Qiuhao Huang

Using Construction Expansion Regulation Zones to Manage Urban Growth in Hefei City, China

AbstractThe management of urban land development, as well as the conservation and optimization of agricultural land and urban green space, is crucial for sustainable urban development. China has experienced rapid urbanization and industrialization since 1978, which brought unintended negative social and environmental consequences. Hefei, the capital of Anhui Province in eastern China, is identified by the Economist Intelligence Unit as one of the top 20 emerging cities in China. Its urbanized area grew from 29  km2 to 268  km2, an 824% increase, between 1980 and 2005. This paper reviews Hefei’s urban growth management since 1987. It then analyzes in detail the construction expansion regulation zone, an innovative measure proposed by the Ministry of Land and Resources China (MLRC). The regulation zone includes four types of zones: a permitted expansion construction zone, a conditionally permitted expansion construction zone, a restricted expansion construction zone, and a prohibited expansion construction ...

Land use information release system based on Google Maps API and XML

Web map service is a new map service mode actualized by the use of internet technology, computer technology and GIS technology. This article applies Web map service to the release of land use information, and tries to use Google Maps API and XML to build a network release system of regional land use information. The system integrates Google Maps data and user data effectively, carries out the display and management of land use information, and has a powerful public participation function. This study shows that Web map service based on Google Maps API and XML can play an important role in the release of land use information, which is also important in the information-based construction of land resources.

Analysis of farmland fragmentation in China Modernization Demonstration Zone since “Reform and Openness”: a case study of South Jiangsu Province

Farmland is a fundamental resource for human survival and development. However, farmland fragmentation has become a serious problem, causing ecological damage and low crop production efficiency in many parts of the world. Based on remote sensing and socioeconomic data, we used landscape pattern indices, Morphological Spatial Pattern Analysis (MSPA), and Markov chain models to analyze the temporal and spatial pattern changes in farmland in South Jiangsu Province (the first “Modernization Demonstration Zone” in China) during 1985–2010. Our results demonstrated that the total farmland area decreased by ca. 24% and the farmland pattern became fragmented during 1985–2008: core farmland decreased and islet farmland increased. Additionally, the farmland patch density (PD) increased and three other landscape indices (NLSI, MESH, and COHESION) showed significant decreases. Although the fragmentation rate slowed after 2008, the convergence rate to a stationary farmland distribution became faster, and transitions tended to be less deterministic after 2000. Economic and population growth and policy changes positively contributed to this phenomenon. Therefore, the primary task of farmland protection should be to preserve contiguous farmlands and reduce scattered patches in order to promote farmland connectivity.

Using Urban Development Boundaries to Constrain Uncontrolled Urban Sprawl in China

Based on constraining the spatial extent of urban expansion, the urban development boundary concept provides guidance on resource constraints and policy development for urban areas and aims to meet the new demands of urban development under the background of a new type of urbanization in China. We applied remote sensing and geographical information system (GIS) techniques, along with the slope, land use, exclusion, urban extent, transportation, and hill shade (SLEUTH) model, to identify urban growth boundaries in Changzhou City, China. We then comprehensively considered various land use regulation policies and the carrying capacity of land resources to construct an urban development boundary model. This model was tested using empirical data on the delineation of flexible and rigid urban development boundaries. We argue that Chinas position as the largest developing country in the world has resulted in significant uncertainties in its socioeconomic development; therefore, the construction of Chinese cities requires both flexible controls and a rigid management structure. The model developed in this study successfully meets the construction needs of Chinas urban development, particularly as it contains an optimal degree of generalizability.

Thematic maps for county-level land use planning in Contemporary China

Land use thematic maps are essential for the implementation of land use planning. China launched the third round of its land use planning in 2003, and the making of land use thematic maps series is one of the innovations for the new planning. The objective of this paper is to provide information about generating county-level land use thematic maps. The study area, Dachang Hui Autonomous County (178 km2), is located in Northern China and shares a boundary with Beijing. Methods for generating thematic land use maps are presented. These thematic maps include an existing land use map, zoning map for proposed land use, prime farmland protection map, zoning map for construction land expansion, planned land consolidation map, and planned major land use projects map. The scale for these maps is 1:50,000. All these maps are useful for researchers and local government, allowing them to be used as a reference for the study of land use mapping and support land resource management and planning.

Toward a sustainable utilization of land resources in China: problems, policies, and practices.

China’s economy is growing explosively with double-digit rates of growth. However, behind the scenes of this economic miracle, a dark underbelly exists. The potential impact of the unsustainable use of land resources is increasing. Each parcel of land has a stationary geographic location, while its utilization is optional. The re-adjustment and optimization of land use patterns ought to be encouraged. Spatial reconstruction refers to the combination of various land elements, which can promote the rational and efficient allocation of land resources through a four-layer action framework: the development of unused land, urban renewal, ecological reconstruction, and spatial displacement. The feasibility and validity of these methods are illustrated by practical cases in different provinces in China. We thus propose that pursuing sustainable development and building an ecological civilization will be necessary for China in future decades.

Constructing Ecological Networks Based on Habitat Quality Assessment: A Case Study of Changzhou, China

Fragmentation and reduced continuity of habitat patches threaten the environment and biodiversity. Recently, ecological networks are increasingly attracting the attention of researchers as they provide fundamental frameworks for environmental protection. This study suggests a set of procedures to construct an ecological network. First, we proposed a method to construct a landscape resistance surface based on the assessment of habitat quality. Second, to analyze the effect of the resistance surface on corridor simulations, we used three methods to construct resistance surfaces: (1) the method proposed in this paper, (2) the entropy coefficient method, and (3) the expert scoring method. Then, we integrated habitat patches and resistance surfaces to identify potential corridors using graph theory. These procedures were tested in Changzhou, China. Comparing the outputs of using different resistance surfaces demonstrated that: (1) different landscape resistance surfaces contribute to how corridors are identified, but only slightly affect the assessment of the importance of habitat patches and potential corridors; (2) the resistance surface, which is constructed based on habitat quality, is more applicable to corridor simulations; and (3) the assessment of the importance of habitat patches is fundamental for ecological network optimization in the conservation of critical habitat patches and corridors.

Illegal land use risk assessment of Shenzhen City, China

In the eastern coastal cities of China, the need for supervision of illegal land use is urgent requiring new ways to promptly identify and put a stop to the practice. In this paper, we present a practical example through the generation of thematic maps for illegal land use risk assessment in Shenzhen city with the assistance of GIS. Thematic maps are useful in relation to the following points. First, they could be a template for generating illegal land use risk assessment maps. Second, illegal land use risk assessment maps indicate the different risk levels of each community, which allows for more effective illegal land use supervision to protect the cultivated and ecological land. Third, with the assistance of GIS, the process of spatial analysis and mapping becomes more efficient as a tool in this supervision.

Mapping land cover types as fuzzy sets

Researches have suggested that fuzzy sets form a more appropriate basis for land cover mapping than traditional Boolean classification. However, to give a crisp answer of which land cover types pixels in remote sensing images belong to, fuzzy clustering methods such as FMC always lost some subtle vague information. In this paper, the result of the Boolean classification using a fuzzy clustering method was analyzed and based on the result of the classification, we tried to map land cover types as type 1 fuzzy sets and type 2 fuzzy sets. Results show that type 1 fuzzy sets and type 2 fuzzy sets kept more subtle information that was lost in the processing of converting the fuzzy classification result to a Boolean one. And the structure of the study area can be more explicit represented.

Adaptable parallel strategy to extract polygons from massive classified images on multi-core clusters

It is always computing intensive and time consuming to extract polygons from massive classified images. Although parallel computing can improve the efficiency of geographical data processing, the performance of the conversion suffers from the trade‐off between data decomposition and result stitching. In this paper, we present an adaptable parallel strategy that accelerates the conversion process on a multi‐core cluster. The strategy improves the method of data decomposition and optimizes task scheduling. In our strategy, an adaptable decomposition method is used to partition raster data according to the data complexity of the raster dataset and computing capability of the computing nodes. Moreover, the hierarchical task scheduling optimizes task allocation and load balance among computing nodes for the procedure of parallel conversion and stitching. We implemented parallel algorithms based on a boundary linking algorithm using the adaptable parallel strategy and compared the performance with the performances of conventional parallel strategies. The results show that the processing time of experimental raster data was reduced from 1362.36 to 165.78 s and that a desirable speedup with the maximal value of 8.23 was achieved. Copyright