Based on a brief introduction of environmental policy of the World Bank on the hydropower project, this paper summarized respectively the longterm ecoenvironmental monitoring plans and the measures for reducing the side effects caused by the four famous hydropower stations (Egypt's Aswan High Dam, Brazil's Itaipu Dam, China's Ertan Dam and Three Gorges Dam). A hydropower project is of negative or positive impacts on the environment in related regions and the negative impacts of largescale dams as mentioned above are focused on. The Egypt's Aswan High Dam was constructed in 1960s while the ecoenvironmental impact issues were not arose. After its completion, the Egypt's High Dam had been praised as the mainstay of Egyptian economy and vilified as an environmental catastrophe. Longterm ecoenvironmental monitorings have shown that a lot of environmental impacts such as bed erosion had been exaggerated and a few such as traditional brick making industry ignored. The Brizil's Itaipu Project had taken measures to reduce the side effects while under construction, including measures for forest area conservation surrounding the reservoir, biological shelters and nature reserves construction, animal rescue centers etc. China's Ertan Project supported financially by the World Bank had carried out the environmental policy to reduce the side effects. By sharing the experiences of largescale hydrpower projects, a series of measures to protect the environment are being implemented for the ongoing Three Gorges Project, in which the largest ecoenvironmental monitoring network has been set up.

In this paper, the author considers that the sustainable development should not depart from the Nation’s and the Region’s developing level.According to the limiting factors on the Yangtze River Basin sustainable development, which include flood hazard, controlflood level, undeveloped socialeconomic level and fragile ecoenvironmental condition, the author examines the effects of the TGP on the Yangtze River Basin sustainalbe development, floodcontrolling, generating power, improving navigation and its own sustainability. In the meantime, the TGP’s promoting effect on ecoenvironmental treatment in Yangtze River uppermiddle reaches and economic development around the TGP reservoir area was discussed. In author’s opinion, the TGP is a key project which promotes the Yangtze River Basin sustainable development in allround, in conformation with China sustainable development strategy.

The vast necessities motivated by the huge investment of the Three Gorges Project(TGP)act as an economic energy circling around the TGP region, expanding to Yichang, Enshi, west region of Hubei Province, and spreading to Wuhan, Jingzhou, Jingmen, Xiangfan, Huangshi, Ezhou, central or east or north region of Hubei. As a result, TGP has provided energy for the provincial GDP increase, cultivated and enlarged four corresponding markets, motivated the technological advancement and improvement in large key enterprises, and promoted the development of hitech enterprises.In 2002, the total GDP of four counties in Hubei TGP region (Zigui, Xinshan, Badong and Yiling) was 14 .044b (at the price in 1990 and the same below), 7.36 times of 1992 with an annual increase of 19.1%; a total investment in fixed assets of 3.731b, 10.42 times of 1992 with an annual increase of 26.4%; the total industry and agricultural production was up to RMB 13.741b, 4.67 times of 1992 with an annual increase of 16.7%; the total industry production reached RMB 10.293b, 6.31 times of 1992 with an annual increase of 20.2%; the total agriculture production reached RMB 3.448b, 1.45 times of 1992 with an annual increase of 3.8%; the financial revenue reached RMB 647 m, 3.61 times of 1992 with an annual increase of 13.7%; the average income per farmer reached RMB 1 965, 3.64 times of 1992 with an annual increase of 13.8%.Yichang and Enshi are the places where TGP dam and reservoir locate. The economy in these two cities develop quickly in the drag of investment motivation of main project and resettlement. In 2002, the GDP of Yichang and Enshi was 5.87 and 4.14 times of 1992 respectively; the total investment in fixed assets was 8.89 and 8.14 times of 1992, total industrial and agricultural production was 4.78 and 4.6 times of 1992; financial revenue was 2.26 and 1.52 times to 1992; farmers average income was 3.51 and 3.05 times to 1992.In participation in TGP bid, the construction activity has an important impact on the GDP increase of Hubei province. The average amount of contract in TGP for enterprises in Hubei was up to RMB 3.585b, with the highest amount of contract up to RMB 8.657b,and the lowest amount of contract to RMB 2.14b. The annual highest impact on absolute GDP increase Hubei Province was up to 18.07%, and the annual lowest impact reached 8.59%.

The Three Gorges Project draws world wide attentions. As the freshwater flows into the sea, environmental factors in estuary are changeable. The special physical, chemical and biological characteristics in estuary make it a complex and functional ecosystem, but sensitive and being weak. The construction of such a gigantic project on the mainstream may act on the environment not only in the reservoir, the middle and low reaches of the river, but also in the estuary and its adjoining sea. It is necessary to study the effects caused by the construction of the Three Gorges Reservoir. In order to understand the influence by the Three Gorges Project and supply basal information of estuary environment before sluice, a study was carried out on the Changjiang Estuary and its adjoining area from 1998 to 2001. This paper discussed mainly the influence by the Three Gorges Project on estuary environment of the Changjiang River. This paper analyses the hydrophysics, deposit environment, hydrochemistry, primary productivity, plankton, benthon and fishery resources of the Changjiang Estuary and its adjoining area, and further the relationship between the environment and runoff of the Changjiang Estuary.

Single factor method was used to assess the water quality status according to the data of the Three Gorges Reservoir from 1996 to 2001. The result indicates that the water quality of the Reservoir is in good condition. The averages of all parameters assessed meet respectively Class II water quality criterion. CODMn、TPb and NH3—N are primary polluting factors in this area. The water quality in flood season is inferior to that in nonflood seasons. The PWQTrend, a professional analysis software on water quality change trend，was used to analyze the water quality trend of the Reservoir，and the result shows that the change on the content level of parameters and the pollutant transport rate is mainly unremarkable indicating that the water quality of the Three Gorges Reservoir maintains stable in general during the past 6 years.

For managing and forecasting water environment effectively, it is worthy of investigating the technologies for integrating water quality models with water environment information system because of their complementary action in water environment protection. To enhance the function of forecasting water quality in the information system on control of water pollution and management of water environment in Three Gorges Reservoir (TGR), five water quality models for solving different kinds of water pollution problems existing in TGR at present are selected and integrated with the information system. With the discussion and the comparison, the advantage and disadvantage of the technologies for integrating water quality models with the information system, a semitight integration technology is applied to achieve the selected water quality models embedding into the information system on management of water environment in TGR. By developing the code of preprocessing module, postprocesssing module and interface module, the multilayer finite element model makes an example of blending water quality models into the information system on management of water environment in TGR. The successful simulation of water flow fields and water quality in Wanzhou Reach of TGR computed by the integrated water quality model shows that the method of integration with the technologies of GIS, database and graphics interface both enhanced the ability of forecasting and analyzing water quality in the information system and improved the models' simulating efficiency by means of automating data preparation and date transfer as well as graphing the simulating results conveniently which also makes models much easier for users. The present work constructs an information system on management of water environment in TGR with five water quality models suitable for the actual condition of water pollution in TGR and it will servey as an effective tool for controlling water pollution and protecting water environment in TGR.

In this paper, we established a three dimensional hydrostatic equilibrium airsoil coupling model in G―Chen coordinates system which fully contained the thermal and dynamic process of terrain, vegetation and water surface in detail. The unique characteristis of this model are that the influence of terrain had been considered in the radiation and energy balance equations of forest crown canopy and land surface. The observation showed that the daily variation of river surface temperature is below 3℃. The rushing water of Three Gorges of Yangzi River is full of turbulence. The depth of the river is different everywhere. These make the simulation of thermal and dynamic process of water very difficult. We neglected the daily variation of river temperature. In our study the changes produced by the formation of the reservoir is only the elevation of water surface and the extent of its water surface area. The water surface temperature is a constant.We use this model to simulate the diurnal variation of meteorological elements field before and after the formation of the Three Gorges Reservoir. Then we calculated their differences and analyzed the microclimate Produced by the formation of of the reservoir. The result shows that the temperature, wind and humidity field will be changed in the near area within ten kilometers away from Three Gorges Reservoir, but with a rather limited degree.

Based on the analysis of survey and literature, the paper shows the vegetation in the Three Gorges Reservoir Region is of sparse and uneven with unclear vertical distribution and is disturbed seriously by human activities. Among the 75 vegetation types there are 25 forest types. At present, there is little distribution of forest below the elevation of 800 m. The Pinus massoniana and Biota orientalis occupy the largest area in the region, and are also the main forest species in the sparse forest grown by aerosow and artificial planting. The cultivated land on the slope above 25 degrees accounted for 17.5% of total cultivated land. The firewood forest offers only 10.78% of total energy in the countryside. Irrational land use and forest cutting have resulted in the serious degradation, the decrease of land productivity and the water and soil erosion in the fragile soil system and forest system. The soil erosion volume is up to 290 million tons per year. The effects of the Three Gorges engineering construction and largescale population migration on the forest systems are of longterm. The paper also shows that there are rich plant species diversity in the Three Gorges Reservoir Region. The plant species are at least up to 5 032 with the rich native species. In combination with the key forestry programmes such as Natural Forest Conservation Program and Land Conversion Program in the middle and upper reaches of the Yangtze River and other forest restoration actions, such as closing the mountain for raising forest, returning the cultivated land on the slopes above 25 degrees to forest, developing the firewood for energy and building the forestry management system with the multiple functions and mixed management models, the forest management environment will be improved to restore the forest efficiently. This is important for the reservoir forests shelter system and will promote the ecological and environmental construction and sustainable development in the region.

To understand the morbidity level and trend on zoonosisborne diseases in the population in the Three Gorges Area, disease surveillance were surveyed from 1996 to the present in 15 surveillance points in the Three Gorges Area. A total of 157 cases of Epidemic Hemorrhagic Fever, Leptospirosis, Encephalitis B and Malaria were reported. No outbreaks of the four diseases occurred and no human plague cases were reported. The morbidity rate of Epidemic Hemorrhagic Fever or Malaria was lower than the nationwide rate. But there was high level of morbidity on Leptospirosis or Encephalitis B. The descending trend of morbidity of the four diseases were observed from 1996 to 2002. The obvious changes of morbidity on vectorborn diseases and zoonosis diseases have not been found during the project construction of the dam in Three Gorges Area.

The construction of the ThreeGorge Reservoir may bring not only new opportunities for regional development, but also new problems in relation to ecological environment. After the completion of the ThreeGorge Reservoir in Yangtze River, wetland regions will appear, where the water level will be fluctuating with seasons along both banks in the reservoir. This kind of wetland can provide special structures, functions, and environmental landscapes, as an important ecotone. Attention should be paid to the protection and exploitation of ecoenvironment and resources of the wetland zone. According to the geographical conditions for the wetland in the reservoir, the countermeasures for ecological protection and land use are put forward.

There are complicated coupling mechanisms between the process of urbanization and the evolvement of ecoenvironment, by which the relationship between urbanization and ecoenvironment evolves along an invertU curve. This coupling curve has five spatial types when using spatial samples to measure, i.e. descending type, U type, ascending type, invertU type and another descending type. The evolvement sequence of these types obeys the “law of denial's denial”. By the methods of CA (Correlation Analysis), PCA (Principal Component Analysis), and AHP (Analysis of Hierarchy Process), this paper synthetically evaluates the urbanization level and ecoenvironment conditions of the 15 districts in the Three Gorges \{Area,\} and argues the coupling relationships between them. The results are as follows: the spatial type of relationships between urbanization and ecoenvironment in Chongqing reservoir area is" U" curve; Urbanization and environment have the common trend along the Yangtze River. All of above reflect that the coupling relationships between urbanization and ecoenvironment have "dualistic structure" characters; the urbanization in the study area has more dependency than destruction on the ecoenvironment.

Using RS images as the main data source, and GIS technology, aiming at the main ecological problems in the Three Gorges region, choosing precipitation and heat, topography, land use, soil erosion as assessing factors, we established comprehensive assessment model for ecological environmental quality and studied the spatial distribution of assessed results. We put then forward corresponding measures for different regions. The result is that the quality of the Three Gorges Reservoir Area is poor as a whole, only 4.25% area reaching good level, more than 60% area under relatively poor level. Furthermore, the spatial difference of the ecological quality is evident. So more measures should be taken and adjusted to local conditions in order to make ecological environment better.

By analyzing the composition of cultivated scarp land in the Three Gorges Area, we noticed that the soil erosion in this Area was quite serious. In order to control the soil erosion in cultivated scarp land, seven different hedgerows with different plants were set up and their effect on the control of soil erosion and pesticide pollution was examined. It is found that hedgerows can control the soil erosion by maintain mostly less than 0.02 mm soil particles from washed away, which are identified as fertilizer carriers, and thus the environmental capacity increases as a result. It is further proposed that hedgerows should be employed to build up ladder fields, with wild buckwheat Rhizome and Bahiagrass as suitable plants for the cultivated land in the Three Gorges Area.

The plant species observation and experimental station was an important component of the biological and environmental monitoring system for the Three Gorges Project. 5 onehectare permanent plots were established from 1996~2002, including broad leaved evergreen forest, mixed broad leaved deciduous and evergreen forest, deciduous forest and evergreen conifer forest. All the permanent investigation plots provide the basis for the longterm biodiversity dynamic research. In this paper, some achievements in the research stations were introduced. The distribution of a mixed broad leaved deciduous and evergreen forest patterns were detected. Two dominated species, Fagus engleriana and Cyclobalanopsis oxyodon, were all clumped. The oxyodon population was divided into three size classes as DBH 1 ~4 cm, DBH 4 ~8 cm and DBH > 8 cm, all of which were clumped, and might be influenced by the age of the forest and the topographic factors. Microsite heterogeneity was one of the important mechanisms in maintaining species diversity in plant community. To examin the heterogeneity of the topography, a DEM was built using the interpolation method. The slope and aspect driven form DEM showed strong heterogeneity. The slope varied from 18.2° to 74.6°, and from south, to southwest and southeast. Twentyfour species were chosen to calculate correlation coefficients between slope, aspect and position. The topographic adaptation of these species was different, for example Fagus engleriana was positively associated with slope, and Sorbus alnifolia was positively associated with other aspects and so on. According to topography, these species were classified into six groups using a hierarchical cluster analysis. All the achievements in the research station will contribut to the biodiversity reservation in the future.

The conservation of plant species diversities in the Three Gorges reservoir area was carried out by collection and conservation of dominant species of communities and species of practical value, with emphasis on rare and threatened plants. More than 200 species in the Three Gorges reservoir area have been planted in experiment stations since 1996, the survival percentage was 93%, while 8 species failed to success. By 2002, more than 30 species (including 24 wood plants) developed flowers and set fruits normally; 8 species were selected to record their growth process; Several species were cuttage reproduced and spore propagated; Collection of some species faced great difficulty. There are some problems and difficulties in the study and conservation of biodiversity in the Three Gorges reservoir area, for example, the missing items, the species list of Three Gorge district, the invasive species, effect of isolation on biodiversity, and function of biodiversity, etc., which need further concern and studies.

Of the known vascular plants, 127 families, 404 genera and 633 species (including taxa below the species level) were found along the riparian zone based on plot investigation. It included 9 families, 11 genera , and 12 species of the pteridophyta, 118 families, 393 genera，and 621 species of the seed plants. Of seed plants, there were 4 families, 8 genera , and 9 species of gymnosperm, 114 families, 285 genera, and 612 species of angiosperm. Among the plant taxa at the riparian zone, it accounted for 65.8% of Shennongjia Region in family level, 47.3% in genus level, and 26.7% in species level. The high level taxa of vascular plants are rich at the riparian zone in Xiangxi River Catchment. There are 29 protected plant species distributing along the riparian zone.In the component of the flora, the areatypes of families were mainly tropical; and of the genera chiefly temperate. The component of flora in riparian zone was similar to that of Shennongjia region. The result showed that the riparian zone has an important role in maintaining regional biodiversity.

The four famous Chinese carps, i.e, the black carp (Mylopharyngodon), the grass carp (Ctenopharyngodon.idellus), the silver carp (Hypophthalmichthys molitrix) and the big-head carp(Aristichthys nobilis) are the main species for freshwater fishery and aquaculture in China. According to the monitoring results from 1994 to 2001 and historical data, this paper deals with the analysis of the status of fishery resources of Chinese carps.The results obtained are: (1) The ratio of Chinese carps in fishery has droped in the middle and upper reaches of the Yangtze River; (2)The proportion of the low age groups of Chinese carps increased and the advanced age group decreased; (3) The runoff of fry of Chinese carps was 3.587 billion, 2.747 billion, 2.154 billion,2.864 billion , 1.904 billion in the Jianli Section of the Yangtze River from 1997 to 2001 respectively,when comparing with 6.700 billion in 1981, Base on the main influencial factors strategies to manage the four famous Chinese carps resources were proposed, such as protecting spawning grounds, preserving relatively stablization of natural waters, enhancing fishery management, building the carps releasing stations，establishment the man agment system of germplasm resources in the Yangtze River.

In April 2002, 33 species of planktonic crustacea in 26 genera (11 Copepoda and 22 Cladocera) were sampled from 17 sites in the middle and lower reaches of the Hanjiang River, the largest tributary in the middle reaches of the Yangtze River. ShannonWiener, Simpson, and Pielou indexes calculated from species composition and abundance were used for evaluating the community diversity characteristics in different reaches. Spatial variations of the communities in different reaches were compared by method of SelfOrganizing Map (SOM) artificial neuronal networks. The results were summarized as followings: (a) the density of planktonic crustacea in middle reach was higher than that in the lower reach whereas the species abundance and community diversity index in the lower reach were higher than that in the middle reach; (b) the planktonic crustacea communities presented high density but lower diversity in the upper part of the middle reach, lower density but high diversity in the lower part of the middle reach and estuary, and lower density and diversity in the lower reach except the estuary.

Artificial propagation of A. nigrocauda,an endemic fish to the upper reaches of the Yangtze River, was taken in 2001~2003. The parent fish came from the Longxi River, one of the firstorder tributary of the Yangtze River at Luzhou,Sichuan Province. LRHA, HCG, pituitary gland (PG), or their mixture were used for spawning inducing. The stripped eggs were fertilized using the dry method. Totally 70 females and 89 males were injected. All males released sperm and 46 injected females spawned. Fertilization rate ranged from 8.33% to 100.0%, whereas hatching rate were between 0.50% and 94.71%. Average latency was 11.8 hours during water temperature 20.5~28.0℃. The incubation lasted bout 38 hours from fertilization to hatching whereas the development took about 26 days from newly hatched larvae to juveniles covered with scales initially. Technical details on gravid fish selection, spawning inducement, and larvae breeding were summarized in this paper.