Vulnerability of natural ecosystems has become a key issue both in assessing the impact of climate change and in planning the adaptation to climate change. In the paper, we elucidated the concepts of vulnerability, sensibility and threshold, analyzed distributions of the ecolble for global warming will change. The productivity and carbon flux of terrestrial ecosystems are also highly sensitive to climate change. The Net Primary Productivity （NPP） of terrestrial vegetation has been increasing since the 1980s in China. Annual Net Ecosystem Productivity （NEP） varies between 0.32 and 0.25 Gt C a～-1, wit h a mean value of 0.07 Gt C a～-1. Terrestrial ecosystems in China are cur rently a carbon sink, but the carbon uptake rate ogical sensitive zones, vulnerability of natural ecosystems and adaptation to climate and ecosystem changes in China. Numerous studies show that natural ecosystems are high sensitivity to climate change, particularly in the transitional zones （i.e. ecotones）. The first-class sensitive zone in China is the region be tween the east of Inner Mongolia and the southeast of Tibetan Plateau. The climate zones and vegetation zones will produce a northward or westward shift, and the proportion of vegetations is one of the factors responsimay diminish as anticipated with the rapid warming of climate in this century. Seven regions vulnerable to climate change in China account for 20% of the whole country, in which five are in the west of China. The natural hazards are associated with climate change such as drought, fire, pest infestationetc. Excessive use of resources will increase the vulnerability of ecosystems. Applications of some measures are helpful to the adaptation to the climate change and mitigation of the vulnerability. However, there are still high uncertainties in assessing the vulnerability of natural ecosystems, many issues warrant further studies.
More and more importance has been attached to the extreme weather and climate events related to climate warming and their impacts. Changes of extreme events are directly related to climate change, while the impact of the extreme events is as well as depended on the adaptation behavior of human being.A case study is made in this paper on change of cool summer hazard under an adaptation behavior to the climate warming in Heilongjiang Province, Northeast China. Heilongjiang Province in Northeast China located in the highest latitudes of China is one of theriod (1990-1999), almost no cool summer hazard happened. Theoretically the risk of crops planting impacted by the cool summer hazard will be decreased accordingly. However, it does not mean that the frequency and intensity of the cool summer hazard rea lly decreased. Because farmers may change the variety of the crop or the crop's structure to adapt to the climate warming in order to obtain more economicbene fits. In fact, human regions where agriculture is most sensitive to temperature variations in China. The impact of climate warming and adaptation behavior to the cold summer hazard in Heilongjiang Province is analyzed in this paper. It is found that the growth period mean temperature increased and the standard deviation of the temperature decreased. In theory, the probability of extreme low summer temperature would decrease accordingly. If the planting mode was kept unchanged, that is, the criterion of cool summer hazard was not changed, the frequency of cool summer hazard would be reduced to about 10% in the warm period (1980-1999) and about 30% in the cold period (1960-1979) in most parts of Heilongjiang Province. In the intensive warming pe being's adaptation interfered the impact of climate warming on the probability of cool summer hazard. In general, people seek for maximal economic benefits instead of the minimal risk. When climate warms up, people would select plant varieties more suitable to warmer climate to obtain more economic benefits, but the probability and intensity of cool summer hazard might not always decrease as climate warms.
Based on the snow and rainfall archives in the Qing Dynasty, the seasonal precipitation grade series of 6 prefectures in Jiangsu province from 1736 to 1908 were established. Then the temporal and spatial patterns of the precipitation in Jiangsu province were analyzed and the extreme events in Jiangsu province from 1736 to 1908 were also identified. The results can be summarized as follows: (1) Although the interannual variations of precipitation for 6 prefectures are different, the interdecadal variations are similar except in a few decades. In Jiangsu province, it was rainy in spring and summer during the 1750s, 1790s, 1830s-1840s and 1880s, whereas it was rainless in the 1770s-1780s, 1810s and 1870s. The autumn precipitation in Jiangsu province was higher than the normal in the 1750s, 1840s-1850s and 1860s, but lower in the 1770s, 1810s and 1890s. The winter precipitation in the 1830s-1840s, and 1890s was relatively high, but it was relatively low in the 1820s, 1850s and 1870s. (2) From 1736 to 1908, there were 15 extreme events of flood or drought in Jiangsu province. In which 1755, 1823, 1840, 1849, 1883, 1885 and 1906 were extreme flood years; and 1768, 1778, 1785, 1814, 1856, 1873, 1876 and 1891 were extreme drought years. (3) There was probably an abrupt change of climate around 1830 in Jiangsu province. From 1736 to 1830, the climate was stable and the variation of precipitation was moderate. Whereas after 1830 the climate showed the instability, and the rainy and droughty periods alternated frequently with ano maly increased extreme events of flood or drought. A comparative analysis showed that the instability of climate was correspondent with the high frequency of E lNino after 1830. These results are not only important reference for the preci pitation projection in the future in Jiangsu province, but also great significance for the study on the long-term variations of East Asian Monsoon.
An extremely severe weather process happened in the southern Shaanxi province during 8-9 June 2002 which is rare in history causing flashflood, landslide and a death of more than 450 people.The MM 5 model, successfully simulated the weather systems and related mesoscale convec tive complex, that caused the severe heavy rain in the southern Shaanxi province during 8-9 June 2002.The simulated precipitation is quite similar to the obse rvations at three extremely heavy centers at Ningqiang, Foping and Ningshan of southern Shaanxi. On the basis of successful control simulations(CTRL), two sens itivity experiments about surface sensible and latent flux are done. By analyzing the results of the sensitivity experiments about surface sensible and latent flux which is important for extremely heavy rainfall in the southern Shaanxi proince during 8-9 June 2002, it is found that the distributions of surface tempe rature, surface sensible and latent flux are highly correlated with special topo graphy of eastern Tibetan Plateau, with isolines of surface temperature and heat flux parallel to the isohypse of terrain, with obvious features between plains and mountains which indicate that orographic thermal forcing plays a key role in heavy rainfall; and that simulations with no surface latent flux are much less than observations especially in Foping and Ningshan counties on the southeastern slope of Qinling mountains where precipitation decreased by over 100 mm, and su rface latent flux is more important than surface sensible flux which makes preci pitation reduction in the mountainous areas and increment in plains and valleys because of mountain-valley wind circulation. The effect of surface flux on rai nfall is realized by increasing surface convergence and vorticity over the south eastern slope of Qinling mountains, forming lee vortex, furthermore causing seco ndary vertical circulation by topographic mechanical and thermal forcing.
A transitional zone in landscape has a character of high spatial heterogeneity, from which demarcation lines are usually needed to be drawn for delineating various categories of landscapes and their extents. According to distinct differences of landscapes on both sides of the demarcation lines, and using GRID in ARCGIS, this paper provides a simpler and easier method based on cell-by-cell neighborhood processing. First it divides all the cells alternatively into two classes by an attribute, and then deduces which category the processed continuous or dispersive cells should belong to at random directions. And it sets a critical value according to location characteri stics of borderlines and double-handed attributes on classification. Then grid sclose to the demarcation line are selected by their short distance, because af ter neighboring processing, the closer grids have a higher attributive degree than the farther ones, and the discontinuous and lonely grids are abandoned so that the continuously distributed cells near the demarcation line can begot. After vectorization of grid layer, the line coverage can be used to select the demar cation line with the help of reference maps, such as hillshade or land use distribution maps. Taking the regions near the Capital, China, this paper gives defi nite mechanics of neighborhood processing, draws morphological boundaries out of landforms, checks accuracy of the method, and briefly discusses its meanings and availability. Also, it applies this method to other fields of landscape analy sis for application and validation. The neighborhood processing can trace the borderline between two classes of landscapes which are distributed complicatedly on two-dimensional space, and can be used to search the demarcation lines of agro-pastoral transitional zone, geomorphological demarcation line, or shoulder line of valleys on the Loess Plateau, etc.
The intensity of sand-drift activities is the important theoretic base for both studying the formation and evolution of aeolian geomorphology and carrying out the sand-damage control measures. Based on statistics and calculations of wind data, this paper studied the intensities of the sand-drift of Taklimakan Desert and drawn some preliminary conclusio ns as follows: ① Except Ruoqiang district, the whole Taklimakan Desert belongs to low-energy environment and the drift potential in most areas is less than 20 0VU. ② With the increase of wind velocity, its frequency decreases gradually, so the most effective sand-moving winds range from 6.1m/s to 10.0m/s, but the most contributors to sand flux concentrate between 9.0 m/s and 11.0 m/s. ③ The intensity of sand-drift activities has great temporal and spatial variation s. As seasons concerned, the sand-drift activity is the strongest during spring and summer and is the weakest in winter, and the autumnlies between them. Ho wever, in the interior of the desert there is a phenomenon called as "wind-temp erature synchronization", that is, the monthly mean temperature and wind velocity get their maximum values during June and July. On the fringe of the desert, the maximum temperature occurs in June and July, while the maximum wind velocity in April and May. According to the calculated results of drift potential and sandflux, the intensity of sand-drift activities is stronger in the central and eastern parts than that of western, southern and southwestern parts. Although this study has got some results, there is still some important work to carry out in future. At first, to give a rational explanation of the temporal and spatial variations of the intensity of sand-drift activities, in combination with the circulation patterns at different elevations. Secondly, to give a det ailed explanation of the "wind-temperature synchronization" phenomenon through scientific experiments. And finally, to integrate the intensity of sand-drift activities with the degree of sand dune activities, so as to provide more effect ive base for sand-damage control measures.
In this study, we examined the pedoe co logical effects of three shrub species that occur generally in shifting, semi-s hifting and semi-fixed sand lands in the Horqin Sandy Land. Several important conclusions were drawn from this study. （1） There were significant differences in the interception and retention of sand and aeolian dust among three shrub spe cies. Of the three shrubs, the mean amount of the interception and retention of sand and aeolian dust perplant was the greatest （0.49 m3） in Caragana microphylla, followed by Artemisia halodendrom （0.16 m3） and Salix gordejvii （0.03 m3）. Regression analyses showed that the sediment a mount of sand and aeolian dust perplant was positively and significantly correl ated with its average canopy （accounting for 18-58% of the variance）, branching number （accounting for 16-31% of the variance） and shoot diameter （accounting for 14-17% of the variance）. （2） All three shrubs exhibited significant effects of "island of fertility", i.e. the soils under shrub canopies were significa ntly higher in nutrient availability than those beyond shrub canopies. Such effects may create a nutrient-rich substrate, thus providing a better environment for further invasion and establishment of other plant species on bare sandy land . The effects of "inland of fertility" varied markedly with the type of shrubs pecies. Of the three shrubs examined, Caragana microphylla had the greatest "fertile island" effect, followed by Artemisia halodendrom and Salix gord ejvii, largely because of significantly higher levels of organic matter, total N and available P in soils （0-20 cm） under the Caragana microphylla canopies than those under Artemisia halodendrom and Salix gordejvii canopies. Shrubs differed appreciably in accumulation efficiency of different nutrients. For example, the accumulation efficiencies of organic matter, total P, available P and total N in soils under shrub canopies averaged 1.20-1.44, 1.08-1.2 3, 1.11-1.36 and 1.17-1.40. （3） Wind direction appeared not to influence the spatial distribution of soil physical properties, but showed an effect on the spatial distribution of organic matter content. Organic matter contents in soils at the SE and NE directions of the shrubs were somewhat higher than the other directions.
Stream structure in urbanized river network area has unique characteristics under the effect of physical factors and human modification. Hence the issues of what and how such changes worked on river network storage and flood control capacity become the focus of this study. Taking Shanghai as a sample area, which is one of the largest cities in China located in the eastern Yangtze Delta, by using Horton-Strahler classification and Horton laws as reference based on the stream classification system that is commonly adopted in Shanghai and other cities around it, this paper analyzed the stream structure characteristics in each catchment under various urbanization levels;approached the effect of urbanization on stream structure development; and demo nstrated the possible relations between stream structure and river network storage and flood control capacity. The flood storage and control functions of streams in each order were further discussed in this paper. The main results are: (1 ) The stream number and length within the river network were highly developed in the study area. Stream number developed better than stream length. (2) The stream structure could only be modified when urbanization was up to a certain high level. Physical laws still played important roles in those catchments with lower urbanization level. (3) The stream structure expressed the possible trends from comprehension to simplicity, from multiform to singleness during the process of urbanization. (4) There was an obvious converse change between river network storage and flood control capacity and urbanization level. River network stor age and flood control capacity was influenced both by the quantity of water area and stream structure and much more closely related to the number and length of streams in the lower order. (5) For those streams in the higher order, the stor age capacity was stronger than the control capacity and the converse situatione xisted in those streams in the lower order. (6) proper quantity of water area and better stream structure were the infrastructures to assure ecological flood storage and control in urban area.
Eco-water demand is a focus of attention in ecological and water science research at present. Under the macroscopical background of implementing the west development strategy, pursuing the ecologi cal project of converting farmland into forest and grassland and realizing regional sustainable development of China, water and land resources distribution, esp ecially the deficiency of water resources has restrained the development and utilization of western region's resources and become an urgent problem awaiting sol ution. Just because of this, the assessment of the scale and intensity of basin ecosystem eco-water demand is of positive and realistic significance. This paper, with western arid climate and hungriness environment as the research object , through analyzing the structure characteristics of different ecosystem's eco-water demand, synthetically estimates the scale of eco-water demand and analyzes the question of equilibrium of supply and demand of eco-water requirement in terms of maintaining the basic amount of ecological base flow of the fundamental eco-environmental function of the drainage channels, keeping basin channels' moisture balance for sediment and salt discharge and maintaining the basin's ecol ogical balance by minimizing water consumed for vegetation evapotranspiration.The research result indicates that the total eco-water demand in the whole basin is about 6.93×109m3/a, accounting for 50.5% of the total amount of the basin's recent available surface water resources, groundwater mining and many years spring average foot-path flow.The development and utilization degree of this basin surface water has already exceeded rational threshold value. The average minimum eco-water demand per ha of vegetation is 413.9 m3/a.Of the eco-water consumed for different types of vegetation, marshland, meadow and forest land separately account for 47.6%, 43.4% and 9.0% of the total water requirement. Marshland and meadow are the principal eco-water consumers. Resear chresults have important reference value to make development and utilization plan of water and land resources, for local government, guarantee the benign cycle of the water resources, realize the sustainable utilization of the water resources, restore and rehabilitate the eco-environment.
The dramatic change of hydrological cycle and natural condition and the increasing intensity of human activity usually result in the step trend of streamflow. Change point detection in streamflow series is an important way to understand and diagnose the step trend. Up to now, many methods have been developed to detect the change point, among which the one derived from basic statistics theory is most widely used for its simplicity, but is also limited for its much assumption for data at the same time. In terms of theory of analysis of variance, a detection method based on Brown-Forsythe test is proposed in this paper, which retains the virtue of simplicity and loose the limitation for data. The method based on Brown-Forsythe test is used in change point detection of Kaidu streamflow of Xinjiang which indicates that 1973 and 1986 are two change points. However, other traditional methods take 1990 as the second change point. Which is true? On the one hand, Kaidu river is mainly influenced by climate, especially precipitation and some researches have indicated that the characteri stics of climate and hydrology of Xinjiang changed acutely in 1973 and 1987. On the other hand, taking 1986 as a change point will make not only the level diff erence between separated series but also the step between change point and next year more significant than in 1990. So it is reasonable to make 1973 and 1986 as the real change points and the method based on Brown-Forsythe test is suitable for hydrological time series. The normality and randomness violation of Kaidu streamflow data is probably the main reason for traditional method to get false results. In the future, the research about change point detection will still be focused on improving the sturdiness of methods for skew data.
Urban earthquake prevention and disa ster alleviation is one of the important factors which improve the ability of natural disaster prevention in the areas where earthquakes may occur frequently. Combining with the practice of constructing urban information management systems for anti-earthquake and seismic hazard reduction in Yongan City of Fujian Province,this paper not only discusses the mathematic models of earthquake prevention and disaster alleviation, but also analyses the critical techniques of model in tegration.In addition,a seismic hazard prediction and emergency simulation system was established based on GIS for seismic risk evaluation,vulnerability analys is of buildings,estimation of casualty and economic loss, search and rescue man agement. GIS has notable advantages for spatial analysis and graphic display.We can predict the influence of earthquake in virtue of many seismic mathematic models,such as the model of vulnerability analysis of buildings, estimation of casualty and economic loss, the influence of epicentrum. By GIS and relevant models,we can identify the coverage of earthquake which can directly affect the precision of final result. It is believed that the loss of earthquake depends on the intensity of the earthquake. Certainly,it is true.In the mathematic models, the scale and the direction of seismic grade affect the distribution range of ellipse. Another factor is also very important, that is the quality of buildings, which are affected by the materials, years and stories of a building.According to the result that leads to the formation of the models, we can take proper meas ures to reduce hazard before earthquake. The practical application of the system shows that it can not only intensify the weakness in urban earthquake preventi on according to the analysis of seismic hazard prediction result,but also provide auxiliary information for disaster affected area's decision-making and quick response.Therefore, the comprehensive abilities for urban earthquake prevention and disaster alleviation are improved evidently.
With the measurement data of the down ward atmospheric radiation and the air temperature and humidity of the surface layer in 2004 in the Xiaotangshan region of Beijing, the verification was done by making use of the widely-used downward atmospheric radiation model,includingt enmodels for cloud-free days: ngstr(1918), Brunt(1932), Swinbank1( 1963), Idso & Jackson(1969), Swinbank2(1963), Brutsaert1(1975), Brutsaert2(1982) , Idso(1981), Prata(1996), Iziomon et al.(2003),and two models for cloudy days:Jacobs(1978) and Iziomon(2003). The results show: (1)for cloud-free days, I ziomon(2003)'s model has a good performance and can be used directly for the are a; and (2) for cloudy days, the two models, Jacobs(1978) and Iziomon(2003), have relative large errors. With measured data, this paper puts forward a modified downward atmospheric radiation assessment model based on Iziomon(2003)'s model and the measurement information.A better match between the estimation value and the actual measured value is achieved.The application of the data about the air temperature and humidity from the regular weather stations only represents the contribution of the surface layer which could not reflect the effect given by the whole atmosphere to the downward atmospheric radiation, so there will be errors if the water vapor situation is different from the surface layer and the upper layer. The basic idea of the modi fied model is to calculate the downward atmospheric radiation with an expression of the atmospheric emissivity in Iziomon's model by making use of the observati on value from the thermal infrared thermometer with an angle of 37°.
The key problem of the regional economic dynamics is the economic growth. As the resources shortage issue had not been fully realized,the binding force and the carrying capacity of resource to labor (population) and regional economiy were not taken into consideration in the classical theory of regional growth. Based on Rabenau and Miyao’s modern economic growth models, a dynamical regional growth model of ternary variables binding by resource, in which the labor, capital, environment capability and efficiency of management are taken as the regional growth elements, is set up in this paper. The analysis of equilibrium states shows that the regional economic growth ( Gross National Product) is proportional to two factors, one is the abundance degree of the resources and environment, the other is the summation of management efficiency, capital investment, science and technology, and labors. It is obvious that natural resource and environment instead of the granted capital, technology or labor are the bottleneck factors in the regional economic cask. In practi cal production, management, capital, technology and labors are compensatory and balanceable in the economic development while environmental resource is fatal.The results of the study by a series of analysis and numerical simulations s how: (1) The model can be used not only to simulate the different stages of regional growth, but also to discover the relations between the regional growth and the economic factors; (2) natural resource and environment instead of the granted capital, technology or labor are the bottleneck factors in the regional economic cask; and (3) the bearing capacity of environmental resources will play anim portant role in the social gross output value.
After the 1980s, the organization model of world aviation network changed greatly to meet air transportation demand, and a new aviation network model-Hub and Spoke System were applied in many count ries which impacted profoundly the evolution of world aviation networks. In this paper, the authors expounded the development of international Hub and Spoke Sy stems and research progress made internally and internationally, and analyzed the aviation transportation development, current problems and international develo ping environment in China. Then the authors analyzed the main aviation network models, including:1)City to City systems;2)Linear networks;and 3)Hub and Spoke System, especially discussed the organization mechanism of Hub and Spoke System and its competitive advantages. Based on the theory of Hub and Spoke Systems, the authors constructed the ideal organization model of aviation networks in China . Firstly the authors designed the evaluating indexes for choosing and appraising hub airdromes in China, and divided them into three kinds, the international hubincluded Shanghai and Beijing, internal hub included Shanghai, Beijing and Guangzhou, and regional hub included Shenyang, Wuhan, Xi`an,Urumqi, Chengdu and Kunming. Then the authors designed the trunk air networks linking the hub airdro mes which included three kinds and constituted the main part of the hub and Spoke systems. But the trunk lines could not be constructed if the distance between two hub airdromes exceeds 2000 km. It is very important to design lateral networks for the construction and management of Hub and Spoke Systems, of which lateral lines are produced between hub airdromes and lateral airports or among the lateral airports. But if the distance between two airports exceeds 800 km, it is impossible to construct the lateral city to city systems but linear networks.According to these standards, the ideal aviation networks of Hub and Spoke Systems was constructed in China.
Urban Man-made Landscapes are vario us rising and falling artificial landmark associations that are formed by human ac tivities. With constant promotion of urbanization process, the development of Urban Man-made Landscapes demonstrate certain law. This study, taking Dalian as an example,` has set up the responding model to the urbanization development course of Urban Man-made Landscapes. Meanwhile, this thesis studied the coupling coefficient of Urban Man-made Landscape development and urbanization process changes. Based upon the above analysis it also analysed the response of Urban Man-made Landscapes to the changes of the urbanization process.Finally, the deve lopment laws of Urban Man-made Landscapes of Dalian under urbanization function are summaried.The main conclusions of the study are as follows: (1) The responding equatio n of Urban Man-made Landscapes of Dalian city under urbanization function accor ds with actual conditions of Dalian, meanwhile , the responding equation is basi cally identical with urban growth curve,which proves that this responding model is accurate and reliate.(2) The development of Urban Man-made Landscapes of Dalian demonstrates the obvious stages with stages of the urbanization process, which proves the inherent regularity of the two changes.(3) The changes of respon ding coefficient and coupling coefficient of Urban Man-made Landscapes of Dalian are consistent,namely, the greater the responding coefficient, the greater cou pling coefficient is.The consistency of the two has confirmed the accuracy of this responding model further.(4) With constant promotion of the urbanization process, the development of Urban Man-made Landscapes of Dalian experiences a three-mode expansion with level space in domination-level expansion with vertical growth in coordination-vertical space growth of city in domination.
Optimum scale of cities is inexistent in historical view. But the optimum scale of cities in a concrete region exists in aperiod of time. Firstly, this paper proposes the hypothesis that the oper ating objective of cities is maximization of their economic profits.Then it an alyzes the transformation trend of incomes and costs of the cities when the scales of cities heighten. Next, the necessary and sufficient condition when optimu mscale of cities exists is resulted. The optimum scale of cities is in a stabl estate of the cities. Cities regulate their scales to reach the optimum scale basing on raising economic level or enlarging scale, when their scales are not optimum.The scales of cities are the urban ranges of cities. This paper chooses GDP sas incomes and budget expenditures as cost of cities. The dynamical models of incomes and costs of cities are established using territorial area and populati on, GDP per capita as independent variables based on statistical data of Jiangsu province. The model to calculate the optimum scale of cities in Jiangsu Province is drawn. The evolutionary trend of the optimum scale of cities with different population sizes is simulated using GDP percapita as independent variable.Some important results are concluded. The more the population is, the more the optimum scale, when the GDP per capita of cities keeps invariant. The last opti mum scale of cities covers an area of 2030 km～2 in Jiangsu Province when th e GDP percapita is high enough, whatever the population of cities. The speed to reach 2030 km～2 is faster when the population of cities reaches 2.8 million.Finally, this paper evaluates the adjustment of the administrative divisions of cities in Jiangsu Province in the last two years.The adjustments of Suzhou , Wuxi and Nanjing are appropriate and the adjustment extents of Huaiyin and Yan gzhou are too great. It is necessary for Changzhou, Zhenjiang and Nantong to enlarge their urban ranges. The existing scales are greater than the optimum scale of Xuzhou, Lianyungang, Yancheng, Taizhou and Suqian because of their low GDP percapita.
Since the 1970s, there has been an obvious tendency in western countries to approach to humanistic, micro-level and multidisciplinary studies of human geography, hence providing a more comprehensive understanding of their increasingly diversified cities.This paper is concerned with consumer activities at night, which has long been neglected in geographical studies in China. Based on the questionnaire survey and interviews on consumer behavior of Shenzhen residents, the authors analyzed the general characteris tics of consumer activities at night, especially their temporal-spatial charact eristics. Further, the author made correlated analyses in terms of residents' a ttributes. The characteristics of consumer activities of Shenzhen residents at night can be summarized as follows: (1) The consumer activities of Shenzhen resi dents at night flourish in general and the main types of consuming activities are shopping, eating & drinking and entertainment; (2) the average consuming time does not last long and consuming at deep night happens less frequently compared with that in western countries; (3) the frequency of consuming activities at night is relatively low; (4) the spatial characteristic of consumer activities at n ight is according to the distance decaylaw and can be abstracted as a concentri c-circle-structure: the inner circle with a radius of 1km is the primary space,the middle circle with a radius of 5km is the major space and the outer circle with a radius of 10km is the daily space; and (5) the activity space of different types of consumer activities at night also varies: the inner circle with aver aged 2km radius is shopping space, the middle circle with averaged 3km radius is eating, drinking & entertainment space and the outer circle with averaged 4.5- 5km is business and activity in gymnasium space.
In this paper, the author points out that the characteristics of economic development are the mechanisms of the develo pmental models in less-developed areas. On the one hand, they lag behind them anagement of agriculture integration in developed areas; on the other hand, some good experiences in rural development are obtained in practice. Based on the experience, the author tries to find the developmental models of less-developed areas.Because county seat is the focus of a less-developed area, combining with the problems of regional image at present and the construction of new regional image in the future, the author takes Lankao county as a case to carry out the study and puts forward the developmental model for the less-developed county in which the county seat plays a leading role.He points out that the construction of symbol image, accessorial image and basic image should be the most important links. In rural less-developed area, the developmental models of the interrelati onships of varied industries,that driven by elites and that coordinated and guided by local government are based on their own characteristics, and are all good experiences to be popularized. Some strategies should be put forward to ensure the development of the less-developed county. New image strategy refers to improving the developmental environment and drawing people's attention. Trademark strategy refers to emphasizing the industries, which are preponderant in less-developed area. Urbanization strategy can guarantee the development of the whole county. Finally, the government should take measures to carry out and popularize the developmental strategies and models.
