Abstract:Based 011 the sedimentary feature.spore-pollen analyses.the contents of geochemical ela ments and organic matter,together with the chronological results of the lacustrine sediment of Balikun Lake in the northern part of Xinjiang,this paper focuses on the climatic change during Late Glaciation.The climate during this period was characterized by alternation 0f several stadials and interstadials.and there still exists a disposal regime of hydro-and thermal-conditions.which is represented by cold humid and warm-dry on the time scaIe of 100 years.differentiating from the eastern monsoonaI area in China and the other areas over the world.but the process of climatic evoltion is synchroneous, What the paper has revealed is a non-linear climatic change during Late Glaciation in the northern part of Xinjiang,the most extreme arid inland area.which may be all important significance for providing some fresh insights into “The Climatic Abrupt Change Events”.

Abstract:The organic materials in lake sediments mainly come from (1)autogenous materials (21)al lochthonous materials. As in the second case.the organic materials in sediments mainly come from the plants which were brought into the lake by flowing water,So the δ¹³℃ vaktes of the or ganic m aterials are controlled by the plants types.The values of δ¹³C of the organic materials l1 sediments can supply the information of w hat types of plants the organic materials come froln. According to the plallt types the paleoclimatic information Can he obtained, Aco rding to the verticaI distribution of the δ¹³C in Dabusu Lake.has been reconstructed the paleoclimate evolution of this region since 1 5000 years as fo[iows： 15400-14000 aB P (depth 8.10-7.30m )： the climate was cold and wet. During this stage there was a high lake level and stable environment. 14000 12200 aB P (depth 7,30-6,30m )：the climate was dry and tem perate. The Lake level descended rapidly, 1 2200-9500 aB P (depth 6,30-4,85m )：The climate was cold and wet, 9500-7800 aB P (depth 4.85～4,00m )：The climate came back to warm and dry.and Ihe lake Ieve1 was Iow. 7800～5500 aB P (depth 4.00-2,80m ) The temperature fell and the lake level rose.The climate was cooI and wet. Since 5500 aB P (depth 2.80-0m )：The climate bacame warm and dry. The Lake water condensed rapidly and finally the lake evolved into a saline hke.

Abstract:The sediments deposited in the anoxic Great Ghost Lake in southern Taiwan, China were undisturbed due to the lake's unique hydrological and geographic conditions. As a result, past cli-matic and environmental records were well preserved. The distinctive white laminations appeared in the generally black sediments are characteristic of lower organic-matter content. and lower C/ P,N/P,S/P and Si/Al ratios,but higher Si/P, Fe/C, Mn/C,Fe/Mn and Mg/Al ratios. These indicate times of cooler/driver climate,poorer plant growth around the drainage area, low-er water-level and more oxidized conditions in the soil and in the water column. On the other hand.the organic-matter-rich black sediments were deposited in a warmer/wetter climate under a more reduced condition. In addition, the variations in the Mg/Al rations seem to reflect at least 12% changes in salinity or water volume, or 2m changes in the water level.

Abstract:The Artemia cysts used in the experiment are sampled from the following 9 inland salt lakes of the People's Republic of China： Aibi Lake (AB),Balikun Lake (BLK), Dabancheng Lake (DBC) (Xinjiang Province). Gahai Lake(GH). Xiaocaidan Lake (XCD) (Qinghai Province). Huhetnolegainor Lake (HHT). Ejinor Lake (EJN) (Inner Mongolia), Xiechi Lake( YC) (Shanxi Province). The following characteristics of different Aremia strains are analyzed： (l)Biometrics： diameter of hydrolic cysts and decapsulated cysts. chorion. length of nauplii. dry weight of de-capsulated cysts and nauplii. weight loss during hatching. (2)Hatching characteristics： hatching percentage, hatching efficiency, hatching rate. (3)Nutrition analyse：protein content, fatty acid composition.Significant differences (P90 of all the strains.except BLK and HHT. is less than 24h.The protein and total lipid content of all the strains are within 45%-57% and 125. 68-177. 94 mg/g. respectively. The strains of GH.XCD and BLK have higher EPA (20 : 5ω3)strains from Inner Mogolia have the lowest EPA content. No DHA wasA present in all strains.

Abstract:Based on the lake energy budget and fake eddy diffusion equation * the lake thermal model was constructed and used in the simulation of thermal properties of Qinghai Lake, the largest saline and deep lake in China,The simulated items include the water surface temperature? tem perature profile, ice formation and thaw procedure? snow aging process etc. With the aid of the four-GCMs output about the climate condition of doubling C0₂ in this area,the potential change degree of the water thermal properties has been evaluated and discussed.

Abstract:The denitrfication rates (DR) of sediment in Saginaw Bay, Lake Huron, have been measured with No production method. Triplicate samples of sediment core were collected at two GLERL long-term monitoring sites of the Bay in July and August of 1995. The DR is 16. 0-39,6 and 22. 7-26. 1 micromol N:/(m²·h) in the Inner and Outer regions of Saginaw Bay. respectively. The spatial and temporal characters of DR in Saginaw Bay was studied also in this paper, The DR was influenced by the interaction between the Saginaw River as a main pollution source and Lake Huron as a reservoir of high quality water. According to the measured DR, it has been evaluated that the nutrient condition of Saginaw Bay is oligotrophic/mesotrophic level in the present period. The molar ratios of N₂ : TIN were kept constant at both sampling sites and not seriously changed with sampling time. The DR was positively correlated to O₂ consumption rates in the headspace of timecours. Additionally,a negative correlationship between NH⁺₄ and NO^-₃ concentrations in the overlying water was found.

Abstract:Factors and processes such as intense human activities and rapid eutrophication. controlling the concentrations of organic substances, nutrients and organic pigments in sediments were analyzed before and after fish culturing in four fishponds. Results show that rapid sedimentation rate is more favorable for reservation of pigments that can be a significant indicator for trophic state of water bodies. In the meantime, there are close relations among organic substances, nutrients and organic pigments in sediments. These can be useful in sedimentary environmental explanatioa by way of organic pigments index.

Abstract:The distribution of ciliated protozoans was studied in Meiliang Bay of Taihu Lake from Apr. 1993 to Jan. 1994. 7 orders and 19 genus were recorded. On the basis of the trophic state index [TSI(chla)],the study area was separated into mesotrophic and eutriphic regions. Some of the genus were restricted to eutrophic situations, such as： Paramecium spp., Euplotes spp.Acti-noholina spp., Didbiium spp.Dileptus spp.,Carchesiuin spp., Opisthostyla spp. The mean monthly abundance and biomass of total ciliates were positively correlated with the trophic gradient. Ciliated protozoan was a good indicative community for the lake eutrophication. The orders (Oligotrichida and Peritrichida) dominated the ciliate assemblages and incresed with the rising of the TSI(Chla). Oligotrichida was mainly dominant in the mesotrophic region. The mean volume of the ciliated protozoans in eutrophic lake region waswith significant difference.

Abstract:In eutrophic lakes, the sediment usually plays as a large sink for phosphorous, but its capacity to take up more phosphate is quite limited. In this investigation, phosphorous saturation of the top sediment in East Taihu Lake was studied and used as an index of lake eutrophication. Eight sample points were sited along a line across the lake, and the top 10cm sediment was collected. The top sediment samples was also taken from am old fish farming pond and a pen as contracts. One series of row samples was cut into peacs of lcm and analyzed for total phosphorous (TP) and reactive phosphorous (RAP) content. It was found that the content of TP in the top sediment varies from 0. 0465% to 0. 0993%.and RAP from 3. 48 mg/kg to 19. 84 mg/kg. The fish-pond sediment had the highest TP and RAP content among all the the samples,but there was no remarkable difference between pen sediment and lake sediment.Ten experimental systems were prepared by mixing 2-kg sediment with the lake water in plastic tanks of 90L volume. The tanks were covered, aired with a pump and kept in dark. Phosphate (53mg P) was added to each system in four times to detect phosphorous saturation of the sediment. The sediment samples from fish-pond and pen were already phosphorous-satura-tred, and the lake sediment samples were nearly phosphorous-saturated. After adding 53 mg phosphate-phosphorous in each system. phosphate level of the water phase became as hign as 200-300/xg/L (25-48 times as high as in the lake water),but TP content of the sediment only increased 0. 037-0. 077 mg/g in the sediment (0. 06%-0. 14% of content). This indicates that the lake is now very sensitive to phosphorous pollution. Good care has to be taken for keeping a phosphorous balance in the lake ecosystem.

Abstract:Lake restoration is a complicated systematic engineering in which non-point pollution control is a very important aspect. This article deals with the sources of non point pollutants in Dianchi Lake. According to its pollution features and the catchmeents ecological characteristics.the catchment is devided into six pollution control zones with corresponding treatment measures.

Abstract:The mineralization of heterotrophic bacteria in low-wetland fish pond of the Huang-Huai-Hai plain was studied in 1993. The results were oheained as follows： (1) The respiration rate of heterotrophic bacteria were related with the content of organic matter and the water temperature of fish ponds. (2) The bacteria biomass of fish ponds showed a clearly seasonal change· but the distribution of heterotrophic bacteria biomass showed no difference in surface and bottom water. (3) The dymamic characteristics of heterotropic bacteria decomposition organic matter were as follows：At first,the transferee! organic matter was little,following the temperature and the bacteria biomass, the mineralization increased and reched the maximum in autumn, and then stopped with decaresein the temperature. (4) The intensities of mineralization organic matter varied in fish ponds to stock different fishs.

Abstract:Weir fishery has contributed more than 70% of the total annual yields in HonghuLake since the 1970s. It was estimated with GPS that about 11000 weirs were setin Honghu Lake in 1993. three times more than the number in the early 1980s. Large species such as Ctenopharyngodon idellus,Charma argus% Cyprinus carpio and Silurus asotus made up 47. 6% of weir fishery in 1986 and less than 7% in 1992-1994. Three small species (Carassius auratus auratus.Pelteoba-grus fulvidraco, Cultrichthys erythropterus) increased from 51. 0% in 1986 to 87. 6% in 1992-1994 with the average size declining from 22. 2g,30. 9g, 44. 5g in 1986 to 11. Ig,15. 4g 25. 3g. in 1992, respectively. Seasonal changes in composition of species were observed in 1986,Cutas-sius auratus auratus and Pelteobagrus fulvidraco dominated the catches in spring and summer·and catches of some river-run species increased dramatically after late summer.It is obvious that the fisheries in Honghu Lake were enhanced in the 1980s because of restrictive measures and rehabilitation programs,e.g., the closed season during spawning of fish, stocking of fry. introduction of fry from the Yangtze River and propagation protection pens. However,the fisheries declined again in the 1990s due to increasing fishing intensity and weakened management.

Abstract:Based on the growth information for Protosalanx hyalocranius transplanting in Daoguanhe Reservoir, Hubei Province,the growth index,the growth rate and the other indexes were calculated. The regrssion relationship of the body length and the body weight were gained： W=1. 2120X10^-6L^3.1820 and Von Bertalaffy growth equation： L_t = 193. 03[ 1-e^{-0.3050(1-3328)}] W_t = 22. 72[l-e^{-0.3050(l-0.3328)}]³. This paper stated in detail the growth character of Protosalanx hyalocranius transplanted in Daoguanhe Reservoir, divided the growth into four stages and compared it with those in other reservoirs.It was concluded that Protosalanx hyalocranius had both biological effect and production benefit as well in the waters of Hubei Province.

Abstract:Bakeyao Lake is located in the Horqin Sand Land, in the eastern part of Inner Mongolia. In estimating the dates of the lake sediment, the author found that the radiocarbon dates were nearly 2000 years older than thoes derived from²¹⁰Pb measurements. In order to find out the reason. the author made sonce investigations on some other carbon dating results for lake sediments in the arid and semi-arid areas of China,and found that most of them seemed to be 1000-2000 years older than expected. This makes the author conclude that the usually older dates derived from the radio carbon dating may have been induced by the “hard water” effect.Caution therefore should be paid to the carbon dating problem in the future studies in North and West China.

Abstract:Great environmental changes have been witnessed in China's lakes and reservoirs during the past years.According to the data revealed in recent investigations as well as the references available.at least five aspects could be pointed out in view of the main water environmental problems,i.e.common water quality deterioration,especially pollution； overwhelming eutrophication? shrinking lake areas heavy deposition in reservoirs； and higher salinity in some inland lakes.The increasing nutrient-rich inflow is one of the main causes of pollution and eutrophication in China's lakes and reservoirs.More and more pollutants/nutrients from industrial.agricultural.domestic sources have been added in.The wastewater treatment in urban areas lags far behind the economic growth.As a result,the has leen made unbalanced in some basins.The shrinkage of lakes and resevvoirs in South China results from heavy intake deposit and reclamation by human activities in the past years.In the North and North west China,the shrinkage of lake area usually has taken place with water of higher salinity.The accelerated global warming-up dominates a dryer climate in inland China,resultingm more evaporation and less precipitation.Still,inflow with low salinity to the lakes is more or less blocked away in order to meet the needs of human activities,especially economic development.There are many heavily sediment:-ladden rivers in monsoon areas of South China.while in North China the Loess Plateau and/or.loess-rich areas provides a steady source of deposits to ihe river.Heavy sediment available makes much of the reservoirs a real pool of deposit.That the sedimentation condition was not fully considered in the planning of the reservoir building worsens the situation in some reservoirs.In order to change the environmental status quo in China's lakes and reservoirs and the corresponding basins,some immeediate measures must be taken.1) Guide wastewater discharge and operate more wastewater treatment plants.2) Apply reasonable fertilizers； restrict using phosphate-containing detergents; encourage ecological fish farming.3) Initialize water/soil conservation projects in the upper and middle reaches.4) Harmonize between utilization and resources protection in inland areas ； take every step to mitigate the salinization process.5) Employ careful planning before and effective managent after reservoir built.6) Strengthen pollution control and Rarnessing within water bodies,such as ecological engineering aquatic macrophyttes restoration,sludge-dredging in certain districts,etc.7) Enhance integrated environmental management in the whole basin.

Abstract:There exist several ideas upon the cause of formation of Baiyangdian Lake. North China Plain. Recently, Zhu Xuanqing, et nl (1994) pointed out that Baiyangdian Lake used to be an outcome of human activities in the book titled “Environmental Evolution and Prediction of Baiyangdian Lake” (Xi'an Atlas Press, 1994. ). That conclusion drawn by Zhu,et al (1994) was based on the follows: 1) The geographical environment during the Middle Holocene in the plain was not suitable for lake formation ； 2) The existence of Ltitnprotula spp. fossils in the sediment revealed a corresponding fluvial sedimentary condition; 3) The historical remains of Neolithic Age and Zhangguo Dynasty demonstrated that there was not a vast and unified lake at that time. The authors here present a new look on the above views. It was the differential accumulations of various rivers that formed Baiyangding Lake,a lake between alluvial fans and rivers. The lake has its own emergence, development as well as dry-up processes during its evolution history. Human activities could trigger the outcome of expansion,reduction and even dry-up in history. whereas each was merely one of the different stages in the evolution history of Baiyangdian Lake, instead of the cause of formation instead.