This paper presents a literature review on the measurement of geographical concentration and agglomeration of industries. Indices of concentration should meet the following criteria: (1) being comparable across industries and spatial scales; (2) taking a unique (or known) value under the null hypothesis that there is no systematic component to the location of the industry;( 3) the significance of the results should be reported where appropriate; and (4) measures should be unbiased with respect to arbitrary changes to the spatial classification and industrial classification. There are many concentration indices, including coefficients of variation, Herfind-ahl index, Hoover coefficient, Entropy index, Theil index and Gini coefficient. Those aggregate measures of geographical concentration, however, ignore the impact of plant distributions on geographical concentration of industries. Based on the model of plant locational choices, economists propose agglomeration indices designated to measure the excess of raw geographic concentration on productive concentration. However, both concentration and agglomeration measures only describe the location of industries on a single scale based on administrative regions. Distance- based methods, such as Ripley’s K function, serve to describe the spatial structure of industries at different scales at the same time. Existing literature also attempts to propose quantitative methods to identify industrial clusters. Location quotients and standardized locational quotients, spatial and industrial linkages, factor analysis and graphic methods based on input output have been applied. The identification of industrial clusters not only requires the consideration of industrial linkage, but also geographical proximity.
The geographical clustering of manufacturing employments and establishments is pervasive. Companies and plants are not distributed uniformly in space, but rather agglomerate in some places. Industrial agglomeration has been a popular economic phenomenon all over the world and has been paid a lot of attentions to by scholars and government’s officials. Industrial agglomeration is one of the main issues of economic geography, regional economics and other related disciplines. In this paper, the progress of theories and empirical studies in industrial agglomeration research is reviewed. Marshall has pointed at three types of externalities: labor pooling, intermediate inputs and knowledge spillovers. Classical and neoclassical location theories emphasize the role of transportation costs, labor costs and demands in promoting industrial agglomeration. Neoclassical trade theories stress technology or resource endowments and comparative advantages. In new economic geography models, the distribution of economic activities is driven by the interaction of transportation costs and scale economies. Empirical studies on industrial agglomeration confirm that a variety of significant variables, including factor endowments, external economies, scale economies, transportation costs, market demands and other non- economic factors, influence the formation of industrial agglomeration.
The sea area, as well as the land, is the assets of territory resources, and the paid use for sea area is an important system that enhances the coastal management. Based on the theory of land evaluation and combining the special attributes of nature and social economy in sea area use, this article has established the theory framework of sea area use and evaluation, and discussed the index system of grading the sea area, the selection of dominant factors, and the preliminary principles of grading sea area. We also have some empirical study to grading the sea area in Liaoning province , where the sea area is divided into four grades: the first grade, including the city of Dalian; the second grade, including cities of Huludao, Yingkou, Jinzhou, Zhuanghe, Wafangdian, Pulandian and the county of Changhai; the third grade, including the cities of Panjin, Donggang, Xingcheng, Gaizhou and Linghai; and the fourth grade, including the counties of Suizhong, Panshan and Dawa.
Housing cost and commuting cost are two major and interrelated endogenous variables in urban spatial models. Households make trade - off between these two costs when choosing their residential locations, which in turn generate the spatial structure of housing price, construction density and commuting patterns. This paper reviews the theoretical equilibrium relationship between commuting cost and housing cost, discusses the impacts of various factors in real world on such a relationship, and provides some empirical evidence using the data from a special- designed survey in Beijing. We also discuss two implications of the empirical results in our paper for the public policies in urban growth management. One is that commuting cost should be considered together with housing cost when studying urban Households' housing affordability; the other is that the extreme departure of housing and jobs may produce negative outcomes, e.g., the bed - community at city edge, traffic congestion, air pollution, and spatial mismatch problem for disadvantaged population groups.
Reclamation of tidal flat is one of the dominating methods for coastal countries to colonize territory and reconcile conflict between human and environment. The reclamation of tidal flat will decline the elevation of tidal flat, alter hydrodynamic processes and suspended sediment transport, reconstruct characteristic of sediment, and so on. So the vegetation community presents secondary succession and the flat which have been reclaimed will become artificial environment. Based on review of the international phylogeny of reclamation, this article probed into the influence of reclamation on coastal zone from four aspects: hydrodynamic processes and suspended sediment transport on tidal flat, geo- biological cycle of substances on coastal zone, ecology of botany and zoology on tidal flat, and salt marsh restoration and ecological reconstruction. Then the authors point out the difficulties, the shortages and main problems existing in the study. Finally, the article puts forward that special attention should be paid to multi- subject integrated research on environmental effects of tidal flat reclamation, especially, the changes of hydrological, sediment, soil characteristic of and function of coastal ecological system after reclamation. It should be based on comprehensive analysis of natural and artificial succession of coastal zone to investigate evolutional mechanism of coastal zone system which is influenced by reclamation and to seek sustainable utilization of coastal zone that considers both land demand and coastal environment preservation.
The sediment budget affords an effective conceptual framework for quantifying soil erosion, sediment mobilization, transportation, deposition and storage within, and sediment output from, a drainage basin. And it constructs a more complete picture of sediment generation and distribution within basins and permits an assessment of the efficiency of the sediment delivery system. A range of studies on it have been undertaken with more and more advanced methods such as GIS, RS, GPS, fallout radionuclide measurements, etc. around the world and have got some satisfying results, but sediment budget has been applied in few studies and has not been well developed in China, so the recent developments of methods in sediment budget researches were concluded and their advantages were evaluated to encourage the national development of sediment budget researches, and some problems in these researches were mentioned too, that will make sediment budget a helpful tool to establish a reliable and scientific basis for formulating catchment management strategies.
Water erosion creates negative impacts on agricultural production, infrastructure, and water quality across the world. Regional- scale water erosion assessment is important, but limited by data availability and quality. Remote sensing technologies have been used in erosion research for many years, satellite image was applied in many respects of erosion assessing during the past 30 years. It is helpful to assess erosion by using remote sensing technologies, which can supply spatial data for assessing erosion. Satellite data can be directly used for detecting erosion and its consequences. Distinguishing the total feature of erosion can divide erosion regions. And then detection results can be achieved by assessing erosion intensity based on empirical relations. In the paper, applications of satellite images and sensors in erosion were discussed. A large number of earth observation satellites has orbited, and is orbiting our planet to provide frequent imagery of its surface. From these satellites, many can potentially provide useful information for assessing erosion. Many examples of detecting erosion features, eroded areas, and erosion consequences by remote sensing were presented.
210Pb and 137Cs techniques can be used to infer a geochronology with incomparable su-periority in accuracy and timescale, which were widely employed for dating recent sediments deposited in fluvial, lacustrine, marine and other sedimentary systems on a timescale of about 100 years. The achievements and current situation of 210Pb and 137Cs dating in the coastal zone of China were summarized, which were in the primary stage when compared with the same kind of achievements overseas. Based on the characters of the sedimentary environment in the coastal zone, the problems and limitations of 210Pb and 137Cs dating for sedimentary rate were revealed, indicating that undisturbed sampling, high- precision sampling and partition, moderate adjustment, accurate descriptions of the regional distribution patterns of 210Pb and 137Cs concentration and comparison of 210Pb method with 137Cs time- mark counting were very important for correcting results. Further analysis of the model establishment for diffusion and mixing of 210Pb and 137Cs techniques was required. Referring to foreign research, the needs of some further improvements and some additional intensive work, especially in the coastal zone of China, were also suggested.
Using ArcGIS software as a basic platform, taking Du’an County as a case, and by the aid of spatial superimposing analysis and geographical statistical analysis methods among them, Regional Karst Rocky Desertification Information System, or RKRDIS, a specialty GIS based on Arc Objects, is designed out. In this system, specialty analytic model of Karst rocky desertification is taken as the nucleus, with spatial data as information materials, with the computer network as transport vehicle, in order to realize abstracting “information”from“data”. The information processing technology supports data analysis, query, display and management for Karst Rocky Desertification research, and provides spatial data analysis of Karst rocky desertification for dynamic monitoring, driving diagnosis, early- warming analysis, calamity assessment, and policy making. Development of this system involves a variety of knowledge and professional skills like GIS, software engineering, natural geography, remote sensing, database design, computer technology and, etc., and is indeed a comprehensive integration of multidisciplinary knowledge. In particular, space analysis on Karst desertification disaster data, such as temporal - spatial monitoring, drive diagnosis, etc., is a full incarnation of features unique to GIS technology, since assembly system development method and method of management of space data by using relationship database, system structure based on C/S model, customized user interface and complete user functions, can better satisfy the requirements for application by users. So this is definitely a beneficial attempt that GIS technological application has ever been made in Karst desertification disaster field. The system can provide new study methods and means for integrated assessment and analysis of Karst desertification by using geographical information system in combination with mathematical models, and for prevention and treatment of disasters in Karst desertification areas. Moreover, it is of particular importance for providing guidance to the scientific treatment and construction in Karst desertification areas.
The ecosystem fragibility in the Karst area of Southwest China has been pay more and more attention to recently, especially of soil erosion. It is the most important question in this area to improve the environment capability and disaster carrying capability. The southwest Karst area of China is located in the center of the east~Asia Karst area, one of the three largest Karst areas in the world. Karst environment is very fragile and soil is in severe erosion and degradation, and the local people must confront with the concentrated poverty population and the lack of cultivated land. The development in Karst area in Southwest China is also easy to plunge into a vicious circle of poverty and environmental degradation. On the severe environmental question of soil erosion and degradation in the Southwest Karst area, primary achievement had been briefly reviewed in this paper in three aspects: current research, mechanism study and ecology reconstruction. The regionalization and classification of soil erosion in Karst area are presented. And this paper also generalizes the reason research of soil erosion in physical process and humanistic process, as well as the approaches of ecological restoration and reconstruction of the eroded land in Karst area. Some existing problems in this research field at present have been expounded and efficient research approaches and methods for soil erosion and ecological reconstruction in Karst area are put forward.
Study on land use degree is one of the superiority fields of land arrangement and sustainable land use research. Classification of land use degree provides guidelines for utilization and conservation of regional land use as it can indicate regional differentiation regularity and existent problems. A considerable amount of research has been done on land use degree during the last decade. In this paper, Yunnan Province is taken as a case and unsupervised artificial neural network, namely Self- Organizing Feature Mapping (SOFM), is used in land use degree classification. The results indicate that classification of land use degree based on SOFM networks is a promising approach to land use studies. In this paper, Multiple Cropping Index is employed to the land use degree model so as to indicate the quality differences within a specific land use type. More improvements of the model should be brought through by further consideration. As for the data employed as input for training, not only the status quo of land use degree but also the influence factors are included. After the iterative learning phase in the SOFM analysis, six output units representing different classes of land use degree come forth, i.e., High land use degree - high population pressure - high economy pressure region, High land use degree - medium population pressure - medium economy pressure region, Low land use degree - medium population pressure - medium economy pressure region, Low land use degree - low population pressure- low economy pressure region, Medium land use degree- medium population pressurelow economy pressure region, and medium land use degree- low population pressure- low economy pressure region. Accordingly, some advice on utilization and conservation of land use is proposed based on the studying result. From the results obtained so far, it seems that SOFM is superiors over others in many aspects and has been trained to perform complex functions in various fields of application, including land use degree classification. But more improvements should be conducted before further applications.
Land suitability evaluation, playing a basic role in land use planning all along, has progressed at a rapid rate since 1990s in china. The land suitability evaluation for agriculture develops continually. The agriculture land suitability evaluations aimed to protect the land in ecologically fragile regions have been put in practice widely, and the evaluations for individual crops have developed steadily. In addition, the evaluations for non- agriculture purposes such as urban land use, tourism land use, land consolidation and other land uses have been popularly and successfully carried out. As the expansion of the land suitability evaluation fields, some new evaluation purposes emerge gradually; and the attention of evaluation factors has been paid to not only natural ones but also social, economic and behavior ones, which have developed the results of evaluation perfection. The new evaluation viewpoint was advanced thanks to the introduction of the landscape ecology theory, and the idea of sustainable land use have been accepted and penetrated into most evaluations. While some conventional methods such as the Weighted Sum Model, the linear Regression and the Analytical Hierarchy Process (AHP) have been applied still to land suitability evaluations, several advanced approaches such as the Fuzzy mathematics Model, the Artificial Neural Networks (ANN) and the Genetic Algorithms have been attempted to improve the evaluation models. Geographical Information System (GIS) has been popularly applied to land suitability evaluation, and the integration of evaluation models into GIS has made the process of land suitability evaluation more flexible.
It is urgent to improve the agricultural land use intensity owing to more people and less land resources. Taking counties in Hebei province as evaluation units, an index system was established from four aspects: land investment degree, utilizing intensity, utilizing efficiency and sustainable development status. The weight of each index was calculated by the entropy method. The agricultural land use intensity during 1985～2005 was calculated by employing the methods of comprehensive index, and the spatial- temporal variance of the agricultural land use intensity was analyzed also in order to provide a basis of policy for intensive and sustainable use of agricultural land in Hebei province. The results show that the agricultural land use intensity was prone to be influenced by land investment degree and took on obviously territorial differences. The agricultural land investment degree and sustainable development status increased during 1985～2005, while the utilizing intensity and efficiency decreased.
Based on regional water resource carrying capacity research, this article took urbanized areas as a research object and began from water cycle process in the urbanized area to discuss water resource transform process that is influenced by intensive humanity activity and to analyze water resource carrying capacity connotation of urbanization area. The basic theories were proposed for water resources carrying capacity research in urbanized area, namely: the water cycle theory under changing environment, the interaction theory between urbanization, and the "social economy- water resources- ecological environment" composite system and sustainable development theory. Moreover, under the sustainable development principle, we brought the urbanized area water resource carrying capacity research into the complicated system of region " social economy - water resources - ecology and environment", and analyzed the coordinated relationship among water resources, social economy development, and ecological and environmental protection. We also proposed the theory frame and the method of water resources carrying capacity quantification research in urbanized areas. The research results may provide a theory support for implementation of water saving strategy, water resource reasonable disposition and sustainable development in urbanized areas..
