Search Results (36)

In ecologically fragile karst regions, surface water leakage and spatial mismatches between supply and demand exacerbate water scarcity and ecosystem degradation. In this context, sustainable water resource allocation is of great significance for achieving the United Nations Sustainable Development Goals (SDGs). This study proposes a Dual-stage Prediction and Optimization Coupled Allocation Model (DPOCAM), which integrates an LSTM–Transformer-based intelligent water demand forecasting model with the NSGA-III multi-objective optimization algorithm. The forecasting model was trained on data from 2001 to 2020 and tested on data from 2021 to 2024, achieving a mean absolute percentage error of 2.89%. The model incorporates ecological water demand as an independent optimization objective, quantified using the Tennant method, aiming to coordinate the relationship between domestic and productive water use with aquatic ecosystem protection. Applied to Sinan County, a typical karst area in Guizhou Province, China, the model projects sectoral water demands for 2035 and conducts water resource allocation based on water network planning. Results show that under the current water network, the comprehensive water shortage rate reaches 17.7%, with ecological deficit accounting for 10.1%, posing dual threats to human water security and ecosystem integrity. Following the planned construction of a water network centered on the Huatanzi Reservoir, the overall shortage rate drops to 0.6%, and the ecological deficit declines to 4.6%, demonstrating significant improvements in both water supply reliability and ecological flow guarantee. The water network construction plays a positive role in reducing water shortage rates and enhancing ecological flow protection, providing a scientific basis and practical reference for sustainable water resource management in karst regions. Full article

Ice-jam formation during winter low-flow conditions represents a persistent hydrotechnical hazard in small and medium-sized rivers of Central Europe. Despite extensive monitoring efforts, preventive structural measures remain insufficiently developed and rarely evaluated under real geomorphological constraints. This study proposes and hydraulically verifies a low-profile riverbed sill designed to suppress the initiation and stabilization of frazil and anchor ice during critical winter discharges. The analysis integrates 20 years of hydrological and water-temperature data (2004–2024), 26 detailed cross-sectional surveys, a high-resolution longitudinal profile derived from DMR 3.0, and a newly formulated Ice-Jam Risk Index (Iice) combining flow velocity, depth-to-width ratio and thermal deficit. Application to the Torysa River (rkm 42.8–43.6) revealed a clearly defined high-risk zone (rkm 43.20–43.38), where hydraulic conditions frequently fall below the critical thresholds for ice accumulation (U < 0.35 m·s⁻¹; h/B < (h/B)_crit; ΔT > 0.5 °C), indicating shallow and laterally widened channel sections prone to anchor-ice stabilization. Model simulations demonstrated that the proposed sill increases mean velocity by 22–35% during Q₆₅–Q₈₅ conditions, reducing the local I(ice) by 61%, while preserving the conveyance capacity for discharges above Q₅₀ and avoiding measurable backwater impacts upstream. Field-based morphology, risk index interpolation and hydraulic modeling all confirm that the structure effectively disrupts the formation of stable anchor-ice nuclei, which have historically triggered severe ice-jam floods in this reach (2011/12, 2016/17, 2021/22). The results show that a properly dimensioned low-profile sill provides a passive, low-cost, and transferable engineering solution for winter flood risk mitigation, outperforming reactive ice-management techniques while maintaining ecological and hydraulic compatibility with small natural rivers. The methodology is replicable for other rivers where supercooling, low-flow hydraulics and channel morphology jointly control ice-jam initiation. Full article

Monitoring stem sap flow is essential for understanding plant water-use strategies and eco-physiological processes in the ecologically fragile karst region. In the study, we continuously monitored four co-occurring species—Cryptomeria japonica var. sinensis (LS), Liquidambar formosana (FX), Camptotheca acuminata (XS), and Melia azedarach (KL)—using the thermal dissipation probe method in a karst farmland-to-forest restoration area. We analyzed diurnal and nocturnal sap flow variations across different growth periods and their responses to environmental factors at an hourly scale. The results showed (1) A “high daytime, low nighttime” sap flow pattern during the growing season for all species. (2) The proportion of nocturnal sap flow was significantly lower in the growing than in the non-growing season. (3) Daytime sap flow was primarily driven by photosynthetically active radiation (PAR) and vapor pressure deficit (VPD) during the growing season. In the non-growing season, daytime drivers were species-specific: relative humidity (RH, 39.39%) for LS; air temperature (Ta, 23.14%) for FX; PAR (33.03%) for XS; and soil moisture at a 10 cm depth (SM1, 25.2%) for KL. Nocturnal flow was governed by VPD and RH during the growing season versus soil moisture (SM1 and SM2) and RH in the non-growing season. These findings reveal interspecific differences in water-use strategies and provide a scientific basis for species selection and afforestation management in the karst ecological restoration of this research area. Full article

Assessing ecosystem service (ES) supply–demand relationships and identifying their driving forces are essential for ecological security and sustainable ecosystem development. Using ES supply–demand mismatches as a basis, this study characterized the spatiotemporal evolution of ES supply and demand from 2000 to 2023. Additionally, a SHAP-informed Stacking Bayesian optimization model was employed to identify key drivers of supply–demand imbalances. Building on this, threshold-aware spatial optimization of ecosystem service flows was performed using an improved minimum-cost algorithm within an NSGA-II multi-objective framework. The results showed that: (1) The YREB’s supply–demand balance (SDB) exhibited significant spatial heterogeneity. Water SDB declined with fluctuations, decreasing from 5.343 × 10¹¹ m³ to 4.433 × 10¹¹ m³, whereas carbon SDB shifted from a surplus (+1.514 × 10⁹ t) to a deficit (−1.673 × 10⁹ t) during the study period. Crop SDB rose from 1.361 × 10⁸ to 1.450 × 10⁸ t across the study period. (2) Nighttime light intensity (NLI) was the dominant factor for water SDB and carbon SDB, while cropland area was the key driver for crop SDB. (3) Over 2000–2023, water SDB flow increased from 8.5 × 10⁹ m³ to 1.43 × 10¹⁰ m³. Carbon SDB flows more than tripled from 9.576 × 10⁷ tons to 2.89 × 10⁸ tons. Crop SDB flow increased nearly twelvefold over 2000–2023, from 3.3 × 10⁵ t to 3.93 × 10⁶ t. The findings provide scientific support for coordinating ecological conservation and high-quality development across the Yangtze River Economic Belt. Full article

The Vietnamese Mekong Delta (VMD) is experiencing accelerated coastal erosion, driven by upstream sediment trapping, sea-level rise, and local anthropogenic pressures. This study evaluates the effectiveness of pilot breakwater structures in mitigating erosion and supporting mangrove regeneration along the western coast of Ca Mau Province—one of the delta’s most vulnerable shorelines. An integrated methodology combining field-based wave monitoring, remote sensing analysis of shoreline and mangrove changes (2000–2024), and high-resolution Flow-3D hydrodynamic modeling was employed to assess the performance of four breakwater typologies: semi-circular, pile-rock, Busadco, and floating structures. The results show that semi-circular breakwaters achieved the highest wave attenuation, reducing maximum wave height (H_max) by up to 76%, followed by pile-rock (69%), Busadco (66%), and floating structures (50%). Sediment accretion and mangrove stabilization were most consistent around the semi-circular and pile-rock types. Notably, mangrove loss slowed significantly after breakwater installation, with the annual deforestation rate dropping from 7.67 ha/year (2000–2021) to 1.1 ha/year (2021–2024). Simulations further revealed that mangrove width strongly influences wave dissipation, with belts under 5 m offering minimal protection. The findings highlight the potential of hybrid coastal protection strategies that combine engineered structures with ecological buffers. Modular solutions such as floating breakwaters offer flexibility to adapt with evolving shoreline dynamics. These findings inform scalable coastal protection strategies under sediment-deficit conditions. This study contributes to Vietnam’s Coastal Development Master Plan and broader resilience efforts under Sustainable Development Goals (SDGs) 13 and 14, providing evidence to inform the design and scaling of adaptive, nature-based infrastructure in sediment-challenged deltaic environments. Full article

Cultural ecosystem services (CESs) reflect the interaction between ecosystems and human well-being. Owing to constraints in data availability and existing methodological limitations, deriving information from non-material ecosystem attributes was inadequate. We took Yulin City, located in the northern Shaanxi Loess Plateau, as a case study. Based on open-source geospatial data and user interaction data from social media, a coupled multi-source model was applied to elucidate the spatial distribution of CESs’ supply–demand flow. The Maxent and LDA model were utilized to quantify CES supply–demand, whereas the breakpoint and gravity model were applied to explain the direction and intensity of CES flow. The results indicated the following: (1) aesthetic was the most perceivable CES in Yulin, with 27% high supply areas and four demand topics. And the perception of the educational CES was the least pronounced, with only 2% of high supply areas and two demand topics. (2) Yulin exhibited a notable mismatching in CES supply–demand, with the supply–demand matching area constituting only approximately 10%. In the center of the city, CESs displayed a spatial pattern of a supply–demand deficit, while areas farther from the city center presented a spatial pattern of a supply–demand surplus. (3) The flow of CESs followed a pattern of movement from peripheral counties to central counties and from less developed counties to more developed counties. We proposed the following targeted recommendations: introducing low-perception CESs to promote the enhancement of ecosystem services (ESs); and alleviating CES supply–demand mismatches by enhancing transportation accessibility and protecting the ecological environment. Simultaneously, attention should be directed towards the developmental disparities between counties, providing differentiated guidance for CES spatial flow. Our study provided a theoretical foundation for understanding CES supply–demand flow and offered scientific insights for the spatial development of urban CES. Full article

Neglecting ecosystem services has impeded sustainable urban–rural development, particularly in terms of the efficient flow of water supply services between urban and rural areas. This study focuses on the Fenhe River Basin, evaluating water supply and demand at the sub-basin, as well as county levels. Using the InVEST model to analyze basin-level geographic, meteorological, hydrological, and socio-economic data, the study reveals significant spatial and temporal mismatches between water supply and demand from 2010 to 2020. Through the calculated ecosystem services supply and demand ratio (0.3731 in 2010, −0.1555 in 2015, and −0.1063 in 2020), it is found although both supply and demand increased over the period, persistent deficits emerged, with water supply concentrated in upstream areas and demand primarily in downstream regions. The improved network connectivity by 2020, supported by water-saving policies and technological advancements, partially alleviated earlier imbalances. This research contributes a multi-scale framework to analyze ecosystem service flows and compensation mechanisms across grid, sub-basin, and county scales. Overall, the study underscores that research into ecological compensation plays a crucial role in enabling efficient resource flow, enhancing governance systems, and fostering an ecologically friendly urban–rural development model. Full article

This study presents a simulation–optimization framework that integrates deficit irrigation strategies with ecological considerations to mitigate the impact of water abstraction on potential fish populations in river ecosystems. The framework addresses two primary objectives: minimizing fish population loss, an ecological index reflecting environmental impacts, and minimizing the yield reduction of rice crops caused by deficit irrigation. Regression models and adaptive neuro-fuzzy inference systems were employed to simulate the physical and water quality parameters of the river. Additionally, a multivariate linear regression model was developed to estimate potential fish populations using combined physical and water quality indices as inputs. Multi-objective particle swarm optimization was applied to achieve the defined objectives. Results from the case study demonstrate the model’s ability to balance ecological requirements with rice production through deficit irrigation. The ecological degradation of river ecosystems was found to be comparable during dry and normal years, while rice yield decreased by approximately 10% in dry years. Comparisons with unsustainable practices, where ecological flow was disregarded, revealed that significant reductions in rice production are inevitable to sustain river ecosystems. The proposed method provides a practical approach for achieving a fair balance between agricultural benefits and environmental sustainability in river basins, making it a valuable tool for water resource management. Full article

Climate change impacts on runoff, coupled with population and production growth, pose significant risks to aquatic ecosystems. These risks are heightened in countries with rigid institutional frameworks that prevent water extraction from adapting to ecological requirements. Central Chile presents a particularly compelling case due to the coexistence of private water rights, challenges in establishing ecological flows, projected reductions in runoff, and the high country’s population share. This study aims to determine current and future ecological flow deficits using two indicators: the accumulated water volume deficit and the frequency of runoff falling below ecological flow thresholds. Given the absence of defined ecological flows in some basins and uncertainties about future water system operations, an original methodology tailored to the Chilean context is proposed. This analysis focuses on the Mapocho Alto system (five basins), which is highly affected by water extraction and outdated ecological flow definitions. Results indicate that annual deficit volumes during the historical period are low across basins and are concentrated between September and November. Under climate change scenarios (three basins), the deficits remain relatively stable in two basins but shift in January–July. However, in the Arrayán en la Montosa basin, climate change significantly increases the deficit volumes and frequencies due to imbalances between the natural water supply and water demand. The conclusions underscore the necessity of addressing institutional constraints, such as static ecological flow definitions, to prevent severe ecosystem issues in basins where runoff is projected to decline while demand remains constant or increases, a concern applicable to other countries with similar institutional frameworks. Full article

Ulmus pumila L. occupies an important niche in arid ecosystems. This study aimed to investigate the sap flow characteristics of declining Ulmus pumila L. in arid regions and its relationship with environmental factors. During the 2023 growing season (June to October), continuous sap flow monitoring was conducted using thermal dissipation probes (TDPs) on Ulmus pumila L., along with measurements of soil moisture, air temperature, relative humidity, solar radiation, wind speed, and vapor pressure deficit (VPD). The results showed that when the sap flow rate of elm individuals reached 0.92 mL/cm²/h, the trees entered an extremely severe decline stage. Sap flow rates were significantly positively correlated with net solar radiation, relative humidity, VPD, and soil moisture, but negatively correlated with wind speed and real-time rainfall. VPD was identified as the key factor influencing sap flow across different decline stages, while solar radiation was critical in assessing the severity of decline. A weakened correlation between sap flow and solar radiation marked the onset of severe decline. Additionally, soil moisture exhibited a significant positive effect on sap flow rates overall. These findings not only advance our theoretical understanding of plant ecology in arid areas but also offer practical insights for managing Ulmus pumila L. decline, thus contributing to more sustainable resource management and environmental protection strategies. Full article

Understanding the flow processes and pattern optimization of ecosystem services (ESs) supply and demand is crucial for integrated regional ecological management. However, the understanding of the flow process of ESs at the 1 km grid scale is still limited, especially in areas dominated by mineral resource development. The landscape in these areas has undergone significant changes due to mining activities. It is urgent to construct a regional management model that integrates the flow of ecosystem services and mine restoration. This study developed a framework that links ecosystem service flows (ESFs) and ecological security patterns (ESP) based on multi-source ecological monitoring data, constructed an ES supply-demand flow network through the flow properties, and determined the sequence and optimization strategies for mine rehabilitation to achieve integrated regional management. The results show that, except for food production (FP), other services were in surplus overall, mostly in synergistic relationships, but the spatial distribution of their supply and demand was not coordinated. Surplus areas were located mainly in the eastern woodlands, and deficit areas were located in the northwestern production agglomeration centers, suggesting that areas of supply-demand imbalance can be mitigated through ecological integration. Among these, water yield (WY) had a small number of sources and sinks and is limited in area range. Habitat quality (HQ) sources and sinks had the largest area coverage and the highest number. The distribution of ESF corridors, influenced by factors such as the number of sources and sinks, flow characteristics, and spatial resistance, varied significantly. HQ exhibited a more uniform distribution range, while WY had a longer average length of flow path. Overlaying ecological and mining factors, we identified ecological strategic spots, important supply areas, beneficiary areas, and mine priority restoration areas to further optimize the overall layout and rationally allocate the intrinsic structure of the patches based on ES supply and demand. Full article

This study investigates the spatial correlation and service flow of supply and demand for water purification ecosystem services at multiple scales (i.e., the Taihu Lake Basin, sub-basin, and county) by quantitatively assessing the supply–demand relationship of nitrogen and phosphorus and introducing the SPANS algorithm to characterize the service flow paths. Through quantitative analysis, the supply–demand relationship between nitrogen and phosphorus was evaluated, and the SPANS algorithm was introduced to characterize the service flow paths. The results show that the water purification ecosystem services in the southwestern region and around Taihu Lake exhibit a good supply–demand balance, while a significant supply–demand deficit is observed in the northern and southeastern regions. Service flow analysis indicates that surplus areas are primarily concentrated in hilly and urbanized central regions, whereas deficit areas are mainly located in non-urban centers. Based on these findings, ecological compensation suggestions are proposed, including dynamic adjustment, differentiated compensation, cross-city collaboration, and guidance of social capital participation, to promote continuous improvement in water quality and sustainable development within the basin. Full article

This study aimed to evaluate the ecohydrological regime and ecological water demand of the Huangshui River Basin under changing environmental conditions, seeking to safeguard its ecosystem. Based on monthly data spanning from 1956 to 2016, the ecohydrological regimes of the Huangshui River and the Datong River were evaluated using methods such as the Pettitt mutation test, the Tennant method, and ecological deficit and surplus analyses. The data were mainly obtained from Xiangtang Station of the Datong River and Minhe Station of the Huangshui River. The results showed the following. (1) The most abrupt increase in measured runoff at Xiangtang Station occurred in 1993, while the point of abrupt change in measured runoff at Minhe Station occurred in 1990. (2) Following an increase in human activities, changes in the ecological surplus at Xiangtang Station were negative in January, April to May, July, and from September to November, while the changes in the ecological deficit were positive from January to April, July to August, and October to December. Changes in the ecological surplus at Minhe Station were negative from March to July and from September to December, while changes in the ecological deficit were positive from January to April and from July to December. (3) The annual average ecological flow of the Datong River, Xiangtang section, was 28.42 m³/s, and the annual average ecological water demand was 896 million m³. The annual average ecological flow of the Minhe section was 19.98 m³/s, and the annual average ecological water demand was 631 million m³. According to a calculation of the degree of ecological water demand and ecological flow satisfaction, prior to the implementation of the Water Diversion Project from the Datong River to Huangshui River, the water volumes in both rivers were generally sufficient to meet the ecological water demand. However, high water consumption during the irrigation period led to an ecological deficit. To address these issues, it is crucial to evaluate the potential impacts of human activities, such as water diversion projects, on river ecological flow. Recommendations include expediting the Water Diversion Project from the Yellow River to Xining to secure sufficient water flow in the Huangshui River and enhancing water conservation efforts in agricultural irrigation. Full article

Regional integration strategically reorganizes spatially heterogeneous resources to maximize the overall benefits. Ecosystem services (ESs) are promising targets for regional integration due to their inherent heterogeneity and mobility, yet research in this area remains limited. This study quantifies crop production (CP), water yield (WY), carbon storage (CS), and habitat quality (HQ) for the years 2000, 2010, and 2020 using the InVEST model and identifies four ES bundles through a K-means cluster analysis. A conceptual ecosystem service flow (ESF) network at the service cluster scale is constructed based on county-level ESF data. The results reveal the following: (1) there is an upward trend in the ES budget for all services from 2000 to 2020, coupled with spatial mismatches between supply and demand; (2) deficit nodes for CP and CS services are concentrated in densely populated districts, while deficits in WY and HQ services are mainly in western Jilin Province; (3) Bundles I and II act as “sources” of ES, Bundle IV serves as a “sink”, and Bundle III is the only cluster with a CP surplus, balancing CP services across the province. In addition, this study provides ecological perspectives for understanding regional integration by suggesting differentiated integrated management for different ecosystem bundles. Full article

Clarifying the issues related to the supply, demand, and flow of ecosystem services is crucial for regional landscape management. This study employs the equivalence factor method and demand index quantification to analyze the supply and demand of ecosystem services in the Zheng-Bian-Luo region in 2000 and 2020. We used hotspot analysis tools and the minimum cumulative resistance model to establish the ecological corridors, identifying the spatial flow paths of ecosystem services in our site. By calculating the flow volume of the key corridor value through the breakpoint formula and field strength theory and combining this with the ratio of the regulating service value, we computed the ecological compensation amount, thereby realizing the value of the ecosystem service. The results indicate that the area of balance between ecosystem service supply and demand gradually decreased and the deficit area in the Zheng-Bian-Luo region increased 43.62% from 2000 to 2020 along with rapid urbanization. The total value flow of ecosystem services by the important ecological corridors in 2000 and 2020 was USD 242.40 million and USD 365.92 million, respectively. In 2020, it was predicted that Luanchuan County would receive ecological compensation totals of USD 237.76 million from each ecological demand area, and mainly from Jinshui District. Our findings support enhancing the quality of the ecological environment and optimizing the landscape management of the Yellow River’s Henan section. Full article