On the basis of understanding the connotation of the spatial structure and defining the scope of research，applying the principal component and cluster analysis methods，the spatial division of the Yangtze River basin has been attained．The spatial structure of the Yangtze River basin，which conforms to the mode of the coreedge structure，includes three firstorder cores，eight secondorder cores，two big transprovincial growth triangles，one main axis，two secondary axes，three locational axes，one peripherical region and one edge region．The spatial structure of the Yangtze River basin was formed after the lowlevel dispersal period，the polarization developing uneven period，and the diffused multicore uneven period，and will enter the regionintegration highlevel even period in the future．From three aspects of the assembly and diffusion theory，the spatial interaction and the national macroregional developing strategy，the evolution mechanism of the spatial structure of the Yangtze River basin has been analyzed．To optimize the spatial structure of the Yangtze River basin，we should start with the internal factors and the external force．Firstly，we should speed up the development of individual node and the formation of core region，especially in upper reaches region we should build up a growth polygon that has two cores of Chengdu and Chongqing and includes a big scope from south to north．Secondly，we should quicken the construction of eastwest passageways and the buildup or the perfection of passageways between main axis and secondary axis．Thirdly，we should bring forth new ideas in the regional spatial administrative system based on the market integration.

Based on the West Development,the article analyzed the mutual affections of five main cities in Chengdu Plain Urban Agglomeration by the way of urban flows.The basic departments and the intensity of urban flows of each city are found out.And conclusions are reached that:extraversion service and differentiated development of cities in Chengdu Plain Urban Agglomeration is obvious;industries of transport,storage and post are fine developed,while industries of real estate,restaurants,culture,sports,entertainment,public management and social organization are in disequilibrium development;Chengdu is the core city of Chengdu Plain Urban Agglomeration with high inclination of urban flow;Mianyang is facing a problem of insufficient introversion development;There is a wide gap between Chengdu and other four cities in the level of urbanization.Thus a brief advice and prospects are given to enhance the mutual affections of five main cities in Chengdu Plain Urban Agglomeration.

Aquatic macrophyte community plays a very important role in the ecological restoration of lake,while,artificial aquatic macrophyte community is prone to the environmental disturbance and its stability was poor.So,it is important to study the structure and dynamics in the ecological succession of aquatic macrophyte community in order to establish restoration approaches for degraded vegetation communities.In 2003,the rehabilitation of aquatic macrophyte community was studied with physical and ecological engineering in the etrophic lake.The dynamics in the succession of aquatic macrophyte community had been investigated in the past three years.The result showed:only the aquatic macrophyte with wide niche could be introduced into eutrophic water as pioneer plant because of the water characteristic of high pollution and low transparency,as a result,the competition of species became intense so that one species was replaced by another species with their niche overlapping.The enclosure was dominated by one species during the same period.With the decline of niche overlapping,species niche was divided by the competition of species,interspecific relationship and community structure tended to be stable.However,it was possible that the species with similar growth period coexisted if the spatial location of species was separated.So the introduction of aquatic macrophytes with similar niche should be avoided.We should pay attention to the separation of seasonal and special structure of aquatic macrophytes.In addition,the stability of these common aquatic macrophyte communities was discussed by the competition of these species.However,the stability of community was influenced by multiple factors such as algae population,zooplankton population,macrobenthic population,fish population,microorganism population and sediment environment.These factors should be deeply studied in future.

Aesculus wilsonii,a rare tree species and endemic to China,usually sporadically distributes in the evergreen and deciduous broadleaved mixed forest in China,and there are very few natural Aesculus wilsoniiommunities with considerable area in the nature.In the present study,the biodiversity,space distribution pattern,size class of population and community structure of an infrequent natural  Aesculus wilsonii community,which was found at the Qizimei Muontain in Xuan'en of Hubei Province,were analyzed by using the methods of community ecology and contiguous grid.The results showed that: (1)  Aesculus wilsonii  was a dominant species in the community,and its importance value was 22.7,far larger than that of  Meliosma oldhamii, whose importance value was 13.7 and was the second largest one in the community;(2) Species in the community were very abundant.Abundance index and evenness index of the tree layer were much lower than those of the shrub layer and the herb layer,while dominance index of the tree layer was far larger than that of the shrub layer and the herb layer,which illuminated that the species in the tree layer were fewer than in the shrub layer and the herb layer.In addition,most of the dominant populations displayed an uneven distribution pattern,and the role of the dominant species in the tree layer was marked and the stratification was evident in the  Aesculus wilsonii community;(3) According to the age structure, Aesculus wilsonii  community was presently stable,but the seedlings and saplings of all the five dominant populations were severely insufficient in the  Aesculus wilsonii  community,which would make the community considerably susceptible to the potential influences on its survival and development.As a result,some measures should be taken to protect the community.

Chuandian farmingpastoral ecotone located in the southeast margin of the Tibetan Plateau in China has a unique and complex geomorphology.Study on the effect of the terrain features on the land use can help people understand the relationship between the human activity and the physical geography,which has practical significance in regional development and environment protection.Based on the RS＼GIS technology,this paper analyzed the land use in 1988 and 2000,and discussed the effect of geomorphic factors on land use pattern.The result indicates:1) Cultivated land,forest land and grass land are mainly land use types in research area.From 1988 to 2000,the land use type transform frequently and the inner structure of each kind of land use changed obviously.2) The geomorphic factors have significant effect on land use pattern,among them the altitude controlled the spatial distribution of different land use type in vertical direction.The study also showed that the terrain features are the foundation of regional land use pattern in research area.The reason was the terrain factor,such as high altitude,determines the redistribution of rainfall,heat,and other natural resource in inner domain,which finally affect the land use type and degree of human being.

The conceptions and methods of tourism resource capitalization should be put forward,to aim at the outstanding problem in development and management of tourism resources at present in our country,and also meet the needs of tourism practice.It is a capitaldriven managerial idea and method for tourism resource development.Under legislation and policy,tourism resources can be consolidated as a form of capital and invested together with monetary capital,physical capital,human capital,and other inputs into tourism development activities to carry out marketoriented development,operation,and management,resulting in good benefits in economy,environment,and whole society.It will also increase the values of tourism resources and the equities for their owners.It should be got deep into discuss with the problems of internal mechanisms,external terms,realized routes,modes,etc,in which the tourism resources turn into capitals. Capitalization of tourism resources emphasizes the value and profit of tourism resources,which will optimize the allocation of resources,improve the utilization of resources,increase the efficiency of development and management,and achieve the sustainable development of the tourism industry.

Using geostatistical and GIS methods,a case study on Dengxia catchment of hilly area in southern Jiangsu Province was conducted to examine the spatial variability characteristics of soil nutrients in the topsoil(0~20 cm).The indicators of soil nutrients included the pH,total nitrogen(TN),total phosphorus(TP)and available potassium(AK).The results showed:（1）The spatial variability of soil nutrients at the studied area was significant difference,and the variance coefficients followed the order of as total phosphorus>available potassium>total nitrogen>pH.The theoretical semivariogram model of pH was linear model,but TN,TP and AK of which all were exponential model.(2)The spatial distribution of pH and AK also was higher in the north part than that in the southeast,but there were several high value centers existing in the middle and south part just as small block,and they fluctuated acutely.The distribution of TN presented obviously beltshape and was higher in the north than in the southeast,with several lowest value centers embedding in the middle and south part of the area.But the distribution of TP was higher in the middle part than that in the north and southeast part,with several high centers embedding in the middle part.These results provide theoretical foundation for soil nutrients management and vegetation restoration in the studied area.

Rainfall erosivity is an important factor for soil loss estimation,yet how to estimate rainfall erosivity in regions with limited rainfall information is critical for water and soil conservation.In this study,several empirical models were used to estimate rainfall erosivity based on daily rainfall data from 4 meteorological stations in the Danjiangkou Reservoir region,i.e.Danjiangkou，Shiyan，Yunxi and Yunxian of Hubei Province.By comparing the estimated results with existing research results,one of the best performed models was selected for regional rainfall erosivity computation.The average rainfall erosivity is 3 331.94,3 272.40,3 501.21,3 187.94 MJ·mm/hm²·h·a for Danjiangkou,Yunxi,Shiyan and Yunxian,respectively.The estimated rainfall erosivity shows homogeneous distribution cross the reservoir region.The rainfall erosivity concentrates in May to September,comprising more than 8860% of its annual value.The single rainfall erosivity has large variability,especially for Yunxi and Shiyan where the maximal single rainfall erosivity accounts for 6.94% and 4.87% of the total rainfall erosivity respectively.The coefficient of change trend r(ranging from 0.45 to 0.58)and the coefficient of variation Cv(ranging from 005 to 008)indicate that the rainfall erosivity has been relatively stable in the past half a century in the reservoir region.

Polycyclic aromatic hydrocarbons (PAHs),a kind of environmental hormones,are harmful to environment and the healthy of human being.Therefore,PAHs have attracted much attention from researchers.In the paper,PAHs in soils around a steel mill in Nanjing were investigated and examined.Based on the analysis of residue of PAHs,the paper discussed the sources of PAHs pollution in order to deal with the pollution problems and serve for environment planning and management.Results showed that PAHs residue in this area ranged between 312.2 and 27 580.9 ng/g.The PAHs with more than 4 rings were the main pollutants.The individual pollutants were mainly Phe,Phe,Fla,Pyr,Baa,Chr,Bkf,Bap,Bgp and I1p.The contents were closely related with direction of the prevailing winds of the year.It could be predicted that the discharge of the gas pollutant was the main source of PAHs in the soil within the research area.The descending of the atmosphere probably resulted in PAHs pollution in the research area.Besides,the outflow of surface water,the discharge of solid wastes and the burning of coal all might lead to the higher residues of PAHs in soil in some of samples.The results also showed that the total content of highringed PAHs in soil samples was decreased with the distance of the main pollution sources,while the degree of pollution decreased when samples in the south district were further analyzed.Based on the characteristics of source profile of PAHs,sources of PAHs in different parts of soil samples were compared and deeply discussed by use of all kinds of parameters,such as molecular weight dominance,relative abundance of rings,characteristics index,and so on.It was inferred that PAHs pollution was caused by fossil burning at different degree.Coking plant inside the steel mill was one of the most important sources in the area.

The determination of evolution stage of debris flow gully is the first step of forecasting，evaluation and control of debris flow and the scope and frequency of the debris flow.Utilizing artificial threeply intelligenceBP neural network model,then selecting catchment area,main groove length,groove gradient ratio,average aspect,relative height difference,round ratio and relative cutting degree of the catchment evolution geomorphology as assessment index of the evolution stage of debris flow gully,the stage of debris flow gully was divided into four stages:young stage、developing stage、active period and decline stage.Authors pretreated the 80 debris flow data along Chengkun railway in Sichuan province (systematic classification、standardization) in order to avoid artificial error,secondly,network training the 80% of the data,and then built forecasting model,the simulation of the residual 20% of the data shows that the average relative error is 8.22% with satisfactory result.The evolution stage of the 6 debris flow gullies along Kundong railway was determined based on the model,the result showed that:the 6 debris flow gullies are in active period and the evolution score is between 3～3.5,so the monitor and forecast should be strengthened in these six debris flow gullies in order to avoid disasters.The intelligenceBP neural network model can be used as an advantageous method to determinate the evolution stage of debris flow gully.The result can provide theoretical basis and technical support for debris flow forecasting，evaluation and control.

The concent ration of dissolved organic matter (DOM) is an important index to assess natural water quality.Fluorescence fingerprint technique was widely used to characterize dissolved organic matter (DOM) in river from different sources.In this paper，the authors analysised  the fluorescence  spectral characteristics of different series water by fluorescence method.According to the channel transverse，hydrological condition，sewage outfall distribution，and branch status，experimental samples were collected from eight crosssections in the Wanzhou section of the Yangtze River and Zhuxi River.The result showed that  an  expanse fluorescence can be generated from emission wavelengths 350 nm to 550 nm when the ultraviolet excitation wavelengths are 290 nm.The authors also studied the 3dimension fluorescence  spectral characteristics of  different sample of water，different sites.Higher peak values were found in 4#，5# and 2# water sample.In 4# and 5# water samples Dom content is higher due to the pollution of Zhuxi river.But in 2# sample due to upstream  chemical factorys.The peak values are generally related with the point pollution of these regions.Characters of this method are sensitive，simple and fast.It can be an effective measure method of  water quality.

Large cascaded reservoirs generally hold very large regulating storage.The running of the reservoirs exerts great effects on the natural discharge process along the river course below the dam.The runoffgroup’s characteristics are changed which have important ecological meaning，such as flood，high flow pulse，low flow and extreme low flow.Pingshan section’s ecological flow group’s characteristic value under natural condition was given，based on the river’s ecological flow discharge effect theory，suggested by BRAIN，after considering the relation between the Pingshan section’s hydrology and river’s ecology of Jinsha River and choosing target year group to make calibration to the parameters of high flow pulse and extremely low flow.The daybyday flow discharge processes were modeled after the construction of cascaded reservoirs along Jinsha River course，the characteristic value of every ecological flow group was given and the modeled result was compared with that under natural condition，the effect on the Pingshan section’s ecological flow process caused by the WudongdeBaihetanXiluoduXiangjiaba cascaded reservoir constructed along Jinsha River course was analyzed.The results show that some changes of “extreme low flow never appeared，low flow increased，high flow pulse fragmented and flood kept” may take place at the Pingshan section  after the dams’ construction.

Ecological Potential is an indicator to measure the comprehensive effects of multiecological factors confecting.Jinsha River watershed (Yunnan section) is abundant in landscapes and discrepancy in the topography and physical，chemical characteristics of the soil from the upper down to the lower of the watershed.These variations result in the different spatial distributions of the ecological potential in each landform unit.GIS is characterized by the powerful spatial analysis function，which provides the quick and convenient analysis tool for the study on the complex spatial distribution of the ecological potential.Using ArcGIS as the spatial analysis software，based on the vegetation classification map，this paper studied the spatial variation laws and made the 3D fluoroscopy of the ecological potential power of Jinsha River watershed (Yunnan section).With these data，the paper compared the relationship of the ecological potential and soil spatial distribution in different landform units within the watershed by selecting the soil element.The results of this study are as follows.The ecological potential of the watershed increases in the direction of northwest gradually.From the result of Variation Function，the ecological potential of the watershed is of the anisotropy，and is of good autocorrelation along the strike of the watershed.The soil type plays a certain control role in the spatial distribution of ecological potential.The GIS methodologies adopted in this paper，particularly the 3D fluoroscopy function and application of Variation Function provides references to the other similar researches.Additionally，the distribution laws of ecological potential in Jinsha River watershed (Yunnan section) calculated in this paper provides the theory base to the ecological protection in this region.

Since the concept of “Environmental Safety Agriculture” was first proposed by the Ministry of Agriculture，Forestry and Fisheries of Japan，much importance is being attached gradually in Japan to the nonpoint pollution mainly of agricultural pollution.Since then，the Japanese government，in accordance with the changes of nonpoint pollution in various periods，brings into legalization diversified policies，objectives and economic measures on pollutions of agricultural production，poultry raising and solid waste as well as speedway pollution and urban living pollution，and has in succession introduced a series of laws and regulations advantageous to the prevention of nonpoint pollution.These laws and regulations are not specific，but their contents are characterized with compatibility，systematization and maneuverability，and the punitive measures pertinency and hierarchy，together with the combination of economic measures and legal responsibility，which objectively plays a significant role in the prevention of nonpoint pollution.To use for reference the experience of Japan in legislation，in preventing the nonpoint pollution，China should further perfect its laws and regulations，definitude the respective responsibility of the authorities，reinforce the legal responsibility，and induct，through different measures making the citizens to prevent the nonpoint pollution consciously.

Based on the data of Lightning Location System (LLS) from 2002 to 2007 in Suzhou，the spatial and temporal characteristics of cloudtoground lightning (CG) were analyzed.The results show that the lighting activity is more frequent in Suzhou and Zhangjiagang.The CG lightning in Taihu area and Suzhou city have stronger lightning currents.The thunderstorm days in Suzhou change as the normal distribution，and there are the most thunderstorm days in summer in Suzhou.The daily stroke numbers change as the double peak distribution，fewer lightning activity occurs at about 10〖DK〗∶00 am，the most of the CG lightning occur at 02〖DK〗∶00 am and 07〖DK〗∶00 pm，and the peak value of the lightning activity appears at 07〖DK〗∶00 pm.Most mesoscale convective systems (MCS) appear at about 07〖DK〗∶00 pm in summer.Also，the lightning protection in country of Suzhou was analyzed in this paper.It was found that the reasons of lightning disasters include not only the geographical position but also human factors.Two suggestions about country safety were presented，the lightning protection design parameter should be properly chosen and the lighting forecasting should be strengthened.

From the middle Jan.to the beginning of Feb.in 2008，an extreme weather and climate event with continuous low temperature，snow and sleet had occurred in the middle and lower reaches of the Yangtze River.The event had caused heavy snow disaster.Taking Hubei Province as an example，the snow disaster is dynamically monitored and evaluated based on RS and GIS.Using many days of successive satellite data from EOS/MODIS and observation data of snow depth from Hubei weather stations，the normalized difference snow index (NDSI) was calculated，and then the snow distribution information was obtained with the support of geographical information system.According to different height above sea level，the thresholds of NDSI related to the snow depth at different levels were determined，and then the recognition of three levels snow depth (0~10，10~20 and 20~30 cm) was implemented.Snow areas of different depth in the different land use type were respectively counted according to different land use classification data and snow distribution data.Dynamic monitoring result of the heavy snow disaster process expressly shows that about 90% land areas in Hubei Province were covered by heavy snow，the snow disasters in Jianghan plain，northeast and southeast Hubei were the worst，snow depth in parts of region in Hubei Province was above 20 cm；heavy snow worst affects farm land such as paddy field，dry land and water body such as lake，reservoir，ditch；biggish range in residential areas was also hit by snow；since Feb.2，2008，the area of heavy snow had gradually reduced；after Feb.8，2008，heavy snow almost thawed.Based on the study above，the operation flow of heavy snow monitoring in the middle and lower reaches of the Yangtze River with the support of remote sensing and geographical information system has been formed.