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With landsat-series multi-temporal image data, percentage of vegetation cover (PVC) was estimated by pixel dichotomy. The linear regression analysis and center of gravity migration methods were used to explore the characteristics of the spatiotemporal changes of vegetation cover in Shenzhen from 2000 to 2018. The CA-Markov model was combined to predict future land cover in Shenzhen. The results showed that the PVC in Shenzhen demonstrated obvious regional differentiation characteristics from 2000 to 2018. The eastern region occupied larger proportion than the wes-tern part, while the southern region was larger than the north part. This feature exhibited good consistency with regional topographic effect. The spatial migration characteristic of the center of gravity of PVC was from northwest to southeast, and then from southeast to northwest, with a migration rate of 551.2 m·a -1 . This process was closely related to urbanization in Shenzhen. The PVC in Shen-zhen tended to be generally improved from 2000-2018, with a improvement rate of 0.005·a -1 . The percentage of significantly improved and degraded PVC area was 30.8% and 12.8%, respectively. The CA-Markov method was used to predict the land cover/use pattern of Shenzhen in 2024 under two scenarios, theoretical scenario and natural scenario. There was no significant difference in proportion of the area of the land cover/use patterns obtained by the two kinds of prediction method, with the difference threshold being 0-1.2%. Compared with the data before 2018, the proportion of arbor forests and arable land converted into construction land in Shenzhen would be significantly reduced in 2024, whereas the contradiction between supply and demand would be still tense.

Cities and urban areas are an important part of global sustainable development, and the health and well-being of urban residents are closely related to the quality, quantity, and diversity of urban ecosystem services. Although the rapid urbanization process has changed the structure and function of urban ecosystems, which is notably different from natural ecosystems, the affected ecosystem services and their interactions—the trade-off impact of urbanization intensity on ecosystem services—remain to be discussed. Using land use/land cover and impervious surface area remote sensing datasets, and InVEST and RUSLE-related ecosystem services models to evaluate seven typical ecosystem services in Shenzhen, this study explored the evolution of multiple ecosystem service trade-offs and synergies during the transition from a natural ecosystem to an urban ecosystem, and how they are affected by urbanization intensity through correlation analysis and a discrete time-step simulation model. The results show that: (1) from 1978 to 2018, in the process of ecosystem transformation, grain production dropped from 228,795 tons to 11,733 tons, fruit production peaked in 1990 at 271,508 tons, and service capacity of both showed obvious degradation. Conversely, the cultural service capacity was remarkably enhanced. (2) With the increase in urbanization level, the trade-off and synergy of ecosystem services gradually transition from linear to nonlinear. The rapid urbanization process drives the nonlinear degradation of ecosystem services and the nonlinear enhancement of synergy. (3) Over the past four decades, ecosystem service bundles within the same kilometer grid have shown a quadratic curve-like decrease with increasing impervious surface area, slowly in the early stages and faster in the later stages. This study concludes that urbanization intensity has a significant impact on ecosystem service trade-offs, which can provide support for the formulation of ecological protection and restoration strategies in territorial space based on ecosystem services. [ABSTRACT FROM AUTHOR]

Highlights • Sharp decline, abandonment, spatial fragmentation of cultivated land exist in the high urbanization area of China. • Cultivated land protection system with administrative rigidity should transit to "promoting protection by utilization". • An framework for the transition of cultivated land protection is constructed and implementation paths are provided. • It has been achieved initial success in Shenzhen provide a positive reference both in China and globally. Abstract Cultivated land is a key resource and environmental factor for human survival and development, and internationally, special protection is generally imposed on cultivated land. China conducts the most stringent cultivated land protection system worldwide, but the restraint mechanism of rigid control with pure administration cannot change the continuous decreasing trend in the acreage and quality of cultivated land. Shenzhen, which is the city with the fastest economic growth in China and a highly urbanized area with a non-agricultural population, has very serious issues regarding cultivated land encroachment, spatially fragmented distribution, and land abandonment, which has rendered cultivated land protection extremely difficult. In this article, the present cultivated land protection situation in China and other countries is summarized, and the acreage change, spatial distribution, and land abandonment of cultivated land in Shenzhen are summarized and analyzed. Then, we propose an institutional framework for the transition of cultivated land protection in Shenzhen, which includes spatial optimization, management innovation, and safeguard systems. The implementation path to the transition of cultivated land protection includes a basic farmland reformation project, spatial usage control and zoning of cultivated land, tender and bid management for cultivated land leasing, and management innovation for facility agricultural land. The pros and cons of how non-agricultural populations impact cultivated land protection and the compound benefits, including the political, ecological, cultural, and technical aspects, of cultivated land protection in highly urbanized areas are discussed. This article notes the potential risks in management innovation in facility agricultural land. The proposed institutional framework for the transition of cultivated land protection and its implementation paths provide a reference for cultivated land protection and utilization in highly urbanized areas and suburbs with a heavy contradiction between economic growth and cultivated land protection in developing countries. [ABSTRACT FROM AUTHOR]

As an effective approach to sustainable urban planning, integrated urban land-use zoning can contribute tofully understanding the integrated characteristics of urban land-use system, indicating the trend and possibility of land-use transformation, and thus mapping the spatial direction of urban development. However, compared with various case studies on land-use intensity, few land-use zoning is conducted with a special concern on land-use transformation. This paper used Shenzhen City in China as a case study to establish a systematic indicators model for integrated urban land-use zoning with a focus on both current intensity and structure of land-use system and transformation potential derived from socioeconomic system, and then to direct associated spatial development of urban growth in the future. The results show the following: (1) compared with traditional land-use degree index, the revised one through impervious surface area is more suitable in highly-urbanized area for its effectiveness in characterizing small differences among various assessing units; (2) according to current status and transformation potential of urban land-use system, four land-use zones are clustered with the application of self-organizing feature map method and aggregation index, i.e., transfer development zone, moderate development zone, prior development zone, and restrict development zone; and (3) five spatial axes of urban development associated with the zoning scheme are in high accordance with urban comprehensive plan of Shenzhen City. Therefore, the proposed integrated land-use zoning model is effective to characterize current land-use system, and its transformation potential exerted by socioeconomic system, and thus to make certain the primary landscape functions of various land-use zones and provide practical guidance for urban planning. [ABSTRACT FROM AUTHOR]

The thermal-environment effect exists in the field of rapid urbanization. It has adverse effects on the urban atmosphere, regional climate, energy consumption, and public health. Shenzhen, a representative of rapidly urbanizing cities in China, was selected as a case for pattern dynamics analysis of the thermal environment. The surface temperature was acquired from the thermal infrared data of Landsat TM and ETM+ images in 1986, 1995, and 2005 by Jiménez-Muñoz and Sobrino's generalized single-channel method, which was used in assessing the distribution and spatial patterns of the thermal environment. The relative thermal environment curve (RTC) was combined with Moran's I analysis to assess the pattern dynamics of the thermal environment in different urbanization periods. Moran's I index and the RTC represent a process of aggregation-fragmentation-aggregation, which shows the aggregation pattern of a decrease during the rapid urbanization period and then an increase during the steady urbanization period. High-temperature areas gradually expanded to a uniform and scattered distribution in the rapid urbanization period; while the high thermal-environment effect was gradually transformed into a steady spatial pattern in the stable urbanization period. To characterize the increasing development in this multiple-center city, we chose profiles along an urban-development axis. The results suggest that heat islands have expanded from internal urban to external urban areas. Four profiles were obtained showing differences in shape due to spatial differences in the process of development. [ABSTRACT FROM AUTHOR]

Abstract: Landscape fragmentation is usually caused by many different anthropogenic influences and landscape elements. Scientifically revealing the spatial relationships between landscape fragmentation and related factors is highly significant for land management and urban planning. The former studies on statistical relationships between landscape fragmentation and related factors were almost global and single-scaled. In fact, landscape fragmentations and their causal factors are usually location-dependent and scale-dependent. Therefore, we used geographically Weighted Regression (GWR), with a case study in Shenzhen City, Guangdong Province, China, to examine spatially varying and scale-dependent relationships between effective mesh size, an indicator of landscape fragmentation, and related factors. We employed the distance to main roads as a direct influencing factor, and slope and the distance to district centers as indirect influencing factors, which affect landscape fragmentation through their impacts on land use and urbanization, respectively. The results show that these relationships are spatially non-stationary and scale-dependent, indicated by clear spatial patterns of parameter estimates obtained from GWR models, and the curves with a characteristic scale of 12 km for three explanatory variables, respectively. Moreover, GWR models have better model performance than OLS models with the same independent variable, as is indicated by lower AICc values, higher Adjusted R 2 values from GWR and the reduction of the spatial autocorrelation of residuals. GWR models can reveal detailed site information on the different roles of related factors in different parts of the study area. Therefore, this finding can provide a scientific basis for policy-making to mitigate the negative effects of landscape fragmentation. [ABSTRACT FROM AUTHOR]

Building sustainable and resilient cities has become one of the most pressing development challenges facing the world today. Ever-increasing environmental pressures – from emission reduction to pollution prevention – underline the need to balance economic progress with the concern for the environment. Finding new ways of facilitating economic growth within environmental constraints is central to urban sustainable development. In this study, we develop a robust-optimization-based urban agriculture planning (ROB-UAP) model to help decision makers make decisions that are both economically viable and environmentally sustainable. The model enables consideration of more stringent pollution controls in response to the inherent uncertainty in the complex system. Shenzhen City, as the economic engine of the Guangdong-Hong Kong-Macau Greater Bay Area, also faces challenges of urban sustainability transitions. The proposed model is applied to the planning problem of Shenzhen City's urban agriculture system to support environment-oriented agricultural restructuring. We produce six risk-based scenarios to help evaluate the trade-offs between economic returns and environmental impacts. The results show that under expected economic conditions the overall output of the system could be increased by at least 8%, indicating that agricultural restructuring could indeed contribute to the economic growth of the city. In addition, the total amount of the major pollutants could be more or less reduced in the risk-averse and risk-tolerant scenarios; thereby delivering robust decision-making is essential for enabling environmentally low-impact outcomes in planning practices. [Display omitted] [ABSTRACT FROM AUTHOR]