Chishui River is located at the joint area of Sichuan,Yunnan and Guizhou,the total area is 18 932 km2,and it runs through 13 counties and cities of three provinces.By far,Chishui River is still the branch river in upper reaches of Changjiang with best ecological environment and water quality.The local governments find it is difficult for them to enhance the environmental protecting and economic developing harmoniously in the field of river basin management.Through research,the authors find that there are typical industries respectively in upper reaches,middle reaches and lower reaches of Chishui Rivers.In upper reaches,the leading industry is coal and electricity factories,which pollute the environment badly,and the excessive cultivating causes the heavy soil and water erosions at the same time;the light industry of highquality wine dominates in middle reaches,but the local government promotes the heavy industry in the official development planning oppositely;in lower reaches the natural ecological environment enable the local government to develop the tourism industry,which is also influenced and restricted by upper and middle reaches.Therefore,the development of these industries affects heavily the environment protection and economy development of Chishui River Basin,however,the current management ignores the integrated industry distribution.The authors analyzed the environmental problems and industrial development and relationship between them,and brought forward the strategy of united environmental protecting mechanism of Chishui River Basin by the method of integrated river basin management;in such a way the environmental features will be transformed into the elements of economy development to balance the environment protection and economy development.

Companying with quick speed of industrialization and urbanization, urban land expanding with a high speed, the contradiction between the construction and feed become more and more severe. It comes to be a problem pressing for solution how to use urban land rationally and effectively in the process of quick urbanization. By the remote sense image of several time phases and correlative models, analyzing and simulating the temporal-spatial features of urban land expansion can provide the scientific foundation for the arrangement of urban land. By selecting the remote sense image taken in the years of 1987,1990,1997,2001 and 2006, through interpreting, the urban land use data were obtained. On this basis, the expansion characteristics of urban land of Nantong City within nearly 20 years were analyzed, and trends of its expansion were simulated. The results show that urban land expansion in Nantong City possesses different characters in four periods of the year 1987 to 1990, 1990 to 1997, 1997 to 2001 and 2001 to 2006; the heat point of the expansion is mainly concentrated in the region along the Yangtze River, and the heat extent of the expansion in the region along the sea is rising gradually; the expansion of urban land exhibits the trend of the city and town groups, and especially the scope of Nantong Urban Area is more clearly.

Based on inventory data investigated during the “Eighth Five Year”,forest biomass carbon density and storage were estimated by a classical method converting timber volume to total forest biomass.Also,potential carbon sequestration was estimated according to the regressions between forest biomass and net production of different tree species.Average carbon density and total carbon storage in upper and middle reaches of the Yangtze River is 2575 t/hm2 and 1 39459 Tg (1 Tg = 1 012 g),respectively.Carbon storage of stand (including nonwood),shrub and bamboo is 1 20430,13437 and 5592 Tg,accounting for 8636%，963% and 401% of the total carbon storage,respectively.Potential carbon sequestration was estimated as 36856 Tg/a.Forest carbon density,storage and potential sequestration were higher in Sichuan Basin Jialinjiang Valley and the West Region with Mountains and Gorges,and lower in Boyang and Dongting water systems,leading to a declining trend in forest carbon density,storage and sequestration from west to east in upper and middle reaches of the Yangtze River.

According to the latest results of the investigation and assessment of water resources in China,the current situation and features of water resources in China were analyzed:rich total,small percapita quantity;uneven distribution among years and occasion,frequent droughts and floods,obvious contradiction between water supply and demand;uneven space distribution,imbalance between water and soil resources;low utilization rate of water resources and serious pollution.On this basis,the main issues existing in water resources security in China are showed in this paper:floods and drought hinder the economic development;water shortage and waste coexist;ecological degradation and serious water pollution;industrial structure and layout are unfit for water conditions；lack of scientific system of water resource management.The contradiction of water resource in China will be more intensified in the 21st century.Largescale reforms and strong measures must be curried out to promote reasonable utilization and protection of water resources.

At present,Chinese world natural heritage tourism value has being vigorously developed by tour operators and local governments at all levels.Natural heritage sites' tourism economic development is prospering,but it also brings environmental degradation and serious impairment of natural heritage resources.Traditional tourism economic accounting takes care of measuring the region's economic development situation and the growth of tourism economic,however the environment of tourism site and natural resources depletion is neglected.Now,using SEEA2000 framework with Chinese national conditions,the environmental and economic accounting framework of Chinese world natural heritage has been put forward.After reintegration,it outstands the production status of the beautiful and unique natural part.In this article the original SEEA2000 consisting of 5 parts and 10 steps is regulated into 4 parts and 9 steps and its current objective maneuverability was analyzed.Although,it is difficult at the present time to implement exactly the Chinese world natural heritage's environmental and economic accounting,to make the accounting thoughts clearly is of practical significance.

The research on variations of P in paddy fields in riceduck (RD) and ricefish (RF) complex ecosystems and its environmental impact were conducted by field experiments from May to September in 2007.It is found that the P concentrations of soil and floodwater reached peaks immediately after the application of P fertilizer,and then decreased 1 week after fertilization.Compared with CK(coventional rice 〖JP2〗fields),RD and RF could significantly enhance total P concentrations in floodwater,dissolved P concentrations in floodwater,available P concentrations in soil and P uptake by rice plants,and slightly increase total P concentrations in soil.Close relationships were observed between dissolved P concentrations in floodwater,available P concentrations in soil and P uptake by rice plants.The analysis on environmental impacts of floodwater P showed that it was a pivotal time in one week after fertilization to control P losses by leaching from paddy fields.While ducks and fishes were reared,drainage of water from paddy fields and leaching due to runoff should be controlled.Moreover,since RD and RF could enhance contents of soil available nutrient,the consumption of fertilizers may be reduced,leading to the reduced detrimental impact on environment.

Research on the negative impact of agricultural activities onto soil salinization is conducive to reasonably distribute public investment in agriculture,and to promote the coordinated development of production and the environment.Based on the status of soil salinity in our country,this paper analyzed the determinants of soil salinity.Furthermore, we explored the impact of agricultural activities on soil salinity using provincial panel data model.The results showed that irrigation and unit potash fertilizer input have significant impact on soil salinization.The larger irrigation area and potash fertilizer input per unit has,the higher soil salinization probability will be.In addition,the paper also found that irrigation and drainage have significant impact on soil salinization inhibition.Thus,addressing the negative impact of agricultural production activities on agricultural ecological environment and on the background of increasing agricultural public investment,this article suggests that the government should strengthen agricultural infrastructure construction and guide farmers to use reasonable agricultural production pattern in order to coordinate the development of agricultural production and agricultural ecological environment.

According to the difference between different origin cultivated land data,the paper modifies the data series from 1949 to 2006.By introducing the change rate and gravity center of cultivated land,the paper studies the change process of cultivated land and spatial difference in Jiangsu Province nearly 60 years,then uses the correlation analysis and the factorial analysis to discuss the main driving forces leading to quantity change of cultivated land,and establishes the multiple regression model of quantity change.The results indicate that the change of cultivated land has experienced by an increasesudden reductionslow reductionrapid reduction process;the cultivated land in Subei coastal plain area,central Lixiahe shallowbillabong plain area and NingZhenYang low hills area has increased,but in Yangtze River delta plain area it has drastically reduced;the gravity center of cultivated land has moved to the regions where there are more reserve resources and less contradiction between human and land.The population growth,the progress of science and technology in agriculture,the economic development and the agricultural restructuring are the main driving forces.The research forecasts that total quantity of cultivated land will reach 45449×104 hectare in Jiangsu Province by 2020,per person 0053 hectare.Protecting the limited cultivated land,it must transform the way of land utilization and implement the strict protection policy.

Increasing sown area and production of rapeseed plays an important role in enhancing China’s oilseed supply ability.The Yangtze Basin is the biggest rapeseedproducing area in the world,where rapeseed and wheat are the main winter crops and compete with each other for cultivated land resources.Based on a theoretical analysis on competition mechanism of rapeseed and wheat,this paper elaborated the internal relationships among the influencing factors of cultivated land competition,and made a thorough analysis of the two crops’ competition relationship with field survey data and results.It shows that the main factors influencing cultivated land competition include yield per unit,purchasing price,level of mechanization,labor price and national policy.The stabilization of purchasing price is the key to raising rapeseed’s competitiveness,and as the rural labor costs increase,the level of rapeseedproducing mechanization becomes an important influencing factor of production benefit.In addition,a great rapeseed production potential is revealed in the Yangtze Basin.

^{The characteristics of surface sediment types,distribution and deposition district in the Yangtze River Estuary and the north of Hangzhou Bay are investigated on the based of sediment particlesize data and corresponding morphology and hydrodynamics.The results suggested that the characteristics of sediment distribution are the result of combined actions among hydrodynamics,morphologic features and sediment sources.The longitudinal (from west to east) distribution of surface sediments of the Yangtze River Estuary presented from coarse to fine particle sizes,the degree of sorting from good to poor level,and transversely,in the three bifurcations of South Branch into the sea,sediment sizes gradually fined from the North Channel,North Passage to South passage.Sediment grain sizes are coarser in the main channels with strong hydrodynamics and mouth shoals with frequent wave actions,and the grain sizes are finer on the mouth tidal flats with weak hydrodynamics and on the adjacent sea area off the estuarine mouth.Moreover,according to the differences in the distribution and location of the sediments,the Yangtze River Estuary and its adjacent waters can be divided into four main sedimentary zones:(1) The bifurcational river channel section of Yangtze River Estuary,where the main channel sediments are mainly fine sand and silty sand with a median size of 25 to 4and good sorting,and its side flat silty clay with a median size of 7 to 8 and poor sorting;(2) The mouth bar area alternated shoals and troughs,where the shoal sediments are slightly coarse due to wave actions;(3) The offshore area,where sediments between north and south have greater differences to about 31 °20'N for the community,coarse grain sediment in the north due to shelf residual sands and North Jiangsu erosional sands,and fine grain sediment in the south because of Yangtze River source;and (4) The north of Hangzhou Bay,where sediments are mainly clayey silt.}

During the period from April 2002 to April 2003，markstakes and field observations were conducted on tidal flats in eastern Chongming Island of the Yangtze Estuary.The seasonal erosion and deposition cycle differed in southern part，east part and northern part.From spring to summer，the southern part was eroded，other parts were deposed；from summer to autumn，the northern part eroded，other parts deposed；on the contrary，from autumn to winter the erosion and deposition was different from other seasons；from winter to the following spring，the middle part was eroded，other parts deposed.Erosion and deposition were very much different in high tidal flat，middle tidal flat and low tidal flat in the same researching route.Based on the analysis of sediment grain size，suspended matter concentration in the water and other indicators，and on the examination of tidal variation data in the Yangtze Estuary，we found that the seasonal erosion and deposition cycle is closely linked to the morphology，suspended matter concentration in the water，hydrodynamics，tidal variation，wind direction，etc.But different effects may be observed in different parts and different seasons

The influence of river network fractal characteristic on runoff was studied.The studyareas are eight basins controlled by eight hydrostations respectively， located in the upper and middle courses of Gan River.The river network characteristic is described by the fractal dimension， and the characteristic of runoff series is described by the Hurst exponent.Then the relationship between the river fractal dimension and the Hurst exponent was analyzed.And the influence of river network characteristic and the river network changes on the flood/drought are analyzed.The result shows that the higher the river network fractal dimension is， the more complex the river network will be， which is represented by higher Hurst exponent of runoff depth， so the runoff process is more simple.The complexity of runoff series can reflect the probability of flood/drought happening.Generally speaking， the higher the river network fractal dimension is，the lower the probability of flood/drought happening will be.The relationship between the river network fractal dimensions and the Hurst exponents of runoff depth indicates that when physical geography conditions' changes are not obvious， the degeneration of river network can result in higher probability of flood/drought happening.

In November，2006，sediment and water samples in Jinsha River，the Yangtze River mainstream，Ming River and Tuo River were collected respectively.And then a series of indices of phosphorus of the sediment samples were tested，including total phosphorus，available phosphorus，fixed phosphorus and dissolved phosphorus.The results showed that the available phosphorus in Ming River sediment samples and Tuo River sediment samples were significantly higher than those in Jinsha River and the Yangtze River mainstream，which reflected the phosphorus pollution of the Yangtze River branch in Sichuan Basin was severer than that in the mainstream.The available phosphorus in mainstream samples increases from upstream to downstream，while the fixed phosphorus decreases.It reflects that the sediment in mainstream has absorbed the dissolved phosphorus from the branches in Sichuan Basin，so the fixation capacity of sediment in mainstream was reducing.According to the difference values of available phosphorus in sediment samples from Jinsha River (Yibing Station) and the Yangtze River (Zhutuo Station)，calculated value of dissolved phosphorus absorbed by sediment in Jinsha River was 382 t/a and the capacity of dissolved phosphorus absorbed by sediment in Jinsha River was 6 885 t/a，which account for 26% and 468% of the annual dissolved phosphorus of the Zhutuo Station，respectively.It is likely that the real value of dissolved phosphorus absorbed by sediment in Jinsha River lies between 382~6 885 t/a，which reduced the load of phosphorus entering the Three Gorges Reservoir，although the real value needs further researching.When the Xiluodu Hydropower Project were built up，assuming that the sediment outflow from the reservoir is a fixed value in the 50 years，the value of dissolved phosphorus entering the Three Gorges Reservoir would increase 16%～294%.

Using GIS for the planning of water pollution control in a river basin，the simulative river system was obtained from digital elevation models (DEM) of Yongjiang River Basin in Ningbo City of Zhejiang Province，using arc hydro tools in ARCGIS 9.0 platform.Therefore，the water control cell was set up as a basin work cell to calculate environmental capability and distribute total amount of drainage water pollutants.The basic GIS database were found to manage the information relative to geographical space such as pollution source，water system，water quality monitor station etc.Then，the correspondence of water environmental function regionsewer outletsland conflux area，and the administrative cell corresponding to the control cell were built up using overlay based on GIS.Therefore，water quality evaluation and pollution source survey and evaluation were also finished as the platform in ARCGIS 90.The planning schemes of quantity control pollutant were generated based on analysis of pollution sources and environmental capability in each water control cell，and were visualized through GIS to aid decisionmaking.The research shows that the technology of geographic information system (GIS) is a cogent instrument to solve data management，and to figure database visualization and decisionmaking assistant.

To research purifying effects of periphyton on nitrogen and phosphorus of the eutrophic water body，static incubation test was adopted by utilizing situ water and periphyton attached to the fishing nets paling in“863 demonstration project”submerged macrophyte restoration area of Meiliang Bay of Lake Taihu.The results showed that removal effect of periphyton on nitrogen was significant.Cumulative removal ratio of nitrogen was up to 60%，the nitrogen concentration decreased from 5 to 2 mg /L or so within two weeks.Cumulative removal ratio of nitrogen was closely related with nitrogen concentration，working time and biomass of periphyton.In the first cultivation stage，as relatively high concentration of phosphorus，phosphorus from water column was removed to a certain extent by periphyton.The end of the incubation，as low concentration of phosphorus periphyton releases phosphorus to water column instead of removal phosphorus from water，this may closely relate to the alkaline phosphatase secreted by periphyton in water body.

As the exploitation along the Yangtze River is developing in greater depth，the contradiction between regional ecological security and development and construction is becoming increasingly conspicuous.With the conception of interaction between construction along the Yangtze River in Jiujiang and spatial structure of regional ecosystem and function of the ecosystem service，adopting the technology of RS and GIS，based on minor watershed units，choosing industrial concentration area，town residents' ground and road structure as the token of influence of constructing activity，with the river class，the amount and the area of lake，geography type，slope，overlaid plant，category of important ecosystem function area as the token natural ecosystem background，environmental pressure plots are posed after comprehensive superimposed.According to it，an ecological security pattern should be established，consisting of 5 ecological sources and 9 ecological corridors for functions of resisting pollution，abating pressures and protecting biodiversity so as to abate pressure，resist pollution，stabilize regional ecosystem and impel the construction，make the environment protection space and regional economic and social development.And then the important protection areas of ecology function should be governed and preserved.

Through the selection of a representative of spot in Mianyang Economic Area，the vertical distribution of polycyclic aromatic hydrocarbons (PAHs) in soils was studied using GCMS.The results showed that in the entire soil column，surface soils with 5~20 cm depth have the highest concentration of PAHs.In addition，the soil below 40 cm，while the concentration of PAHs reduced very fast.As the surface layer (0~5 cm) have the frequent exchange between the soil and atmospheric，PAHs content were relatively low.The 5~20 cm depth soil was covered by surface soil，therefore the soil was enrichment PAHs fastest.Then the concentration of PAHs achieves the highest value in the whole soil column.The concentration of PAHs decreased with depth in the vertical profile.The highest concentration of PAHs was observed in the economic forest of Jiangyou City spot (33024 ng/g) followed by Santai County spot (29989 ng/g) and Youxian District spot (11274 ng/g).The principal PAHs compounds in study area were naphthalene，phenathrene and chrysene.The difference of soil and plant impact PAHs that were enrichment and transportation speed; therefore PAHs in different depths have changed.Compared with the corresponding environmental guideline values，the content of PAHs in Jiangyou City spot and Santai County spot were a bit high，and Youxian District spot was under the standard.

Based on remote sensing images，spatial gradient variations of the representative vegetation classes in Tangjiahe Nature Reserve was quantitatively analyzed from east to west，south to north，and northwest to southeast by using GIS technology.The results showed that：Secondary deciduous broadleaved forest，evergreen broadleaved and deciduous broadleaved mixed forest，coniferous and broadleaved mixed forest and coniferous forest classes showed distinctive peaks and different gradient variations in different direction.Among them，with space change from northwest to southeast，gradient variations of evergreen broadleaved and deciduous broadleaved mixed forest are the most complex.There are fluctuant variation tendency for the number of patch and class area that change from “increasing at first” then “decreasing”then “increasing” to “decreasing at last” and change from “increasing at first” then “decreasing” to “decreasing at last” in the reserve.But the edge density and mean nearest neighbor distance have same variation tendency that change from “increasing at first” to “decreasing gradually at last” in the reserve.The two terminals of this direction have bigger degree of fragmentation with the higher values of proximity in the reserve，and in the middle it was opposite.With space change from north to south，gradient variations of coniferous forest is the simplest one due to decreasing class area，fragmentation and complexity.While the number of it be distributed relatively more on the two terminal of this direction and less in the middle.The research of spatial gradient variations which happened to the vegetation landscape in different direction will also provide important guiding significance for the useful protection and management of vegetation in Tangjiahe nature reserve after the serious earthquake.