Abstract:Of all the cloudless 340 satellite imageries 11 were shot by Landsat MSS/TM/ETM sensor since 1979, 216 by EOS MODIS sensor since 2002, 10 by CEBERS CCD sensor since 2005 and 3 by IRS P6 LISS-3 sensor in 2007. On the basis of the spectral analysis, an applicable model was developed to extract the cyanobacteria bloom information from multi-source remote sensing images. And then, the model was used to acquire cyanobacteria bloom-covered area and its spatial distribution. The result showed that the initial time of cyanobacteria bloom was moved from June or July to March or April at present, three-four months advanced than the normal. The statistics showed that the cyanobacteria bloom occurs most frequently in June or July and the second was in October or November. Additionally, the duration of cyanobacteria bloom is becoming longer and longer and almost over time of March to December at present. The most intensity of cyanobacteria bloom occurred in September and the second was in June. The north of Lake Taihu, including Meiliang Bay and Zhushan Bay, was the initial location of cyanobacteria bloom and also the heavy disaster area, where the cyanobacteria bloom occurred every year since its first time. However, cyanobacteria bloom also occurred along the south bank of Lake Taihu almost every year since 2001, where the cyanobacteria bloom-covered area was becoming larger and larger and the duration time was becoming longer and longer, and which was becoming the earliest location of cyanobacteria bloom. It was noticeable that the cyanobacteria bloom was pervading gradually from the north, the west and the south to the center since 2003, and it sometimes covered almost the whole non-vegetation area. Additionally, there were cyanobacteria blooms occurring at Gonghu Bay since 2005, and it occurred more frequently in 2007.

Abstract:δD values of terrigenous n-alkanes (n-C₂₅, n-C₂₇, n-C₂₉ and n-C₃₁) extracted from recent lake surface sediments of Lake Qiangyong Glacier, Lake Kongmu Co, Lake Nam Co, Lake Keluke and Lake Xiao Qaidam along the S-N transect of Tibetan Plateau are compared to those of precipitation spanning a wide range from -167‰ to -51‰ and clearly correlate with δD values of meteoric water during the growth, indicating that terrigenous n-alkanes record the precipitation signal during the growth. The isotopic fractionation between precipitation and alkanes of n-C₂₅ and n-C₂₇ cover a range from-45‰ to-70‰ whilst that between precipitation and alkanes of n-C₂₉ and n-C₃₁ vary from -70‰ to -95‰, both being fairly constant along the S-N Tibetan transect with the mean at-57‰ and-82‰, respectively. By comparison with the apparent isotope fractionation of -130‰ along the S-N European transect, it implies that the apparent hydrogen isotopic fractionation between meteoric water and terrestrial n-alkanes along the Tibetan transect is much smaller.

Abstract:The formation of water chemical characteristics in the Paleogene System had good response to the sedimentary conditions and its evolution in Dongying sag. The type of CaCl₂ formation water with high salinity was representative response of the brine lake of the Paleogene System in Dongying sag. The content of total salinity and chloride ion decreased from the deep depth to the lower, which was good response to the evolution of the Dongying sag from salted basin to freshwater basin. According to the vertica1 characteristics of the underground water formation, four hydrological environments can be classified: stronger formation water frequency alternation belt(0-1.1km), feeble formation water frequency alternation belt(1.1-2.0km), formation water alternate blocking belt (2.0-2.5km) and formation water alternate tardy belt (>2.5km). In every belt the total salinity, ions and ion composition ratio had different responses, and the belts corresponded to the distribution of formation pressure. The formation water chemical field experienced deposition and leaching in early time and burial in later time. In the period of Dongying Movement the formation water chemical field was active, and salted water from the Member 4 of Shahejie Formation migrated to the lower, and in the course the faults played important roles, which demonstrated the representative characteristics of faulted basin.

Abstract:Altogether 15 metal elements concentration of 216 lake sediment samples from CC1 core in Chen Co, southern Tibet were measured. Distribution features of all the metal elements and their relationship with grain size parameters was studied. The results showed that all the 15 elements could be divided into three groups according to their distribution features, i.e., 12 elements of K, Na, Mg, Al, Ti, Ba, Cu, Zn,Fe, Pb, Cr and V present similar variation trend against depth;Ca and Sr had very similar variation trend while Mn was not similar with any other element. The correlation analysis between elements concentration and grain size parameters indicate that the variation of Ca, Ti and Pb were not influenced by grain size distribution;8 elements (K, Na, Al, Ba, Cu, Fe, Cr, V) show positive correlation with clay content (<4μm) of the sediment;Mg, Zn and Mn have positive correlation with silt content (4-63μm) while Sr had good correlation with sand content (>63μm). The grain size effects of most elements in this study were coherent with other studies of elements grain size effects in lake sediments and marine sediments. Compared with reconstructed environmental information for the past ca.1400 years from this core, it could be found that the distribution characteristics of elements show rather good correspondence with environmental conditions during different stages. Variations of most elements show influences from sources of materials that is intensity of weathering and erosion in the drainage. However, Ca concentration was not affected by grain size of lake sediments, and performs very good correlation with carbonate content and Sr/Ba of sediments, indicating that influence from sources of materials was not the main controlling factor of Ca concentration, while physicochemical features of lake water, evaporation intensity and sedimentary process would probably the major influencing causations.

Abstract:The conceptual rainfall-runoff model, HBV, was applied to Dongjiang basin and its 13 sub-basins for the purposes of examining the applicability of this well-known model in south China in order to explore the possibility of transferring the calibrated parameter values to ungauged basins. For testing the applicability of the model in gauged basins, an automatic optimization method was used for model calibration. For testing the transferability of the parameter values to ungauged basins, two parameter regionalization methods (proxy basin and global mean) to determine the model parameters for ungauged catchments in the study area were investigated. The results showed that: (1) the HBV model worked well in the Dongjiang basin with average R₂ higher than 0.82 for using calibrated values;(2) Transferring the parameter values with higher R₂ and ME during cross-basins tests into the hypothetic ungaged catchments did not result in better model simulations than those with lower corresponding values;(3) Neither area-weighted-mean nor Thiessen-interpolated-mean approach could markedly improve the precision of parameters estimation by arithmetic mean value. It was concluded that both regionalization methods could effectively estimate parameters for ungauged catchments in the Dongjiang basin, leading to little discrepancy in the two models.

Abstract:Trends of moisture budget were explored during 1961 to 2005, using simple linear regression method, in the Yangtze River basin, China. The results indicated that: 1) the moisture budget decreased in winter, spring and fall, but increased in summer. The trend of moisture budget was significant except for summer in the upper Yangtze River basin. While significant trends could be identified in moisture budget in spring, summer and autumn in the middle and lower Yangtze River basin;2) the correlation between moisture budget and precipitation was significant related at all of the seasons in the middle and lower Yangtze River basin, and was significant related in spring and autumn in the upper Yangtze River basin;3) the summer moisture transport was in significant decreasing trend in the Yangtze River basin, which might be closely associated with lower layer geopotential height. The summer circulation showed increasing continental high over north China, which weakened the southwesterly summer monsoon and limits propagation of the summer monsoon to north China, resulting in more water vapor budget in the Yangtze River basin and less in north China.

Abstract:For selecting macrophyte species in constructed wetland, the abilities to remove NH₄⁺-N and TP in the artificial sewage of 10 macrophyte species were investigated by the manipulative indoor experiment. Macrophyte species which had stronger purification effect were selected, then, assemblies were designed to compare with the single ones. The results showed that the abilities of different macrophyte species to remove nitrogen and phosphorous contrast sharply with one another. Lythrum salicaria, Acorus calamus, Cann indica, Typha davidiana had stronger ability to remove NH₄⁺-N, when treated for 15 days, with an original concentration of 29.69mg/L, the removal rates were 96.6%, 98.6%, 87.7%, 95.1% respectively. Cann indica, Eichhornia crssipes, Lythrum salicaria, Acorus tartarinowii had stronger ability to remove TP, when treated for 15 days, with an original concentration of 4.44mg/L, the removal rates were 99.0%, 54.6%, 69.9%, 36.7%, respectively. In respect of the removal rates of NH₄⁺-N and TP, the assembly of Lythrum salicaria and Acorus tartarinowii (54.2%, -32.6%) did better than Lythrum salicaria(28.7%, -41.5%,), which indicated that the assembly could improve purification effect of NH₄⁺-N and TP simultaneously. The assembly of Lythrum salicaria and Cann indica, the assembly of Acorus calamus and Cann indica, the assembly of Acorus calamus and Lythrum salicaria, the assembly of Cann indica and Acorus tartarinowii, all the assemblies had stronger removal abilities of TP than the single ones. The results of the investigation into selection and assembly of aquatic macrophyte species suggested that, proper assemblies could improve the purification effect of NH₄⁺-N and TP in wastewater in comparison with the single ones.

Abstract:The contribution of the sediment phosphorus to the phosphorus concentration of the water body was studied through measuring the chemical forms of the sediment phosphorus and the environmental conditions at the sediment-water interface and the hydrological parameters of reservoir, and then we calculated the contribution from the concentration gradient of the total soluble phosphorus between the surface sediment and the water body. The result showed that the sediment of shanzi reservoir had a great release potential of the phosphorus and there was an apparent concentration gradient of the total soluble phosphorus between the surface sediment and the water body which releasing flux was from 0.0420μg/(cm²·d)) to 0.167μg/(cm²·d)). The contribution of sediment phosphorus to the phosphorus concentration of the water body was from 0.7% to 6%. The contribution in Autumn and in Winter were bigger than in Spring and in Summer. The sediment phosphorus load would be an important factor of the trophic status of the reservoir if the outside sources had been reduced.

Abstract:Nitrogen is one kind of important elements related to eutrophication of lakes. The removal of exterior pollution source and interior pollution source is significant for eutrophication control of lakes. Ammonia removal by fillings is an important ways for the control of exterior pollution source of lakes. The ammonia adsorption behavior of four kinds of fillings, such as savageness zeolite, haydite, vermiculite and soil were investigated. The main way of ammonia removal by fillings, the effects of solution pH and temperature on removal rate of ammonia were observed. The results indicated that there were significant differences between zeolite and other fillings, and the sorption efficiency in the order were zeolite, vermiculi, soil and haydite. The ion exchange function is the main way of removing ammonia by zeolite, zeolite has the worst sorption ability, whereas other three fillings have almost the same sorption and ion exchange capacities. In addition, adsorption capacities of these four fillings decreased as temperature increased between 15-35℃;as the pH values increased at the range of 3-9 the adsorption capacities of these four fillings increase too. All adsorption experiments reached equilibrium within six hours.

Abstract:To examine the pollutant removal efficiency of different sward buffers to runoff and the correlation with biomass, 5 native grasses were selected to construct buffer strips and conduct an experiment under the simulation of agricultural non-point pollution and rainfall characteristics in Shanghai. The results showed: 1) the clarification efficiency to runoff of sward buffers was significantly better than the blank control, the SS average retention rate of Cynodon dactylon buffer strip was the highest, up to 74%;2) the TN and TP average removal rate of Trifolium repens buffer strip was the highest, up to 28% and 25%;3) the clarification efficiency of Lolium perenne buffer was the lowest because of the high temperature;4) the aboveground biomass of C. dactylon was 6.14kg/m², and T. repens was 6.49kg/m², higher than the other species;5) the growth rate of C. dactylon was the fastest, whose biomass in September was almost as six times higher as in May;6) the clarification efficiency of the sward was increased with higher biomass, there was a significant linear correlation between sward biomass and SS removal efficiency.

Abstract:The un-restored post-mined lands in Lake Fuxian watershed is large scale, potentially covering over 142×10⁴m². The investigation of the amounts of pollutants releasing from mined lands and transporting by runoffs was conducted. The erosion and eluviation on exposed phosphrite layer and overburden the resulted in the releasing of fluoride and phosphorus and water polluting. The releasing and transporting amounts of pollutants were calculated according to the results of column leaching studies and acreages of exposed phosphrite layers and overburdens. The results showed that the amounts of fluoride and phosphorus releasing were 60.65t/a and 27.34t/a, respectively, and the amounts of fluoride and phosphorus transported by surface runoffs were 22.58t/a and 7.27t/a, respectively. In conclusion, phosphorus mining activity is an important non-point source of water contamination of Lake Fuxian.

Abstract:The phytoplankton community in the Lake Baiyangdian was characterized based on, five surveys were carried out from April to October in 2006. A total of 155 taxa were identified by microscope. The phytoplankton had an abundance ranging from 55.5×10⁴ cells/L to 1704.8×10⁴ cells/L. The phytoplankton community was dominated by Cyanophyta, Cryptophyta and Chlorophyta. Canonical correspondence analysis (CCA) was applied to explore the relationship between phytoplankton species and environmental parameters by CANOCO 4.5. The species-environment biplots were drawn based by the result of CCA. The result showed that pH and total phosphorus were the most important factors influencing the distribution of phytoplankton species. Besides these, biochemical oxygen demand and dissolved oxygen were also important to the phytoplankton species. CCA ordination shows a slight, but significant method to understand the relationship between spatial distribution of phytoplankton community and environmental factors in lake systems.

Abstract:Gancun Reservoir was a tropical high-yield fishery reservoir located in the Leizhou Peninsula of Guangdong Province. In order to understand the dynamic characteristics of rotifer community in the reservoir in dry season, rotifers were investigated once a week in three dry seasons in 2006-2007. Rotifer was sampled with vertical tows of a mesh plankton net (64μm mesh size) and preserved in 5% sucrose formalin and counted under a binocular microscope. We analyzed the rotifer’s species composition, abundance, biomass and their correlations with ecological factors. Altogether 32 species were identified, the most frequent species were ones from the genera of Brachionus: Brachionus caudatus and Anuraeopsis fissa. Because of the high predation pressure from fishes, the rotifer species in Gancun Reservoir were dominated by the small-sized species with hard armor. In the three dry seasons the rotifer abundance ranged from 170 to 2152ind./L, the difference in abundance was significant in the three dry seasons. The rotifer abundance in the first dry season was much higher than that in the other two seasons, the rotifer abundance in the second dry season was the lowest, because the dry season had just experienced the summer flood period, in which the phytoplankton as food of rotifers was largely reduced, while the fish predation pressure increased. The rotifer biomass ranged from 10.6 to 677.5μg/L, there was no significant difference among the biomasses of the three dry seasons. Cluster analysis of rotifer community structure indicated that rotifer species composition in the two dry seasons before and after the flooding season, were classified into two relatively independent groups, however, the first 8 dominant species of rotifers contributing above 75% of total biomass, which strongly suggestted that the rotifer community structure in the tropical reservoir kept rather stable in the dry seasons.

Abstract:The aquatic macrophytes and water environments in the enclosure aquaculture area and waterway of East Lake Taihu were investigated during 2006 and 2007. The results showed that there were ten species of aquatic macrophytes in the investigated area, among six submerged macrophytes, three emergent plants and one floating plant. The plant species were dominant by Ceratophyllum demersum, Myriophyllum spicatum and Elodea nuttalli in the enclosure aquaculture area, which are pollutant-resistant, regeneration-strong and purification-good macrophytes, while Potamogeton malaianus and Vallisneria spiralis were the dominant species both in the waterway and open water region. Aquatic macrophytes grew vigorously between summer and autumn and the maximum macrophyte biomass was in September when it could reach to 2882.4 ± 748.8g/m². The biomasses of macrophyte in two enclosure aquaculture areas were 1251.2±1012.7g/m² and 993.9±968.6g/m², respectively, which were higher biomass than other water area. The physical factors in water, such as temperature, transparency and pH, had important influences on photosynthesis and seasonal growth of aquatic macrophytes. Through absorption of nitrogen and phosphorus nutrients and inhibition of algae growth by aquatic macrophyte in the water body, the water quality of East Lake Taihu had been improved. The patterns of aquatic macrophyte in the lake could also affect the temporal-spatial difference of water quality.

Abstract:To explore the effects of different types of phosphate on the growth of Microcystis aeruginosa and Chlorella pyrenoidosa, three types of phosphate salts: dipotassium hydrogen phosphate (K₂HPO₄), sodium pyrophosphate(Na₄P₂O₇) and sodium polyphosphate(Na₅P₃O₁₀) were used as phosphate sources in this experiment. The growth curves showed that, at early stage of growth in the K₂HPO₄ medium, the growth rate of C. pyrenoidosa was significantly higher than that of M. aeruginosa, but on the 16th day, the growth rate of M. aeruginosa and its cell density were all higher than those of C. pyrenoidosa. The growth rate of M. aeruginosa and C. pyrenoidosa in K₂HPO₄ medium were significantly higher than those in other two phosphate media. Both in the media of sodium pyrophosphate and sodium polyphosphate, the growth rate of C. pyrenoidosa was higher than that of M. aeruginosa. The changes of unicell alkaline phosphatase (APA) suggestted that, the phosphate utilization of C. pyrenoidosa was higher than that of M. aeruginosa. The results suggestted that the phosphate utilization capability of C. pyrenoidosa was higher than that of M. aeruginosa, indicated that phosphate utilization was not the main cause which resulted in the dominance of M. aeruginosa in water-bloom formation.

Abstract:Ecosystem health was a newly proposed concept in the world with the environment becoming serious issue and on ecosystem health assessment. A method, trophic state-comprehensive index based on researches on the lake ecosystem health had been proposed to evaluate the ecosystem health of Lake West. Firstly, four indices including Chl.a, SD, TP and TN were choosed to calculate the TSI. Secondly, undimensionalizated indices such as physical, chemistry and biology was used to calculate comprehensive index to estimate the ecosystem health state. The results showed that the health state was better in January to March than in July to September, and the trend of ecosystem health is consistent with the level of trophic state. The result reflectted the actual situation of Lake West objectively, so it can provide scientific guidance for Lake West management.

Abstract:Ecological surveys in Tian-e-zhou Oxbow and Laojianghe Oxbow along the middle reaches of Yangtze River were carried out during April 2003 to February 2004. Results indicated that macrozoobenthos communities of oxbows were similar to those of river-isolated lakes in the composition of standing crops, dominated by gastropods and aquatic insects, but were richer in potamophilus and psychrophilic species. Compared with the data of 1990’s, biomass of macrozoobenthos decreased by 48.3%-78.6%, mainly due to the decline of mollusks. The resource deterioration was mainly ascribed to overfishing and river-lake disconnection. Comparison with other types of Yangtze waters indicated that the floodplain waterbodies with an intermediate level of hydrological connectivity have the highest species biodiversities of macrozoobenthos, and have abundant mollusks， especially bivalves. To restore the important function of the oxbows in maintaining biodiversity of the Yangtze floodplain, it is suggested to stock animals rationally and to reconnect with the Yangtze River as frequently as possible.

Abstract:Using the PSR model, this article has build the evaluation index of the ecological security system, applied the entropy method to define the weight of each assessment index, and applied the intimate data method for evaluating ecological security of Fuzhou Shanzi Reservoir. The results showed that the ecological security situations during 2000 to 2003 from superior to inferior states were in the sequences of 2002, 2001, 2000 and 2003 in Shanzi Reservoir, Fujian Province. The model was simple calculation, objective description and comprehensive reflection of the sample position. The index system was more completely reasonable in needs of the reservoir ecological environmental protection objectives.

Abstract:Surface roughness was an important indicator for the formation of surface runoff. This paper takes peat mire of Northeast Jinchuan peat mire as an example, considering impacts of surface slope to measure the roughness index with the chain method in different plant communities. Based on the plant richness, the number of hummock and the coefficient of variation of the hummock forms, we analyzed the mechanism of the changes of surface roughness. The results showed: in three Phragmites australis-Carex schmidtii community, Carex schmidtii community and Betula ovilifolia-Carex schmidtii-Sphagnum palustre community, roughness coefficients changed consistently with changes of species richness and biodiversity of the communities. The changes of the roughness were negatively correlated with number of the hummocks, and positively correlated with coefficient of variation of the hummock forms. It showed that, the smaller the species richness, the larger the ecological dominance;the fewer the dominant plant, the more the number of the hummocks;and the smaller the coefficient of variation of the hummock forms, the more consistence the forming of the micro-geomorphologic relief and the smaller the roughness coefficient. Otherwise, the roughness coefficient became bigger.