Search Results (297)

The spatiotemporal evolution of the regional water use structure holds significant theoretical value for optimizing regional water resource allocation, adjusting industrial structures, and achieving sustainable water resource development. Shandong Province, located at the lowest reach of the Yellow River Basin in China, is a major economic, agricultural, and populous province, as well as a region with one of the most prominent water supply–demand imbalances in the country. As a result, exploring how water use patterns change over time and space in this region has become crucial. Using analytical methods like the Lorenz curve, Gini coefficient, cluster analysis, and spatial statistics, we examine shifts in Shandong’s water use structure from 2001 to 2023. We find that while agriculture remained the largest water consumer over this period, industrial, household, and ecological water use steadily increased, signaling a move toward more balanced resource distribution. Across Shandong’s 16 regions (cities), the water use patterns varied considerably, particularly in terms of agriculture, industry, and ecological needs. Among these, agricultural, industrial, and domestic water use were distributed relatively evenly, whereas ecological water use showed greater regional disparities. These results may have the potential to guide policymakers in refining water allocation strategies, improving industrial planning, and boosting the water use efficiency in Shandong and the country ore broadly. Full article

Research on the supply–demand relationships of ecosystem services (ESs) in alpine pastoral regions remains relatively scarce, yet it is crucial for regional ecological management and sustainable development. This study focuses on the Sanjiangyuan Region, a typical alpine pastoral area and significant ecological barrier, to quantitatively assess the supply–demand dynamics of key ESs and their spatial heterogeneity from 2000 to 2020. It further aims to elucidate the underlying driving mechanisms, thereby providing a scientific basis for optimizing regional ecological management. Four key ES indicators were selected: water yield (WY), grass yield (GY), soil conservation (SC), and habitat quality (HQ). ES supply and demand were quantified using an integrated approach incorporating the InVEST model, the Revised Universal Soil Loss Equation (RUSLE), and spatial analysis techniques. Building on this, the spatial patterns and temporal evolution characteristics of ES supply–demand relationships were analyzed. Subsequently, the Geographic Detector Model (GDM) and Geographically and Temporally Weighted Regression (GTWR) model were employed to identify key drivers influencing changes in the comprehensive ES supply–demand ratio. The results revealed the following: (1) Spatial Patterns: Overall ES supply capacity exhibited a spatial differentiation characterized by “higher values in the southeast and lower values in the northwest.” Areas of high ES demand were primarily concentrated in the densely populated eastern region. WY, SC, and HQ generally exhibited a surplus state, whereas GY showed supply falling short of demand in the densely populated eastern areas. (2) Temporal Dynamics: Between 2000 and 2020, the supply–demand ratios of WY and SC displayed a fluctuating downward trend. The HQ ratio remained relatively stable, while the GY ratio showed a significant and continuous upward trend, indicating positive outcomes from regional grass–livestock balance policies. (3) Driving Mechanisms: Climate and natural factors were the dominant drivers of changes in the ES supply–demand ratio. Analysis using the Geographical Detector’s q-statistic identified fractional vegetation cover (FVC, q = 0.72), annual precipitation (PR, q = 0.63), and human disturbance intensity (HD, q = 0.38) as the top three most influential factors. This study systematically reveals the spatial heterogeneity characteristics, dynamic evolution patterns, and core driving mechanisms of ES supply and demand in an alpine pastoral region, addressing a significant research gap. The findings not only provide a reference for ES supply–demand assessment in similar regions regarding indicator selection and methodology but also offer direct scientific support for precisely identifying priority areas for ecological conservation and restoration, optimizing grass–livestock balance management, and enhancing ecosystem sustainability within the Sanjiangyuan Region. Full article

Desert ecosystems play a critical role in global climate regulation. Current research reveals a relative lack of research regarding desert ecosystem service (ES) supply and demand. Therefore, we selected the Ulanbuh desert, one of the eight major deserts in China, as study area. Using specialized models, we quantify the supply and demand of four ES, including water yield (Wy), soil conservation (Sc), windbreak and sand fixation (Ws), and carbon sequestration (Cs), from 1985 to 2020. Univariate linear regression analysis and panel data analysis (PDA) were used to examine trends in desert ES supply–demand ratio (ESDR) and its determinants. The findings indicated that ES supply presented increases in Sc and Cs, and decline in Ws from 1985 to 2020. Demand patterns showed a growth trend for Wy and Cs. ESDR revealed that Sc, Ws, and Cs show an excess of supply over demand and are in a decreasing trend, while Wy displays a supply deficit relative to demand with no significant change. The comprehensive ESDR decreased over the study period, with a supply-deficit status emerging in the southwestern area. Natural factors (NDVI and precipitation) and socio-economic factors (GDP and population density) served as the main factors affecting the comprehensive ESDR. This research provides a novel perspective for desert ecosystems management and conservation, emphasizing the necessity of incorporating the ES supply and demand balance into regional development policies to achieve sustainable development in arid regions. Full article

Groundwater storage refers to the water stored in the pore spaces of underground aquifers, which has been increasingly affected by both climate change and anthropogenic activities in recent decades. Therefore, monitoring their changes and the factors that affect it is of great importance. Although the influence of natural factors on groundwater is well-recognized, the impact of human activities, despite being a major contributor to its change, has been less explored due to the challenges in measuring such effects. To address this gap, our study employed an integrated approach using remote sensing and the Google Earth Engine (GEE) cloud-free platform to analyze the effects of various anthropogenic factors such as built-up areas, cropland, and surface water on groundwater storage in the Lake Urmia Basin (LUB), Iran. Key anthropogenic variables and groundwater data were pre-processed and analyzed in GEE for the period from 2000 to 2022. The processes linking these variables to groundwater storage were considered. Built-up area expansion often increases groundwater extraction and reduces recharge due to impervious surfaces. Cropland growth raises irrigation demand, especially in semi-arid areas like the LUB, leading to higher groundwater use. In contrast, surface water bodies can supplement water supply or enhance recharge. The results were then exported to XLSTAT software2019, and statistical analysis was conducted using the Mann–Kendall (MK) non-parametric trend test on the variables to investigate their potential relationships with groundwater storage. In this study, groundwater storage refers to variations in groundwater storage anomalies, estimated using outputs from the Global Land Data Assimilation System (GLDAS) model. Specifically, these anomalies are derived as the residual component of the terrestrial water budget, after accounting for soil moisture, snow water equivalent, and canopy water storage. The results revealed a strong negative correlation between built-up areas and groundwater storage, with a correlation coefficient of −1.00. Similarly, a notable negative correlation was found between the cropland area and groundwater storage (correlation coefficient: −0.85). Conversely, surface water availability showed a strong positive correlation with groundwater storage, with a correlation coefficient of 0.87, highlighting the direct impact of surface water reduction on groundwater storage. Furthermore, our findings demonstrated a reduction of 168.21 mm (millimeters) in groundwater storage from 2003 to 2022. GLDAS represents storage components, including groundwater storage, in units of water depth (mm) over each grid cell, employing a unit-area, mass balance approach. Although storage is conceptually a volumetric quantity, expressing it as depth allows for spatial comparison and enables conversion to volume by multiplying by the corresponding surface area. Full article

This research is focused on water governance problems in La Marina Alta District, in the province of Alicante (southeastern Spain). The district has a public management body, Consorcio de Abastecimiento y Saneamiento de Aguas de los Municipios de La Marina Alta (CASAMA), which has been inoperative since its creation in 1987. Although La Marina Alta has sufficient water resources in situations of hydrological normality, they are significantly affected by the impacts of climate change, insufficient water treatment technology and the absence of storage and regulation infrastructure. As a consequence, periods of scarcity and overexploitation of aquifers, together with high-demand situations, have generated scenarios of a lack of drinking water with reputational damage and uncertainty for the future of agricultural operations. Thus, the aim of this work is to propose the adoption of integrated water resource management strategies that will increase the resilience of this sub-basin in La Marina Alta. To this end, the contribution of new non-conventional resources to the water pool, combined with an efficient network of infrastructure, and all this supported by effective governance structures, would be essential to achieve a sustainable balance between demand and supply, preserving the environmental values of the territory. Full article

This paper constructs a modified hypothesis extraction method (MHEM)–structural decomposition analysis (SDA)–structural path decomposition (SPD) analytical framework and employs the 2018–2022 Chinese input–output tables to discuss sectoral consumption correlations, driving forces of consumption, and the transmission paths of carbon energy (CE), oil and gas energy (OGE) and electric energy (EE). The results of the study indicate that energy-exporting sectors are primarily energy production or conversion industries, while energy-importing sectors are mainly in the construction sector. China’s energy consumption has shown consistent year-on-year growth, with the primary driving force being the intensity of energy consumption and the secondary factor being per capita demand. The consumption of all three types of energy is primarily directed toward domestic consumption and capital formation. Regarding energy consumption transmission paths, the first-order path with the largest overall impact on CE is “electricity, gas, and water supply sector → domestic consumption”, while higher-order paths are primarily subpaths of “electricity, gas, and water supply sector → capital formation”. For OGE, the main supply and transfer path is “coke, refined petroleum, and nuclear fuel sector → domestic consumption”, along with its subpaths. In contrast, EE transmission is more balanced, with a high demand for electricity across all sectors. Full article

Complex feedback mechanisms and interdependencies exist among the water–energy–food–ecosystems (WEFE) nexus. In water-scarce regions, fluctuations in the supply or demand of any single subsystem can destabilize the others, with water shortages intensifying conflicts among food production, energy consumption, and ecological sustainability. Balancing the synergies and trade-offs within the WEFE system is therefore essential for achieving sustainable development. This study adopts the natural–social water cycle as the core process and develops a coupled simulation model of the WEFE (CSM-WEFE) system, integrating food production, ecological water replenishment, and energy consumption associated with water supply and use. Based on three performance indices—reliability, coupling coordination degree, and equilibrium—a coordinated sustainable development index (CSD) is constructed to quantify the performance of WEFE system under different scenarios. An integrated evaluation framework combining the CSM-WEFE and the CSD index is then proposed to assess the sustainability of WEFE systems. The framework is applied to the Beijing–Tianjin–Hebei (BTH) region, a representative water-scarce area in China. Results reveal that the current balance between water supply and socio-economic demand in the BTH region relies heavily on excessive groundwater extraction and the appropriation of ecological water resources. Pursuing food security goals further exacerbates groundwater overexploitation and ecological degradation, thereby undermining system coordination. In contrast, limiting groundwater use improves ecological conditions but increases regional water scarcity and reduces food self-sufficiency. Even with the full operation of the South-to-North Water Diversion Project (Middle Route), the region still experiences a 16.4% water shortage. By integrating the CSM-WEFE model with the CSD evaluation approach, the proposed framework not only provides a robust tool for assessing WEFE system sustainability but also offers practical guidance for alleviating water shortages, enhancing food security, and improving ecological health in water-scarce regions. Full article

The combined effects of rapid urbanization and climate change are increasingly exacerbating the risk of urban flooding. This study develops a data-efficient framework for estimating a city’s Urban Stormwater Carrying Capacity (USCC)—the maximum stormwater volume that can be safely infiltrated, stored, and conveyed. The framework couples three rainfall scenarios—frequent, heavy, and extreme—with nine widely adopted drainage and storage measures, ranging from green spaces and permeable pavements to pipes and underground emergency reservoirs, and expresses USCC through a streamlined water-balance equation. Applied to the 24 km² Zhangmian River district in Weifang, China, the framework yields capacities of 4.84, 5.86, and 9.80 × 10⁶ m³ for the three scenarios, respectively; underground reservoirs supply ≈ 40% of the extreme-event capacity. Sensitivity analysis shows that increasing the imperviousness coefficient from 0.65 to 0.85 raises peak drainage demand by 30.8%, whereas halving reservoir depth lowers total capacity by 27.8%. Because the method requires only rainfall depth, land-cover data, and basic facility dimensions, it enables rapid, transparent scenario testing and helps planners prioritize cost-effective upgrades. The approach is transferable to other cities and can be extended to incorporate water quality or digital-twin modules in future research. Full article

Intelligent algorithms and decision models are key tools for improving the efficiency and adaptability of multi-objective optimization and allocation, and for achieving sustainable utilization of water resources. This study takes Hancheng City as a case study to develop a water resource optimization allocation model based on economic, social, and ecological benefits, analyzing and predicting the supply and demand of conventional and unconventional water resources in the study area. The model is solved using the NSGA algorithm, and solutions are screened from the Pareto front using the TOPSIS-CCDM two-level decision model, with the RSR method used for comparative verification. The results show that the schemes II-2022-21 (water shortage of 17,802.35 m³/d, economic benefits of 21,019,556.17 yuan, pollutant emissions of 745.92 tons), II-2027-ACS (shortage of 14,098.76 m³/d, economic benefits of 29,401,252.75 yuan, emissions of 712.07 tons), and II-2032-ACS (shortage of 12,709.33 m³/d, economic benefits of 36,660,367.83 yuan, emissions of 700.96 tons) are in line with the water resource allocation planning for Hancheng City before 2035. These schemes not only meet the regional planning requirements but also maximize economic benefits while minimizing water shortages and pollutant emissions. The study finds that NSGA-II has an advantage in selecting more coordinated schemes, while NSGA-III focuses more on the selectivity of specific targets. Although the TOPSIS-CCDM model performs well in comprehensive evaluation, it also exposes limitations such as sensitivity to data fluctuations and high computational complexity. By developing and applying advanced optimization and decision models, this study provides a scientific water resource allocation scheme for Hancheng City, supporting the sustainable management of regional water resources, and offering a reference for future research in addressing data uncertainties and improving computational efficiency. Full article

Jordan is a relatively small country with limited natural resources, but it faces a burgeoning demand for water, energy, and food to accommodate a growing population, refugee migration, and the challenges of climate change that will persist through the rest of this century. Jordan’s Main Water Conveyance System is the backbone of distributing scarce water resources to meet domestic and agricultural demands. Therefore, understanding how the future energy requirements of this system may change is critical for managing the country’s water, energy, and food resources. This paper applied a water balance model to calculate the energy consumption of Jordan’s Main Water Conveyance System between 2015 and 2050, and the results point to high energy requirements for the future of distributing Jordan’s water. In the base year of 2015, the unmet water demand was 134.55 MCM, and the supplied water volume delivered was 438.75 MCM, while the energy consumption was 1496.7 GWh. The energy intensities for water conveyance and water treatment were 7.11 kWh/m³ and 0.5 kWh/m³, respectively. We examined five scenarios of future water and energy demand within Jordan: a reference scenario, a continuation of current behavior, two scenarios incorporating improved water management strategies, and a pessimistic scenario with no interventions. According to all scenarios, the energy consumption is expected to be doubled by the year 2050, reaching approximately 3172 GWh. It is recommended that Jordan prioritizes solar-powered conveyance and pumping to reduce the projected doubling of energy demand by 2050. Across all scenarios, the demand for nonrenewable energy associated with water conveyance is projected to rise significantly, particularly in the absence of renewable integration or efficiency interventions. Total water demand is expected to increase by up to 35% by 2050, with urban and agricultural sectors being the primary contributors. Full article

From the urban sustainability perspective and from the steps essential for regulating/balancing the microclimate features, the creation and maintenance of urban green spaces (UGS) are vital. The UGS include vegetation of any kind in urban areas such as parks, gardens, vertical gardens, trees, hedge plants, and roadside plants. This “urban green infrastructure” is a cost-effective and energy-saving means for ensuring sustainable development. The relationship between urban landscape patterns and microclimate needs to be sufficiently understood to make urban living ecologically, economically, and ergonomically justifiable. In this regard, information on diverse patterns of land use intensity or spatial growth is essential to delineate both beneficial and adverse impacts on the urban environment. With this background, the present study aimed to address water requirements of UGS plants and trees during the non-rainy months from Panaji city (Koppen classification: Am) situated on the west coast of India, which receives over 2750 mm of rainfall, almost exclusively during June–September. During the remaining eight months, irrigating the plants in the UGS becomes a serious necessity. In this regard, the daily water requirements (DWR) of 34 tree species, several species of hedge plants, and lawn areas were estimated using standard methods that included primary (field survey-based) and secondary (inputs from key-informant survey questionnaires) data collection to address water requirement of the UGS vegetation. Monthly evapotranspiration rates (ET_o) were derived in this study and were used for calculating the water requirement of the UGS. The day–night average ET_o was over 8 mm, which means that there appears to be an imminent water stress in most UGS of the city in particular during the January–May period. The DWR in seven gardens of Panaji city were ~25 L/tree, 6.77 L/m² hedge plants, and 4.57 L/m² groundcover (=lawns). The water requirements for the entire UGS in Panaji city were calculated. Using this information, the estimated total daily volume of water required for the entire UGS of 1.86 km² in Panaji city is 7.10 million liters. The current supply from borewells of 64,200 L vis a vis means that the ET_o-based DWR of 184,086 L is at a shortage of over 2.88 times and is far inadequate for meeting the daily demand of hedge plants and lawn/groundcover. Full article

With the high penetration of renewable energy, the imbalance between heat supply and demand is becoming increasingly severe. Installing additional heat storage bypass pipelines in the heating network can significantly enhance the heat storage capacity of the system, and regulating the supply and demand balance of heat stations can achieve a stable heat supply for users. This paper proposes a heat storage bypass configuration scheme and a dual-valve-coordinated control system. Based on the control valves’ ideal and operational flow characteristics, this paper delves into the minimum and maximum control impedance mechanisms in control valves, analyzing their impact on operational performance. Aiming at the fluctuation in the water supply temperature in the secondary pipe network (dead zone of 1%), the influence of control valve parameters on the dynamic response was systematically analyzed. The optimal parameter-matching scheme of the bypass control valve and the heat exchange control valve was finally determined through an optimization analysis. We verified its correctness based on the measured engineering data. This study improves the stability and operational efficiency of the supply and demand balance and decoupling control of the heating heat exchange unit, thereby establishing a critical technical foundation for advancing the high-efficiency integration of renewable energy sources within urban energy systems. Full article

More than half of the cultivated land belongs to the Irrigation Association. Therefore, there have been no farmland consolidation, irrigation, and drainage projects. The cultivation in the non-irrigation area suffers from poor geographical conditions and a lack of water sources. A practical planning strategy is required for expanding irrigation services. The mountainous area of Nantou County, Taiwan, has 7477 ha of available land and 4656 ha of agricultural land outside the irrigation area. Rain and streams are the main water source. There are 82 ponds, 80% of which belong to the loam soil, and the rainfall from October to February is limited. The water requirement of crops is 1.5–3.1 mm/day. Wild streams, groundwater, and rainwater are the only potential water sources due to elevation and terrain. The potential runoff is estimated to be 0–0.927 cms (m³/s) when using the SCS-CN method. Water supply and demand from October to April are limited, and the rainfall comprises 22% of the total water supply. Large reservoirs and water storage towers are required for flooding and in dry seasons. To address water storage challenges and stabilize the balance between water supply and demand, it is essential to construct additional ponds. Full article

Xinjiang is located in an inland arid area, and it faces significant challenges in water resource supply and demand, with a fragile ecological environment. Exploring the internal relationship between the time–space distribution of agricultural water–soil matching and the evolution of the ecosystem service value (ESV) in the Tailan River Irrigation District of Xinjiang from 2000 to 2020, this study provides theoretical guidance for the balance of agricultural water–soil resources and the healthy and sustainable development of the ecological environment in the irrigation district. By integrating the water–soil matching coefficient and the equivalent factor method, the spatiotemporal distribution of agricultural water–soil matching and the spatiotemporal evolution of the ESV under the change of land use (LU) in the irrigation district are analyzed. Based on the Pearson correlation, the trade-off synergy between the two is explored. The results show that the following occurred in the past 20 years: (1) Grassland and dryland are the two categories of land with the biggest transfer-out and transfer-in areas in the Tailan River Irrigation District, and the conversion areas are mostly in Jiamu Town and Guleawati Township. (2) The area and reclamation rate of the irrigation district increased gradually, among which the highest reclamation rate was 85.93% in Kezile Town and the lowest was 76.37% in Guleawati Township. The average Gini coefficient of agricultural water–soil in the irrigation district is 0.118, which is absolutely fair. (3) Kezile Town has the highest agricultural water consumption, but the matching of agricultural water–soil always fluctuates between the best and the worst. The agricultural water consumption in Communist Youth League Town is the lowest, but the matching of agricultural water–soil has remained the best for many years. (4) The ESV of the irrigation district showed an overall increasing trend, from CNY 243 million in 2000 to CNY 678 million in 2020; in addition, soil conservation, hydrological regulation, grassland, and dryland contributed the most to ESV in each period. (5) There was a significant trade-off relationship between agricultural water–soil matching and ecosystem services in the Tailan River Irrigation District, while there was a significant synergistic relationship between ecosystem services. Full article

The decarbonization of the heat supply is crucial for the German energy transition. Integrating Power-to-Heat technologies like heat pumps (HPs) into district heating grids (DHGs) can support this process. The efficiency of HPs can be increased through temperature reduction in the DHG, though decentralized reheating may be required to supply sufficient heat for the end consumers. In order to investigate the associated trade-off, this study evaluates the economic, ecological, and technical effects of temperature reduction in DHGs using the software tool nPro. In a three-step process heat demand, the DHG design and operation are modeled. Three operating temperature scenarios are considered: 60 °C, 50 °C, and an ambient dependent flow temperature varying between 40 and 50 °C. As the temperatures decrease, the balance shifts between centrally produced HP heat and decentralized heat from instantaneous electric water heaters (IEWHs). The initial temperature reduction leads to reduced CO₂ emissions, primary energy demand, heat losses, and total annual cost (TAC). However, with a further reduction in the operating temperature, an increase in these parameters occurs. While the necessary cost and primary energy for central components decrease, an increase in the decentralized heat generation is necessary to properly supply the heat demand. This leads to higher TAC and CO₂ emissions overall. Full article