From a theoretical and practical point of view, a new value system of the Grand Canal, including four fundamental points, is defined: (1) the value of cultural heritage, as an entity of national identity; (2) the value for it's realistic function, as a life line in the region's daily life, both in city and in country, including water transferring, navigation, and irrigation; (3) the value of being regional ecological infrastructure, as a key security pattern for the ecological health of the national land; and (4) the value of being a potential recreational corridor, as a strategic resource of recreation and education. For the need of the conservation and development, the values of the Grand Canal heritage should be thoroughly studied and appropriately planned. Based on the foregoing discussion, a strategy for development and conservation of the Grand Canal is represented: to establish a national heritage corridor, a security pattern, and an ecological and recreational corridor along the Canal combined with the South- North Water Transferring project. The following should be done in advance: (1) the conservation plan of the Canal, by using the “negative planning” theory; (2) the inventory of the resources; (3) an integrated management plan; and (4) a collaborative mechanism among the regions in world heritage application and in the project of the South- North Water Transferring.
The Yellow River is famous in the world because of its high- concentrated flow and high sedimentary rate on the channel bed of the lower reach. The study on the Yellow River, hereinto, is mainly on erosion, hydrology, sediment delivery and channel bed evolution in the middle- lower reaches. It has not been sufficient to pay attention to the river pattern transformations in the main or tributary channels of the Yellow River. Frequent, various and complicated transformations of river patterns in different reaches of the Yellow River are scientific problems which cannot be blench for researchers. This study focuses on the river pattern transformations and their influence factors in the selected river reaches: Maqu reach, the first curve in the upper reach, Tuoketuo reach in the end of the upper reach, and Gaocun reach in the lower reach of the Yellow River. The river pattern transformations in the Maqu reach show changes from anastomosing to meandering and from meandering to braiding. The series transformations present a tend from very stable to very unstable channel patterns that is reverse to the normal trend from unstable to stable channel patterns in the world. These transformations are influenced by crustal rise, restriction of the gorges in upper and lower reaches, hydrodynamic characteristics, sediment characteristics of channel boundary and regional distribution of vegetation cover. The river pattern transformations in the Tuoketuo reach show changes from meandering to straight. That is the transformation from relative stable to very stable channel patterns. It is mainly influenced by the sediment characteristics of channel boundary and hydrodynamic characteristics. The river pattern transformations in the Gaocun reach show changes from braiding to meandering channel patterns. It presents a trend from very unstable to relative stable channel patterns. It is mainly influenced by the sediment characteristics of channel boundary and hydrodynamic characteristics. The artificial levees only restrict the maximum range of the lateral migration of the channel but not influence the channel pattern. The reservoirs built in the upper reach of the braiding reach lead to increase of river flow erosion and sediment coarsening in the braiding channel reach, contemporarily, resulting in a great deal of fine muddy sediments deposit in the meandering channel reach. Obviously, the reservoirs facilitate the river pattern transformation.
“Vulnerability”is a new research frontier in the domain of sustainability science and global environment change, and the term is now a central concept in a variety of research contexts such as natural hazards, climate change, land use change, and sustainable development; meanwhile, vulnerability research is perceived by many researchers as a new science which deals with the mechanism, the process of interactions between human and environment, and the regional sustainable development. Finding a generally applicable conceptual framework and robust assessment methods of vulnerability which are key factors to determine the development of vulnerability science, is a challenge facing vulnerability science. Recent years, researchers from different disciplines draw growing attention to the concept and assessment methods of vulnerability, leading to a rapid progress on the concept and assessment methods of vulnerability. The paper analyzed the different definitions of vulnerability from literatures both abroad and domestic, and illustrated the convergences and divergences among these definitions; based on this, we discussed the exact meaning of the term, maintaining that the sensitivity and coping capacity of system to perturbations impinging on it are the main characteristics of vulnerability of system. In addition, we reviewed the methods used in vulnerability assessment, and classified these methods into five categories according to their assessing process. we evaluated the weaknesses and strengths of each method respectively, then put forward some principles that should be followed in the process of vulnerability assessment, such as choosing simple assessment methods at first and then, with complicated ones later, paying attention to the trade- off between data transformation and results interpretation, focusing on key processes of the generation of vulnerability and making use of multiple methods in a complementary manner. Finally, according to the new trends in vulnerability research, the paper brought forward some issues which should receive more attention in the vulnerability assessment research, such as the vulnerability to multiple perturbations, the vulnerability of coupled systems, the uncertainties of complex system, and the scale issue in vulnerability assessment.
Soil crust, distributing on arid and semi-arid areas, plays important roles in the ecological process of the system of soil-plant-vegetation. Based on large numbers of references, this paper reviewed the fruits and conclusions about soil crust researches in recent several decades, and some problems that need to be studied further also were summarized. The following results were found: 1) Biological soil crust and physical soil crust (two types of soil crust) usually occur together and affect each other in nature; however, few understandings on the relations between them and their multiple effects were known due to separate research for the two types crust artificially; 2) The development of soil crust shows temporal complexity and spatial variation obviously, and also its ecological effects have big differences in different regions or experimental conditions, even some contrary conclusions found; 3) Many researches in such areas as Loess Plateau and Black Soil Region have not been launched untill recent years, and it is necessitous that more studies should be developed to understand favorable or adverse effects of soil crust on soil erosion and its happening conditions and eco-hydrological processes in order to give an academic foundation to physical erosion modeling and effective using of soil crust resources.
Yellow River is very much important to China, but it has long faced alot of problems. From the viewpoint of disaster prevention and reduction, the hydrodynamic properties of Lower Yellow River Channel were studied. The hydrodynamic factors to influence the Lower Yellow River Channel were investigated to find their relations. Sediment movements of Lower Yellow River Channel were explored on the basis of relation between fluid flow and sediment transportation to predict evolutional process of Lower Yellow River Channel to give suggestion for permanently harnessing Lower Yellow River. The problem of beach area of Lower Yellow River is a comprehensive balance among society, economy, environment and natural resources rather than an only physical problem, and suggestions were proposed to solve this problem from the view of sustainable development. This paper also finds that it is necessary to deal with Yellow River together with Huaihe River.
Threshold of water resources exploitation is the basis for reasonable use of water resources and guarantee of ecosystem health in a basin. With the shortage of water resources becoming increasingly obvious a problem, the understandings on threshold of water resources exploitation are more and more deep, developing from the concept of "total water resources", "useful water resources" and "available water resources" to available water quantity considering the ecological water demand and water quality protection. In the paper, based on the concepts on water resource use, a new threshold theory and model of water resource exploitation in a basin is developed, which includes runoff, non - useful flood, water pollution, ecological water demand and repetitive calculation of water quantity. With the model, the threshold of water resource exploitation in a basin can be obtained. The Yellow River Basin is one of the serious water shortage regions in China, and it is at the risk of serious challenges of water scarcity. As one example, the threshold of water resource exploitation in the Yellow River Basin is preliminarily calculated by the model. The result shows that the average threshold is 23.8 billion m3, accounting for about 40% of the total natural runoff, which is accordant with the internationally recognized standards on water resource exploitation within a basin. The threshold of water resource exploitation can be increased by the ways of water diversion, decreasing water pollution, increasing pondage of reservoirs and increasing water use efficiency.
Exploring the relationships between land use and soil erosion at different scales is a frontier research field and a hot spot topic in contemporary physical geography. As a new soil erosion model, the multiscale soil loss evaluation index (SL) has good prospects for analyzing the relationships between land use and soil erosion at multiple scales. Based on the SL equations and SL- factor meanings at different scales, this paper explains the detailed methods and GIS techniques for SL and SL- factor calculation at slope scale, small watershed scale and watershed scale. The SL- factor include rainfall erosivity factor, soil erodibility factor, topographic factor and cover/ management factor. And the GIS techniques include kriging interception, field calculation, raster calculation, expanding zones, and so on. It is expected that the methods and GIS techniques of SL calculation will be helpful for SL development and the profound research of land use and soil erosion at multiple scales.
Temporal reconstruction of evapotranspiration (ET), which means deriving continuous, complete annual ET from fragmentary satellite measurement, is a problem full of uncertainty in remote sensing application. Traditionally, evaporative fraction (LE/H) is simplified as constant in a short period so that weekly or long term ET could be estimated from a single clear satellite image. In this way, variation of daily ET is often neglected and the amount of ET is hard to compare with those at the same time in another year. The objective of this research is to develop a new reconstruction algorithm to retrieve continuous and actual ET dataset and provide valuable temporal profile for agriculture and ecology application. This algorithm considers both the spatial and temporal discontinuity, and is a combination of SEBS (Surface Energy Balance System) and Penman- Monteith model: SEBS model is used to derived latent heat in clear days, and then surface resistance is inverted from PM equation; Leaf area index (LAI), is interpolated and smoothed to daily term by using HANTS (Harmonic Analysis of Time Series) method. Then surface resistance of the cloudy days is related to those from neighboring clear days with a function of LAI, minimal air temperature and vapour pressure deficit. Daily ET estimation is compared to lysimeter measurements recorded in Yucheng agriculture site and shows a good correlation coefficient in crop growing season (R2≈0.7). Model result is not satisfactory on bare and sparse land because of the limitation of the one- layer assumption in PM equation, which requests that an independent component of soil evaporation should be added into the algorithm.
With the growth of FDI and its more and more important role in globalized economies, the issues on FDI theory and FDI location decision have become interesting topics in many disciplines. The FDI theory in the true sense emerged in the early 1960s, and since the Hymer's Monopolistic Advantage Theory, the FDI theories have emerged one after another incessantly. Before 1980s, the theoretical FDI researches were mainly focus on the FDI behaviors in the developed country, and there emerged a series FDI theories such as Monopolistic Advantage Theory, International Product Life Cycle Theory, Comparative Advantage Theory, Theory of Dynamic Location Advantage, Internalization Theory and Eclectic Theory of International Production, in which can represent the development vein and the essentially mainstream theories. In 1980s, the growing prosperous outward FDI in the emerging industrialized countries gave the birth of the FDI theories for the developing countries. The representative theories include Development Stage Theory, The Theory of Small- scale Technology, The Theory of Localized Technological Change and The Theory of Technological Competence. Competitive Advantage Theory and Strategic Alliance Theory are the most recent progress for the FDI theory. Either the mainstream FDI theories for the developed countries or those for the developing countries can only explain the FDI behaviors for some countries (regions) in some specific scope and conditions to some extent. The current FDI theories are far from satisfying the real needs. So more systematical and mature FDI theory framework is still a subject for the future research. There are partial - equilibrium analysis and general - equilibrium analysis for the FDI location decision research. The former is focus on how single exogenous factor affect the firm's FDI decision, while the latter focus on a model framework and empirical specification that lays out the primary long- run determinants of FDI location. In the early years the classic factors such as size of market, taxes, labor costs and so on were took as the important ones influencing the FDI location, and recently agglomeration and regional integration have been emphasized. However, it is still an open issue on how to measure the agglomeration economies accurately and separate them from the classic factors. The general- equilibrium analysis is an ideal theoretical framework for FDI location decision research, but it also an open problem for lack of theoretical foundation support and appropriate empirical specification in practice. To sum up, there are 7 issues should be paid attention to for the future FDI research: (1) Construction of more systematic and mature theoretical framework for FDI theory. (2) The relationship between classic factors and agglomeration. (3) The location decision for different FDI types. (4) Multivariate interaction for firm- level and country- level factors on FDI location. (5) The conditions for the factors'effects on FDI location. (6) The regional integration effects on FDI location. And (7) The theoretical foundation and empirical specification for general- equilibrium FDI location analysis.
As the trend of economic globalization and regional economic integration is increasingly apparent and popular, urban agglomerations have become the extremely important and significant parts which participate in regional collaboration in some countries and regions. However, the related research on the connection between the tourism development and tourism environmental carrying capacity of urban agglomerations in china is not enough or extremely deficient at present. To describe quantitatively the potential carrying capacity of tourism environmental system and the sustainable carrying state of tourism environment, and to construct an evaluation system of tourism environmental carrying capacity and a measurement model of tourism environmental sustainable carrying capacity, the paper provides a new idea and method for quantitative study of tourism environmental carrying capacity. Then taking Shandong peninsula urban agglomeration as an example, tourism environmental carrying capacity and carrying state of it from 2000 to 2005 have been studied empirically. At the same time, it applies the grey model to simulate and forecast the regional tourism environmental carrying state from 2006 to 2010. Finally, some optimum and adjustment suggestions to enhance and improve tourism environmental carrying capacity of Shandong peninsula urban agglomeration have been elaborated.
Sometimes tourism development can bring negative influence to the destination. In order to diagnose its whole l evel of development, we use the “pressure - condition - response” frame model and take “gegentala grassland tourist center of Siziwang Banner of Inner Mongolia” as an example to analyze the ecological security state of region tourism. Three aspects (ecological environment pressure of tourism, ecological environment quality, and ecological environment renovation and construction ability for protection of tourism) are considered, according to analytic hierarchy process principle and each appraisal target's reciprocity, so as to hierarchical structure models and 23 targets. By computing insecurity index value of appraisal target, we determinie the normal value as well as the target's weight value, and again use degree of insecurity formula of various targets and degree of insecurity formula of overall ecosystem to calculate tourism ecosystems which are at insecure state, and to discuss methods that ecosystem has limited by various factors. To certain degree, this research has the practical significance to ecosystem safe analysis of region tourism development.
Guaranteeing China's food security is the basic foundation of all the development. With the realities of agricultural infrastructure resources becoming scarce and China's entry into WTO, the food security faces new challenges and opportunities. This paper reviewed the evolution of the concept of food safety, and summarized the research on the relationship between basic natural resources and food security, the status quo and evaluation of food safety, the impact of international trade and economic globalization on food safety, and food security warning and administration. Besides, the paper also had a prospect on future hotspots of food security. The research shows that, from now on, we should emphasize the research on the following aspects: in researching contents, not only focus on food quantity and safety, but also pay more attention to food quality and safety, sustainable use of food resources and risks evaluation of food security; in terms of research scopes, not only attach importance to macroscopic food safety research, but also put more emphase on microcosmic food safety research. In researching ways and means, modern science and technology should be used completely, such as computer technology, network technology, space technology and 3S technology, so as to strengthen the quantitative study of comprehensive food safety risk.
Through generalizing related literature, we summarized some properties of cognitive distance and reduced all research on this concept into two aspects: pure value, and real cognitive distance. Further, we proposed a Distance Estimate Index (DEI) to quantify the scalar cognitive distance distortion. As far as vector cognitive distance distortion is considered, the Distortion Index (DI) computed by bi- dimensional regression is adopted to descript the degree of vector cognitive distance distortion. Based on these quantification methods, we conducted a survey on sampled Beijing residents, requesting the subjects to estimat the pairwise distances between 8 landmarks. And then we calculated the distortion of the two types of cognitive distances respectively by using linear regression and multidimensional scaling methods. Further, through ANOVA, we analyzed the factors that would possibly have influence on such distortion, like age and neighborhood. The result shows that the years of residence and the resident districts are the demographic variables that could influence an individual's accuracy in cognitive distance.
The agro- pastoral zone in China is the ecotone between the traditional agricultural regions and pastoral regions in our country, which is also a fragile zone of eco- environment and a barrier for ecosecurity. Many studies have focused on the agro- pastoral zone and some achievements had been obtained. But there is still no agreement on the boundary definition. For different researchers, the criteria to the boundary definition are different, and then the spatial location and the area of the agro - pastoral zone in China were in difference. Therefore, further studies on boundary definition of eco- environment are needed. The spatial distribution of agro- pastoral zone is controlled by natural factors such as precipitation, but also influenced by human activities intensively. Land use pattern, reflecting the integrative results of natural factors and human activities, can be used for the definition of agro- pastoral zone. Interms of land- use pattern, the agropastoral zone is none other than the landscape boundary between farmlands and pastures. In this paper, the processes on the boundary definition of agro- pastoral zone in China were reviewed, and the shortcomings of current studies were summarized. To solve these questions, the spatial analysis methods used in ecotone studies were introduced to the definition of agro- pastoral zone since the agro- pastoral zone is one kind of the ecotones. The spatial analysis methods include spatial clustering analysis, discriminate analysis, spatial statistics analysis and multi- fractal analysis.
Land use has effects on grain and ecology security by changing the landscape and the intensification all over the world. How to keep a balance between meeting human needs and maintaining land diversity is the focus of scientists around the world. Great land use change has taken place in China, which will have great effects on the global grain and ecology security. Many researches about the land use change and the effects have been conducted, but few researchers analyzed the household land use objective change with the economic development in China. In this paper, the household land use objectives are divided into four phases and different phases have different effects on grain and ecology security in China. The four household types include subsis-tence land use phase, subsistence and profit optimization phase, profit maximization phase and landscape effect maximization phase. In the first phase, the household land use objective is to gain the family grain needs, but the technical margin yield is very low, so the household has to expand the cultivated land and change the grass and forest land into cropland. In the second phase, the household land use objective is to meet family grain needs and will make good use of other lands to make more profit. They will make good use of the land and improve the intensification. Many households are at this phase and produce high grain yield, which is the support of grain security in China. However, the intensification in land use has negative effects on ecology. At the third phase, the household land use goal is to make money, and farmers will configure the land, labor and the capital to pursue the highest profit. If the land size is too small, they will decrease the input, but the technical margin yield is high. At the last phase, the household has gone beyond seeking for the subsistence and the money, and they will use the land according to the landscape needs. They will decrease the production and input, which leads to the diversity of agricultural lands.
Based on the collective land survey data in Pinggu, Beijing in 2006, the paper analyzes the inner land use structure in rural residential areas of differential regions with the aid of landscape ecology method, thus revealing its geographical distributions. It shows that the difference in productivity caused the characteristic of land use structure of different regions. As far as the diversity index of inner land use structure is considered, Mid- Levels>plains>mountains. As far as the centrality index is considered, mountains>plains>Mid- Levels. Meanwhile, the location index of different land use types change regularly as the regions change. As far as residence land is considered, mountains>plains>Mid- Levels. As far as factory land is considered, Mid- Levels>mountains> plains. As far as service establishment land is considered, Mid- Levels>mountains> plains, as far as idle construction land is considered, plains>mountains>Mid- Levels. In the progress of new rural area construction in the future, the development of urban and rural should be integrated in the view of arranging the industry distribution reasonably, and reflect the principle of land intensive use. Moreover, different rural residential areas should have different scale control modes and approaches of land adjustment.
