he greening of industrial firms is a process in which the industrial firms reduce their pollution and make no harm to environment.Therefore,greening of industrial firms affects sustainable development deeply.In order to make clear the difference of degree in the greening of industrial firms in different regions and to evaluate the regional greening of industrial firms accurately,a framework to evaluate the regional greening of industrial firms has been established.Based on this evaluating framework,employing comprehensive fuzzy evaluation model and data from the investigation of the industrial firms in Jiangsu Province along the Yangtze River,this article evaluated the greening of industrial firms in 8 cities of Jiangsu Province along the Yangtze River.At last,suggestions have been given to promote the development of the greening of industrial firms and also to reduce the gap of the greening level of industrial firms in different regions

This study investigates development mechanisms of Nanjing suburban area,and identifies three major driving forces underlying the rapid development of the area.These driving forces include suburban areaoriented new development strategy,megaprojects,and jurisdiction adjustment.Currently,the rapidly growing Nanjing suburban area is also facing many serious problems,such as unsustainable land use,problems of urban villages,lacks of infrastructure and services,and green belt erosion.The dual track urbanrural system and entrepreneur behaviors of local governments in Nanjing suburban area are major causes of these problems.To overcome these problems,some suggestions are proposed.These suggestions include institution innovation,clear demarcation of suburban area,efficient guidance for real estate and university towns' development in the suburban area,and enhancement of migrant administration and enabling urban villages.

In this paper,Tonglu County of Zhejiang Province was selected as the study area.Different data sources,such as DEM,landuse data of 1996 and 2004 were used to analyze the change in spatial distribution of rural settlements in Tonglu County,by means of GIS spatial analysis method.The result indicates four phenomena as followings:①Rural settlements were mainly distributed in river valley plain.However,a trend is shown that the rural settlements centralize from higher hilly areas to river valley plain.②Distribution of rural settlements in Tonglu County had two clear distribution zones:one is from Jiangnan Town,Tonglu Town to Fuchunjiang Town,and the another is from Hengcun Town,Eshan Xiang to Zhongshan Xiang.③There are 3 spatial distribution modes in Tonglu County:gobbet pattern,strip pattern and disperse pattern.Rural settlements in wide river valley plain are in gobbet pattern,and those in narrow river valley plain mainly distribute in strip pattern,whereas rural settlements in higher hilly areas are distributed in disperse pattern.④Natural condition,especially terrain,determines general spatial distribution of rural settlements,but town development,traffic condition and policy guidance have important influence on the change of spatial distribution of rural settlements.

According to“The 11th Fiveyear Plan”and“The Prospective Target of 2020”of hydroelectricity development，the average annual installed capacity will increase by 14.25 GW.The highspeed development of hydroelectricity would cause a large number of rural immigrants who should be settled in livelihood.The characteristics and problems of traditional resettlement modes were analyzed based on industrial division.The theoretical foundation of shareholder resettlement mode was studied on the basis of “The resource value transfer” hypothesis and stakeholder hypothesis.The shareholder resettlement mode cases in the Chinese modern history were reviewed.While the shareholder resettlement mode is defined，two basic realized patterns of the mode and the chosen stock for immigrants in the stock market are proposed.Finally，four advantages of shareholder resettlement mode are summarized：voluntary migration will transform into involuntary migration；the sublimation from development migration to participation migration will be achieved；sponsor' pressure in fund raising can be relieved；small town development can be promoted.

The dominance of basic resourse in the 31 provinces of China,including water resourses,cultivated land resourses,forest resourses〖JP〗,climate resourses,energy resourses and mineral resources,was analyzed.Yunan,Neimenggu,Sichuan,Xinjiang,Heilongjiang,and Guizhou provinces in China are the most dominant in their basic resources,while Shanghai,Tianjin,Beijing,Jiangsu,Hainan,and Zhejiang are the most inferior in their basic resources.The contrast between resource dominance and economy dominance has been studied.The provinces with dominant economy are usually resource inferior.The provinces with dominant resources are usually economy interior.Economic center and resource center are just in different regions in China.The economy dominance depends on not only natural resourses,but also human resources,capital,technology,market,and so on.The mechanism of resousevaluecompensation is not perfect. At last,some suggestions about how to exploit the particular advantages of resources,and to reduce resource constraint in different regions were provided.

Hardin and Zhang′s arguments about the tragedy of the commons are based on the hypothesis that the number of the participants entering into the commons is fixed.But actually it may be variable in the long run because some resources are always public resources even in a long time.And more people will participate in exploiting these resources if there are extra profits，and vice versa.By building mathematic models，we discussed the different results under the following two different institutions，i.e.individual rationality (IR) and collective rationality (CR)，in the long run about the exploitation of this kind of public resources without entrance barriers in this paper.The conclusions are that CR will lead to production inefficiency and less welfare while slowing down the exploiting speed and that IR will get an opposite result.This paper further argues that institutional measures can only be used as a makeshift in dealing with the problem of resource shortage and that the ultimate solution is technical measures.

Water hyacinth is believed to have originated in the Amazon basin in South America,where it was kept under control by natural predators.However,the plant has spread throughout the whole tropical and semi-tropical zone by human introduction,causing various kinds of problems such as the reduction of fish production,its interference with fishing and the obstruction of shipping routes.Water hyacinth is difficult to be disposed because of its high content of lignin and fibrin,and its fast growth and robustness of seeds and absence of soundly applicable technology make it difficult to be controlled. In this paper,the biological characters of water hyacinth and existing controlling methods of the plant were briefly introduced at first. Chemical contents of the plant were also described.The present utilization methods of water hyacinth can be summarized into three modespreparation for fuel (solid fuel,liquid fuel and gaseous fuel),for fodder (fodder and silage) and for manure (organic fertilizer and green manure),and the modes were also compared with each other.It is concluded that the production of biogas and organic fertilizer from water hyacinth is a potential method;as for the disposal of the plant in rural areas,composting and green manure treatment are better ways.

The project of water diversion from the Yangtze River to the Han River is a compensation project of SouthtoNorth Water Transfer Middle Line Project.According to the master plan，its construction should comply with the local planning for water resources development，and should not be designed as enclosed “specus” adding supplemental water to the lower reaches of the Han River.Abiding by the thought on saving resources，protecting the environment，promoting development，it is suggested that the project of water diversion from the Yangtze River to the Han River should take the project of transferring the water from the Yangtze River to north in Jiangsu Province as a model，to expand the project to supply both the Han River and the Yellow River，so as to substitute Phases II of SouthtoNorth Water Diversion Middle Line Project. ①Divert the water from the Yangtze River to Chang Lake by making use of the water course of the Zhuzhang River lower reaches to convey water.In the mean time，rehabilitate Jingzhou City river system，remove three environmental risks as 〖WTBX〗Bilharziasis〖WTBZ〗 spreading and diffusing，the silt entering the lake and the water contamination；②The project of diverting water from the Yangtze River to Han River lifts the water to Xinglong Reservoir by making use of the storage of the Chang Lake，so as to economizing the channel length.③Nianpanshan stagedevelopment adopts onelevel and twostations pumping water storage way to simplify opposite direction water conveyance in the Han River main stream.Pump water to Chuijiayin Reservoir to improve water quality of the lower reaches of the river and increase water resource for the Yellow River lower reaches as the stable and reliable water source. ④The Eryu Channel will be build on east side of the Tang River，in the Nanyangxiangyang lower land pass，to transfer water to Fangcheng and Zhengzhou in stead of to Danjiangkou Reservoir to supply the Yellow River so as to build a water carriage system from north to south.

o find out the rule of soil water resources under different vegetations，six typical vegetations including coniferous and broadleaved mixed forest，coniferous forest，the chestnut plantation，shrub forest，wasteland and sloping farming land were chose in Zhaigou district of Ningshan county at Water Catchment Region of Central Route for SouthtoNorth Water Diversion Project.Physical characteristics and organic content in soil water were measured by sample plot investigation and experiment analytical method.It is found that soil physical and chemical characteristics such as soil density，porosity and organic matter under forests are all better than wasteland and sloping farming land.Soil water content under coniferous and broadleaved mixed forest is the highest and its water retention is much better than other vegetations.On the vertical section，soil water content and soil water retention reduced following with the increase of soil depth，but it decreased quickly under forests and its surface layer water content is evidently higher than the surface layer of wasteland and sloping farming land.Judging from water conservation，it is concluded that coniferous and broadleaved mixed forest is the best，followed by coniferous forest，and then by the chestnut plantation，shrub forest，wasteland and sloping farming.

By using different percentiles（larger than 75 or 95 percentiles）the frequency of precipitation days in the Yangtze River catchment from 1950 to 2000 was explored in this paper.The positive (increasing) trends of the yearly precipitation days at the 75th percentile appeared in most of the Yangtze River catchment，especially in the northern regions of upper and middle reaches of the catchment.The Sichuan basin was the only region with negative trends.For the 95th percentile，the negative trend regions were still mainly in Sichuan basin but extend to northern regions and there were also obviously increasing trend centers in middle and lower reaches of the Yangtze River catchment.On the decadal time scale，the most significant positive trends at the 75th percentiles were in the middle reaches in 1980s and 1990s.The lower reaches showed significant positive trends in 1980s.Those positive phases greatly contributed to the positive trends of the whole catchment during the last two decades.The most significant negative phase also occurred in the middle reaches during the earlier three decades.For this case，it seems that the precipitation days in the middle reaches are more sensitive to changes than other regions in the Yangtze River catchment.Take the Yangtze River catchment as a whole，a positive trend is very obvious for this percentile.For the 95th percentile，the trends between the middle and lower reaches of the Yangtze River catchment are coherent：after two decades (1960s and 1970s) of negative phases，the most significant increasing trend was shown in the last two decades.On the other side，the fluctuation of the precipitation days in the catchment of the upper reaches over the 50 years was somewhat smoother than for other regions.For the whole catchment，the precipitation days in the 1950s and in the 1990s were at positive phase that indicated the frequent heavier precipitation events in those periods.The precipitation days at the 75th percentile increase more obviously than that at the 95th percentile in the whole catchment compared the 75th with the 95th percentiles.This result indicated that an increasing precipitation in the recent two decades was mainly caused by excessive precipitation.The heavier precipitation events occurred mainly in the upper reaches in 1960s，in the middle and lower reaches in the 1950s，1980s and 1990s.According to the different trends at different percentiles，the variation of yearly precipitation days can be classified as the following types：Type 1：the increasing trend at 75th percentile but decreasing trend at 95th percentile.Type 2：decreasing trends of yearly precipitation days for both percentiles.Type 3：increasing trends of yearly precipitation days for both percentiles.

The climate and environment have changed greatly as a consequence of global warming over the last century.Climate change has brought some adverse effect on natural ecology system,especially on water resources,including quantity,quality,spatialtemporal distribution,water supply and water demand.After the “South to North Water Transfer (E)” project being set up in practice, the selfpurification capability will be decreased in the Yangtze River,especially in lower water period,so the wastewater discharge of Shanghai will have an influence on wetland environment in the mouth of the Yangtze River.Using the simulation of four CCCma models provided by DDC of IPCC,the situation of climate change along the mouth area of the Yangtze River in the next 50 to 100 years due to the effects of human activities was analyzed in this paper.It is indicated that the climate change in this area has some effect on precipitation.The precipitation will show,to some degree,an increasing tend,and the increase in annual precipitation intensity is obvious.

According to the trend of global climate changes,impact of climatic variation on net primary productivity (NPP) of natural vegetation in three regions，Nanchang,Ji'an and Ganzhou，in Jiangxi Province in recent 40 years was studied.The change trend was simulated based on combinations of thermal and hydrological conditions.Also,NPP pattern of the whole region of Jiangxi Province was analyzed with vegetation productivity in 1980s.The average values of NPP in the three regions during past 40 years were 1319,1311,and 1320 t/hm2〖DK1〗·a,respectively,showing an overall tendency of slight increase.Based on the presumption that the temperature and precipitation increased by 2℃ and 20%,respectively,the value of NPP would ascend by 149%~1585%.When the temperature and precipitation increased by 2℃ and -20%,respectively,it would decreased by 477%~516%.For the scenario of increased temperature (+2℃) and unchanged precipitation,the increase of NPP was predicted as 530%~569%.A radius form from the center to east,south and west characterized the spatial pattern of NPP distribution,and it declined from mountains to hills and plains.

Based on daily minimum and maximum temperature data in 11 meteorological stations obtained in the period from 1961 to 2005 over Sanjiangyuan region,the spatial and temporal characteristics of climate extremes were studied.The main results are summarized as follows:The trends for the annual number of warm days ( 26 d/10 a) and warm nights (44 d/10 a) are on the rise,while decreasing trends are found in the number of cold days (41 d/10 a) and cold nights (85 d/10 a);The changing trends of annual minimum temperature (042℃/10 a) is higher than that of maximum temperature(029℃/10 a);The increasing number of warm days and warm nights mainly occurs in winter and summer,while the decreasing number of cold days and cold nights occurs in spring and fall,and the trend of cold nights decreases significantly;The change in extreme in the source regions of the Yangtze River is more sensitive to the climate warming compared with the other two source regions.

Data of cultivated land in Jiangsu Province from 1996 to 2004 are analyzed by statistics.The results showed that the change of the cultivated land in the research region was descending and the descending rate was increasing from the North to the South.〖JP2〗This paper mainly focuses on the corresponding〖JP〗 type of cultivated land use to different stages and state of industrialization and urbanization respectively and the regularity between them.In order to determine the relationship between the cultivated land and the stage of industrialization and urbanization,we try to analyze the different stage of industrialization and urbanization in each cities and the change rate of the cultivated land according to comparison of each other.The study showed that there were obvious discrepancies of the cultivated land change in the different stage of cities' industrialization and urbanization.The cultivated land's descending rate takes on the drastic change,rapid change,and slow change (or steady change) in the upperstage,mediumstage,and initialstage of the industrialization respectively.In the same way,there are different changes (drastic change,rapid change,and slow change or steady change) of cultivated land in the initialstage,acceleratingstage,and endingstage of urbanization.At last,industrialization and urbanization index were selected to determine the extent which related with the change of cultivated land.The two coupling coefficients and cultivated land coefficient showed a strong consistency through a comparison.The descending rate of cultivated land was accelerating with the development of industrialization,and the area of the cultivated land was decreasing with the advancing of urbanization.This result showed that the development of industrialization at present mainly benefits from the descending of the cultivated land,and the development of urbanization result in the decreasing of cultivated land,but the change between two coefficients is not happened simultaneously.

This article calculated cultivated land use efficiency of China in 1997~2004 using the method of data envelopment analysis（DEA）,which could set multi input and output indexes,avoiding inadequacy of using only one input and output index.The cultivated land use efficiency was divided into two categories:pure technical efficiency and scale efficiency for seeking the cause of the change of land production efficiency.Finally,according to OLS impacting factors cultivated land use efficiency were analyzed.The results suggest that the calculated use efficiency fluctuated in 1997~2004,the average efficiency was 0732,which indicates land use efficiency was low.Cultivated land use efficiency and pure technical efficiency had the same change trend,which farther shows that the change of cultivated land use efficiency mainly induced by pure technical efficiency.Meanwhile,cultivated land use efficiency was different among 31 provinces in China.There are many factors impacted on land use efficiency,which can be lined as follows from high degree to low，natural conditions of cultivated land resources,the distribution of cultivated land resource,the development of economy，natural environment and agricultural production conditions.

Based on emergy theory，the emergy input and output of agricultural system were analyzed in Fujian Province during the period from 1981 to 2004.The nine emergy indices analyzed are emergy density (ED)，emergy dollar ratio (EDR)，emergy yield ratio (EYR)，emergy production ratio (EPR)，emergy investment ratio (EIR)，environmental carrying capacity (ECC)，emergy sustainable index (ESI)，system dominant degree (SDD) and system stability degree (SSD).The total emergy input and total emergy output increased during the 24 year period；the ED，EIR，EPBR，SDD，ECC increased continuously，indicating that the economic exploitive degree of the agriculture system raised continuously and the productive benefit far exceeded the mean level in the world.The agricultural products in this region had obvious advantages in terms of price，and the structure of agricultural system was optimized；but this may also indicate a pressure on the environmental resources.EDR and ESI decreased continuously，SSD decreased a little，indicating that the sustainability and stability of the agricultural system decreased due to the increase of the exploitive intensity and the exploitive degree in the agricultural system.Comparing all the emergy indices with other regions，it is found that the agricultural producing environmental resource condition was a lot more superior in Fujian Province，and its producing environment is still in a good condition.

The research of river health is one of the hotspots in the current field of river ecology research.The generation,development and various connotations of river health are introduced firstly and the concepts of river ecosystem health,watershed ecosystem health and river health are distinguished.River health is that river can both keep its integrity and maintain various service functions providing the society.This review focuses on the practical research and the methods of river health assessment based on the analysis of the connotation of river health.The methods of river health assessment are divided into predictive model method and multivariate statistical method based on their principle.Aiming at the main existent problems in this field,the future development trend of river health research is put forward.It is suggested that the further study of river health should be emphasized on aspects of choice of assessment indicators,establishment of assessment standards,choice of assessment scale and the integration of river health assessment and river management.

Trend of the sediment load and streamflow of Pingshan,Yichang,Hankou and Datong station along the mainstem Yangtze River and the Beipei station in the Jialingjiang River,the Huangzhuang station in the Hanjiang River was analyzed with the help of MannKendall trend analysis.The results indicate that:①The sediment yield of the upper catchment of the Yangtze River is in significant upward trend and is in downward trend in the middle and lower cachment of the Yangtze River;②Various influencing factors combined to result in the complicated changing patterns of the sediment yield and streamflow in different parts of the Yangtze River catchment.Natural factors (e.g.precipitation changes) exerted more influences on streamflow changes in the upper catchment of the Yangtze River.In the middle and lower cachment of the Yangtze River,climatic changes and human activities (human use of water resources) combine to have impacts on streamflow variability;③Jump time of sediment yield is in good agreement of the time when the construction and function of water reservoir starts;④Water reservoirs exert more influences on the sediment yield changes and these influences are more obvious in the river catchment of smaller drainage area than in river cachment of larger drainage area;⑤Smaller riverbed slope leads to tremendous deposition of sediment yield in the middle cachment of the Yangtze River,which together with construction of Three Gorges Dam will further reduce the downstream discharge of the sediment yield in the middle and lower catchment of the Yangtze River.

The development of three stages river restoration in Shanghai City was introduced and characteristics of each stage were presented.The technologies of multinaturalness river restoration were summarized,such as river morphology,biotechnique for slope protection,biology multiformity,water quantity and quality mathematics simulation,water environmental capacity evaluation,wastewater collection and treatment,water quality restoration,etc.The research results show that the diversity of river morphology is the base for creating biology habitat,biotechnique for slope protection can improve the biology habitat,breeding biology multiformity can restore the riverbank ecosystem,sludge dredging and wastewater collection and treatment are the ultimate method for water quality restoration,water resource dispatching can improve the water environmental capacity and biochemistry method expedites the process of water quality restoration.The water quality and biology inspection data of some rivers in Shanghai City show the performance of different technologies for the multinaturalness river restoration.

The distribution of major and trace elements reflects not only the source of material,but also the level of pollution.Chemical elements were determined in water bodies, suspended particulate and sediments for Caoqiao River,Liangxi River and Dapu River discharged by different pollutants.Data showed that phosphorus is high in three rivers and metals were high in the reaches of town and industrial regions.Primary component analysis displays the significant diversity because of rivers receiving industrial wastewater,manucipal sewage and farmland runoff.The elemental pairs of correlative elements revealed the different values in water bodies,suspended matter and sediments,and those differences reflected the characteristics of farmland runoff,industrial and municipal effluences and could be considered indicators of different pollutants.The partition coefficients of particulate to dissolved metals（KD ）decrease with Fe>Al>Zn>Cr>Ni>K,Most of them are highest in Caoqiao River and lowest in Liangxi River.KD of Zn is highest in Dapu River and lowest in Caoqiao River,which revealed the different pollution in rivers.It is useful to distinguish the rivers receiving different pollutants in the intense anthropogenic regions.

The Meiliang bay is suffered from eutrophication problem.Considering the unique geographical position of Meiliang Bay at Lake Taihu，both fixed and validated twodimension water quality model and alga growing model were used to simulate the effect on nutrition and algae concentration in Meiliang Bay by main zone of Lake Taihu under southeast and northwest wind.The simulated results showed as follow: in August，2001，the average concentration of algae of Meiliang bay was 43.18 mg/m³.At the same time，the average concentration of nitrogen and phosphorus were 2.48 and 0.248 mg/L.If the parameter of flow index induced by southeast wind was added to these models，the concentration of algae，nitrogen and phosphorous were obtained to be 41.92 mg/m³，2.07 mg/L and 0.231 mg/L and 42.55 mg/m³，2.19 mg/L，0232 mg/L respectively under the influence of northwest wind effect.Considering both the influence of flow and excursion caused by southeast wind，the concentration of algae，nitrogen and phosphorous changed to be 53.86 mg/m³，2.06 mg/L and 0.229 mg/L and 50.71 mg/m³，2.17 mg/L，0.233 mg/L when wind direction transferred to northwest.The results indicated that the concentration of nitrogen and phosphorus in Meiliang Bay were affected by the flow of Lake Taihu to a certain extent and the change of alga in Meiliang Bay was mainly caused by the excursion of algae.The results agreed with the observation data very well and were considered to provide some supports for dealing with eutrophication of Lake Taihu.

The contents of Zn，Cd and Ni in the sediment of Xuanwu Lake were measured with ICPMS，and their potential biological toxicity was analyzed using sediment quality guidelines(SQGs)and geoaccumulation index.The contents of Zn，Cd and Ni in the sediments of Xuanwu Lake were 75.26~17911，517~898 and 4776~14728 mg/kg，respectively，and the contents of Zn，Cd，Ni were respectively 108~291，5170~8980 and 133~411 times of the their background values in soil environment in Nanjing.These suggested that the pollution degree of Zn was slight in Xuanwu Lake while Cd and Ni were much serious，which may be affected by human activities significantly.The contents of heavy metals were not evenly distributed in sediments of Xuanwu Lake.The maximum mean and peak concentrations values of Cd and Ni were in the Southeast Lake(SEL)，indicating that it was polluted by heavy metals significantly.Similar results were also obtained through appraising the biological toxicity risk on the surface sediments in Xuanwu Lake using geoaccumulation index and biology database guideline.The potential biological toxicity risk in sequence was Cd>Ni>Zn，and among these sampling points，SEL had the highest potential risk on biological toxicity.

Moshui Lake is a representative of urban lakes heavily polluted by heavy metals in China.Study on distribution characteristics of heavy metals in the overlying water and pore water of the sediments of Moshui Lake was carried out.The change and transport patterns of major heavy metals were comprehensively discussed.According to the diffusion fluxes of heavy metals in the pore water of the sediments，the influence on the overlying water was qualitatively estimated.The results showed that the concentration of the following six heavy metals in Moshui Lake decreased in the order of Mn>Fe>Zn>Cu>Cr>Pb.The concentration profiles of heavy metals in the overlying water and pore water of the sediments were in typical peak shapes indicating the widespread occurrence of remobilization of heavy metals after deposition.The concentrations of Fe and Mn in the pore water of the bottom sediments were much higher than those in the overlying water，and redox processes mainly controlled their distribution patterns.The concentrations of Cr，Cu，Pb and Zn in the pore water of the surface sediments fluctuated under the impact of redox processes and mineral equilibrium.The quality of the overlying water is influenced by the diffusion fluxes of heary metals in the pore water of the sediments.

Spatiotemporal variation of redox potential (Eh) in the integrated verticalflow constructed wetland (IVCW) and purification efficiency of pollutants in different function units have been studied.The results showed that the Eh of downflow surface strata,bottom strata and upflow surface strata in IVCW were 402～585 mV,-87～-130 mV and 308～432 mV,respectively.The IVCW system could be divided into three function units along the water flow direction—oxic A unit,anaerobic unit and oxic B unit.Oxic A unit is the predominant area for pollutants removing,of which the removal efficiency of BOD5、CODCr、NH+4N were 430%,484%,541%,respectively,especially the NH+4N,accounting for 79% of the total removal efficiency.Denitrification and anaerobic decomposition of organic matters primarily occurred in anaerobic unit.The further removal of organic matters after anaerobic decomposing and further nitrogen removal occurred in oxic B unit.It was also observed that there was significant correlation between the removal efficiency of NH⁺₄-N and Eh of different function units in the system（p＜001）,but the correlation between the removal efficiency of BOD₅、COD_Cr、NO^-₃-N and Eh of different function units were not significant.

raditional methods for the enhancement of phosphorus removal efficiency in wastewater often concentrated on the selection of substrates and wetland plant species.In this research，another method by adjusting the process of combination of wetland to improve phosphorus removal efficiency were tested.The author compared the removal efficiency of phosphorus in eutrophic lake water in eight different combination systems，including plugflowdownflowup flow wetland，downflowupflowplugflow wetland，oxidation ponddownflow，downflowpond，plugflow constructed wetland in twoyear inspection.It was indicated that the pond process could not be installed as the end process.The results also showed that the process of downflow combined with upflow wetland was better than other kind of combined process in cold and warm weather，the endurance of this kind of combination to high hydraulic loading was also more preferable than others.That is to say，the downflowupflow process was an ideal combined wetland process in treating wastewater.This kind of novel constructed wetland should be well used in the purification of eutrophic water.

The specific growth of 〖WTBX〗Microcystis aeruginosa〖WTBZ〗 and 〖WTBX〗Scenedesmus obliquus〖WTBZ〗 was studied on the condition of pure culture and different mixed cultures with different phosphorus concentration in laboratory，and P half saturation constant of each algae in different culture conditions was calculated.As a result，within the setting scope of phosphorus concentration，it is shown that the growth rates of the two algae both became greater as raising phosphorus concentration，with a greater influence on Scenedesmus obliquus〖WTBZ〗 than on 〖WTBX〗Microcystis aeruginosa〖WTBZ〗.The growth rate of 〖WTBX〗Microcystis aeruginosa〖WTBZ〗 was greater than that of 〖WTBX〗Scenedesmus obliquus〖WTBZ〗 in 1〖DK〗∶1 mixed culture when phosphorus concentration is lower than 100 μg/L；the facts pointed to a contrary conclusion if the phosphorus concentration was higher than 100 μg/L.Both the growth rates and the maximum amounts of the two species were affected by different inoculation densities-the growth rates of Microcystis aeruginosa increased with the decrease of inoculation densities while Scenedesmus obliquus〖WTBZ〗 had a contrary law.Scenedesmus obliquus got the maximum specific growth rate in the 10〖DK〗∶1 mixed culture，and Microcystis aeruginosa was at its minimum specific growth rate in the 101 mixed culture.P half saturation constant of 〖WTBX〗Microcystis aeruginosa decreased with the reduction of its proportion and got a minimum value of 1035 μg/L，but the P half saturation constant of 〖WTBX〗Scenedesmus obliquus did not show a distinct law，the constant getting the minimum value of 1982 μg/L in the 1〖DK〗∶10 mixed culture.No matter which culture system was used，P half saturation constant for Microcystis aeruginosa growth was lower than that of Scenedesmus obliquus〖WTBZ〗.So 〖WTBX〗Microcystis aeruginosa is easier to win in the competition in comparative low nutrition environment.

The dominant method in the field of nonpoint source(NPS)pollution research is NPS simulation model，in which export coefficient model is widely used.But for basins with obvious spatial differences of precipitation and terrain，such as upper reach of the Yangtze River，the model accuracy is limited for the sake of its neglecting of precipitation and terrain impact on NPS pollution.Considering that，an improved export coefficient model is proposed in this article，and the method for determining precipitation and terrain factors was also offered.The model was applied to simulate the total nitrogen load of upper reach of the Yangtze River in 1990 and 2003.It is indicated that average values of relative error for various watersheds reduced from 4502% to 2393% and from 4249% to 1838% respectively by using the improved model.Relative error values for watersheds control by Zhimenda，Luoduxi and Tuojiangdaqiao stations decreased obviously.The relative error values of Zhimenda Station reduced from 20729% to 2484% (1990 year) and from 16325% to 1816% (2003 year) respectively，those of Luoduxi Station decreased from -3372% to -1924% (1990 year)and from -4120% to -2435% (2003 year)respectively，and the relative error value of Tuojiangdaqiao Station reduced from 3247% to -215% (2003 year).It can be concluded that the improved model is feasible and the predicted result is approximately in accordance with the monitoring data.For large scale basin，especially those with obvious spatial differences of precipitation and terrain，the improved model has its theoretical and practical significance.

Intertidal elevation acquisition is the fundamental work in understanding the intertidal sedimentation/ erosion trend and reasonably developing intertidal resources.To counter the problem of high cost and effort to measure the intertidal elevation on the spot，this paper reports the development of an elevation acquisition method based on multitemporal remote sensing images.The method mainly consists of three steps，i.e.remote sensing images selection，waterline extraction and waterpoint elevation calculation.Usually，the waterline is assumed as a contour.But Jiuduansha intertidal mudflat is so wide that the waterline is not horizontal completely and shouldn’t be assumed simply as a contour.In this paper，three groups of waterlines are extracted from three Landsat TM images acquired under different tidal conditions in 2004.Taking all vertexes of one waterline group as a group of waterpoints，the authors calculate their elevations by using a simple trend surface interpolation based on the instantaneous tide levels of four tide stations around Jiuduansha.These waterpoint elevations are compared with the in situ measurement elevations.It is revealed that the average absolute error of the waterpoint elevations is about 0.138 m，and the precision is about 93.74%.

The assessment of ecological security is a new topic in the field of untraditional research on security and sustainable development，〖JP〗and is also the basis to set up warning system for ecological security and environment management.In order to establish an effective evaluation method for regional ecological security，the authors built an evaluation index system and then decided the evaluation criteria based on pressurestateresponse conceptual model.The level of ecological security of 17 regional cities in Anhui Province was evaluated by back propagation (BP) neural network channels.It is shown that Xuancheng，Chizhou and Huangshan are in grade Ⅱ；Bozhou，Suzhou，Fuyang，Chuzhou，Liuan，Chaohu and Anqing are in grade Ⅲ；Hefei，Huaibei and Bengbu are in grade Ⅳ；Huainan，Ma’anshan，Wuhu and Tongling are in grade Ⅴ.It is indicated that the method can truly reflect the situation of regional ecological security.Since regional ecological security evaluation of BP neural network method has explicit meanings and simple computational process，and is able to sort and rank subjects according to their ecological security level，it can be applied in the comprehensive assessment of other kinds of ecological systems which have evaluation criteria.