Advanced Materials Research Vols. 610-613

Abstract: Annual rainfall values in Fortaleza in Brazil from 1849 to 1979 are modeled with extreme values theory. Generalized Extreme Value (GEV) distribution with and without trend are estimated by using maximum likelihood method for these rainfall values. Moreover, return levels, which is inferred from estimation result of GEV, associated with various return periods are analyzed.

Abstract: At the end of 2010, almost all reservoirs in Taiwan have sedimentation problem. Sedimentation in major reservoirs, such as Wushoh reservoir, had reached 63.73% of its storage capacity in 2009, and must undergo dredging. However, agencies responsible for the final processing stages of reservoir sediments failed to come up with a breakthrough. Limitations established by environmental protection laws also hindered proper dredging of the reservoirs. Hence, further investigation was required for solidifying and reusing reservoir sediments. This research focused on the reuse of Wushoh reservoir sediments. Experimental results showed that when bacteria Bacillus Pastuerii(B.P.) was utilized in sediment solidification, higher bacterial concentrations could induce higher sedimentation of calcium carbonate. In a 70% Urea-CaCl2 medium, a bacterial concentration of 100% resulted in the highest compressive strength that was 30% higher than the control group (bacterial concentration of 0%). Therefore, bacteria can be used to solidify sediments and improve compressive strength. In specimens treated with higher concentrations of bacteria, more square and polygonal crystals were observed via SEM. X-ray powder diffractometer (XRD) analysis showed that bacteria-treated sediments contained calcium carbonate crystals in every stage of processing. Hence, it was shown that bacteria can promote solidification by inducing calcium carbonate sedimentation.

Abstract: The amounts of phosphorus fractions in the sediments of Meiliang Bay were examined using the SMT sequential method. Results indicated that the TP concentration in surface sediment averaged 594.90 mg/kg (284.06-945.14 mg/kg) and mainly composed of IP (60%-80%). Pollution was more serious near the four inflow rivers. Phosphorus fractions in the core sediment showed a decreasing trend. Correlation analyses showed that NaOH-P was the main factor controlling TP.

Abstract: Shortage of water resources has become bottleneck which constrains China economic and social sustainable development. With urbanization development, urban population growths and urban-economic-activities increase, shortage of urban water resources has become severer. This paper analyzes urbanization development influences on water resources qualitatively and quantitatively, water resources’ restrictions on regional urban development taking Beijing as an example, and proposes countermeasures and suggestions to build management mechanism of water resources.

Abstract: Vegetation influences the runoff through affecting rainfall interception, soil water infiltration capacity and surface evaporation and other factors etc. In this paper, remote sensing data is used to analyze the major vegetation types of Poyang Lake Basin, and then a hydrological model (VIC model) is employed to simulate and compare runoff under different vegetation type scenarios. The simulation results show that the presence of vegetation will reduce the runoff and rate of decrease varies according to vegetation type: runoff reduction reaches the maximum when the vegetation type were mixed forest, followed by evergreen coniferous forest follows, and reaches the lowest when the evergreen broad-leaved forest predominates.

Abstract: This Study Takes Bengbu Segment as an Example, Analyzes the Aquatic Organisms Evolution, Rainfall Process, Runoff Process, Water Quality, and Points Out their Interrelations and Interaction Process. the Reduction of Aquatic Organism Is Mainly Affected by Channel Morphology, Runoff Cyclical, Water Quality, and their Ecosystem Structure at the same Time. Aquatic Organisms Evolution Has the same Trend as the Cyclical Variations of Rainfall and Runoff.

Abstract: A drastic change of hydrological characteristics of a deforested basin causes severe runoff, sediment yield, and environmental contamination. In these days, many forest suffered from more frequent wildfires than before due to the climate change and human activities in Korea. A bared soil surface caused by wildfires results higher peak discharge and serious erosion over the basin. Ultimately, the increased sediment erosion results the nonpoint source contamination of water and soils of the basin. Systematic researches on sediment yields had been carried out with a mountainous watershed which had been suffered from wildfires. The experimental watershed has being operated with six standard plots and one sedimentation chamber last four years. The cover management factor of RUSLE and the characteristics of SDR (Sediment Delivery Ratio) for burned mountain basin were suggested from the field investigation.

Abstract: There are lots of natural attenuation functions and one of the most important is volatilization. The test was carried out to study the influence of the thickness of unstructured zone. The results indicated that, BTEX compounds are easy to volatile when the thickness of unstructured zone is thin and the zone entirely belongs to capillary zone but contrary to it when the thickness of unstructured zone is bigger than capillary zone.

Abstract: This paper puts forward and studies the concept, features as well as regulation process of real-time dispatch of basin water resources. The real-time regulation of basin water resources features temporal regulation system of multiple time-step nesting, dynamic balance regulation system of self-adapting demand-supply, dynamic information-based feedback regulation system, and three-element regulation system in combination of reservoir dispatch, river reach water distribution and flow forecast control. With example of lower Yellow River reaches below Xiaolangdi, a real-time regulation model of water resources in river basin with multiple time-step nesting and scrolling-amendment has been developed. The developed model has been put into actual practice and resulted in the safety of water supply and avoid of dry-up in consecutive low flow yeas of Yellow River Basin.

Abstract: A method for analyzing high fluoride groundwater in chemical ground was developed in this paper. The types of the fluoride's environmental areas in groundwater were divided into 5 types. Based on the analysis, two treatment methods for high fluoride area of groundwater, i.e., sources control and change the chemical field, were developed.