Research on the evolution characteristics, driving mechanisms and multi-scenario simulation of habitat quality in the Guangdong-Hong Kong-Macao Greater Bay based on multi-model coupling

Since the 20th century, the global urbanization has led to a series of pollution issues, posing a severe threat to the habitat quality of human habitat. The quality of habitat determines whether ecosystems can provide suitable living conditions for humans and other species. Therefore, systematic study of the habitat quality is essential for the maintenance of sustainable development. In this study, we coupled models such as SD, InVEST and PLUS with a series of indicators to analyze the characteristics of land cover and habitat quality evolution in the Guangdong-HongKong-Macao Greater Bay Area (GBA) from 2000 to 2020 and deconstruct the driving mechanisms of habitat quality. Then simulate the evolution of land cover and habitat quality under different scenarios in 2030. The results show that: 1) Over the historical research period, the GBA exhibited "rapid expansion of artificial surfaces and rapid shrinkage of ecological land". Artificial surfaces increased by approximately 4878.95km2,while ecological land, such as agricultural land, decreased by about 3095.93km2.2) The degradation of habitat quality gradually accelerated and the habitat quality was characterized by "stepwise decline from the periphery to the interior", which was directly related to the land cover changes brought about by the topographic gradient effect in the Bay Area.3) Pollution control driven by environmental investments has had a moderating effect on habitat degradation, but it has not been able to change the overall degradation trend. 4) Scenario analysis suggests that future habitat quality in the GBA will degrade to a certain extent due to the impact of artificial surface expansion. We deduce that this will affect the structure of the city's ecological network as well as the conservation function of the ecological zones. This study provides a scientific basis for understanding the historical and future trends of habitat quality in the GBA, offering new insights into the intrinsic driving mechanisms of habitat quality. It also provides a theoretical support for relevant authorities to undertake sustainable development initiatives.

Ecosystem service valuation and multi-scenario simulation in the Ebinur Lake Basin using a coupled GMOP-PLUS model

The Ebinur Lake Basin is an ecologically sensitive area in an arid region. Investigating its land use and land cover (LULC) change and assessing and predicting its ecosystem service value (ESV) are of great importance for the stability of the basin's socioeconomic development and sustainable development of its ecological environment. Based on LULC data from 1990, 2000, 2010, and 2020, we assessed the ESV of the Ebinur Lake Basin and coupled the grey multi-objective optimization model with the patch generation land use simulation model to predict ESV changes in 2035 under four scenarios: business-as-usual (BAU) development, rapid economic development (RED), ecological protection (ELP), and ecological-economic balance (EEB). The results show that from 1990 to 2020, the basin was dominated by grassland (51.23%) and unused land (27.6%), with a continuous decrease in unused land and an increase in cultivated land. In thirty years, the total ESV of the study area increased from 18.62 billion to 67.28 billion yuan, with regulation and support services being the dominant functions. By 2035, cultivated land increased while unused land decreased in all four scenarios compared with that in 2020. The total ESV in 2035 under the BAU, RED, ELP, and EEB scenarios was 68.83 billion, 64.47 billion, 67.99 billion, and 66.79 billion yuan, respectively. In the RED and EEB scenarios, ESV decreased by 2.81 billion and 0.49 billion yuan, respectively. In the BAU scenario, provisioning and regulation services increased by 6.05% and 2.93%, respectively. The ELP scenario, focusing on ecological and environmental protection, saw an increase in ESV for all services. This paper can assist policymakers in optimizing land use allocation and provide scientific support for the formulation of land use strategies and sustainable ecological and environmental development in the inland river basins of arid regions.

Spatiotemporal dynamics of wetlands and their future multi-scenario simulation in the Yellow River Delta, China

Wetlands, known as the "kidney of the earth", are an important component of global ecosystems. However, they have been changed under multiple stresses in recent decades, which is especially true in the Yellow River Delta. This study examined the spatiotemporal change characteristics of wetlands in the Yellow River Delta from 1980 to 2020 and predicted detailed wetland changes from 2020 to 2030 with the patch-generating land use simulation (PLUS) model under four scenarios, namely, the natural development scenario (NDS), the farmland protection scenario (FPS), the wetland protection scenario (WPS) and the harmonious development scenario (HDS). The results showed that wetlands increased 709.29 km2 from 1980 to 2020 overall, and the wetland types in the Yellow River Delta changed divergently. Over the past four decades, the tidal flats have decreased, whereas the reservoirs and ponds have increased. The gravity center movement of wetlands differed among the wetland types, with artificial wetlands moving to the northwest and natural wetlands moving to the south. The movement distance of the gravity center demonstrated apparent phase characteristics, and an abrupt change occurred from 2005 to 2010. The PLUS model was satisfactory, with an overall accuracy (OA) value greater than 83.48 % and an figure of merit (FOM) value greater than 0.1164. From 2020 to 2030, paddy fields and tidal flats decreased, whereas natural water, marshes and reservoirs and ponds increased under the four scenarios. The WPS was a relatively ideal scenario for wetlands, and the HDS was an alternative scenario for wetland restoration and food production. In the future, more attention should be paid to restoring natural wetlands to prevent further degradation in the Yellow River Delta. This study provides insights into new understandings of historical and future changes in wetlands and may have implications for wetland ecosystem protection and sustainable development.

Optimization of land use planning under multi-objective demand-the case of Changchun City, China

Modeling and scenario analysis are the core elements of land use change research, and in the face of the increasingly serious ecological and environmental problems in urbanization, it is important to carry out land use simulation studies under different protection constraints for scientific planning and policy formulation. Taking Changchun City, the capital of Jilin Province, a pilot national eco-province, as an example, a CLUE-S model with coupled landscape ecological security patterns was constructed to predict and simulate the land use structure and layout under multi-objective optimization scenarios in the planning target year (2030), and the results were analyzed based on landscape index evaluation. The study found the following: (i) the proportion of ecological land area under low, medium, and high security levels in the study area was 8.7%, 64.8%, and 26.5%, respectively; (ii) under the current development trend scenario, the trend of increasing fragmentation of cultivated land patches in Changchun in 2030 will remain unchanged, with construction land spreading along the periphery in a compact and continuous pattern, while ecological land will be seriously encroached upon; and (iii) in the 2030 multi-objective optimization scenario, land use patches of all types will begin to show a tendency to cluster, with less landscape fragmentation and more connectivity, while cultivated land and construction land will also begin to converge and do not deteriorate as a result of spatial conflicts over ecological land.

A simulation-based approach for assessing regional and industrial flood vulnerability using mixed-MRIO model: A case study of Hubei Province, China

Given the unstoppable forces behind regional economic integration trends, damages from a flood disaster in a specific area will influence correlative cities through industrial linkages and make economic systems more vulnerable. Assessing urban vulnerability is an essential part of flood prevention and mitigation, and also a hot topic of recent research. Therefore, this study (1) constructed a mixed multiregional input-output (mixed-MRIO) model to explore ripple effects on other regions and sectors when production in a flooded area is constrained, and (2) applied this model to characterize the economic vulnerability of cities and sectors in Hubei Province, China by simulation. First, various hypothetical flood disaster scenarios are simulated to reveal the ripple effects of different events. The composite vulnerability is assessed by analyzing economic-loss sensitivity rankings across scenarios. Then, the model is applied to the case of a 50-year return period flood that occurred in Enshi City, Hubei Province, on July 17, 2020 to empirically verify the usefulness of such a simulation-based approach in evaluating vulnerability. The results indicate vulnerability is higher in Wuhan City, Yichang City, and Xiangyang City and for three manufacturing sector types: livelihood-related manufacturing, raw materials manufacturing, and processing and assembly manufacturing. Such cities and industrial sectors with high vulnerability will significantly benefit from prioritization in flood management.

Simulation of land use landscape pattern evolution from a multi-scenario simulation: a case study of Nansi Lake Basin in China

Reasonable regulation of the total amount and layout of land resources is the significant cornerstone for releasing the potential of land resources. This study explored the spatial layout and evolution characteristics of the Nansi Lake Basin from the perspective of land use and simulated the spatial distribution pattern under multiple scenarios in 2035 with the Future Land Use Simulation model which more effectively reflected the process of land use change in the actual situation, revealing the land use change of the Nansi Lake Basin under the influence of different human activities. Analysis indicated that the simulation results obtained using the Future Land Use Simulation model strongly agree with reality. By 2035, the magnitude and spatial distribution of land use landscapes will change significantly under three scenarios. The findings provide a reference for the adjustment of land use planning in the Nansi Lake Basin.

Spatiotemporal pattern and multi-scenario simulation of ecological risk in mountainous cities: a case study in Chongqing, China

Scientific descriptions and simulations of the ecological risks in mountainous areas can promote the sustainable use of land resources in these areas and improve the reliability of decision-making for ecological risk management. Taking Chongqing, China, as an example, we constructed a landscape ecological risk (LER) evaluation model based on land use data from 1995 to 2020 and analysed the spatiotemporal evolution characteristics of the LER pattern. Moreover, we coupled the patch-generating land use simulation (PLUS) model and multi-objective programming (MOP) method and input multiple scenarios (inertial development, ID; economic priority development, ED; ecological priority development, PD; and sustainable development, SD) to simulate the ecological risk pattern in 2030. The model coupling the "top-down" and "bottom-up" processes obtained optimal land use patterns in different contexts, and it was used to perform a spatially explicit examination of LER evolutionary trends in different contexts. The results showed that LER evolution in Chongqing has had obvious stage characteristics. The high-risk area decreased significantly under various constraints, including topographic, economic, and other constraints, and the distribution showed a trend of high in the west and low in the east. The LER spatial clustering characteristics were highly coupled with the risk level pattern. The ED scenario presented the most severe risk, the PD scenario presented a moderate risk, and the SD scenario balanced the land demand for economic and ecological development and had a better land use structure and LER compared with the other scenarios. The coupled model proposed in this study helps to obtain the optimal land use structure and mitigate ecological risks, thus providing a scientific basis for future urban development.

Simulating future land use by coupling ecological security patterns and multiple scenarios

A land use simulation model with coupling constraints of ecological security patterns (ESPs) and multiple scenarios (MSs) was developed using the PLUS model. The research scale was zoned with environmental functional regions, where land management policies were formulated. A case study in Anji County successfully demonstrated the application of the ESP-MS-PLUS model. First, we constructed three different levels of ESPs as ecological constraints by utilizing ecosystem services evaluation and circuit theory. Second, four scenarios of land use and land cover changes (LUCCs) in 2034 were assumed, namely business as usual (BAU), priority given to urban development (PUD), priority given to ecological protection (PEP), and balanced urban development and ecological protection (BUE). Then, the basic ecological constraints (ecological red line areas and waters) and three types of ESPs were coupled with the four scenarios. The results of the simulation and analysis of landscape metrics under each scenario showed that the PEP and BUE scenarios would effectively reduce the degree and speed of ecological destruction. In addition, there were three environmental functional areas that could be used as priority areas for urban construction to ensure economic development. This study provides a new mechanism for land use optimization in the context of ecological protection at scales conducive to practice.

Evaluation and prediction of land use change impacts on ecosystem service values in Nanjing City from 1995 to 2030

Land use changes have a considerable impact on ecosystem services (ESs). In recent years, land use changes caused by urban expansion in Nanjing City have been obvious and are expected to further change in the future. Therefore, it is urgent to quantitatively assess ecosystem service value (ESV) changes caused by previous land use changes and future potential changes in Nanjing. In this study, land use data products based on remote sensing images, Dyna-CLUE model, and the ESV equivalent coefficient method were applied to assess the impact of land use changes on ESVs in Nanjing City over the past 23 years (1995-2018), and to forecast the changes of ESV in 2030. The results indicated that the total ESVs of Nanjing City displayed a trend of first increasing and then declining in 1995-2018. From the land use classification, the water area had the largest ESV in Nanjing, followed by arable land. Additionally, the regulating service value was the highest among the four primary ESs in Nanjing from 1995 to 2030, with the highest value of 13.73 billion yuan in 2015. Among the three forecast scenarios, the ecological protection scenario had the highest total ESV and was followed by the urban expansion and business as usual scenarios. These findings may assist for the scientific decision-making of sustainable land use and ecosystem management in Nanjing City.

An integration method to predict the impact of urban land use change on green space connectivity under different development scenarios using a case study of Nanjing, China

Urbanization leads to land use change and fragmentation of green patches, affecting natural habitats and their connectivity. Scientific prediction and analysis of the impact of future land use change on green space connectivity are an effective tool for planning and evaluating urban sustainable development, especially for ecological protection in rapidly developing areas. In this study, an integrated method is proposed that uses the CA-Markov method and combines a morphological spatial pattern analysis (MSPA) with a graph theory analysis to jointly evaluate the impact of land use change on the habitat connectivity index under different urban development scenarios from two aspects of structural and functional connectivity. Using China's rapidly developing Nanjing as the study area, the land use changes under four scenarios in 2030 are forecast, and the connectivity index is analyzed. The results showed that only under the ecological land protection scenario will forest and grassland increase, but the strong barrier effect is still brought about by urban expansion from the analysis of the structural connectivity. At the level of functional connectivity, we identified the important connecting patches and future change trends of species with different diffusion distances. In addition, we identified the key connecting patches (i.e., stepping stones) and changes and suggested giving priority to the protection of these patches. This method can be applied to other rapidly developing cities, and the conclusions can be used as a spatial explicit tool for urban green space and land use planning.

Impact of urban expansion on carbon storage under multi-scenario simulations in Wuhan, China

Carbon storage in terrestrial ecosystems, which is the basis of the global carbon cycle, reflects the changes in the environment due to anthropogenic impacts. Rapid and effective assessment of the impact of urban expansion on carbon reserves is vital for the sustainable development of urban ecosystems. Previous studies on future scenario simulations lacked research regarding the driving factors of changes in carbon storages within urban expansion, and the economic value accounting for changes in carbon storages. Therefore, this study examined Wuhan, China, and explored the latent effects of urban expansion on terrestrial carbon storage by combining the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) and Patch-generating Land Use Simulation (PLUS) model. Based on different socioeconomic strategies, we developed three future scenarios, including Baseline Scenario (BS), Cropland Protection Scenario (CP) and Ecological protection Scenario (EP), to predict the urban built-up land use change from 2015 to 2035 in Wuhan and discussed the carbon storage impacts of urban expansion. The result shows that (1) Wuhan's urban built-up land area expanded 2.67 times between 1980 and 2015, which is approximately 685.17 km² and is expected to continuously expand to 1349-1945.01 km² by 2035. (2) Urban expansion in Wuhan has caused carbon storage loss by 5.12 × 10⁶ t during 1980-2015 and will lead to carbon storage loss by 6.15 × 10⁶ t, 4.7 × 10⁶ t and 4.05 × 10⁶ t under BS, CP, and EP scenarios from 2015 to 2035, accounting for 85.42%, 81.74%, and 78.79% of the total carbon loss, respectively. (3) The occupation of cropland by urban expansion is closely related to the road system expansion, which is the main driver of carbon storage reduction from 2015 to 2035. (4) We expect that by 2035, the districts facing carbon loss caused by the growth of urban built-up land will expand outward around secondary roads, and the scale of outward expansion under various scenarios will be ranked as BS > CP > EP. In combination, the InVEST and the PLUS model can assess the impact of urban expansion on carbon storage more efficiently and is conducive to carrying out urban planning and promoting a dynamic balance between urban economic development and human well-being.

How to reconcile land use conflicts in mega urban agglomeration? A scenario-based study in the Beijing-Tianjin-Hebei region, China

With the development of global urbanization, land use conflicts have become one of the major issues hindering sustainable land use and human-environment coordination in urbanized areas. In this context, reconciliation of land use conflicts requires urgent attention. By taking the Beijing-Tianjin-Hebei (BTH) urban agglomeration as a case study area, the spatial comprehensive conflict index (SCCI) was constructed to identify and evaluate land use conflicts. Besides, the impacts of rapid urbanization and terrain restriction on land use conflicts were also explored using the coupling coordination degree (CCD) model and terrain index, respectively. Then, the Dyna-CLUE model was adopted to simulate land use conflicts under three adaptive scenarios in 2030. Results show that: (1) During 2000-2015, land use conflicts in the BTH region demonstrated an overall mitigating trend, and their spatial patterns remained relatively stable, characterized by significant cluster and belt agglomeration. (2) Land use conflicts were significantly intensified in areas experiencing rapid urban-rural transformation and terrain transition, and two typical conflict zones were identified, i.e. the urban-rural interface of the Beijing-Tianjin region and the terrain transition area located in the Taihang Mountains, Yan Mountains and Bashang Plateau. (3) In 2030, land use conflicts in the BTH region manifest overall mitigation under the ecological security (ES) scenario, while demonstrating an intensifying trend under the business as usual (BAU) scenario and cropland protection (CP) scenario. Based on simulation results, land use spatial optimization modes at county level for the BTH region were formulated. In face of increasingly prominent land use conflicts globally, this study will provide a scientific reference for policymaking in pursuit of sustainable land use management for the BTH region and urban agglomerations in other parts of the world.

Dataset of the land use pattern optimization in Horqin Sandy Land

This dataset uses downloadable public datasets such as the Harmonized World Soil Database (HWSD) to account for ecosystem services such as net primary productivity (NPP) in Horqin Sandy Land in 2015 through ecological process models. The land use pattern of Horqin Sandy Land under three scenarios in 2025 was obtained by CLUMondo model. Based on the spatial distribution of ecosystem services in Horqin Sandy Land in 2015, the land use under three scenarios in 2025 was used as a variable to obtain the optimal pattern of ecosystem services in Horqin Sandy Land through Netica software. This dataset combines land use simulation with ecosystem service optimization, and can provide reference for decision makers and stakeholders to formulate ecosystem governance policies [1].

Optimization of the land use pattern in Horqin Sandy Land by using the CLUMondo model and Bayesian belief network

Land use and cover change is an important concept in the study of ecosystem services, especially in ecologically fragile areas. This study generated three scenarios, namely historical trend (HT), national planning (NP), and windbreak and sand fixation (WS), by using the CLUMondo model and Bayesian belief network (BBN) to explore land use with diverse demands. The CLUMondo model was utilized to simulate the land use probability surface of Horqin Sandy Land in 2025 under different scenarios. A BBN was constructed to investigate the net primary productivity (NPP), crop production (CP), and wind protection and sand fixation (WPSF) of Horqin Sandy Land in 2025 under uncertain land use to identify the short board areas of various services. The following results were obtained from the analysis. (1) The land use pattern of Horqin Sandy Land in 2025 under the HT scenario will be dominated by cultivated land expansion and grassland reduction. Under the NP scenario, forest will increase, and unused land and grassland will decrease considerably. Under the WS scenario, cultivated land will still maintain a similar growth state, but the difference is that forest and grassland will significantly increase. (2) NPP had the highest probability of being the Highest and the lowest probability of being Low, whereas CP and WPSF obtained the highest probability of being Medium and the lowest probability of being Higher. (3) Tuquan County and Wengniute Banner with a high probability of providing few ecosystem services should be regarded as key areas for ecological restoration. Kailu County and Horqin Left-wing Middle Banner can provide higher ecosystem services. The methodology adopted in this study establishes the connection between the land use probability surface and the optimized pattern of ecosystem services and can therefore be applied in areas where multi-objective comprehensive improvement of ecosystem services is expected.

Multi-scale evaluation and multi-scenario simulation analysis of regional energy carrying capacity-Case study: China

The analysis of energy carrying capacity (ECC) is an important basis for measuring the sustainable development level of regional energy carrying systems (ECS) and the selection of regional development models. This study establishes a regional ECS structure model from four subsystems: energy resources, economic development, social development, and ecological environment. The synergistic development relationship between subsystems and the feedback relationship between key elements are analyzed. Using a system dynamics model, the catastrophe progression method and the coupling coordination model are applied to rate the ECC and the coupling coordination degree (CCD) of China's ECS from 2004 to 2018. Furthermore, the status continuation scenario (SCS), policy planning scenario (PPS), strengthen policy scenario (SPS), and policy comparison scenario (PCS) are set up to carry out the multi-scenario simulation of China's ECC, and ECC and CCD in four scenarios from 2019 to 2050 are analyzed. The results reveal that from 2004 to 2018, the socioeconomic, the energy resources, and the energy environment carrying capacities to varying degrees, and the level of China's ECC and CCD increased year by year. It entered a comparably weak carrying level in 2010 and optimized from the uncoordinated stage to the primary coordinated stage in 2008. From 2019 to 2050, the ECC will reach the platform period in 2036 under PPS, and under SPS and PCS it will reach the platform period in 2030; the ECC stages and development coordination optimization nodes are both manifested as that SPS is the earliest, PCS is second, and PPS is the latest. In the future development process, it is recommended that take PPS as the bottom line and SPS as the goal, with high carrying capacity and superior coordinated stages as the guide, and the sustainable development capacity supported by ECS should be strengthened.