showing a gradual increasing trend, the numbers of ecological sources were 25, 35, and 32, showing an increasing then decreasing trend. In Shenzhen, there were important ecological patches that were not included in the ecological control line, and some patches within the ecological control line had poor ecological sustainability. Targeted protection and management policies could be formulated based on such pattern. The results could provide spatial guidance for the delimitation of ecological management and control units in Shenzhen.

Integrating river health into the supply and demand management framework for river basin ecosystem services

Healthy rivers provide many beneficial ecosystem services (ESs) to humans in their basins, necessary to achieve high-quality human well-being. The relationship between the supply and demand of ESs in the basin can reflect the coordination level of the basin's ecology and economy. A clear understanding of the relations between ESs supply and demand is the foundation for sustainable river basin ecosystem management. However, there are differences in the health state of different rivers. Unhealthy rivers may be unable to effectively meet the needs of ecosystem services in their basins, thus threatening the ecological health state and sustainable economic development in the basin. Therefore, in this study, a quantitative analysis framework for the supply and demand of river basin ecosystem services (RBES) based on river health states was developed to achieve the basin's rational utilization and sustainable development. Guangdong Province of China was selected, the supply and demand of four ESs relevant to multi-stakeholders (water retention, soil retention, carbon storage, and water purification) in four representative sub-basins were quantified. The ecological supply-demand ratio (ESDR) was introduced to reflect the surplus or shortage of ESs at different river health states. The results showed that the study area exhibited a spatial mismatch between ESs supply and demand. The ESDR of water retention, soil retention, and water purification services in healthy sub-basins were higher than sub-healthy ones, indicating a certain synergy between the health state of the river and its supply and demand state of ES. Implementing targeted spatial management and control is an important measure to ensure the sustainable development of river basins. This study can provide references for sustainable management of river basins and targeted governance under different river health states within and beyond China.

Influential paths of ecosystem services on human well-being in the context of the sustainable development goals

Ecosystem services (ESs) and their demands from people are closely related to human well-being (HWB). Understanding of the influential paths of ecosystem services on human well-being is significant to sustainable landscape management. This study explored the supply of ecosystem services and the ecosystem service supply-demand relationships (i.e. the ecological supply-demand ratio, ESDR) in the Central and Western Inner Mongolia, as well as HWB by combining the Millennium Ecosystem Assessment (MA) and the sustainable development goals of the United Nations (SDGs). A structural equation model (SEM) was built to quantify the influential paths of the ESs on the HWB. The results indicated that: (1) The HWB was improved during 2000–2018. (2) The supporting services promoted the provisioning services and the regulating services directly. (3) The provisioning services and the regulating services had positive direct influences on the HWB, and also affected the HWB through the ESDR indirectly. The combination of the supporting services and the ESDR presented a panorama of the influential paths of ecosystem services on the HWB and promoted the understanding of the driving mechanisms. Assessments on the ESs, the HWB in the context of SDGs, and their influential paths were instructive for decision-making towards sustainable landscape management.

Decentralized P2P power trading mechanism for dynamic multi-energy microgrid groups based on priority matching

In order to promote the interaction among interconnected microgrids (MGs) with multiply distributed energy resources (DERs) to local energy utilization, a decentralized peer-to-peer (P2P) power trading mechanism based on priority matching is proposed. The priority indices are calculated based on scheduling results and quotations by an independent MG operator (IMO), which protect effectively the privacy and represent the bargaining willingness of MGs. According to the supply–demand ratio within a matching pair, each MG is permitted to update its quotation multi-times until the convergence or updated number limitation is reached. The clearing price of each pair is calculated by the mid-market rate (MMR) method. Because the imbalanced power is different with the autonomous scheduling in a MG at different dispatching time, the different power requirements of MGs results in the formation of the dynamic MG groups. The simulation results in an interconnected multi-microgrid system (IMMGS) with 4 MGs show the proposed decentralized P2P mechanism is reasonable and effective.

Threshold effects and supply-demand ratios should be considered in the mechanisms driving ecosystem services

Understanding the spatial associations of ecosystem services (ESs) driven by socio-ecological factors is essential for regional ecosystem management and effective resource allocation. Yet previous studies of mechanisms driving ESs have focused mainly on the supply or demand for ESs, rarely consider their threshold effects and supply–demand ratios. Taking the upper reach of Ganjiang watershed (URGW) in southern China as an example, the supply, demand, and supply–demand ratio of ESs (ESDRs) were quantified for grain production (GP), water yield (WY), soil retention (SR), carbon sequestration (CS), and green space recreation (GR). Correlation analysis and random forest models were used to investigate the spatial associations of five ESDRs and the relative importance and marginal effects of 9 socio-ecological factors upon them. At the watershed scale, only SR incurred a supply–demand deficit (ESDR < 0), while the other four ESs (GP, WY, CS, and GR) met the internal demand (ESDR > 0). When considered across 188 sub-watersheds, all ESs had different supply–demand deficits. The trade-offs in ESDRs mainly derived from two ESs (GP, SR) and the other three ESs (WY, CS, GR). The supply–demand ratio of SR was mainly determined by topography (i.e., slope gradient), while land use (i.e., proportions of cropland and forest land areas) played a decisive role in the supply–demand ratios of GP and WY. The supply–demand ratios of GR and CS showed similar spatial distribution, driven mainly by the normalized difference vegetation index and human population density. Specific socio-ecological factors (e.g., slope gradient and proportion of forest land area) had significant threshold effects on the ESDRs. Accordingly, research on the mechanisms driving ESs should consider ESs’ supply and demand in tandem, and pay particular attention to the potential threshold effects of socio-ecological factors.

Modeling the dynamic of ecosystem service supply and demand in Chengdu-Chongqing twin-city economic circle, China

Research on ecosystem service supply and demand relations is necessary for effective ecosystem management and rational allocation of resources. Based on the Ecosystem Services Value Evaluation, calculation of Land Use Development Index(LDI) and Ecosystem Services Supply-Demand Ratio(ESSDR), the coupling pattern of ecosystem services supply and demand in the Chengdu-Chongqing Twin-city Economic Circle were described. The results showed that the ESSDR in the researched area basically maintained a pattern of gradual improvement from the dual core to the peripheral circle in terms of spatial structure. An obvious inter-annual difference in the supply and demand patterns was also observed, which showed that the change trend of ESSDR before and after 2000 was opposite. The accelerated urbanization and population migration brought about by the Western Development Strategy exacerbated the imbalance between supply and demand of ecosystem services, the relationship between supply and demand of ecosystem services show an overall negative correlation, but there were obvious regional difference. The coupling status was significantly greater in the southern Sichuan urban agglomeration than others in terms of the quantitative characteristics.

Mapping and assessing ecosystem service supply–demand to identify critical areas: A case study of a waterside area in Shanghai metropolitan area

In the past decades, rapid urbanization in China has dramatically transformed natural spaces into construction land, leading to serious degradation and supply–demand imbalance of ecosystem services (ESs). The identification of critical areas and ecological security patterns is crucial for balancing ESs and improving human well-being in rapidly urbanized regions. The purpose of this study was to establish a comprehensive assessment framework of ES supply–demand including provisioning, regulating, supporting, and cultural services, so as to provide theoretical support for the identification and refined management of regional critical areas. Taking a typical waterside area in Shanghai metropolitan area as an example, based on multi-source data and ES quantitative models, we used ecological supply–demand ratio and bivariate local indicators of spatial association to quantify the relationship and matching patterns of ES supply–demand, then explored the identification, protection, and restoration of ecologically critical areas at the regional scale. The results showed that: 1) the ES supply–demand relationship in the study area was quantitatively determined. The ecological supply–demand ratio was as follows: regulating &amp;gt; provisioning &amp;gt; supporting &amp;gt; cultural, in which the supply of supporting and cultural services was less than the demand, and the problem of the supply–demand mismatch is prominent; 2) we have identified 41 supply critical areas that require priority protection, with a total area of 206.79 km2 accounting for 9.65% of the total study area, showing a spatial pattern of more in the northwest and less in the southeast; 3) a total of 11 demand critical areas that need ecological restoration were identified, accounting for 31.43% of the 35 administrative towns in the study area, which are mainly distributed around three urban centers and a high-tech zone. The study is of great significance for the construction of regional ecological security patterns and rational ES allocation, and can provide a scientific framework for the ecological protection and restoration of critical areas around metropolises in developing countries.

System-dynamics-based scenario simulation and prediction of water carrying capacity for China

• System dynamics is applied to predict water carrying capacity at national level. • The scenario design considers both water resources condition and development mode. • The study is valuable for supporting regional systems planning of water resources. Water carrying capacity (WCC) is essential to support regional sustainable development. In this study, a nation-wide system dynamics model was developed to predict WCC of China for the near future period (2019–2030) based on system analysis of water resources and historical data from 2000 to 2018. The system dynamics model considers three water resources conditions (i.e., normal, wet, and dry) and four development modes (i.e., business-as-usual, priority-for-economy, environmental-constraint, and sustainable development) to holistically represent possible future conditions. From the prediction, the total population and GDP of China would continue growing under all scenarios, and the total wastewater discharge would generally rise first and then decline largely due to the growth of GDP per capita. The water supply-demand ratio would be greatly affected by development mode, depending on the combinative effects of population, GDP and water intake under each development mode. The impact of the wet condition on the modeling results is limited, but that of the dry condition is significant, especially on supply-demand ratio due to the limited water resources. From decision analysis, the four development modes have their own advantages. But from a long-term point of view, the sustainable development mode would outperform others due to its more balanced consideration. The study methodology and findings are valuable for assisting national or regional systems planning of water resources and water quality, especially in face of various challenges such as climate change, eco-environmental deterioration, and water resources shrinkage.

Ecological Sustainability Assessment of Water Distribution for the Maintenance of Ecosystems, their Services and Biodiversity

Water provision and distribution are subject to conflicts between users worldwide, with agriculture as a major driver of discords. Water sensitive ecosystems and their services are often impaired by man-made water shortage. Nevertheless, they are not sufficiently included in sustainability or risk assessments and neglected when it comes to distribution of available water resources. The herein presented contribution to the Sustainable Development Goals Clean Water and Sanitation (SDG 6) and Life on Land (SDG 15) is the Ecological Sustainability Assessment of Water distribution (ESAW-tool). The ESAW-tool introduces a watershed sustainability assessment that evaluates the sustainability of the water supply-demand ratio on basin level, where domestic water use and the water requirements of ecosystems are considered as most important water users. An ecological risk assessment estimates potential impacts of agricultural depletion of renewable water resources on (ground)water-dependent ecosystems. The ESAW-tool works in standard GIS applications and is applicable in basins worldwide with a set of broadly available input data. The ESAW-tool is tested in the Danube river basin through combination of high-resolution hydro-agroecological model data (hydrological land surface process model PROMET and groundwater model OpenGeoSys) and further freely available data (water use, biodiversity and wetlands maps). Based on the results, measures for more sustainable water management can be deduced, such as increase of rainfed agriculture near vulnerable ecosystems or change of certain crops. The tool can support decision making of authorities from local to national level as well as private enterprises who want to improve the sustainability of their supply chains.

An iterative auction for resource-constrained surgical scheduling

We consider a decentralized surgical scheduling problem with conflicting multiple renewable resources requirements under surgeon’s private availability restriction. The objective of the surgical scheduling planner is to maximize the weighted sum of the number of potential selected surgeries. Due to the information asymmetry and the efforts taken by self-interest decision makers to maximize their own benefits, the coordination between the surgical schedule planner and surgeons for achieving efficient scheduling is difficult. In order to solve the decentralized surgical scheduling problem, we propose an auction mechanism in which surgeons only need to submit partial availability information when necessary. In the mechanism, surgeons submit bids based on their availability and renewable resources requirements for performing a surgery, while the winner determination model is formulated to select bids when the termination condition of the iterative bidding procedure is not satisfied. Under the proposed mechanism, we prove that myopic bidding is surgeons’ weakly dominant strategy. The results of our computational experiments also show that the proposed mechanism can achieve high efficiency compared with optimal solutions on different supply-demand ratio configurations. We also observed that the privacy loss incurred during the bidding process is negatively correlated to the supply-demand ratio.

Modeling Health Seeking Behavior Based on Location-Based Service Data: A Case Study of Shenzhen, China

Understanding residents’ health seeking behavior is crucial for the planning and utilization of healthcare resources. With the support of emerging location-based service (LBS) data, this study proposes a framework for inferring health seeking trips, measuring observed spatial accessibility to healthcare, and interpreting the determinants of health seeking behavior. Taking Shenzhen, China as a case study, a supply–demand ratio calculation method based on observed data is developed to explore basic patterns of health seeking, while health seeking behavior is described using a spatial analysis framework based on the Huff model. A total of 95,379 health seeking trips were identified, and their analysis revealed obvious differences between observed and potential spatial accessibility. In addition to the traditional distance decay effect and number of doctors, the results showed health seeking behavior to be determined by hospital characteristics such as hospital scale, service quality, and popularity. Furthermore, this study also identified differences in health seeking behavior between subgroups with different ages, incomes, and education levels. The findings highlight the need to incorporate actual health seeking behavior when measuring the spatial accessibility of healthcare and planning healthcare resources. The framework and methods proposed in this study can be applied to other contexts and other types of public facilities.