5.2 Assessment System and Main Conclusions

The EIS takes the Yangtze Valley as an integrated system and divides it into sub--systems as the reservoir area, the middle and lower reach region, and the estuary region' The impacts on the natural and social environmental factors (Fig.5 -- 2 ), such as local climate, water quality, biota, rare species, inundation and resettlement, landscapes, historical relics, and so on, have overall been analyzed, qualitatively or quantitatively, by using mathematical modeling, characteristic indices, analogies, etc., according to the legislation of the State and referring to the international practice. Furthermore, the mitigation measures have also been recommended in order to alleviate the negative impacts. Finally, the ecological and environmental monitoring system has been proposed.

The main conclusions of the EIS indicate that the Three Gorges Project will exert both positive and negative impacts on the environmental and ecological system, the former mainly in the middle and lower reaches of the Yangtze and the latter concentrating on the reservoir area. Most of the negative impacts can be alleviated by taking suitable countermeasures, the environmental issues, therefore, will not affect the feasibility of the project.

5.3 Major Environmental Benefits

(1)The chief purpose of the project is for flood control.  After completion of TGP, the flood control standards in the Jingjiang reach of the Yangtze River will be raised from the present less than 10—year flood frequency to a 100-- year frequency. ln case of a flood like the year of 1870 happening, a large number of losses of lives and damages to properties could be avoided' TGP will produce a safe environment for the living and the further development in the Jingjiang region where there is a population of 15 million and about 1.53 million ha fertilized farmland as well as a lot of cities and towns. Meanwhile, there will be several other benefits from the regulation of the reservoir such as control of schistosomiasis, decrease of sedimentation in Dongting Lake and extension of the lifespan of the said Lake.