Resources and Environment in the Yangtze Basin 

About: Resources and Environment in the Yangtze Basin is an academic journal. The journal publishes majorly in the area(s): Land use & Population. Over the lifetime, 1239 publications have been published receiving 3455 citations.

Structure of poyang lake wetland plants ecosystem and influence of lake water level for the structure

Abstract: With an analysis of the hydrologic processes and landform of Poyang Lake,wetland types were classified by using 3S technology,the habitats of wetland plants,structure of major plants community and its distribution rules were investigated in this paper.Poyang Lake has complex system of wetland plants and is extremely rich in biodiversity.The wetland plants are colonel reproduction of plants using roots or stems as the the main reproductive organs,so the distribution pattern of plant communities presents the main features of the cluster distribution.In micro-scale,the plant communities distribute based on the moisture gradient by the influence of lake's landform,the elevation,the water lever and exposed time of the beaches.In landscape-scale,the distribution of plant communities present community mosaic structure by the influence of soil moisture,groundwater depth and soil structure.In microcosmic-scale,the distribution of plant communities presents community complex structure in some regions by the influence of the micro-topography and soil nutrient.Wetland plant's extreme sensitivity to moisture gradient leads the structure to become mutability and fragility.In recent years,the long-lasting low water lever of Poyang Lake causes damage to ecosystem.

A study on total suspended matter in lake taihu

Abstract: Total suspended matter plays an important role in internal loading release and water environment Total suspended matter determines the transparency of water and the distribution of underwater light, which ultimately determines the lake primary productivity Based on long-term and two times fixed-point field observations of total suspended matter, wind and wave, the composition, temporal and spatial variations, vertical variation and the relationship between total suspended matter and wind and wave are analyzed The results show: Organic suspended matter accounts for 30% of total suspended matter; Total suspended matter is characterized by regional variation, with the highest value in Lake Center and the lowest value in East Taihu Lake; Obvious seasonal variations of total suspended matter are characterized in Lake Center and East Taihu Lake; Vertical variations are characterized by the increase of concentration of the total suspended with depth; The critical wind speed of sediment resuspension is between 5 and 65 m/s; Increase of total suspended matter results in decrease of transparency and increase of beam attenuation coefficient

Studies on biological characteristics and change of resource of coilia nasus schlegel in the lower reaches of the yangtze river

Abstract: Studies on biological characteristics,change of catch per boat and maximal sustaining yield(MSY) of Coilia nasus schlegel in the lower reaches of the Yangtze River were carried out during the period from 1993 to 2002.The result showed that average body-length and body-weight were 29.19 cm and 94.33 g in fishing season.The correlative equation between bodylength and body-weight could be expressed as Y= 0.004 8X~2.906 9 and the coefficient of fullness was 0.379.The average value of absolute fecundity and relative fecundity were 23 695 eggs/fish and 229 eggs/g body weight respectively,and the diameter of matured egg was 0.77 mm.The correlative equationY= 0.017 2X~4.101 might be used between absolute fecundity and body-length and it was Y= 305X-5 410.1 for absolute fecundity and body-weight.Most of the fish were two years old in fishing season.The average value of the total catch per boat was 393.14 kg.Average annual catch was 891.51 t and MSY evaluated by model of Schaefer was 2 061.81 t in the lower reaches of the Yangtze River.Compared with historical data,the miniaturization of the fish was evident and the community age structure tended to be onefold and low-aged,at the same time,the resource of C.nasus had decreased significantly.

Organic pollutants in source water in jialing river and yangtze river (chongqing section)

Abstract: The organic compounds in the Jialing River and the Yangtze River that are the source of drinking water for Chongqing City have not been found previously. The Solid Phase Extraction-GC/MS method was employed in this study. 100 or more organic compounds were identified in source water, 60 in the Jialing River and 50 in the Yangtze River, the most of which are phthalic acid, esters, keton, phenol, benzene and derivatives. The organic contamination character was different in the source water of the Jialing River and the Yangtze River. Organic contamination levels in Jialing River were much higher than in Yangtze River, and in spring were much higher than in summer in Jialing River, and vice verse in the Yangtze River. The compounds of higher rates detected were di-iso-butyl-phthalate( 100%), di-butyl-phthalate(100%),chloro-4-nitro-benzene(60%), 1,1,3,3,3-pentachloropropane (50%), butylated hydroxytoluene (40%). In addition, many metabolites on intermediate of methamidophos pesticide were detected in B water treatment, with the highest concentration of a single being 56.5μg/L.

Preliminary discussion on eutrophication status of lakes,reservoirs and rivers in china and overseas

Abstract: With human's increasing development and use of environmental resources, industrial and agricultural production have rapidly expanded and developed, especially since entering new century. Industrialization results in urbanization, which a large amount of domestic sewage containing nitrogen and phosphorus are discharged into nearby lake, reservoir and river, and increase nutrient load of water bodies. For improvement of agricultural production, more and more chemical fertilizer and livestock night soil are used year after year, and thus nutrient in water increases gradually by rain scouring and penetration. Human activities that cause excess nutrients to enter water body speed up the eutrophication process. Investigation shows that about 30%～40% of the worldwide reservoirs and lakes have been eutrophied to a different extent, and lake eutrophication trends to aggravate in recent years in China, from 41% eutrophied lakes in the later 1980s to 77% in 1990s. Reservoir eutrophication is also serious, i.e. number and storage of eutrophied reservoir account for 30.8% and 11.2% of the total. In general, the extent and scope of water body trend to aggravate. Extent of eutrophication in urban lakes and reservoirs nearby city are higher than that in other region. Eutrophication in the relative still water bodies, such as lake and reservoir, is more serious than those in other regions Eutrophication in the relative stagnant water bodies, such as lakes and reservoirs, is more serious than that in rivers, but river eutrophication shouldn't neglect. Eutrophication has become one of important environment issues in world water environment protection.