Abstract:The state of primary production in a lake is greatly affected by the optical conditions in the water, and closely related to the euphotic depth Zcu, The apparent optical parameters such as Zcu depend on the transferring of solar radiation in vvatcr, consequently, on the optical coefficients of water body such as absorptance aud scattering. In this paper, the field data of suspended materials in Taihu Lake are used for computing of inherent optical parameters of the lake. With the computed results, a numerical model is developed to study the transferring of solar radiation in the lake in which the concentration of suspended materials is considered to be variable vertically. Using this model the factors which influence on the transferring of radiation in the water are discussed.

Abstract:The average annual precipitation of Taihu Lake is 950-1000mm on NE shores, which increases to 1200-1250mm on SW shores progressively. The annual precipitation course is characterized by a double-peak model with the maximum value being 147-105mm at all stations in Jun. and the minimum value 33-l8mm on the most stations in Dec.. The estimated precipitation effect of Taihu Lake shows that there exists a low value region of precipitation on the lake surface fundamentally. The precipitation effect of Taihu Lake enables the precipitation on lake shores to average 20mm less than that of far from the lake shores, <3% of the annual precipitation. This means that the influence of Taihu Lake on the precipitation is not evident, but it has a little impact on the precipitation distribution of this region. The precipitation on the Taihu Lake region is one of the decisive factors of the water level fluctuation.

Abstract:The evolution of mountain lakes of Central Asia in late Quaternary was discussed in this paper.

Abstract:There exists a large of aquatic Myriophylhvn and Cyperaceae Pollen and Pediastrum algae fossils in Core Chao-2 in Dianchi, Comparing the pollen and algae fossils with the distribution of sporollen and algae in the surface of Dianchi Lake, it is clearly shown that the lake used to be a shallow lake with the water level shallower than that of the present stage about 40000-50000 yr.(B.P.). The lake basin extended gradually and the lake-level rose slowly up to the maximum of about 4.5m above the present one. But the lake became reduced about 28000yr.(B.P.). At the beginning of the Holocene, the basin began to shrink, the lake-level began to drop down, the whole lake basin was gradually filled up.

Abstract:The salifiable elemental behavior on concentration as well as the variation of brine chemical types and pH value have been revealed. Some conclusions were drawn:1.The main ionic evolutional direction of brine is incremental in the order:Ca²⁺→Na⁺→K⁺→Mg²⁺→Ca²⁺(cation) as well as CO₃^2-→HCO₃^-→SO₄^2-→Cl^-(anion). 2.In addition to the Separation of solid salt, the trace elements have a high degree of centralization in the final concentrative brine and the remnant brine after salt separation. More than 63 elements have been investigated in brine, such as K, Mg, B, Li, Rb, Cs, Sr, U, Th, Tr, D(²H), etc. Which have constituted a precious resources with comprehensive use.

Abstract:By using multivariate discriminant analysis of 4 morphological characteristics(total-length, body-length, body-high, body-weight), the morphological discriminant function for the identification of Carossius aurattis curieri T, et S. and Carasstus auratus auratus (L.) is yielded. Instead of general taxonomic method, this mathematical method is simple and easy to be applied in fishery practice. The function has been tested as of high significance, with 100% correct rate.A brief introduction to the use of multivariate discriminant analysis in biology is also presented.

Abstract:With the development of limnological researches, lake mapping has made rapid progresses as mainly shown as follows:1.Lake mapping has been developed toward thematic atlas or comprehensive atlas from some simple illustrations;2.Mapping areas have been extended to lake's surrounding areas or a whole lake drainage from lake water body;3.Mapping elements have been extended to interrelated elements of lake's surrounding areas from some elements of water body; 4.The main contents of lake mapping have been varied from physical elements to economic elements;5.Attention should be paid to lake environmental quality;6.Origin and evolution of a lake are also included in the map contents;7.Map subjects selected aims at serving national economy and environment protection;8.Comprehensive mapping is commonly adopted.

Abstract:This paper described the measurement results of the dissolved oxygen(DO) in the water bodies of seventeen lakes over Hengduan Mountains. The average DO content in the lakes is about 5.86 mg/L to 8.35 mg/L, and the maximum value is 14.54 mg/L. The distribution of DO content is varying with different lakes at different altitudes and the value decreases with the increasing of elevation. Because of the water movement, the DO content in the upper part of lake water is nearly stable. But in deep lakes, the DO content is obviously different between upper part and lower part, and the value decreases with the increasing of the water depth, for example, in the Mahu Lake there is no oxygen beneath the depth of 100 m, so no living creatures exist. Through the themocline about 10 m to 50 m beneath the water surface in some lakes, DO content decreases sharply. In addition, the DO content distribution in some lakes is also affected by aquatic plant growth and organic pollution.

Abstract:This paper reports the analytic result of the sediment sampled from an experimental area of pen fish-culture in East Taihu Lake. The contents of OM(organic material), TN(total nitrogen) and TP(total phosphorus) in the sediments within the enclosure increase respectively by 48.81%, 13.75% and 22.22% after pen culture for one year, by 70.63%, 47, 62% and 25.00% after two years, by 90.18%, 65.08% and 30, 56% after three years and by 116.86%, 90.48% and 55.56% after four years, as compared with contrast sediments, 20 meters far away from and out of the encircling gear, due to the accumulation of the remains of fish food and seretion. In order to decrease the nutrient load of the sediments in the enclosure net, four points are suggested as follows：1.The type of fish food should be changed. 2.The fish population in the enclosure should be controlled in a proper way. 3.Dead fish should be cleared away from the enclosure in time. 4.The pen culture and plant culture should be carried out alternately.

Abstract:Fang Zhongyan (989-1052), a well-known politician in Song Dynasty. He had made contributions on the harnessing of Taihu Lake at that time.

Abstract:According to sequence of deposition of undissolving salts, two radios are got differentiate the brine type, having the same result as the method of feature ratios and the method of Baляшхом.г., and being also useful to deduce the deposition.

Abstract:This paper demonstrates the features of Dongting Lake, Hunan Province, and the importance and feasibility of its harnessing. If no measures are taken urgently, the lake may be extincted in about 100-500 years, as a result of huge accumulation of sediments from the Yangtze River and other rivers. It is suggested that Dongting Lake be tackled in a comprehensive way to reduce water source and develop drainage, i.e. to harness the Yangtze River first, and then to increase reservoir and drainage, i.e.to harness the lake itself, and to maintain and strengthen flood defense works.

Abstract:Some important historical materials on the Changjiang River Three-Gorges Project are presented in this paper.