Land use change is a key component for global environment change, and a representation of the impact of human activities on physical environment Supported by the 1 km grid global database, IGBP, IHDP and other international organizations have implemented a series of researches including land cover dynamics, mechanism and global and regional models The 1 km grid data is an effective way of data integration, which can promote regional land use change monitoring, predication and driving forces analyses This paper, based on remote sensing,GIS and Landsat TM digital images, analyzed the structural features and spatial patterns of land use change in Beijing from 1985 to 2000 The primary findings show that conspicuous conversion, with a rate of 40 78% and 37 60% respectively, occurred for woodland and built up areas with internal conversion of woodland, conversion from woodland to grassland, internal conversion of built up areas and afforestation or grassland restoration in abandoned mining land as its main conversion categories At the same time, the net change of each kind of land use is characterized by conspicuous areal differentiation The decrease of dry land of central eastern and southern Beijing, 129,874 17 hm 2 in total, is dominant and conspicuous while that of northeastern by sparse distribution The increase of arable land, dominated by paddy field is sparsely distributed in northern and central western Beijing Forest area trends are enlarging in spatial distribution, especially in protection forest of Northeast, North and Northwest China and mountainous areas of southwestern Beijing The decreased area of grassland is almost 6 times of the increased. The former happened chiefly in mountainous areas while the latter in reused arable land or grassland areas For a long time series during 1985～2000, the trend of water body expansion obviously occurred in central western, southeastern mountainous areas and some reservoir areas of northern and eastern Beijing Above all, the most conspicuous feature of land use change in Beijing for the past 15 years is still urban expansion, undoubtedly affected by the macro social and economic conditions in China, which is densely distributed in central eastern and central southern Beijing and expanded around the downtown as well as around the towns of each county in Beijing These findings promote our understanding of land use change and contribute to the decision-making of local governments
This paper focuses on GIScience-techniques with the involvement of two technques of data mining,the Markov Chain method and Artificial Neural Network(ANN)method.The results were used to the strategic planning and development of the city of Shanghai.In order to estimate state transtation matrix,firstly the city was divided into 5 zones based on GIS,remote sensing images and electronic maps,and then the total amount of land use in Shanghai in 2002 and 2005 was estimated by Markov Chain method. Secondly,changes in land use types in core areas of Shanghai were forecasted with ANN method which shows the ANN Model 2 (Fig.3)is better than Model 1(Fig.1).This indicates that each one has its strong point,for the ANN method can be better used to forecast directional aspect of land use,and the Markov Chain method can be better used to forecast changes of land use within the zones.Here Markov Chain method was found that is wreath to take the inside variety, ANN considered fit the land that make use in class direction is good.It is further found out that merely for the converted land use types,the standard ANN-BP method gives greater error.This can be explained as the transform process of land use types of Shanghai city is directional,a general ANN-BP arithmetic gives each land type conversion with the same weight function.Although it is self-contradictory in directionality of the transformation,the modified model can still overcome this difficulty.
Natural secondary succession, forest planting and agricultural practices after deforestation or human disturbance affect soil properties in many aspects. Characterizing soil nutrients in relation to land use/land cover types and history is important for understanding how ecosystems work and assess the effects of future land use change. A study was initiated in Wolong Nature Reserve, Sichuan province, China to elucidate the complex relationships in the humid mountainous region. Six typical ecosystems (natural forestland, grassland, shrubby land, secondary forestland, cultivated land and reforested land) were compared.Significant differences among land use were found for soil bulk density (BD), total nitrogen (TN). Cultivated land had the lowest levels for most soil nutrients compared to other ecosystems and shrubby land had a higher soil organic carbon (SOC), total nitrogen (TN) and available nitrogen (AN). There was no much difference in 0-40 cm soil carbon mass between different land use practices. Soil carbon storage (TC) of different land use indicated that land use had a greater effect on SOC greater than on BD. The comprehensive soil deterioration index (DI) showed that the cultivated land, grassland and reforested land had the lower and negative values, while the shrubby land and secondary forestland had positive values, 12% and 1% respectively. The results gave a hint that in areas where the climate is fit for secondary succession "leave the nature as it is" is a better choice for the policy of "returning farmland to forest land" in China especially for the mountainous region lack of labor and finance support. Five reforestation periods were arranged from 0-10, 11-20, 21-30, 31-40 and 41-50 years. The results showed that reforestation could greatly change soil properties. The BD, SOC and TN were significantly different between the reforested periods, but the pH, TK, AN, AP and AK showed no significant trends.Further studies on the relationship of reforestation and the soil properties gave the results that the TC and TN had a good linear relationship with the reforested years and the DI index increased since reforestation.
Study on the decomposition of 12 kinds of forest defoliation and the role of soil animals in Pinus koraiensisbroad-leaved mixed forest and spruce-fir of Xiao Hinggan Mountains.The method of eliminating the role of soil animals of different groups from different mesh decomposition bags was adopted.The results show that the decomposition efficiency of the defoliation is large mesh > small mesh >check, that is to say the role of large-type and middle-small-type soil animals and microorganism > the role of middle-small-type soil animals and microorganism > the role of microorganism only.The average decomposition efficiency of three years is 28.9%(large mesh), 28.2%(small mesh) and 26.2%(check mesh).By the end of the third year, the degree of decomposition of three kinds of mesh bags is 86.7%(large mesh), 84.6%(small mesh) and 78.7% (check mesh). The decomposition of latifoliate defoliation is entirely higher than conifer defoliation in three kinds of mesh bags.In latifoliate defoliation, the decomposition degree of Phellodondron amuriensis,Fraxinus mandshurica,Ulmus laciniata,Juglans mandshurica andAcer mono is the highest.But in conifer defoliation, the decomposition degree of Pinus koraiensis is the highest.From the decomposition of 12 kinds of defoliations in 3 years, the decomposition of defoliation is effected not only by large-size soil animals but also by middle-small-size soil animals, but the degree of function is different.In the prophase of decomposition, the role of soil animals was gradually increasing and the biggest value appeared in October of the second year.Subsequently, the sole of soil animals was decreasing, and the role of large-type soil animals > the role of middle-small-type soil animals.The role of soil animals is different when the kind of defoliation and the time of decomposition are different.
The fractal theory, a new study tool, has been widely applied in soil sciences in recent years. The fractal features of soil granule as well as progress made in soil science research on grain distribution, soil moisture, soil bulk capacity variance and so on are discussed. Based on the fractal theory and relative model, the fractal features of soil granule structure of forest land and different reclaimed farmland were studied in this paper. The results show that the fractal dimension of soil granule structure of forest land and different reclaimed farmland are between 2.32～2.91. The less the contents of the granule >0.25 mm and the water-stable granule, the more the fractal dimension of soil granule and the higher the soil fertility are. There exists close relationship between fractal dimension of soil granule and the contents of soil granule or water-stable granule composition in all kinds of land. The soil physical properties of forest land and different reclaimed farmland vary with the variations of the fractal dimension. The less the fractal dimension, the more the contents of >0.25 mm soil granule and the less the soil bulk density, the better the soil self-restraint capacity. The more the fractal dimension, the less the contents of >0.25 mm soil granule and the greater the soil bulk capacity, the less the soil self-restraint capacity. The results show to certain extent that man-made unreasonable land use is the main cause of soil degradation and eco-environmental deterioration.Vegetation recovery and vehabilitation as well as increase ground coverage are principal countermeasures to reduce the Yellow River sedimentation and accelerate comprehensive control of the Loess Plateau.
surface sediment samples were collected from Yuehu during November- December 1998 and August-September 1999, respectively.These samples were analyzed using a Cilas940 L Laser Analyzer and by sieving (for particles with a diameter of <2 mm and >2 mm, respectively) to obtain grain size parameters. Three grain size parameters, i. e., mean grain size(μ), sorting coefficient(δ) and skewness(sk) are then calculated by a moment method.Five main sediment types are present in Yuehu according to the sediment classification scheme proposed by Shu Gao(1993, slight modification based on Folk(1980) classification scheme). The result shows the sediment appears annular distribution and is mainly composed of fine materials: From bank to center the sediment becomes finer gradually, i.e., from gravel sand, muddy sand, sandy mud to mud in turn. Sand is only distributed on ebb delta and north-east corner of the lake. There is a close relationship between mean grain size for sediment and sediment types in Yuehu where the mud area is mostly enclosed by 6 contour. The mean grain size for sandy mud is between 6 and 4 and muddy sand is between 4 and 2. In the sand and gravel sand distributed area the mean grain size is less than 2. Sorting coefficient and skewness value for sediment in Yuehu is 2.0～2.5 and 1～2 respectively. But the sediment located over flood delta is not well sorted with the sorting coefficient value between 3.0 and 3.5. At the same time the sediment near the mouth is negatively skewed with a value of 0.5 and the skewness is near 0 in a small area to the east of the center. The two dimensional model for grain size trend analysis proposed by Gao and Collins(1992 ) is adopted to identify sediment transport pathways in the study area. The net sediment transport pathways derived by using this model show that sediment is transported from bank towards the center, except the net sediment transport pathways are not obvious over ebb delta and main channel.At the same time the result shows that the north and west part of the top of the lake, flood delta and center are deposition centers. Such patterns are highly consistent with the sediment distribution pattern. Therefore this model is applicable for such a small area as Yuehu.
The West Liaohe River Basin is located to the east of Inner Mongolia of China and lies approximately between 117°00′～123°30′E and 42°00′～45°00′N. This region is a transitional zone of forest, forest steppe and steppe. According to researches on many archaeological sites of middle Holocene found in this region, wild pig ( Sus scrofa ) occupied a dominant position in the wild herbivores, and the bones of David's deer( Elaphurus davidianus ) was found in individual site.Wild pigs normally dwell in coniferous forest and mixed coniferous and broad leaved forests.This means forests played an important role in vegetation in middle Holocene in this region. And in the beginning of the Christian Era, wild horse ( Equus przewalskii ) was the main local product. This means that the steppe might have expanded. But in the Medieval era (during the beginning of the 10th to the beginning of the 12th century A.D.), the nomadic Qidan nationality established powerful Liao Dynasty, and there were a lot of documents about the West Liaohe River Basin. During this period, the David's deer( Elaphurus davidianus ) was recorded by many travelers, but however,no record of wild horse could be found in all historical documents during this period. This means that the forests had been expanded. And in the beginning of the Qing Dynasty (the 17th century AD), the wild horse was recorded as one of the local products. This means that the steppe could be expanded, and the forest reduced. And before the mid Qing Dynasty (the 18th century AD), tiger, beer and leopard were extensively distributed.However, after the mid Qing Dynasty, especially after the end of the 19th century, tiger and leopard became less and less and could not be found in any historical documents. The changes of animal geography before the 18th century were the result of natural changes, because the population was very sparse during this period of time. However,the changes of animal geography after the 18th century were induced by human activities, because the agricultural population migrated massively from the Yellow River Basin to the West Liaohe River Basin plus rapid population growth after the mid Qing Dynasty.This resulted in forest reduction and steppe expansion.
The West Liaohe River Basin is a typical ecotone and eco-vulnerable zone in northern China. Shaped by the long-term human's overuse, regional eco-environment in West Liaohe River Basin was seriously destroyed, which has threatened the harmonious and sustainable development of future human and nature relationships. Archeological studies show multifold cultures had evolved in this typical area since Holocene and civilization has been lasted through to present. By using GIS software, the authors first build DEM model of the study area and cultural landscape layers of different phases during the early historic period.They then overlay them to create DEM model of cultural landscapes of the early historic period, which distinctly revealed the relationships between distribution of cultural landscapes and natural landscape. All the analyses are based on four different spatial scales, which are typical archaeological site, Jiaolaihe River Valley, Aohan Banner and Chifeng area. Based on these studies, this paper identifies the basic evolving modes of the vertical change and horizontal change of the cultural landscapes during the earlier historic period of Holocene in West Liaohe River Basin. At the smaller scales of the three typical archaeological sites and Jiaolaihe River Basin, cultural landscapes mainly showed vertical change, including vertical expansion and downwards migration. Vertical changes of cultural landscapes had close relationships with cultural development, changes of production modes and life styles, and evolution of geomorphic landscapes. Evolution of the geomorphic landscapes, especially the river terraces, was an important driving factor. Configuration of small or middle scales of landform units and water sources, development of river systems, and combination of landform units directly influenced the formation of cultural landscapes at these scales. At the larger scales of Aohan Banner and Chifeng area, cultural landscapes mainly showed horizontal change. From Xiaohexi Culture to Hongshan Culture, cultures of this region were in expansion period, mainly featuring the spatial expansion of cultural scales. During Xiaoheyan Culture period, culture was in a period of contraction. After Xiaoheyan Culture period, culture of this region entered into a new expansion period again. Heterogeneity of regional natural landscape shows great influence on the formation of cultural landscape patterns during the earlier historic period.
The concepts of landscape are diverse. Cultural landscape is the evidence of landuse history and relics can be seen as a living model of sustainable landuse and can provide human beings more chances to enjoy scenery,happiness as well as natural and cultural diversities. It is also the last reserve of biodiversity and the buffer zone of absolutely protected area. Thus, more attention has been paid to the protection of landscape. The Yuanyang Terrace,famous for its large area, wide distribution, astonishing architecture,uniqueness in China and rarity in the world, was designated as the core area of the cultural landscape of Hani terraces by the government of Honghe Hani and Yi Autonomous Prefecture of Yunnan Province, China. The terraces were the physical basis of Hani peoples' life and the symbolization of Hani peoples' spirit. And the cultural landscape of Hani terraces was the model of sustainable landuse and harmonious human ecosystem between culture and nature. In this paper, we selected Malizhai administrative village located in Shengcun Township of Yuanyang County as a study area.Using semi-directive interview and field survey mothods,we analysed the characteristics,spatial structure and functions of Hani terraces and concluded that the Hani terraces have antiquity,uniqueness,sustainability and aesthetic values. The vertical structure of the distribution of forest,village and terraces along with altitude can benefit both environment and Hani terraces. Finally we put forward corresponding conservation strategies of the cultural landscape of Hani terraces in light with the risky situation of facing landslides,collapse,etc.
The urban gravitational model taking the form of the law of universal gravitation has been regarded as an experiential model for lack of theoretical basis so far, in contrast with Wilson's spatial interaction model based on entropy-maximization.It is of significance to make a theoretical proof as well as an advance that will lead us to its underlying rationale.In the paper contributing to spatial interaction of cities, the gravitational model, I = GM i M j r - b , is derived out of the general function, I = A * f ( x 1 , x 2 ,..., x n ), on the assumption of general fractality of urban system, and then the model is transformed into the new expression such as F ( r , τ )= GR ( τ ) r - b = Gr -b F - 1 [ S ( ω )] by introducing time-varying function, M i = f i ( t ), M j = f j ( t ), and time-lag parameter τ , while taking into account the cross-correlation function R ( t )=∫ f i ( t ) f j ( t + τ )d t , where S ( ω ) is energy-spectral density, and F ( r , τ ) the integral of the gravitation, I .Thus the analytical method of power spectrum for urban interaction is developed based on the new gravitational model.The new model was applied to characterize the process of spatial interaction between two cities,Beijing and Tianjin,from 1949 to 1998, and the experiential analysis can be divided into three steps.First, the spatial cross-correlation was described by means of the primitive time series of urban population, and some kinds of regularity were revealed through the patterns of cross-correlation coefficient and the corresponding power spectrum.Secondly, after taking the trend component parts out of the time series using fit equations, the spatial cross-correlation and power spectrum analyses were made based on the data with some periodic change to bring to light more hidden regularity on urban spatial network.Going a step further, we can make more deep analyses by taking out the periodic component parts, this step fails to be taken as space is limited.Inspite of this, the anti-intuitional rules have been discovered conforming to which the cities interact spatially.This paper will initiate the power spectrum analysis of urban interactions based on the gravitational model by giving an entire typical example, and more studies will be expected in this field in the future.
This paper introduces a new kind of evaluation approach of residential environment based on Area Source Model. Cell (1 km×1 km size of raster unit) is partitioned in the study area, which is realized in raster GIS platform (ARC/INFO GRID sub-modular). Dalian city is divided into 162 cells whose attributes are acquired and calculated from the questionnaires. When processing, evaluative indexes are determined by MDS method. Independent degree of resident attributes and evaluation of residential environment are tested by the method of Crosstab. Parallelism of evaluative difference of residential environment is discussed by the method of Factor Analysis. Finally the paper analyzes spatial difference of evaluation of residential environment by the spatial analysis of GIS, and the following points are resulted. Firstly, evaluative values of convenient environment fall from the center to the skirt step by step. Secondly, evaluative values of circumferential environment are affected by zone characteristics, especially the types of urban land-use to a great extent. Thirdly, evaluative values of human environment are not regularly diverse. Finally, evaluative values of residential environment have three epicenters of Zhongshan Square, Carrefour Supermarket and the edifice of municipal government.
Urban-rural integration is an urbanization process suitable to Chinese conditions. For China it is a new task. The focus of research on urban-rural interaction and integration is to evaluate the status and development extent of the urban-rural relationship scientifically. Urban-rural interaction and integration means the highest stage of urbanization. Urbanization means the absolute equality between the urban areas and rural areas. This paper tries to debate and testify the predications that urban-rural integration is actually the free change of natural resources and economy and social elements between city and countryside, and the amount and speed of the exchange are decided by the correlative-degree of urban and rural areas.For a long period of time, we only used one evaluating indicator-the proportion of non-agricultural population to total population to measure the degree of urbanization. We think that is far from enough. The equality between city and countryside also includes the equality of status and other rights. So we start our tentative research based on the analysis of the representation, characterization and the influencing factors of urban-rural interaction, and the authors constructed the evaluating indicator system by AHP. The system reflected the characteristics of interaction between urban and rural areas in all aspects, which can be used in practice. By this system, the comprehensive evaluation indicator correlative-degree was used to evaluate the development level of urban-rural interaction in 31 provinces (municipalities) of China in 2000. The result of evaluation revealed the real condition of the factor's transfer between urban and rural system, and showed development level of interaction between them. The method of correlative-degree of urban-rural interaction was a valuable attempt in quantitative research of urban-rural interaction.
Developing the west is a proactive policy to boost national economic development in the 21st century, which bears great importance for the sustainable development of the west and the country as a whole. The keystone of developing the west is eco-environmental protection, infrastructure and industrial restructuring; so the problem is how to harmonize the relation between eco-environmental protection and economic growth. Based on this viewpoint, firstly,the article expatiates small and medium-sized enterprises upon developing the west. Secondly, the article analyzes the problem of developing the west by discussing the relation between the development of small and medium-sized enterprises and eco-environmental protection. In addition, a completely new consideration of the policy for eco-environmental protection is made in the paper. Finally, the article puts forward some advice for eco-environmental protection in the development of small and medium-sized enterprises. We believe that economic development is a sticking point to solve the problem of environment in west China, especially, to improve the living condition in the region. It is an important strategy to accelerate the development of small and medium-sized enterprises. Properly lifting restriction on pollutant discharges and carrying out flexible policy to close down small enterprises are two important measures for the further development of small and medium-sized enterprises of the western region.
This paper explores the methods for studying regional economic difference in the aspects of research unit's being decided, measurement index's being chosen, and measurement means' being selected. It also points out the advantages and disadvantages of each method by taking 31 provinces, autonomous regions, and municipalities in mainland China as regional study unit,and per capita GDP as total index to measure regional economic difference.It quantitatively measures the overall leveland the characteristics of dynamic variation of the recent inter-provincialeconomic difference from the angles of standard deviation , and standard deviation coefficientof every region's per capita GDP.The absolute difference rose linearly and the relative difference wavelike. The frequencies distribution of every region's per capita GDP is a kind of positively slanting distribution, deviating normal distribution greatly. Every year, only a few provinces' per capita GDP is above the average level of the whole country. It also quantitatively measures the characteristics of spatial structure of this differential variation from the angles of the ratio of every region to the whole nation, and the difference of every region's relative development rate. Coastal areas are developing faster, in contrast with the inland areas, especially some western regions. There is a narrowing tendency in economic difference among coastal provinces, but in contrast there is a widening tendency among the east, the middle and the west. The spatial structure of the three belts was strengthened in the 1990s. The regression model between the growth rate of whole nation's GDP and the standard deviation of every region's per capita GDP was set up and according to this model the warn standard of inter-provincial economic difference was probed in this paper. Theoretically, the standard deviation of per capita GDP in 1994 had already broken warn standard. Moderately balancing policies should be carried out right then, so as to control the widening difference and to make each region develop harmoniously.
Regional economic difference has aroused wide interests of numerous scholars and many academic papers have been published discussing on this.Most of the papers on regional disparities in China are concentrated on the macro scale approach, namely western China, middle China and coastal China problem. For a long period of time coastal China has witnessed fairly quick development with average GDP growth rate being over 10%, along with quite a number of less developed areas coexistence in the process. According to extreme difference analyses in provinces(or cities) concerning the ratio between the highest level and lowest level about per capita GDP, Guangdong and Shandong belong to strongly differetiated areas, Jiangsu and Fujian belong to obviously differentiated areas,and Zhejiang belongs to relatively equal area. In this paper, less developed coastal areas refer to those areas where economic situation is relatively low compared with the surrounding coastal regions. Here per capita GDP is used as a principal indicator to classify economic types. Among the 72 cities, 34 of them are economically less developed areas. The distribution of the less developed coastal areas is characterized by two main aspects: first, they are situated between three highly developed economic belts of Jingjintang (Beijing-Tianjin-Tangshan) and Jiaodong (Shandong province), Yangtze Delta, Zhujiang Delta and Hongkong; second, most of the coastal less developed areas are situated along provincial boundaries. Unfavorable location, natural conditions, economic structure and regional policy are the major restirction factors that hinder their economic development.The most important task is to quicken the pace of economic development in these areas.First,the regional infrastructure construction should be improved;second,the endogenous advantageous resources should be fully made use of;and third,relevant preferential policies should be formulated.
