Abstract:Based on records of the Guliya Ice Core (35.6°N,80.5°E) pollen and high lake levels in the Tibetan Plateau and its adjacent area, there appeared a particular warm and wet stage with the mean temperature 2-4℃ higher and large precipitation much more than that of the present.The reconstructed precipitations with Kutzbach's water and energy balance model of closed lake basin are estimated up to 640mm,560mm and 260mm in the Qinghai Lake,Chabyer Caka/Laguo Co, and Akesaiyi/Tianshuihai Lake which are 1.7,3,5 times of thatin the present respectively.The large precipitation extended to the north slope of Qilian Mountains at the north and to Yunnan Province at the south-east of Qinghai-Xizang plateau had played an important role in the geomorphological evolution of some liveis originated from the Tibetan Plateau.The upstream river pattern of the Yellow River same as present, had come into being for the Zoige Palaeolake overflowing to meet the headward erosion of the Yellow River in the borderland of Gansu and Sichuan Provinces.The formation of the deep channels with their bottom lower than present sealevel in the Three Gorge area in the middle reach of the Yangtze River might be related to high speed flood resulted from the upstream large precipitation in the Tibetan Plateau.While flood currents were narrowish and hindered in the gorge channel the high energy turbulent flow carried large quantitative gravels to cut the river bottom and formed the deep channels (formed before 40kaBP).Some ¹⁴C dates of the buried woods between 40-30kaBP, in the gravel deposits at the channel bottom indicated the upper mechanism process.Some separated closed lake catchments in the Tibetan Plateau, such as,Serling Co,Nam Co and Pangkog Co were merged into a great closed catchment by water overflow.This high lake leveleventis mainly caused by the particularly strong Indian monsoon for enhanced cross equator aircurrent from south hemiphere over Indian Ocean activated by high solar radiation of precession cycle in low latitude.On the other hand we infer in the period between the event H4 (35.5kaBP) and H3 (28-27kaBP) the southward-shifted westerlies,from the warm North Atlantic Ocean for northern Eurasia ice sheet gave passive impact on high lake levels for arousing much precipitation.

Abstract:Taihu Basin is one of the most developed region in China.Flood disaster was the main natural disaster during the past decades the water conservancy situation and its function in flood control in the basin was analyzed in this paper By summarizing the flood control experiences the author puts forward some idea about flood control of water conservancy in new situations.Finally, the flood disaster mitigation goal and controlling countermeasures of Taihu Basin were given.

Abstract:Hydrology prediction is a complexnon-linear dynamic process and the station water-level often shows dynamic changing character owing to all kinds of factors.In the Huaihe Basin Wuhe station water-level will be influenced by the backwater influence of Hongze lake and shows the non-statinoary changing.In the paper based on the neural-network model of time series and the data characteristics of hydrology a non-stationary multi-station variable dynamic sequence prediction model is made by using artificial neural-network and practised in Wuhe station water-level prediction of Huaihe River.The calculation results indicates that the model is not only reasonable but also its predicting period is longer.It is valuable when being used in practices.

Abstract:The water resources are the important and limited source in the world itis necessary to allocate a certain amount of ecologicalwater demand for sustainable developmental river.Based on the ecology and water environmental capacity theories, the ecological water demand of continental river system is analyzed and calculated in this paper from three aspects i.e.,the water demand for maintenance of aquatic living life survival the water demand for the maintenance of natural dilution and purification of water body and the water demand to cover the net evaporation deficiency.Itis noteworthy that this study will be beneficialfor water resources proper allocation in progress.Finally,as an example the ecological water demand in Guishui River Yongding River Basin, Beijing is calculated.

Abstract:Qinghai Lake is the biggest brackish lake of China.It lies in the northeast of the Tibet Plateau.That the location of the lake is influenced by the East monsoon,Siberian-Mongolian monsoon and the Westerlies enables its deposits record the climatic and environmental change sensitively. Based on the analyses of environmental proxies (magnetic susceptibility,carbonate content,TOC etc.),we reconstructed the environment change of Qinghai Lake in the past 900 years Itis indicated reliably by the results that this area has undergone five periods of warm and dry as well as five periods of wet and cold during the past 900 years.The existence of Mediaeval Warm Age Little Ice Age are obvious and the temperature has been rising since the 20th century.Human activity from the 1950's was reflected by magnetic susceptibility clearly.

Abstract:Now, People have got to know the importance of the environment.Researchers in the environment field should realize the significances to observe the environment of Taihu Lake from the view of sociology and humanities.The author contrasts the facts and data collected by the author in the recent investigationsin Lake Biwa Japan and in Taihu Lake China and then draws several conclusions: (1) Although Japan and China show different modernization paths there are both close mutual actions between the human life and environment in the two countries.We can not resolve the environment problems in Taihu Basin entirely by only researching on the objective reality where the population density is so high.(2) To the residents in a certain area,sometimes, the environment exists exceeding its physical and chemical characters.People always notice how the environment influences their lives.So we have to consider this when we make policies of environment development and protection.(3) Even the residents are in a small place, their understandings to the environment problem are quite different because there are obvious differences in their culture backgrounds and environment preferences.Clarifying these differences and the reasons that they forms is the first step to prevent the release of the contamination.

Abstract:As a most developed region in China Taihu Basin which with a quickly economic development has a important status in China economic development.The economic characters of Taihu Basin are quick development,large urbanization and economic difference in spatial distribution.Impacts to floods by some pyromania of eco-society development,such as land use change urbanization economic development polder construction were analyzed in this paper.The main conclusions included: (1) economic development made flood losses increase; (2)as land use changed, runoff increased; (3) land surface sedimentation resulted flood control engineering lost some capacities;(4) polders protect some land from flooding, but polder construction led quicker runoff.

Abstract:Since the reforming and opening-up of China in 1980s Taihu basin has witnessed great progress in social-economic development and economic restructuring as well as the deterioration of water environment.The paper focuses on the change of manufacturing structure and its impacts on the water environment in the Suzhou-Wuxi-Changzhou District.It is showed that there exists certain relationship between the change of industrial structure and TP and COD in Taihu Lake especially the manufacturing structure change in the past 20 years.It is urgent to make adjustments to industry structure and reform pattern of economic development to protect water environment in Taihu Lake basin.The paper also gives some suggestions about the studying on the relationship between industry structure and water environment in the future.

Abstract:It has been observed and studied that the natural restoration process of aquatic vegetation in the experimental enclosure of northern lakeside Lake Taihu,from 1997 to 1999 years.It is found that the local macrophytes for example, the Nymphoides peltata Trapa sp.and Pota-mogeton malainus Mig can be naturally restored in the bare lakeside of big shallow eutrophication lakes by an enclosed protection methods.The cover area by species of Nymphoides peltata and Trapa sp.has taken up to 14.3% and 12.7% of the total enclosure area in the summer of 1998,respectively.The companion species of vegetation are Potamogeton malainus Mig Hy-drilla verticillata Royle and Vallisneria spiralis L.The affection to the natural restore of macrophytes by anthropologic readping and fish culture has also been discussed According to the results of enclosure experiment it has provided a strategy for control of eutrophication in big shallow lakes for example,Taihu Lake.

Abstract:Since the 1960s the water pollution is pricked up in Taihu Lake.The water quality is decreased about one degree per 10 yeais, 70% of the rivers and lakes are polluted, and 80% of river water quality can not fit the need of national quality standard of Class Eof surface water.At present, the whole lake' water is eutrophication and part of the lake is heavy eutrophication. The "Zero" actions have good effect on lightening the water pollution in Taihu Lake and keep within limits the water quality decreasing in some degree.The COD concentration of input rivers was decreased 26.7% averagely from the year of 1997 to 1998.Among the input rivers, the river of COD concentration maximum decrease was at Wutangqiao-39.6%; the river of COD concentration minimum decrease was at Hexi-1.8%.Otherwise comparison with COD concentrations of input rivers in July, 1998 and 1997,the average total decrease was-14.8%.In 1998 the decrease was-39.8% in September-31.9% in November,and-20.5% in December respectively. The COD quantity from watershed to Taihu Lake was decreased by 19.1%.The average COD concentration in Taihu Lake was decreased by 21.2% After the "Zero" actions,in the year of 1999 and 2000,the water qualities in Taihu Lake are deteriorated again.Thus to control the water quality radically other countermeasures are needed except "Zero" actions.

Abstract:Bioaccumulation kinetics of 9 cholorophenols in semi-permeable membrane biomimetic sampling device and in fish was studied under controlled laboratory flowing-through conditions.Based on the difference between bioconcentration process in SPMD and bioaccumulation process of chlorophenols in fish the degradation and the structure/effects relationship of degradation of chlorophenols in fish was examined.The results showed that the chlorophenols under testing could be concentrated by SPMD in a similar way as it was concentrated by fish lipid.The biodegradability of chlorophenols decreased with increase of substitutions of chlorine atoms and is closely related to the position of chlorine substitution in the ring of benzene.

Abstract:The lakeside zone of Taihu Lake is one of the major pollution control regions in Taihu basin.Based on the principles of watershed ecology and management the measures of ecological rehabilitation for lakeside zone in Taihu Lake were put forward in the paper.(1) To develop eco-agriculture should be the effective way to reduce agricultural pollution.(2) Riparian forest belt as a buffer zone between farmland and water body, should be planted along the rivers that enter Taihu Lake.(3) Soil and water conservation should be paid particular' attention to in the hills on lakeside.(4) Fulfilling purification function of lake wetlands is the proper method to prevent eutrophication of Taihu Lake.(5) Man-made wetland system at the mouth of rivers that enter Taihu Lake should be established on the basis of experiment in selected place. Suggestions are made for the purpose of a ccomplishing the ecological rehabilitation of lakeside zone i.e.: 1) To heighten the public consciousness for environmental protection; 2) to strengthen pollution control and management of lakeside zone on the basis of organization and regulation; 3) to establish environmental monitoring and information system, and 4) to advance the tentative ideas for further study of pollution control engineering of lakeside zone.

Abstract:The reseaich on improving efficiency of PSB to plankton structure in low-lying saline-alkaline wetland ponds showed that PSB could enhance the number and the biomass of Cyanophya Cyptophyta Euglenophyta and Cryptophyta.Although Bacillariophyto dropped a little in general the small-type species increased.Moreover,PSB could enhance the number and the biomass of Cladocera and Rotifera especially those of the small-type Rotiferus.But those of Capepoda and Protozoa displayed a dropping tendency.Generally plankton displayed increases of numbers and decreases of biomass.Most species of plankton appeared certain increase,small-size geneses of plankton appeared more common than great-size ones which incrased the feed effect for fishes.In conclusion PSB could adjust and improve the structure of plankton community in saline-alkali wetland ponds.

Abstract:During the investigation from Apr.1997 to Jan.1998,a total of 47 species of zoobenthos were recorded at 14 sampling stations in Fuqiaohe Reservoir, Hubei Province, of which Limnodrilus hoffmeisteri, Tanypus chinensis,Procladius sp.and PChironomus sp.were dominant species.The Shannon index and the Margalef index were lower with the peak in the upper reaches.Changes of zoobenthos similarity coefficients in different seasons were not significant.In horizontal distribution the similarity coefficient between the upper reaches and the cove was the lowest and the highest between the lower reaches and the cove.The density and biomass of zoobenthos in the reservoir were 529.1 ind./m² and 3534.1mg/m²,respectively and both dominated by Insecta.The spatiotemporal change of the zoobenthos standing crops was mainly related to Insecta.It was calculated that the fish production potential from zoobenthos was 1.5×10⁴kg/a It is suggested studies on zoobenthos as an indicator for trophic classification in reservoirs should be conducted.