The importance of uncertainties in scenario analyses--A study on future ecosystem service delivery in Flanders

Urban flood risk differentiation under land use scenario simulation

The frequent urban floods have seriously affected the regional sustainable development in recent years. It is significant to understand the characteristics of urban flood risk and reasonably predict urban flood risk under different land use scenarios. This study used the random forest and multi-criteria decision analysis models to assess the spatiotemporal characteristics of flood risk in Zhengzhou City, China, from 2005 to 2020, and proposed a robust method coupling Bayesian network and patch-generating land use simulation models to predict future flood risk probability. We found that the flood risk in Zhengzhou City presented an upward trend from 2005 to 2020, and its spatial pattern was "high in the middle and low in the surrounding areas". In addition, land use patterns under the sustainable development scenario would be more conducive to reducing flood risk. Our results can provide theoretical support for scientifically optimizing land use to improve urban flood risk management.

Structural and Contentual Complexity in Water Governance

Social-ecological systems and governance are complex systems and crises that affect those systems are likely to be complex as well. Environmental topics are multi-faceted with respect to both structure and content. Structural complexity is about societal and institutional organization and management, whereas contentual complexity deals with environmental (or societal) analyses, knowledge, and problem-solving. Interactions between both are manifold, and it is essential they are included in decision-making. Describing these interactions results in a series of nineteen units, arranged in a matrix according to their prevailing mutual dependencies. These units show dominant processes and concepts, representative of environmental analysis. This approach, called ACCU (aggregation of concepts and complex adapted systems units), is provided with evidence through practices of, in particular, water governance.

Assessing potential ecosystem service dynamics driven by urbanization in the Yangtze River Economic Belt, China

Ecosystem services (ESs) link natural and social processes and play an important role in sustaining ecological security, human well-being, and sustainable development. However, uncertainties in future socioeconomic land use drivers may result in very different land use dynamics and consequences for land-based ESs. In this study, land use transitions in the Yangtze River Economic Belt (YREB) were simulated in the short term (2018-2030), medium term (2030-2040), and long term (2040-2050) using the future land use simulation (FLUS) model based on the local shared socioeconomic pathways (SSPs). According to the projected land use types, six ESs were quantified and assessed regarding how they would evolve under particular land use changes. The results of land use simulations showed that the main features were urban sprawl and a decrease in cropland. In particular, intensive urban sprawl occurred around existing urban areas, and a large amount of cultivated land was converted into urban land. In the YREB, urban land will increase from 88,441 km² in 2018 to 156,173-192,900 km² in 2050, while the cropland area will decrease from 607,131 km² in 2018 to 500,183-596,313 km² in 2050. As a consequence of urban expansion, all ESs exhibited decreasing trends, except for several services under SSP1. Food production (FP), carbon storage (CS), water conservation (WC), soil retention (SR), air purification (AP), and habitat quality (HQ) will decline by 8.98-21.4%, 1.95-6.781%, 2.97-6.5%, 0.9-1.7%, 1.20-5.15%, and 6.11-12.86%, respectively. The ES integrative assessment indicated distinct provincial differences. Developed eastern provinces have higher populations and urbanization; however, these traits result in greater ES losses. We suggest that future land management should control the blind expansion of urban land and enhance the protection of cropland and natural habitats to reduce ES losses.

Future land-use changes and its impacts on terrestrial ecosystem services: A review

Terrestrial ecosystem services (ES) are vulnerable to land use and land cover changes (LULCC). These changes are triggered by different drivers of change (e.g., economic, social, political, environmental - climate change). Understanding the potential future LULCC is an effective way to anticipate the impacts on ES supply. In recent years, some researchers applied different spatial modelling methods to assess the potential LULCC future impacts on ES supply, but so far, no systematic review was carried out. This work aims to do a bibliographic review about future LULCC and their implications on ES supply (provisioning, regulating, and cultural services). After a rigorous bibliographic review, we identified 957 papers. However, only 79 papers meet the criteria to be used in the review. The results showed that (i) the studies have been mainly focused on Asia (55.70%) and Europe (17,72%); (ii) the most common and extensively used models to project future LULCC were cellular automata (30.86%), CLUE-S model (8.64%) and Land Change Modeler (8.64%); and (iii) the most used methods to assess future impacts on ES were the InVEST model (24.04%), and equations used in previous works (12.5%). These studies were mainly focused on measuring future impacts on provisioning (44.11%) and regulating services (43.59%). Also, most of the works lack external validation. The diversity of studies evaluated allowed to recognise gaps and outline insights into the current scientific research on this scientific domain, representing an essential contribution to the current state of knowledge by supporting both practitioners and scientists.

The Influence of Land Use Change on Key Ecosystem Services and Their Relationships in a Mountain Region from Past to Future (1995–2050)

The ecosystem services (ESs) provided by mountain regions can bring about benefits to people living in and around the mountains. Ecosystems in mountain areas are fragile and sensitive to anthropogenic disturbance. Understanding the effect of land use change on ESs and their relationships can lead to sustainable land use management in mountain regions with complex topography. Chongqing, as a typical mountain region, was selected as the site of this research. The long-term impacts of land use change on four key ESs (i.e., water yield (WY), soil conservation (SC), carbon storage (CS), and habitat quality (HQ)) and their relationships were assessed from the past to the future (at five-year intervals, 1995–2050). Three future scenarios were constructed to represent the ecological restoration policy and different socioeconomic developments. From 1995 to 2015, WY and SC experienced overall increases. CS and HQ increased slightly at first and then decreased significantly. A scenario analysis suggested that, if the urban area continues to increase at low altitudes, by 2050, CS and HQ are predicted to decrease moderately. However, great improvements in SC, HQ, and CS are expected to be achieved by the middle of the century if the government continues to make efforts towards vegetation restoration on the steep slopes.

Trade-Off and Projecting Effects of Land Use Change on Ecosystem Services under Different Policies Scenarios: A Case Study in Central China

Predicting the spatio-temporal evolution characteristics and trade-off/synergy relationships of ecosystem service value (ESV) under different policy scenarios is of great significance for realizing regional sustainable development. This study established a framework and used the geographical simulation and optimization systems-future land use simulation (GeoSOS-FLUS) model and bivariate local autocorrelation analysis to stimulate and predict the impact of land use change on the ESV of Anyang City from 1995 to 2025. We also explored the trade-offs and synergy among ecosystem services under three policy scenarios (natural evolution, cultivated land protection, and ecological protection) in 2025. Results show that (1) the land use change in Anyang from 1995 to 2025 was significant, and the degree of land use change under the cultivated land and ecological protection scenarios was more moderate than that under the natural evolution scenario; (2) The total ESV decreased between 1995 and 2015, amounting to losses of 1126 million yuan, and the decline from 2015 to 2025 under the natural evolution scenario was more significant than those under the cultivated land protection and ecological protection scenarios; and (3) an obvious synergy was observed between various ecosystem services in Anyang City under different scenarios in 2025, and the most significant synergy was observed under the natural evolution scenario. In terms of spatial distribution, the agglomeration of “high–high” synergy in the west and “low–low” synergy in the central region was significant. Local areas showed “high–low” and “low–high” trade-off relationships scattered between their built land and woodland or cultivated land. The proposed framework can provide certain scientific support for regulating land use and ecosystem services in rapidly urbanized areas.

Modeling urban encroachment on ecological land using cellular automata and cross-entropy optimization rules

Rapid urban expansion often leads to substantial encroachment on ecological lands and destruction of natural environments. We developed a new cellular automata model (named CA_CEO) that uses cross-entropy optimization (CEO) to reproduce and project urban expansion into coastal areas and to assess urban encroachment on ecological lands. The CEO algorithm automatically searches for the near-optimal CA parameters and is capable of objectively parameterizing CA models to predict multi-objective scenarios. We calibrated CA_CEO by simulating urban expansion at Wenzhou from 1995 to 2005, validated the model from 2005 to 2015 using real data, and then predicted urban expansion for 2025 and 2035. End-state overall accuracies were 93.8% for 2005 and 94.4% for 2015, while figure-of-merit metrics were 27.9% for 2005 and 19.1% for 2015. We predicted four different scenarios to year 2025 and 2035: (1) a business-as-usual (BAU)-scenario using benchmark settings; (2) a District-scenario based on a district-oriented urban development strategy; (3) a Road-scenario based on a road network-oriented urban development strategy; and (4) a Coast-scenario based on a coast-oriented urban development strategy. Each scenario predicts a substantially different pattern of urban encroachment on ecological land and significant loss of farmland, forest, wetland and grassland. These scenarios should be useful in adjusting urban development strategies at Wenzhou and elsewhere.

Investigating spatiotemporal dynamics and trade-off/synergy of multiple ecosystem services in response to land cover change: a case study of Nanjing city, China

Investigating the spatiotemporal trends and trade-off/synergy relationships among ecosystem services can provide effective support for urban planning and decision making toward sustainable development. With Nanjing city in China as a case study, this study assessed the spatiotemporal dynamics of six key ecosystem services from 2005 to 2030. Integration of Markov-cellular automata and ecosystem services models was realized to analyze the potential impacts of future urbanization on ecosystem services by simulating business-as-usual (BAU), cropland protection (CP), and ecological restoration (ER) scenarios. Furthermore, an innovative trade-off/synergy degree was developed to quantify the magnitude of the complex relationship among the multiple ecosystem services under the different scenarios. Due to the rapid expansion of built-up land, carbon storage, habitat quality, and air purification decreased 2.92%, 5.80%, and 7.91%, respectively. The CP scenario exhibited the highest crop production values, and the ER scenario was a better urban development strategy that enhanced the regulating ecosystem services at the expense of crop production. To promote urban ecosystem services and minimize trade-offs, we proposed certain future urban development strategies, including ecological corridor construction and compact development. The study could provide a scientific reference for the effective ecosystem management of Nanjing and other rapidly urbanized regions.

Risk management for optimal land use planning integrating ecosystem services values: A case study in Changsha, Middle China

Land-use change has direct impact on ecosystem services and alters ecosystem services values (ESVs). Ecosystem services analysis is beneficial for land management and decisions. However, the application of ESVs for decision-making in land use decisions is scarce. In this paper, a method, integrating ESVs to balance future ecosystem-service benefit and risk, is developed to optimize investment in land for ecological conservation in land use planning. Using ecological conservation in land use planning in Changsha as an example, ESVs is regarded as the expected ecosystem-service benefit. And uncertainty of land use change is regarded as risk. This method can optimize allocation of investment in land to improve ecological benefit. The result shows that investment should be partial to Liuyang City to get higher benefit. The investment should also be shifted from Liuyang City to other regions to reduce risk. In practice, lower limit and upper limit for weight distribution, which affects optimal outcome and selection of investment allocation, should be set in investment. This method can reveal the optimal spatial allocation of investment to maximize the expected ecosystem-service benefit at a given level of risk or minimize risk at a given level of expected ecosystem-service benefit. Our results of optimal analyses highlight tradeoffs between future ecosystem-service benefit and uncertainty of land use change in land use decisions.