Advanced Materials Research Vols. 610-613

Abstract: Water resources in Qujing urban areas mainly come from the meteoric water．Its natural recharge capacity is limited and the surface drainages have been severely polluted．In general, the amount of the water resources can satisfy the needs of the social development, but its water quality becomes worse and the vulnerability of water supply-security is high．Considering the factors of groundwater recharge capacity, protective layer, water quality, groundwater vulnerability, environmental engineering geologic problems and others, it is concluded that karst groundwater in the eastern margin of Qujing basin is a good water source for emergency. The water-rich blocks such as Jiancaoba and Yuezhou with pressure resistance, rich groundwater recharge capacity, large depth, low groundwater vulnerability, class two water quality, convenience of mining conditions, and not easy to lead to collapse environment engineering geological problems, may become the emergency-type groundwater source fields．

Abstract: It has been accepted that the rainfall and the reservoir water level fluctuation plays an important role in the stability of the reservoir bankside. However, at present, there has not been suitable simplification method for the project application to calculate and appraise. Therefore, based on the Boussinesq’s differential equation of unsteady-seepage and boundary condition, and Laplace’s transform, the curvilinear equation of phreatic line in landslide mass is deduced under the rainfall and the reservoir water level fluctuation conditions, and a simplified formula which can be used in the project is gained by the polynomial fitting. Meanwhile, it holds together the transmission coefficient method to write programs about the bankside stability analysis in the paper. With the Er-Liban landslide of the three Gorges Reservoir area for the computation model, this paper use the program to analyze the change rule and stability of the phreatic line under the reservoir water level fluctuation and rainfall condition.

Abstract: Water resources carrying capacity (WRCC) is very significant to the sustainable developing of society and ecosystem. The main goal of this paper was to predict WRCC of river basins in Fujian province, using index-set method, to provide a adjuvant reference for the planning department while making decisions. Under the guidance of DPSIR framework, 20 indices in total were selected, which can reflect the inherent attributes of WRCC. PP Clustering (PPC) model coupled with generic algorithm was applied to compute WRCC ranking. This model can automatically identify the contribution of every factor to the evaluating objective, as to avoid the subjectivity during the process of index weights. The predictive result shows WRCC of the southeastern area of Fujian is in relative better state of water resources utilization. Special attention needs to be paid to optimum allocation for water resources in the upper reaches area of Minjiang River basin and northeastern area.

Abstract: The evaluation index system of water resources sustainable utilization was constructed according to the actual situation of water resources development and utilization in Huaibei City, using the matter element analysis method, analyzed water resources sustainable utilization. The results showed that water resources sustainable utilization status were significantly different in different areas of Huaibei City. The potential of water resources development and utilization was great in Suixi County. The water resources developments of Duji District and Lieshan District have a considerable scale, but there were still some potential for the development and utilization. The degree of water resources utilization was large and water resources carrying capacity was saturated in Xiangshan District. The evaluation result showed that using the matter element analysis method in comprehensive evaluation of water resources development and utilization was feasible.

Abstract: In order to investigate to quantify losses by Alpine vegetation in Qinghai-Tibet Plateau, typical Swamp meadow and Alpine meadow were investigated in the growth period. The intercepting rainfall of Swamp meadow and Alpine meadow were studied by using water balance method and ANOVA statistical analysis method. The experimental results indicate that: under different coverage of Swamp meadow and Alpine meadow, rainfall interception in the growing period (June-September) both show an increasing trend. And, both the maximum rainfall interception and maximum interception rate emerge in September under different vegetation cover of Swamp meadow and Alpine meadow. However, With vegetation degeneration, interception quantity and interception rate of Swamp meadows and Alpine meadows both show decreasd trends. Interception amount and interception rate show decreased tend along with the degradation of Swamp meadow and Alpine meadow, which indicate that the degradation of meadow is unfavorable for Swamp meadow and Alpine meadow to prevent the rain landing the earth directly.

Abstract: Emergent macrophytes growth and development are believed to play an important role in nutrients physical transport processes and biogeochemical cycles. In the present study, a high-resolution in-situ sampling technology (Porewater equilibrators, Peepers) was employed to obtain vertical porewater PO₄^3- profiles from the vegetated and the non-vegetated sediments, and accurately quantify benthic flux across sediment-water interface by Fick's first law applying porewater profiles of peepers, and coupled with core sediments incubation experiments as comparison. In addition, to distinguish benthic organism contribution to measured apparent benthic flux, we used HgCl₂ (0.5% by weight) to suppress bottom fauna activity during the experiment. The results showed that porewater PO₄^3- concentrations were far lower in vegetated than in the non-vegetated sediments, and also significantly lower in overlying water than in porewater. Whereas, porewater PO₄^3- distribution fluctuated sharply at the upper sediments and kept an approximative constant below 8cm depth. Additionally, the average molecular diffusion flux applying Fick's first law fluctuated slightly within the range of 0.004 to 0.018 mg m^-2 d^-1(i.e., PO₄^3- from porewater diffused into overlying water), which was higher in typha latifolia site, but lower in zizania latifolia site. PO₄^3- average apparent diffusion flux based on core sediments incubation experiments varied between 1.03 and 6.78 mg m^-2 d^-1, and an opposite pattern was observed with respect to emergent macrophyte effects, as the PO₄^3- flux at phragmites australis site was low (only 19% of control), but reached as high as 126% of the control in typha latifolia site. In unsterilized treatments (i.e., benthic organism participation), PO₄^3- average net fluxes were lower up to an order of magnitude and more variable compared with those in sterilized treatments. Our results highlighted emergent macrophytes (e.g., phragmites australis) in estuary wetlands could efficiently relieved release risk from sediments, and reduce dissolved reactive phosphorus diffusion physical barrier crossed sediment-water interface by adding porosity in surface sediment.

Abstract: The structure of groundwater flow system is the core of study of groundwater system and the base of evaluation of groundwater resources. The control role of aquifer system to groundwater flow system is a key of study of the structure of groundwater flow system. The groundwater systems of the Ordos basin are analyzed as a case study. The control role of aquifer system to groundwater flow system is studied by comparison of groundwater flow systems under the control of different aquifer structures in 2-D profile numerical model. The research shows that the groundwater flow systems of the Ordos basin have the multilayer structure characteristics. The groundwater flow systems in the north of the Ordos basin show a cross-formational multi-hierarchy nested flow pattern in the northern aquifer systems without regional impermeable layer where the hydraulic connection between aquifer layers is closely. While, the hydraulic connection is discontinuous in the southern aquifer systems because there are regional impermeable layers in the aquifer systems. The groundwater flow systems in the south of the Ordos basin show a follow-formational flow pattern.

Abstract: The spatial distribution, enrichment, and accumulation of zinc (Zn) in the surface sediments of Jen-Gen River estuary, Taiwan, were studied. Results show that samples collected from 11 stations near the estuary of Jen-Gen River contain 221–627 mg/kg of Zn with average of 502±114 mg/kg. The spatial distribution of Zn reveals is relatively high in the river mouth region, and gradually diminishes toward the harbor region. This indicates that upstream industrial and municipal wastewater discharges along the river bank are major sources of pollution. Enrichment factor analysis indicates that the sediments of Jen-Gen River estuary were severe enrichment with Zn. Geo-accumulation index analysis indicates that the sediments of Jen-Gen River estuary were moderately strong accumulated with Zn. Base on the comparison with sediment quality guidelines (SQGs), the concentrations of Zn in the sediments of Jen-Gen River estuary may cause acute biological damage.

Abstract: A 2D current model about Changjiang River Estuary was set up with Delft3D-FLOW in this research, which was well calibrated and verified with the observed tidal levels and velocities, the computed results of water level and flow velocity magnitude agree well with the measured data. The model has been applied to calculate the flow velocities and the split ebb flow ratio of the North Branch with the diversion angle of 30o and 60o respectively. The computed results show that the smaller the diversion angle of North Branch is, the larger the flow velocities and the split ebb flow ratio will be. Therefore, the diversion angle plays a positive role to the dynamics improvement in the North Branch.

Abstract: Water resources carrying capacity was evaluated by using fuzzy comprehensive evaluation method after the evaluation index system was constructed according to water resources condition, socio-economic development level and economic structure characteristics in Heifei City. The results showed that development and utilization degree of water resources was high and further development and utilization potential was small. The water resources development potential of city proper was the minimum in all regions and WRCC of it was saturated. The development and utilization degree of water resources in Feixi County was smaller than other districts, there were certain development potential. On this basis, some suggestions and measures were proposed for improve regional water resources carrying capacity and ensure regional sustainable development.