Understanding the complex environmental management through a len of food-water-ecosystem nexus: Insights from an ecosystem restoration hotspot in dryland

Systems Modeling of the Water-Energy-Food-Ecosystems Nexus: Insights from a Region Facing Structural Water Scarcity in Southern Spain

The complex relationship between water, energy, food, and ecological systems, known as the WEFE nexus, has emerged as a major topic in the debate about sustainable economic development and resource management. This subject is of special interest in Mediterranean coastal areas as rapid economic expansion driven by population growth, higher influx of tourists, and intensification of agriculture is leading to structural water scarcity conditions. However, addressing the diverse range of issues associated with the nexus is a difficult task due to the existence of intricate interconnections, interdependencies, and nonlinearities within and across its various components. Accordingly, this case study applies a combination of participatory systems modeling and network analysis tools to yield insights into the complexity of this nexus in Axarquia, a region with features that make it an example of water-stressed jurisdictions in the Mediterranean. Overall, our results provide a strong foundation to understand the dynamics that govern this nexus in regions where the availability of freshwater resources is a significant concern. Furthermore, they lay the groundwork for the development of models and scenarios to simulate the impact of various policies and interventions on the overall system.

Water rights trading planning and its application in water resources management: A water-ecology-food nexus perspective

Nexus approach provides an effective perspective for implementing synergetic management of water resources. In this study, an interval two-stage chance-constrained water rights trading planning model under water-ecology-food nexus perspective (ITCWR-WEF) is proposed to analyze the interaction between water trading and water-ecology-food (WEF) nexus, which fills in the water resources management gaps from a novel nexus perspective. ITCWR-WEF incorporates hydrological simulation with soil and water assessment tool (SWAT), water rights configuration with interval two-stage chance-constrained programming (ITCP), and multi-criterion analysis with Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS). The developed ITCWR-WEF is applied to a real case of Daguhe watershed, which has characteristics of water scarcity, food producing areas and fragile ecosystem. Initial water rights allocation is addressed before the trading. Mechanisms analysis is designed to reveal mutual effect of water rights trading and WEF nexus. Optimal water management scenario is identified through multi-criterion analysis. Results reveal that the mechanism of water rights trading with WEF nexus under low constraint-violation risk level of water availability and environment capacity is recommended to promote the rational water resources allocation to balance the economic goals, water environment and water supply security, as well as ecological and food water demand guarantees.

Land cover change in global drylands: A review

As a sensitive region, identifying land cover change in drylands is critical to understanding global environmental change. However, the current findings related to land cover change in drylands are not uniform due to differences in data and methods among studies. We compared and judged the spatial and temporal characteristics, driving forces, and ecological effects by identifying the main findings of land cover change in drylands at global and regional scales (especially in China) to strengthen the overall understanding of land cover change in drylands. Four main points were obtained. First, while most studies found that drylands were experiencing vegetation greening, some evidence showed decreases in vegetation and large increases in bare land due to inconsistencies in the datasets and the study phases. Second, the dominant factors affecting land cover change in drylands are precipitation, agricultural activities, and urban expansion. Third, the impact of land cover change on the water cycle, especially the impact of afforestation on water resources in drylands, is of great concern. Finally, drylands experience severe land degradation and require dataset matching (classification standards, resolution, etc.) to quantify the impact of human activities on land cover.

Land use changes in Zhangjiakou from 2005 to 2025 and the importance of ecosystem services

Changes in local land use affect regional ecological services, development planning, and optimal use of space. We analyzed the effects of changes in land use from 2000 to 2025 on the spatial distribution of ecosystem services using CLUS-S modeling to evaluate ecosystem functions in Zhangjiakou, China. We found that the urban ecosystem area in Zhangjiakou increased and farmland decreased between 2000-2025. Water conservation was relatively high and was concentrated in the nature reserves of southern Zhangjiakou. Soil conservation was mainly distributed in eastern and southern counties. The results of the CLUE-S model showed that the relative operating characteristics of the six land use types were > 0.70, and the logistic regression equation was able to successfully explain the distribution pattern of the different types of land use.

Analysis of Ecosystem Service Trade-Offs and Synergies in Ulansuhai Basin

As an important grain production base and ecological barrier zone in China, Ulansuhai Basin provides a variety of important ecosystem services and ensures human well-being, and it is essential to maintain the sustainable development of the regional ecology–economy–society. Therefore, in order to explore the trade-offs and synergies between ecosystem services in Ulansuhai Basin, we first evaluated the spatio-temporal characteristics of five ecosystem services in 2000, 2005, 2010, 2015, and 2018 based on the InVEST model, including soil conservation, carbon storage, water production, water purification, and food supply. We then further analyzed the trade-offs and synergies of ecosystem services in Ulansuhai Basin and in different functional areas through using the Spearman correlation coefficient. The results show that different ecosystem services had obvious regional differences due to different land-use types in Ulansuhai Basin. Soil conservation, carbon storage, and water production were higher in the eastern region and lower in the central and western regions, while water purification and food supply were higher in the central region and lower in the eastern and western regions. Ecosystem services showed an overall increasing trend from 2000 to 2018. Moreover, trade-off was the dominant relationship between different ecosystem services, and trade-offs and synergies showed strengthening trends to a certain extent. The trade-offs and synergies of ecosystem services in different functional areas were obviously different. Our study aimed to clarify the trade-offs and synergies between ecosystem services and to propose ecological protection and management countermeasures and suggestions, which can provide decision-making reference for regional ecological protection and management.