Kaifeng City, one of China ’s "seven ancient capital cities"and an important member of "Zhongyuan city croup", plays an important role as the regional central city of East Henan province in Henan's urban system City open space is a huge container regulating and controlling urban ecosystem In order to bring Kaifeng City into the situation of sustainable development, it is necessary to improve the construction of Kaifeng ecological city by means of optimizing open space system On the basis of the discussions of the significance and requirement of the construction of ecological city and the necessity of the optimization of city open space system, this paper analyses Kaifeng City ’s salient features and new developing ways, and raises theoretical basis and principles for the optimization of Kaifeng City ’s open space system The overall optimization of Kaifeng City ’s open space system should proceed from two sides The first side is the readjustment of the spatial distribution structure of the city The new spatial distribution structure in Kaifeng City should expand effective area of open space system, strengthen supporting of open space system to ecological capacity of Kaifeng City,and build a base for the integration of the three circles in open space system The second side is the integration of the three circles in Kaifeng City ’s open space system The integration in each circle, and between the three circles, should make Kaifeng City ’s open space turning into an integrated and organic system, from which the construction of Kaifeng ecological city should obtain powerful spatial support The element optimization of Kaifeng City ’s open space system has two contents The first one is the optimization of green open space in the city The municipal government should adhere to the urban ecological norm, create high quality ecological, living and landscape environments, make wooded area, garden area and water area into a natural integration, make point, line and flat green land into an unitary system, thereby, establishing a green basis for the construction of Kaifeng ecological city The second one is the optimization of gray open space in the city The municipal government should adhere to the urban ecological norm, create high quality ecological, operational and building environments, make urbantraffic, outside traffic, square and parking area into a situation of coordinated development,makeroads from east to west, from south to north and loop roads into an unitary system, thereby, establishing a gray basis for the construction of Kaifeng ecological city
Based on progress reviews the of eco city study at home and abroad,the rules of optimization and reorganization of spatial structure of eco city and "the green center with around groups network spatial structure model" was put forward taking Xiangfan as a case First, the present eco city's research status and successful practices abroad, and the concept of eco city, the urban eco areas dividing, planning and design, the evaluation index system and other theories and methods of eco city in China since the 1980s were reviewed Second, the authors put forward the rules based on those reviews, which guide the optimization of spatial structure of eco city They are: ① to perform natural harmoniousness fundamental to human; ② to develop at an appropriate scale and suit measures to local conditions; ③ to practise landscaping and achieve perfection and high efficiency;and ④ to pursue overall coordination and benign circulation And with these rules, the authors commend a new model of spatial structure named "the green center with around groups network spatial structure model". Third, based on the analysis of the evolution and problems of its spatial structure, four development forms of urban land use were compared and urban land use for construction were comprehensively evaluated Combining population prediction, the authors suggest that the regional function collaboration of the peripheral area with Xiangcheng and Fancheng should be strengthened, and the planning idea of "a continent, three mountains, three rivers"should be stressed to guide the city change to the green centre with around groups network spatial structure in the process of optimization and reorganization of spatial structure for creating a modern ruralizing eco city Finally, a authors think that the eco city is an inevitable trend of city development; the establishment of the city development leading mechanism makes the city turning gradually to an eco city that is more suited to human settlement;and green centre with around groups network spatial structure model is one of the ideal urban spatial structures
This paper discusses the property and marks of urbanization as a self organizing process, which can be thought of as a kind of phase transition from a rural to an urban settlement system. Several empirical observations including fractal structure and rank size distribution can be used to identify the self organized criticality (SOC) of urbanization dynamics. Fractal structure such as central place landscapes in spatial field and the rank size distribution associated with Zipf ’s law in hierarchical field always ‘emerge ’ while urban systems in a region approach to the self organized critical state of urbanism. The central place hierarchy can be characterized with a set of scaling laws as follows: N m=N 1r m-1 n,P m=P 1r 1-m m,A m=A 1r 1-m a . From these exponential scaling laws, we can derive the power laws such as the three parameter Zipf law, P(r)=C(r-ζ) -d , and the law of allometric growth, A m=ηP b m .The exponential distribution indicates random process, while the power law implies some order in complex systems, but we find the unity of opposites between order and chaos of urban systems through the derivation of power laws from the exponential type scaling laws. Moreover, this means that the spatial network of central places and the hierarchical structure of city size distribution reach the same goal by different routes. This in fact corroborates the viewpoint that both the urban hierarchy and spatial network represent the different sides of the same coin. The self organized networks of cities usually become scale free because of the dynamics of urbanization. The map of the urban network patterns in hierarchical field is just the rank size distribution, which appears in the larger picture, not at the level of an individual city. Once the distribution forms, it will become very stable over a long period of time. The formation of the scale free network of cities associated with the rank size distribution is an information rich evolution, which can be simulated using cellular automata (CA) models, cellular space (CS) model, multi agent system (MAS), and so on. Simulation as an experimental tool may be very useful for us to research spatial complication proceeding from urbanization dynamics. However, the simulation based on computer graphics doesn't help us conceptually in understanding the rules of behavior of urban systems at the higher level. As a complement, post modern mathematical theory esp. fractal geometry, chaos mathematics, renormalization group, etc., will play a significant role in the studies of self organizing urbanization.
This paper deals with the physical and chemical properties characteristic and its affected factors of latored soils in southern subtropical hills Results showed that compared with the soil under zonal natural vegetation it suffered more physical and chemical properties degradation under secondary or man made vegetation It was found that the physical properties degradation in latored soils was characterized by the lowering of aggregates stability with decreasing water stable aggregates, the deteriorating of soil porosity with increasing bulk density and decreasing bigger pore content and the deteriorating of water properties with lowering water permeability and available water retention capacity For natural latored soils, the increasing bulk density and lowering bigger pore content were more obvious, but for cultivated one, the lowering structural stability was more serious It was showed that the chemical properties degradation was characterized by nutrients improvement and nutrients supplying ability with lowering organic matter, nitrogen, phosphate, potassium and cation exchange capacity Statistic analysis indicated that the 10～0 25mm water stable aggregate and its mean geometric diameter value were obviously positively correlated with the organic matter content and total nitrogen content in the soils, that the total porosity and >0 05mm porosity were also positively correlated with the organic matter content in the soils; that the soil structure coefficient and <0 005mm porosity were positively correlated with soil clay content This means that nutrients improvement, especially the organic matter deficient might be the main factor which caused the latored soils physical properties degradation Natural vegetation destroyed by human disturbance might induce soil nutrients improvement, in order to prevent soil degradation, more attention should be paid to protecting vegetation and increasing soil organic matter content
Limestone dolines are much developed in Lunan Stone Forest National Park with soil mantle We choose 9 sites in the bottom or slope of 4 dolines in Lunan Stone Forest in order to study the soil particle size distribution, water content(%), chemical composition of soil developed in the doline bottom or on the slope and their relationship with doline development Study shows that soil water content, chemical composition and particle size distribution are all controlled by karst topography The soil in the bottom of the depression has a lower water content, total Al 2 O 3 and Fe 2 O 3 content than that of the soil in the slope of the depression, However, total SiO 2 of soil in the doline bottom is higher than that of the slope We mainly study the clay and silt content of the soil mantle soil in doline bottom has higher silt content and less clay content than that of the soil on the slope Research results show that with the increase of soil fine grain size, the SiO 2 content decreases while both of Al 2 O 3 and Fe 2 O 3 content increase The water content of soil is highly positive related with content of fine grain size and strongly negative related with content of coarse silt content In order to determine the limestone erosion rate at different depths, 27 limestone tablets were buried at different depths(20 to 60 or 120 cm, one layer every 20 cm) of soil, which were developed in the bottom and slope of a doline in November 1999 Two years later(November, 2001), 25 tablets were exhumed and sent to lab to measure their weight loss then calculate dissolution rate Result of dissolution experiment shows that limestone dissolution rate in the soil of doline bottom is much higher than that in soil on the slope At the same time, result of correlation analysis shows that limestone dissolution rate is highly positive related with content of coarse silt content(R 2 =0 85) and strongly negative related with content of fine grain size(R 2 =0 84) To some extent, even though limestone dissolution rate was decided by soil CO 2 concentration and soil chemical composition, it is still affected by the soil particle size distribution
Previous studies on relationships between hillslope and gully erosion are mainly concentrated on exploration of water and silt relations, few on quantitative studies of evolution relationships between hillslope and gully landform erosion in small catchments of original scales Quantitative studies on synthetic impact and interactions of hillslope and gully geomorphologic characteristics on catchment dissected extent are still a blank in particular This paper, supported by 3S techniques, based on 1∶5000 digital orthophotomap (DOM), digital elevation model (DEM) and topographic map of the same period and of the same scale, quantitatively analysed the impact and interactions of hillslope and gully geomorphologic characteristics on catchment dissected extent by using orthogonal polynomial regression analysis Research results indicated that gullies play a leading role in the catchment morphologic evolution and ground surface dissected extent When inter gully areas are the same, the 0 1 km 2 gully area is the maximum area affecting erosive evolution intensity of the catchment dissected extent The smaller the catchment area is, the greater the affecting extent of catchment surface fragmentation would be The geomorphologic evolution mechanism of channel slopes and gullies can be explained with synthetic impact of geomorphologic indicator of slope and gully fluvial energy Gullied land plays the leading role in affecting catchment dissected extent indicators of D r and L e , when inter gullied land area ( A p ) is constant, there exists maximum value of the dissected extent indicator L e and critical gully catchment area, the catchment dissected extent is the greatest when gully catchment area is about 0 1 km 2. The smaller the gully catchment area is, the greater the gully density would be. When inter gullied land area increases, the dissected extent indicators D r and L e decrease. When gullied land area ( A g ) keeps constant, the catchment dissected extent indicators D r and L e decrease with the increase of inter gullied land area.Catchment dissected extent is synthetically affected by fluvial erodibility under conditions of varying gradients of inter gullies and gullies and their interactions. The evolution mechanism of slope and gully landforms of gully catchment can be explained via synthetic effect of slope and gully fluvial energy landform indicators and their interactions.According to erosional characteristics of slope and gully landforms, to elevate erosional basement level is the key link for controlling modern gully head advancement and hillslope expansion rate of the catchment basins. Priorities should be given to soil and water conservation management of gully catchment area of 0 1 km 2.
It is well known that the Yellow River is the river with the highest sediment contents of all rivers in the world Several hundred million tons of sediments are transported to the coast and to the sea nearby annually, so the Yellow River Estuary area has witnessed the fastest coastline changes in the world This paper describes the spatio temporal features of the coastline dynamics in the estuary area using remote sensing images since the course of the Yellow River was changed to Qingshuigou channel artificially in 1976 Trying to anatomize the spatio temporal features of coastline evolution, 20 sheets of Landsat images were used as the data source The multi temporal satellite images were rectificated precisely and registered each other, and all the images have the same coordinate system After supervised classification the coastlines were extracted automatically from remote sensing images The result shows that a new land of 330 km 2 was formed during 1976 to 2000 by GIS overlay analysis Finally, combined with the hydrologic data from Lijin station, the relation between coastline change and the runoff and sand transportation was analyzed, and the evolution trend was forecasted The results are as follows: (1) The method in the paper is viable to monitor the coastline change (2) Generally, the land forming speed is faster at the initial stage after course change, and the range of the spit shows a strong linear positive correlation with the net epirogenetic area But the coastline begins to erode after the sediment source is broken off absolutely (3) The evolution process during 1976 to 2000 is divided into four stages based on the spatio temporal features of the coastline (4)There is a consanguineous correlation between the ranges of the spit and the runoff and sand transportation, and the speed of the coastline change will become slow in the future according to the present condition of the runoff and sand transportation
Global warming will lead to changes in many environmental factors and disturbance regimes (e g fire, drought, insect outbreak etc ) As a consequence, changes in characteristics of existing ecosystems, such as species composition and competition, stability and productivity, ecosystem health, ecological safety and ecosystem services, are to be expected Palaeoecological evidence and palaeoclimatic records pointed out plant pole ward migration in latitude and upward shift in elevation with increased temperature after the last glaciation Ecological observations also showed that the elevation of the alpine timberline moved upward worldwide with increasing global temperatures during the last 100 years Current global warming could mean that the plants currently growing at lower elevations or at lower latitudes might progressively migrate to higher elevations and latitudes However, it does not mean that all plants of an ecosystem move upward or pole ward with the same velocity Many species may re adapt to the changed and changing environmental conditions and survive for generations at their present location Many species will shift their ranges to track climate change As climate may change faster than plants are able to migrate from one region to another, species will become extinct An extinction of a plant species will also harm the animals depending on this specific species On the other hand, global warming and new disturbance regimes could favour the invasion of non native species due to the reduced stability and resistance of ecosystems Biological invasions will lead to massive losses of biological diversity on local, regional and global scales Global warming during the past 20 30 years has already had a severe impact on sensitive biological systems As a continued warming has to be expected, the global warming issue should be addressed by conservation planners and policy makers, as one of the most serious and immediate threats to biodiversity
As no single interpolation method is optimal for all regions and data, it is important to compare the results obtained using alternative methods applied to each data set In this study, two methods for spatial interpolation of climatic data from sparse weather station networks were compared Forty year monthly mean temperature and precipitation data from regions in Gansu province were interpolated using a deterministic estimation method termed "Inverse distance weighted" (IDS) and a statistical method termed "Gradient plus Inverse Distance Squared"(GIDS) By design, their power parameters were optimized on the basis of minimum root mean square error (RMSE) Corresponding cross validation tests show that optimal inverse distance had consistently better results than usual: As for temperature, the value of MAE decreases by 6 77% and 9 95% in the method of IDW and GIDW respectively; as for precipitation, the value of MAE decreases by 28 19% and 6 25% in the two methods correspondingly Summary statistics were used to determine if one method was significantly better than the other on the basis of mean absolute error (MAE), mean relative error (MRE) and root mean squared error(RMSE) Based on the mean absolute errors from cross validation tests, the methods were ranked GIDS>IDW for interpolating monthly precipitation and temperature, being average by 0 73℃ for monthly temperature and 4 90 mm for monthly precipitation Based on the mean relative errors from cross validation tests, the methods were also ranked GIDW>IDW for interpolating monthly precipitation and temperature, being averagely 9 02% for monthly temperature and 17 82% for monthly precipitation In addition, GIDW yields more accurate predictions than IDW when the correlation between rainfall and elevation is high (less than 0 80 in the case study) For Gansu province, except January and December, the remaining months in the year see the correlation between elevation and rainfall higher than 0 80,while these two months are not very important for us to study soil water balance, so we prefer GIDW method to our study Furthermore, before the interpolation of precipitation, we try to analyse the data, and the results show it is very important to analyse the character and distribution of data before interpolation In our study area, a cubic transformation improves the accuracy well
Qilian juniper ( Sabina przewalskii Kom ) growing in the mountainous area of the easterm part of Qaidam Basin is sensitive to climate change It can reach one millennial years old and the tree ring width chronology can be used to reconstruct climate change over the past 1000 years Power spectrum analysis, Singular Spectrum Analysis (SSA) and wavelet analysis were utilized to trace the variations recorded in two standard tree ring width chronologies (WL3 and WL4) of Qilian juniper in Shalike Mountain, Qinghai, China The power spectrum of the series showed low frequency periodicity of 200 years are most statistically significant at the 95% confidence level for both chronologies Analysis of the power spectrum of both series also showed evidently that low frequency variations of century scale are present in the chronologies It was found that the most important cycle was 200 years for both chronologies by SSA, cycle of 133 years for WL3 and 100 years for WL4 are also identified by this method The reconstructed components of paired eigenvectors of SSA showed that different scale cycles had different behaviors over the past 1000 years Wavelet analysis can provide information on the amplitude of periodic signals and their variations with time The Morlet wavelet coefficient distributions indicated that the 200 years cycle was most prevailing from the 15th to the 17th century for both chronologies, the century scale cycles were pronounced since the 18th century The prominent low value of the ring width in the second half of 15th century is affected by the cycle of 200 years, the high value in the late 20th century is the contribution of century scale periodicities One possible explanation of the low frequencies in the ring width data might be related to the fluctuations of the solar activity Narrow ring width seems to occur during quiet solar periods such as the Wolf, Sprer, Maunder and Dalton solar minima, suggesting that the low variation of the climate indicated by tree ring width may be affected by the long term change in solar activity
Based upon the development in recent 50 years, historical geography of China has gained great achievements, especially in the following fields: the research on historical territories and boundaries and the compilation of historical maps; historical climate and natural disasters; historical land surface processes; the origin and development of Chinese civilization; the regional integration and historical events; historical human environment relations and adaptation patterns; the accumulation of fundamental data and the application of new technologies Taking into consideration the development trend of current earth sciences, geographical sciences, and international researches of global changes and sustainable development, suggestions were presented for the development of Chinese historical geography in the 21st century The authors suggest that Chinese historical geography should make the collection and mining of geographical evidences of civilization evolution, and the analysis of the spatio temporal characteristics of historical human environment interactions as the foci; and the exploration of the historical pattens of human adapatation to envionment changes as the target An integration of traditional methods,e g ,document analysis, field investigation and archaeology, and modern ones,e g ,experimental techniques and spatial information techniques, is necessary On the basis of the compilation of the thematic maps on Chinese environmental changes and civilization evolution in 5000 years, priority should be given to the researches on the following key aspects,i e ,the establishment of GIS on Chinese civilization evolution, the reconstruction of high resolution environmental factor series and the analysis on their spatio temporal characteristics, historical land use/land cover change researches, adaptability researches, the construction of regional adaptation models, the researches on regional human environment systems in history, the integrated research of Chinese historical environmental changes and the compilation of thematic maps, and the researches of spatial differences between cultures Chinese historical geography will present remarkable contribution to the international researches of global changes and sustainable development
With the application of five year slide average of flood frequency analytical methods, the authors analyse the developing process of the Yellow River in the course of 510 years from the Tang Dynasty (TD), Five Dynasties (FV) to the Northern Song Dynasty (NSD), and explores several major flood afflicted consequences from TD to NSD It is found out a comparatively slight flood occurred at the beginning of TD, whereas severe floods occurred in the middle and late TD. Up till FV and NSD,the Yellow River was breached almost every year, the worst case with a couple of breaches in a year, and the most disastrous flood claimed a casualty of nearly one million people, unprecedented in the Yellow River flood disaster history The analyses and comparisons of the agricultural population migration in the middle Yellow River and from Hekouzhen to Longmen section from Eastern and Western Han dynasties, TD to NSD indicate that the ups and downs of the agricultural population in the middle reaches does not synchronize with flood frequency alteration in the lower reaches The evidence shows the flood of the lower reaches in TD was much slighter than that of Eastern Han, however the population in the middle reaches quadrupled that of EHD at that time Furthermore, population in the middle reaches in mid TD surpassed that of WHD and late NSD as well However, there was a relatively quiet time in the lower reaches in mid TD In accordance with the aforementioned, it can conclude that the local population growth did not contribute to the severe flood disasters in NSD The essay also investigates the conditions of land resources in the middle reaches and from Hekouzhen to Longmen section and concludes that the basin area and the valley plain could already fully satisfy the farming capacity, as a rule, it was unnecessary to open up the available slopes Thus farming activities can not be accountable for the severity of the flood disaster in the lower Yellow River After late TD, Dang Xiang ethnic group expanded their range of activity by establishing the feudal separatist regime in the whole Ordos Plateau and northern Shaanxi of the Loess Plateau and Xia Kingdom later in NSD, which featured the traditional grazing practice of nomadic nationality in this area accounting chiefly for soil desertification and flood disasters in the lower Yellow River
With the development of tourism industry and the exploitation of tourism resources, tourism planning is becoming more and more important in China, and has been identified as a focus of research. However, as it is a relatively new technology, it still lacks systematic analysis on theory, technology, implementation and monitoring, especially on the evaluation technology And the evaluation of tourism planning is actually an important part of tourism planning theory, a high consideration should be given to this point Now in China, most of the evaluations on scenic spot planning are qualitative analysis,with evaluation result being inevitably arbitrary How to solve the problems of evaluating on Master Plan of Scenic Spots through quantitative analysis and decision making in order to select a most suitable plan from multiple choices has become particularly essential This paper set up an "entropy technology based on AHP (Analytic Hierarchy Process)" evaluation model for scenic spot planning First, the weights of each index were obtained through "AHP" method, they were then modified by "entropy" technology, and finally the distance from each plan to the ideal point was evaluated Through this process, we could evaluate which plan is the best with the shortest distance to the ideal point Through three aspects of work, namely, economic evaluation, technological evaluation and environmental evaluation, this paper set up an evaluation index system for scenic spot planning based on 13 indexes chosen Taking Muyan Scenic Spot in Nanjing of Jiangsu as an example, this paper applied the model into the evaluation process, and the result is consistent with the actual evaluation result, indicating the reliability and practicability of the model The "entropy technology based on AHP" evaluation model could turn the qualitative evaluation process into the quantitative process, which provides an opportunity for an objective and a righteous judgment among several plans The authors also pointed out that the limitation of this model is that the index in the model would verify with the characteristic difference of scenic spots,and the parameters may also change in different scenic spots Anyway, this model is a useful exploration means for the scientific, standardized and quantitative evaluation of scenic spots and tourism planning
As is well known China is experiencing a rapid progress in ReBAM tourism in recent years The situation has caught more and more attentions from many researchers The spatial distribution of attractions in the ReBAM has just been qualitatively demonstrated, while there is a big lack of quantitative analysis due to the limitation of data availability For this paper, the authors take 235 specific attractions as samples, which are picked from 14 districts apart from 4 old districts of Beijing, and explore deeply into attraction categories and spatial characteristics of Beijing on the basis of a large amount of statistical data and the predecessor's research According to the method of compound category, the authors cut attractions into nine categories with the attributes of tourism resource and travel activities But only four categories among the nine can be found in Beijing, and they are natural sightseeing resorts, human sightseeing resorts, artificial entertainment resorts and sports resorts Then the authors try to disclose the characteristics of attractions categories and spatial distribution in Beijing with the support of ReBAM theory, space structure and metrological geography and the method of GIS and call in survey Several quantitative methods are used such as rotating radius, spatial distribution curve, discrete index of attraction and so on With the data and the methods, the authors reach the following conclusions: The point of 60 km away from the city center is the critical point of attractions' spatial distribution, at that place where the pushing force of classified rents and the pulling force of traffic resistance get into balance So the area within 60 km from the city center is the optimal place for tourism industry, all the four categories can be found there While relatively less categories can be found in the area beyond 60 km away from the city center Most of the attractions are natural landscape category, which include natural sightseeing attractions and sport and recreation attractions rely on natural resource
Cultural geography study is in the ascendance in China, but study on cultural geography of overseas Chinese is weak in the research field at home and aboard and it needs earnestly to be studied further The thesis takes Guangdong province as an object, where the largest number of oversea Chinese is distributed most widely in the world It sets forth the connotation of overseas Chinese culture that has two cultural headstreams One is the hometown of overseas Chinese and the other is the emigration place Overseas Chinese culture is a cultural type with Chinese and western culture features and extensively operating overseas Chinese magazines It expatiates on the land use landscape formed by introducing foreign crops in the hometown of overseas Chinese It also expounds the architectural cultural landscape formed by introducing the western Qilou and city planning system combined with local environment, the language landscape formed by the combination of foreign languages and local dialects and cultural landscape formed by overseas Chinese with ability The thesis points out their historical influence on the society, economics and culture in the local place On the basis of the combination of the relative coherence of cultural features in the hometowns of overseas Chinese and the comparative intercommunity of the cultural background in the foreign countries where the overseas Chinese live, the thesis, for the first time, divides the Pearl River Delta into the following five culture areas of overseas Chinese as: Guangfu Culture Area, Wuyi Culture Area, Chaoshan Culture Area, Dongjiang Xingmei Culture Area and Northeast of Hainan Island Culture Area It puts forwards their respective culture characteristics and regional effects that are supposed to be opened up and made good use of
