A Regional Sustainable Intensive Land Use Evaluation Based on Ecological Constraints: A Case Study in Jinan CityPublished: 08 March 2019 by MDPI in Sustainability
Intensive development is a sign of human social progress, and moderate intensification is a continuously pursued goal. However, how to conduct a moderately intensive land use evaluation remains a challenge. To solve this problem, this research proposes the concept of sustainable intensification variable and develops a sustainable intensification variable model to determine the appropriate interval of regional intensive land use and evaluate the intensification of land use. The evaluation method of the sustainable intensification variable model is based on the principle and method of the intensification variable, and the regional sustainable development evaluation factors in the model are revised based on rational land use and ecological constraints. To verify the rationality of the model and systematically evaluate the intensification of land use in the city of Jinan, this method was tested using land use data and social economic data on Jinan from 2001, 2011, and 2015. The results show that the model has a high accuracy in judging the moderately intensive interval of regional land use and evaluating intensive land use, and has important reference value for regional sustainable development decision-making.
Do urban planning policies meet sustainable urbanization goals? A scenario-based study in Beijing, ChinaPublished: 01 March 2019 by Elsevier BV in Science of The Total Environment
The global urbanization process has been a concern in recent years, and it is a serious challenge to sustainable development and effective urban governance. Rapid changes in urban land use have caused serious damage to the global ecological environment and ecosystem services (ESs). To help city planners and decision-makers in the process of city planning, it is vital to assess the impacts of urban land use changes on ESs. In this study, urban development under trend continuation and policy planning scenarios were assessed to determine whether the policy planning scenario meets the needs of sustainable urbanization. The two scenarios of future urban expansion in Beijing in 2035 were simulated by the FUTURES (FUTure Urban-Regional Environment Simulation) model, and the spatio-temporal changes of ESs in the two scenarios were explored through the InVEST (Integrated Valuation of Environmental Services and Tradeoffs) model. The results show that the major losses of ESs came from the conversion of cropland land to urban land, which accounts for 79.70% and 69.62% of the total carbon storage loss, 67.88% and 43.94% of the total water yield loss, and 79.94% and 77.72% of the total habitat quality loss, under the Status Quo (SQ) and urban planning development (UPD) scenarios, respectively. Our results emphasize that the policies proposed by the UPD scenario appear to greatly reduce the negative impacts of urban land use change on ESs. However, the government cannot neglect the protection of forest and needs to intensify the implementation of policies implementation in the shallow mountainous areas of the western margins and northeastern and northern regions of Beijing. By understanding the trade-off between future urban structure and ESs, city planners and decision-makers can adjust and optimize suggestions for urban planning policies to achieve sustainable development.
Forest surface area is a fundamental input for forest-related research, such as carbon balance, biodiversity conservation, and ecosystem functioning and services. However, an accurate assessment of the area of forestland in China is not available because the forested area is usually calculated as a 2D projected area rather than a 3D surface area, and the impact of changes in the surface terrain on the area is ignored. In this study, we propose an integrated multiscale method that combines geomorphic regionalization and surface area algorithms to calculate the forest surface area in China. The results show that (1) China’s forested area is approximately 4.91% larger than the conventional estimates and corresponds to a carbon storage estimate that is approximately 383.72 million tons higher; (2) the integrated multiscale method exhibits good adaptability and high precision for large-scale surface area calculations; and (3) the calculation results of this method are superior to those of remote sensing data or single surface area algorithms, and the calculation efficiency is high.
Urban metabolism is a complex system problem that takes into account urban dynamic behavior such as material, energy, and capital flows. The available methods for urban metabolism are all approaches that consider an urban system to be a “black box”, accounting the input and output flows of energy and material, but lacking an analysis of internal elements and the metabolic processes. This study introduced a system dynamics model to study the stocks, flows, activities, and drivers within an urban system, and developed a double-layer model to implement metabolic modeling at two spatial scales. The system dynamics model is built from the perspective of demand-driven to simulate the input of different resources and materials in the urban metabolism. Emergy analysis was used to calculate the value of variables and evaluate metabolic status. A detailed case study for Jing-Jin-Ji agglomeration of China is used to validate the model and identify major drivers. Results show that the system dynamics approach is suitable for the research of urban metabolism. In future work, more metabolic details should be developed in the model to reduce the impact of data limitations, and more component drivers that affect urban metabolism and relationships within the system should be considered.
Unmanned aerial vehicle (UAV) low-altitude remote sensing technology has recently been adopted in China. However, mapping accuracy and production processes of true digital orthophoto maps (TDOMs) generated by UAV images require further improvement. In this study, ground control points were distributed and images were collected using a multi-rotor UAV and professional camera, at a flight height of 160 m above the ground and a designed ground sample distance (GSD) of 0.016 m. A structure from motion (SfM), revised digital surface model (DSM) and multi-view image texture compensation workflow were outlined to generate a high-precision TDOM. We then used randomly distributed checkpoints on the TDOM to verify its precision. The horizontal accuracy of the generated TDOM was 0.0365 m, the vertical accuracy was 0.0323 m, and the GSD was 0.0166 m. Tilt and shadowed areas of the TDOM were eliminated so that buildings maintained vertical viewing angles. This workflow produced a TDOM accuracy within 0.05 m, and provided an effective method for identifying rural homesteads, as well as land planning and design.
In land-use change studies, scenario simulations cannot be effectively realized because of Geographic Information System (GIS) temporal-spatial interoperability bottlenecks. Based on a previous temporal-spatial dynamics method (TSDM) established by the author, this study extended the previous model and proposed an extended TSDM (ETSDM): (1) The neighborhood of cellular automata (CA) model was extended to a “Square + Circle” neighborhood, making the neighborhood more realistic and improving the simulation accuracy to a certain extent. (2) To achieve dynamic data exchange between the CA model and GIS, the scenario simulation of temporal and spatial visual interoperability from a national planning scheme or spatial location delineation to planning implementation effects can be implemented. Based on land-use data for 1995, 2005, and 2013, the simulation accuracy of the ETSDM was verified and development patterns were predicted under the following scenarios. Scenario 1 used the independent Beijing, Tianjin, and Hebei Province, and was designed as a blank control. Scenario 2 used the coordinated Beijing–Tianjin–Hebei (BTH) development area. This area was projected in order to study the probable land-use patterns in temporal and spatial dimensions under the effects of national policy data. Scenario 3 added the Xiongan New Area on the basis of Scenario 2, which was used to explore the influences of sudden land-use policies on regional land-use patterns. The results indicate that: (1) A “Square + Circle” neighborhood details the type of neighborhood cells and has an approximately 1% accuracy improvement relative to the general neighborhood rules; (2) According to the interactive operation in the model, land-use graph-number changes in the specific target region under different land-use policies can be monitored; and (3) Under different development policies, the built-up land gross of Beijing will be conserved approximately 600 km2, along with the coordinated development of the BTH region and the establishment of the Xiongan New Area in 2030. At the same time, cropland conditions will be improved. A reason for the results may be that some of the non-capital functions will be transferred to Tianjin and Hebei Province under the national policies.
Quantitative Analysis of the Determinants Influencing Urban Expansion: A Case Study in Beijing, ChinaPublished: 18 May 2018 by MDPI in Sustainability
A quantitative analysis of spatial influencing factors on urban sprawl can offer better support for urban planning and management. There are many concerns regarding the influence of each factor. However, a quantitative analysis to detect the interactions between factors is limited because of the complexity of the urban systems, especially the role of planning. Additionally, spatial heterogeneity is often overlooked. This study aims to improve and strengthen the knowledge in this field through a spatial statistical method known as GeoDetector. A new spatial quantification of urban expansion was presented in this study and the spatio-temporal characteristics and mechanism of urban growth in Beijing from 2010 to 2015 were also analyzed. The results show that urban expansion presents spatial heterogeneity with different grid cells, and the optimal scale was 4500 m. At this scale, urban expansion in Beijing linearly expands along the traffic trunk. In addition, urban expansion in Beijing is jointly influenced by socioeconomic, geographical, and policy factors. Population density has had the greatest influence on urban expansion from 2010 to 2015, and policy factors rank first. The impact of economic factors on urban growth is gradually weakening. It is important for urban geographical research to further plans and guide urban development.
In the study of spatiotemporal geographical phenomena, the space–time interpolation method is widely applied, and the demands for computing speed and accuracy are increasing. For nonprofessional modelers, utilizing the space–time interpolation method quickly is a challenge. To solve this problem, the classical ordinary kriging algorithm was selected and expanded to a spatiotemporal kriging algorithm. Using the OpenCL framework to integrate central processing unit (CPU) and graphic processing unit (GPU) computing resources, a parallel spatiotemporal kriging algorithm was implemented, and three experiments were conducted in this work to verify the results. The results indicated the following: (1) when the size of the prediction point dataset is consistent, the performance of the method is robust with the increasing size of the observation point dataset; (2) the acceleration effect of the parallel method increases with an increased number of predicted points. Compared with the original sequential program, the implementation of the improved parallel framework showed a 3.23 speedup, which obviously shortens the interpolation time; (3) when cross-validating the temperature data in the Beijing Tianjin Hebei region, the space–time acceleration model provides a better fit than traditional pure space interpolation.
Impact of Land-Use and Land-Cover Change on Meteorology in the Beijing–Tianjin–Hebei Region from 1990 to 2010Published: 12 January 2018 by MDPI in Sustainability
Land use and land cover (LULC) in the Beijing–Tianjin–Hebei region has changed significantly since 1990. To comprehensively understand its impact on meteorology, this paper uses an LULC transfer matrix to discuss changes 10 years before the millennium (BM) and 10 years after the millennium (AM). The Weather Research and Forecasting (WRF) model is used to simulate air temperature, precipitation, and wind speed in January and July using 1990, 2000, and 2010 LULC data. The temperature increase in the AM period (0.118 °C) was greater than that in the BM period (0.042 °C) and increased by 0.36 °C in response to the transformation from croplands to urban and built-up lands (UBL). The change in precipitation showed an obvious seasonal difference, where the trend decreased in winter and increased in summer. There was a small band of precipitation change that extended from Beijing to Shijiazhuang. The wind speed at 10 m decreased by 0.04 m/s in winter and 0.017 m/s in summer. Simultaneously, the impact on meteorology from different classification transformations was quantified. The region where land was transformed into UBL had the largest reduction in wind speed, and was later transformed into woodlands. A comprehensive discussion on the impact of LULC changes on climate should support the future development of more environmentally compatible and sustainable land planning.
The scientific measurement of land use in space is an essential task in urban agglomeration studies, and the fractal feature is one of the most powerful tools for describing the phenomenon of space. However, previous research on the fractal feature of land use has mostly been conducted in urban space, and examines the fractal feature of different land use types, respectively; thus, the measurement of the relationship between different land use types was not realized. Meanwhile, previous prediction methods used for spatial land use mostly relied on subjective abstraction of the evolution, theoretically, regardless of whether they were calibrated, so that complete coverage of all the mechanisms could not be guaranteed. Based on this, here, we treat the land use structure in urban agglomeration space as the research object, and attempt to establish a fractal measure method for the relationship between different land use types in the space of urban agglomeration. At the same time, we use the allometric relationship between “entirety” and “local” to establish an objective forecast model for the land use structure in urban agglomeration space based on gray prediction theory, to achieve a predictive measurement of the structure of land use in urban agglomeration space. Finally, this study applied the methods on the Beijing–Tianjin–Hebei urban agglomeration to analyze the evolution of the stability of the structure of land use and achieve predictive measurement of the structure of land use. The results of the case study show that the methods proposed in this study can obtain the measurement of the relationship between different land use types and the land use prediction that does not depend on the subjective exploration of the evolution law. Compared with the measurement methods that analyzed the fractal feature of different land types, respectively, and the prediction methods that rely on subjective choice, the methods presented in this study recaps some innovations and reference values for relevant future research.
Decentralization and Polycentricity: Spatial Changes of Employment in Beijing Metropolitan Area, ChinaPublished: 24 October 2017 by MDPI in Sustainability
Decentralization and polycentric spatial structure strategies are important ways to alleviate urban disease in China. However, whether the urban spatial structure is meeting expectations is still unknown. Taking the Beijing Metropolitan Area as a case, the author adopted a non-parametric method to identify the subcenters, then an employment density model was used to analyze the spatial changes of employment and the employment centers’ impacts on the urban spatial structure. The results show that the Beijing Metropolitan Area was undergoing processes of employment decentralization, the monocentric structure was obvious throughout this time, but the polycentric model prevailed. The spatial structure of the Beijing Metropolitan Area was characterized as depicting “all centers aggregation” and the spatial structure of the central district of Beijing can be described as “subcenter agglomeration” between 2004 and 2013. The spatial structure became increasingly polycentric in the Beijing Metropolitan Area, but became more scattered in the central district.
Volume estimation is a fundamental problem in the morphometric study of impact craters. The Top Hat Transform function (TH), a gray-level image processing technique has already been applied to gray-level Digital Elevation Model (DEM) to extract peaks and pits in a nonuniform background. In this study, an updated Black Top Hat Transform function (BTH) was applied to quantify the volume of lunar impact craters on the Moon. We proposed an iterative BTH (IBTH) where the window size and slope factor were linearly increased to extract craters of different sizes, along with a novel application of automatically adjusted threshold to remove noise. Volume was calculated as the sum of the crater depth multiplied by the cell area. When tested against the simulated dataset, IBTH achieved an overall relative accuracy of 95%, in comparison with only 65% for BTH. When applied to the Chang’E DEM and LOLA DEM, IBTH not only minimized the relative error of the total volume estimates, but also revealed the detailed spatial distribution of the crater depth. Therefore, the highly automated IBTH algorithm with few input parameters is ideally suited for estimating the volume of craters on the Moon on a global scale, which is important for understanding the early processes of impact erosion.
Design of a Model Base Framework for Model Environment Construction in a Virtual Geographic Environment (VGE)Published: 04 May 2017 by MDPI in ISPRS International Journal of Geo-Information
The model environment is a key component that enables a virtual geographic environment (VGE) to meet the scientific requirements for simulating dynamic phenomena and performing analyses. Considering the comprehensiveness of geographic processes and the requirements for the replication of model-based research, this paper proposes a model base framework for a model environment of a VGE that supports both model construction and modelling management, resulting in improved reproducibility. In this framework, model management includes model metadata, creation, deposition, encapsulation, integration, and adaptation; while modelling management focuses on invoking the model, model computation, and runtime control of the model. Based on this framework, to consider the problem of ever-worsening air quality, we applied the Linux-Apache-MySQL-Perl stack plus Supervisor to implement the model base to support a VGE prototype using professional meteorological and air quality models. Using this VGE prototype, we simulated a typical air pollution case for January 2010. The prototype not only illustrates how a VGE application can be built on the proposed model base, but also facilitates air quality simulations and emergency management.
Urban expansion has become a widespread trend in developing countries. Road networks are an extremely important factor driving the expansion of urban land and require further study. To investigate the relationship between road networks and urban expansion, we selected Beijing, New York, London, and Chicago as study areas. First, we obtained urban land use vector data through image interpretation using a remote sensing (RS) and geographic information systems (GIS) platform and then used overlay analysis to extract information on urban expansion. A road network density map was generated using the density analysis tool. Finally, we conducted a spatial statistical analysis between road networks and urban expansion and then systematically analyzed their distribution features. In addition, the Urban Expansion-Road Network Density Model was established based on regression analysis. The results indicate that (1) the road network density thresholds of Beijing, New York, London, and Chicago are 18.9 km/km2, 37.8 km/km2, 57.0 km/km2, and 64.7 km/km2, respectively, and urban expansion has an inverted U-curve relationship with road networks when the road network density does not exceed the threshold; (2) the calculated turning points for urban expansion indicate that urban expansion initially accelerates with increasing road network density but then decreases after the turning point is reached; and (3) when the road density exceeds the threshold, urban areas cease to expand. The correlation between urban expansion and road network features provides an important reference for the future development of global cities. Understanding road network density offers some predictive capabilities for urban land expansion, facilitates the avoidance of irregular expansion, and provides new ideas for addressing the inefficient utilization of land.
In the current era, competition among countries and regions is in fact among cities. Thus, how to measure urban competitiveness precisely is a basic and important question. The two main approaches to this are comprehensive evaluation based on a set of indicators and network analysis based on inter-city relations. However, both have shortcomings. In this study, we introduced structural equation model (SEM) into urban competitiveness measurement to integrate the two approaches. We built a partial least squares structural equation model (PLS–SEM) according to the analysis of causal relationship among urban attribute indicators → urban functions → urban competitiveness → urban flow intensities. Following the processes of algorithm selection, model building, fitting and assessment, and modification in PLS-SEM modeling, we measured the urban competitiveness of Chinese cities in 2010 and analyzed its distribution quantitatively and spatially. The results revealed relationships between factors contained in the model and urban competitiveness and proved that the PLS-SEM urban competitiveness measurement approach we proposed is theoretically reliable and statistically valid.
A modelling system with adjustable emission inventories for cross-boundary air quality management in Hong Kong and the P...Published: 01 March 2017 by Elsevier BV in Computers, Environment and Urban Systems
Air quality problems are attracting much attention in Hong Kong (HK) and the Pearl River Delta (PRD) in China. The complex and regional characteristics of air quality problems call for a comprehensive modelling system with a highly reliable simulation and effective communication tools for decision-makers and participants from multiple disciplines. In this paper, we used a modelling management method to develop a Cyberinfrastructure system that couples meteorological and air quality models with a visual analysis to improve the cognition and management of air quality problems. The database management of both the data and the modelling parameters is an innovative advantage of this system; this will be helpful not only for sharing modelling knowledge but also for improving the acknowledgement of modelling scenarios, which are usually conducted by various stakeholders. On the basis of 19 categories of emission inventories that provide detailed information about multiple pollutants in the 11 cities in the study area, this system provides an authoritative and adjustable emission inventory to draw an accurate scientific picture for decision-makers. We applied this system to a case study to investigate the effects of emission control of nitrogen dioxide from vehicles in HK and the PRD on air quality. The simulation showed that the air quality improvement from emission control was very limited and suggested that regional and super-regional co-operation involving the comprehensive emission control of multiple pollutants may be more effective in creating a better future.
Corrigendum: Giant barocaloric effect in hexagonal Ni2In-type Mn-Co-Ge-In compounds around room temperaturePublished: 29 March 2016 by Springer Nature in Scientific Reports
The most widespread cooling techniques based on gas compression/expansion encounter environmental problems. Thus, tremendous effort has been dedicated to develop alternative cooling technique and search for solid state materials that show large caloric effects. An application of pressure to a material can cause a change in temperature, which is called the barocaloric effect. Here we report the giant barocaloric effect in a hexagonal Ni2In-type MnCoGe0.99In0.01 compound involving magnetostructural transformation, Tmstr, which is accompanied with a big difference in the internal energy due to a great negative lattice expansion(ΔV/V ~ 3.9%). High resolution neutron diffraction experiments reveal that the hydrostatic pressure can push the Tmstr to a lower temperature at a rate of 7.7 K/kbar, resulting in a giant barocaloric effect. The entropy change under a moderate pressure of 3 kbar reaches 52 Jkg−1K−1, which exceeds that of most materials, including the reported giant magnetocaloric effect driven by 5 T magnetic field that is available only by superconducting magnets.
The aim of this study is to develop a new approach for delineating urban growth boundaries (UGBs) by applying the weight of evidence (WOE) method to land suitability assessments. Rapid urbanization is causing urban areas to encroach on agricultural land in China, posing a threat to national food security. Land use planning with clear delineation of UGBs is an effective method for controlling urban expansion. However, existing methods for delineating UGBs are typically complex or involve arbitrary decision-making. To address these drawbacks, we introduced the WOE method to develop a new UGB delineation approach, and applied this approach to a case study in the city of Jinan, China. This application achieved satisfactory accuracy; therefore, we concluded that the WOE method was an objective and effective approach to land use suitability assessments and UGB delineation. Land use planning could be benefitted considerably from the application of this method to land allocation and other planning decisions.
The correlation of urban metabolism and changes in land use is an important issue in urban ecology, but recent research lacks consideration of the mechanisms and interactions between them. In this research, we did an emergy analysis of the flows of materials, energy, and capital within the socioeconomic system of Beijing. We calculated emergy-based evaluation indices of urban metabolism and land use change, to analyze the relationship between urban metabolism and land use by correlation analysis and regression analysis. Results indicate that the socio-economic activities on built-up land depend on local, non-renewable resource exploitation and external resource inputs. The emergy utilization efficiency of farmland has consistently decreased, but there remains significant utilization potential there. Urban development in Beijing relies on production activities on built-up land, which is subjected to great environmental pressure during extraction of material resources. To keep the economy developing effectively, we suggest that Beijing should commit to development of a circular economy, and change the land-use concept to “Smart Growth”. In this paper, we efficaciously solve the problem of conflicting measurement units, and avoid the disadvantages of subjective assignment. Consequently, this work provides not only a more scientific way to study land problems, but also provides a reliable reference for ecological construction and economic development in Beijing.
Giant Negative Thermal Expansion in Bonded MnCoGe-Based Compounds with Ni2In-Type Hexagonal StructurePublished: 02 February 2015 by American Chemical Society (ACS) in Journal of the American Chemical Society
MnCoGe-based compounds undergo a giant negative thermal expansion (NTE) during the martensitic structural transition from Ni2In-type hexagonal to TiNiSi-type orthorhombic structure. High-resolution neutron diffraction experiments revealed that the expansion of unit cell volume can be as large as ΔV/V ∼ 3.9%. The optimized compositions with concurrent magnetic and structural transitions have been studied for magnetocaloric effect. However, these materials have not been considered as NTE materials partially due to the limited temperature window of phase transition. The as-prepared MnCoGe-based compounds are quite brittle and naturally collapse into powders. By using a few percents (3–4%) of epoxy to bond the powders, we introduced residual stress in the bonded samples and thus realized the broadening of structural transition by utilizing the specific characteristics of lattice softening enforced by the stress. As a result, giant NTE (not only the linear NTE coefficient α but also the operation-temperature window) has been achieved. For example, the average α̅ as much as −51.5 × 10–6/K with an operating temperature window as wide as 210 K from 122 to 332 K has been observed in a bonded MnCo0.98Cr0.02Ge compound. Moreover, in the region between 250 and 305 K near room temperature, the α value (−119 × 10–6/K) remains nearly independent of temperature. Such an excellent performance exceeds that of most other materials reported previously, suggesting it can potentially be used as a NTE material, particularly for compensating the materials with large positive thermal expansions.
Rapid industrialization, as one of the main driving forces promoting sustainable economic growth, has increased the area of industrial land use significantly. Industrial land use manifests that the competition between it and other kinds of land use is growing. During the last decade in China, many targeted industrial land use policies have been enacted to stimulate appropriate industrial land use and to promote healthy economic development. However, it is difficult for scholars and governments of rapidly developing countries to judge and evaluate the performance of such policies. Based on statistical data gathered over almost 10 years and an idea called “industrial land equivalent” (ILE), this paper analyzes the contribution made by the implementation of industrial land use policy to economic development, using a Cobb-Douglas production function by which to quantify the influence of land institutions and land regulation systems. The result of the study shows that factors, such as industrial land, labor and capital, all play an important role in GDP growth. Additionally, it is found that industrial land institutions and regulation systems have a strongly positive influence on economic development. It was also found that the influence of policy in eastern China is greater than that in the west and that repeated, short-term land regulation has a negative effect on the economy. Therefore, it is profoundly important for the Chinese economy that a stable and durable industrial land use policy be maintained as the industrial center migrates to the Midwest. The research philosophy and method offered by this paper have great significance for the quantitative evaluation of policy performance.
We introduce the Gini coefficient to assess the rationality of land use structure. The rapid transformation of land use in China provides a typical case for land use structure analysis. In this study, a land Gini coefficient (LGC) analysis tool was developed. The land use structure rationality was analyzed and evaluated based on statistical data for China between 1996 and 2008. The results show: (1)The LGC of three major land use types–farmland, built-up land and unused land–was smaller when the four economic districts were considered as assessment units instead of the provinces. Therefore, the LGC is spatially dependent; if the calculation unit expands, then the LGC decreases, and this relationship does not change with time. Additionally, land use activities in different provinces of a single district differed greatly. (2) At the national level, the LGC of the three main land use types indicated that during the 13 years analyzed, the farmland and unused land were evenly distributed across China. However, the built-up land distribution was relatively or absolutely unequal and highlights the rapid urbanization in China. (3) Trends in the distribution of the three major land use types are very different. At the national level, when using a district as the calculation unit, the LGC of the three main land use types increased, and their distribution became increasingly concentrated. However, when a province was used as the calculation unit, the LGC of the farmland increased, while the LGC of the built-up and unused land decreased. These findings indicate that the distribution of the farmland became increasingly concentrated, while the built-up land and unused land became increasingly uniform. (4) The LGC analysis method of land use structure based on geographic information systems (GIS) is flexible and convenient.
The cultivated land protection has become a leading concern influencing the actions of the Chinese government and people. This study introduces a method named as the weight of evidence (WOE) using natural and geographical location factors to evaluate the suitability of Jinan cultivated land. Evaluation results show that: (1) weight of evidence method as a pure data-driven approach is suitable for confirming each index’s weight in the cultivated land suitability evaluation, and the weights are objective and easy to be explained; (2) weight of evidence method uses raster data which are convenient for spatial analysis and does not need to unify the evaluation unit; (3)About 60.25% of land in Jinan has superior suitability as cultivated land. The technical ideas and methods proposed in this paper can provide support for taking a fresh look at land suitability evaluation and policy making. It will also help decision-makers optimize land allocation and make better land-use planning decisions. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
This study investigated and simulated land use patterns in Beijing for the year 2000 and the year 2005 from the actual land use data for the year 1995 and the year 2000, respectively, by combining spatial land allocation simulation using the CLUE-S model, and numerical land demand prediction using the Markov model. The simulations for 2000 and 2005 were confirmed to be generally accurate using Kappa indices. Then the land-use scenarios for Beijing in 2015 were simulated assuming two modes of development: 1) urban development following existing trends; and 2) under a strict farmland control. The simulations suggested that under either mode, urbanized areas would expand at the expense of land for other uses. This expansion was predicted to dominate the land-use conversions between 2005 and 2015, and was expected to be accompanied by an extensive loss of farmland. The key susceptible to land-use changes were found to be located at the central urban Beijing and the surrounding regions including Yanqing County, Changping District and Fangshan District. Also, the simulations predicted a considerable expansion of urban/suburban areas in the mountainous regions of Beijing, suggesting a need for priority monitoring and protection.
A spatiotemporal model of land use change based on ant colony optimization, Markov chain and cellular automataPublished: 01 May 2012 by Elsevier BV in Ecological Modelling
This paper proposes a spatiotemporal model of land use change based on ant colony optimization (ACO), Markov chain and cellular automata (CA). These three methodologies have previously been used separately or in pairs to simulate land use change. In this paper, we apply them in combination, using ant colony optimization and cellular automata to manage the spatial distribution of land use, and applying Markov chain and cellular automata to manage the total amount of land use coverage. We first describe the principle and implementation of the model. Then a land use map of an experimental area (Changping, a district of Beijing) based on land use maps from 1988 and 1998 is simulated for 2008 using the model. By analyzing with real situation, accuracy of the simulation result manifests that the model is useful for land use change simulation. And compared with the other two models (CA–Markov model and ACO–CA model), the model is more appropriate in predicting both the quantity and spatial distribution of land use change in the study area. Therefore the model proposed by this paper is capable of simulating land use change. Highlights► Introduce a spatiotemporal model of land use change. ► To manage the spatial distribution of land use, the model uses ant colony optimization and cellular automata to discover the local transition rules. ► To control the total amount of land use coverage, the model uses Markov process to predict the transition area matrix of land use.
A coupled model for simulating spatio-temporal dynamics of land-use change: A case study in Changqing, Jinan, ChinaPublished: 01 May 2012 by Elsevier BV in Landscape and Urban Planning
Land resource security has come to be a popular issue, and the researches mainly focus on static evaluation of the level of land resource security. But the growing lack of land resource caused by various factors requests us turning our researches on land resource security to dynamic adjustment and control urgently. This paper describes a specific directed graph model on which the model of land resource security adjustment and control can be built. The core idea of this paper is applying the visuality, the clearness and the convenience of directed graph into the process of land resource security adjustment and control. At last, we develop program to visual the directed graph model and realize the method of dynamic adjustment which let the decision-maker control the level of land resource security easily.
The land use structure can be understood as a concept of land use types' composition, contrast relations and spatial patterns, which including the numeral structure and spatial structure. Spatial distribution characteristics and spatial relationships of land use are important contents in land use planning. However, the attribute of land use class is nominal variable, which is the simplest property type. Based on land use types classification, this paper proposed a spatial correlation index named adjacency index to quantitatively analyze spatial correlation of nominal variables, and used Visual Studio platform to realize the algorithm's implementation. In the end, this research set Changping District of Beijing, China as an example. Results showed that the method could not only quantitatively measure spatial autocorrelation, and characterize spatial distribution and spatial relations of land use, but also predict the trend of land use changing pattern.
Karst rocky desertification and peasant household anti-poverty livelihood behaviors: Current situation and expectationPublished: 01 June 2011 by Institute of Electrical and Electronics Engineers (IEEE) in 2011 19th International Conference on Geoinformatics
At the micro-level, certain spatial coupling relation is existed between peasant household livelihood behaviors and environment dynamic changes. This paper from object of study, study methods and development of relevant research etc reviews the research on environment transformation and peasant household anti-poverty livelihood behaviors, and sums up the feature and problems by now, and based on that discusses the probability and direction of research on the karst rocky desertification transformation from the view of peasant household livelihood behaviors.
With the development of network technology, more and more people choose service-oriented development mode to construct WebGIS. The integration of SOA and Web Service technology has become a trend in WebGIS. However, WebGIS construction is not only an enormous but also a high cost project. Facing this problem, this paper proposed a solution for quick and efficient construction of WebGIS. Firstly, it analyzed the service-oriented development mode and advantages of Web Service. Then it summarized the status of open source GIS and its characteristics. At last, it designed the service-oriented system basing on rich internet application technology and open source GIS. The results showed that this kind of system can fully reflect service-oriented thinking, with a lot of flexibility and extensibility; and it is easy to realize. Therefore, this solution is practical and can be popularized widely.
Virtual reality is one of the earliest dreams human owns; nowadays, people are still making further research and attempts in this field and accumulating a lot. Virtual urban is one formation of virtual reality, researches were making experiments of urban on the platform of virtual urban through construction of all kinds of urban models. These experiments not only offered incredible simulation effects, but also provided a scientific platform for studying urban rules, which could be further applied in urban management, spatial planning and so on. This paper briefly summarized the developments of virtual reality and virtual urban, it focused on the core for virtual urban research — urban model. In the end, these papers summarized the advantages and disadvantages of urban models, and look into the future trends of virtual urban.
The Relief Degree of Land Surface and its Correlation with Population Distribution in Urban Agglomerations of ChinaPublished: 01 April 2009 by Institute of Electrical and Electronics Engineers (IEEE) in 2009 International Conference on Industrial and Information Systems
Based on the macro-scale digital elevation model data, by using ARC/INFO software, The relief degree of land surface(RDLS) of 10km×10km grid size is extracted and mapped in urban agglomerations of China. Then this paper systemically depicts the distribution rules of RDLS in urban agglomeration and its correlation with populationdistribution by analyzing the ratio structure and spatialdistribution. The conclusions are drawn as follows: theRDLS in more than 72% of the area is less than one (1)(relative altitude is less than 500 m), reflecting the fact that most of RDLS in urban agglomeration of China is low. In general, the RDLS in the west is larger than that in the east and so is the south than that of the north in urban agglomeration of China. Analysis of the correlation between RDLS and population distribution in urban agglomeration and its regional difference shows that the R2 value between RDLS and population density is 0.81 and RDLS is an important factor influencing the spatial distribution of population in urban agglomeration. More than 88% of the people in urban agglomeration live in areas where the RDLS is less than one (1), while the population in areas with RDLS greater than 3 accounts only for 0.5% of the total.