重庆大学虎溪校区人工湖水体工程设计

重庆大学虎溪校区人工湖是一座中型规模的景观水体，通过对水体水量来源与损耗进行分析计算，确定人工湖水量保持方案为：以净化后的降雨径流作为人工湖补给水源、以达标的虎溪河水作为备用水源、以自来水作为应急水源。人工湖水质保持采用外源控制与内源控制相结合、点源控制与面源控制相结合、生态措施和工程措施与管理措施相结合的综合性方案。其设计经验在类似人工水体水量及水质保持系统的建设中具有推广价值。     

Modeling fecal coliform bacteria—II. Model development and application

The episodic nature of their origin and the transience of the receiving water response make the modeling of fecal coliform bacteria contamination events particularly challenging. A two-layer mass balance model was developed to simulate spatial and temporal variability in fecal coliform bacteria concentrations in a polluted, urban lake. Independently validated submodels were used to estimate bacteria loads from tributary and point source discharges, to quantify mass transport and to determine losses due to sedimentation and death. The overall model was validated by successfully simulating spatial and temporal dynamics for dry weather conditions and two wet weather events. Sensitivity analyses indicate that the likelihood of violating public health standards is influenced by environmental conditions, e.g. light intensity and wind mixing. Model simulations are used to illustrate the impact of water quality management actions on bacteria levels at various locations in the lake. The general approach presented here and the techniques used to quantify model inputs may be of value in application to other systems.     

Nowcast modeling of Escherichia coli concentrations at multiple urban beaches of southern Lake Michigan

Predictive modeling for Escherichia coli concentrations at effluent-dominated beaches may be a favorable alternative to current, routinely criticized monitoring standards. The ability to model numerous beaches simultaneously and provide real-time data decreases cost and effort associated with beach monitoring. In 2004, five Lake Michigan beaches and the nearby Little Calumet River outfall were monitored for E. coli 7 days a week; on nine occasions, samples were analyzed for coliphage to indicate a sewage source. Ambient lake, river, and weather conditions were measured or obtained from independent monitoring sources. Positive tests for coliphage analysis indicated sewage was present in the river and on bathing beaches following heavy rainfall. Models were developed separately for days with prevailing onshore and offshore winds due to the strong influence of wind direction in determining the river's impact on the beaches. Using regression modeling, it was determined that during onshore winds, E. coli could be adequately predicted using wave height, lake chlorophyll and turbidity, and river turbidity (R2 = 0.635, N = 94); model performance decreased for offshore winds using wave height, wave period, and precipitation (R2 = 0.320, N = 124). Variation was better explained at individual beaches. Overall, the models only failed to predict E. coli levels above the EPA closure limit (235 CFU/100 ml) on five of eleven occasions, indicating that the model is a more reliable alternative to the monitoring approach employed at most recreational beaches.     

Potential biogeochemical and ecological development of a flooded tailings impoundment at the Kristineberg Zn-Cu mine, northern Sweden

The potential short-term (10(2) years) biogeochemical and ecological effects of diverting stream water (pH 4.9-6.7) into a limed, flooded tailings impoundment (pH 8-12) were studied by combining geochemical and biological data. In the long-term perspective, the successional development of lakes was used as a natural analogue. Based on the vertical distribution of temperature and total dissolved solids (TDS < 0.22 microm), the impoundment can be characterised as a continuous/discontinuous cold polymictic lake, with holomictic summer circulation. A re-inoculation study indicated that the growth of autotrophic, aerobic bacteria (presumably Acidithiobacillus ferrooxidans) presently is inhibited by the high pH in the impoundment. In a short-term perspective, termination of liming and diversion of stream water into the impoundment will result in a complex interplay between physical, biogeochemical and ecological effects. A reduced vertical mixing of the approximately 2-m-deep water column, dissolution of calcite and gypsum (compounds of a sludge formed in the impoundment) and an enhanced microbiological activity are major expected effects. The dissolution of calcite may act as a pH buffer and result in metal remobilisation from the sludge. Excluding autochthonous organic matter produced in the impoundment, streamwater input of suspended matter and formation of settling flocculants are expected to result in a sediment accumulation rate of approximately 1.5 mg cm(-2) year(-1) (1.6-3.3 cm/10(2) years). Settling allochthonous organic C (0.15-0.30 mg C cm(-2) year(-1)) may serve as an oxygen barrier and as a reservoir of organic compounds capable of driving redox reactions. In a long-term perspective, a hydroseral development into a wetland/peatland can be expected, with a bog lake, poor fen or flat bog as final stage. This development presupposes a decreasing pH when liming is terminated and stream water is diverted into the impoundment. It also assumes that the impoundment will be similar to an acidified lake, and that the succession is driven by Sphagnum colonizing the impoundment. If the hydrological conditions/water level is affected (e.g., by climatic changes or a dam failure), a terrestrialization culminating in coniferous forest on peat soil may occur.     

A Water-Resources and Water-Quality Management Plan for the City of Tallinn, Estonia

The increasingly common occurrence of eutrophic conditions in shallow lakes and reservoirs, including the presence of potentially toxic blue-green algae, has given rise to water-quality concerns throughout the world. The need to undertake active catchment management to improve raw-water quality is a key component of the new EC Water Framework Directive.
This paper describes the investigations which were undertaken in Tallinn (the capital of Estonia, the northernmost of the Baltic States) to develop an integrated approach to catchment and lake management, in order to improve the quality of the surface-water resource which provides 90% of the total drinking-water needs of the city. Several tools, including 'geographical information systems'and spreadsheet-based financial and water-resources models, were developed to investigate the source of the water-quality problems. Practical solutions comprising an innovative and cost-effective catchment-management approach to overcome the seasonal raw-water quality issues, whilst also reducing treatment plant operating costs, are described. Some of the recommendations have been tested by Tallinn Water following the investigations, and some improvements in raw and treated water quality have been attained.     

Examining the link between terrestrial and aquatic phosphorus speciation in a subtropical catchment: the role of selective erosion and transport of fine sediments during storm events

This study examined the link between terrestrial and aquatic phosphorus (P) speciation in the soils and sediments of a subtropical catchment. Specifically, the study aimed to identify the relative importance of P speciation in source soils, erosion and transport processes upstream, and aquatic transformation processes as determinants of P speciation in lake sediments (Lake Wivenhoe). Using a sequential extraction technique, NH₄Cl extractable P (NH₄Cl-P; exchangeable P), bicarbonate-dithionite extractable P (BD-P; reductant soluble P), NaOH extractable P (NaOH-rP; Al/Fe oxide P), HCl extractable P (HCl-P; apatite-P), and residual-P (Res-P; organic and residual inorganic P) fractions were compared in different soil/sediment compartments of the upper Brisbane River (UBR) catchment, Queensland, Australia. Multidimensional scaling identified two distinct groups of samples, one consisting of lake sediments and suspended sediments, and another consisting of riverbed sediments and soils. The riverbed sediments and soils had significantly higher HCl-P and lower NaOH-rP and Res-P relative to the lake and suspended sediments (P < 0.05). Analysis of the enrichment factors (EFs) of soils and riverbed sediments showed that fine grained particles (<63 μm) were enriched in all but the HCl-P fraction. This indicated that as finer particles are eroded from the soil surface and transported downstream there is a preferential export of non-apatite P (NaOH-rP, NaOH-nrP, BD-P and Res-P). Therefore, due to the preferential erosion and transport of fine sediments, the lake sediments contained a higher proportion of more labile forms of inorganic-P relative to the broader soil/sediment system. Our results suggest that a greater focus on the effect of selective erosion and transport on sediment P speciation in lakes and reservoirs is needed to better target management strategies aimed at reducing P availability, particularly in P-limited water bodies impacted by soil erosion.     

Model-based predictive control of office window shades

In the automation of interior window shading devices, a control system that relies on a prediction of environmental conditions and a building's thermal response can provide savings to space-conditioning loads beyond what can be achieved using a reactive approach. The development of these control strategies can be difficult because of the uniqueness of each building. A simplified model-based predictive control (MPC) method for window shades is proposed. To this end, a control-oriented model representing the heat transfer problem in a perimeter office space was developed. The parameters of the model were estimated using the ensemble Kalman filter (EnKF). The energy-savings potential of the EnKF-based MPC approach for window shades was investigated using EnergyPlus simulations. This was accomplished by implementing the control-oriented model into the energy management system application of EnergyPlus. Simulations were conducted to assess the energy saving potential of using the EnKF-based MPC for roller blinds in a south-facing perimeter office space in Ottawa, Canada. The simulation-based results indicate the potential for about 35% reduction in electricity usage for space conditioning over manually operated interior roller blinds.     

Control-oriented model of a solar community with seasonal thermal energy storage: development,calibration and validation

The development of a control-oriented model of a solar community with seasonal storage (the Drake Landing Solar Community) is investigated. The proposed approach, intended to facilitate the development and testing of control strategies and targeting an actual predictive control implementation, is based on grey-box models, and enables the prediction of the system state (temperatures at key locations). This paper discusses the concept of state update procedure (whereby the system state is periodically corrected with measurements), which plays a fundamental role for control purposes. Firstly, the DLSC is presented and both operation and monitoring system are described. Secondly, a simplified model is developed for each sub-system: district and solar loops, short-term (water tanks) and seasonal (borehole) thermal energy storage, and existing operation rules are encoded. Finally, the model is calibrated and validated by using measurements at 10-min intervals over two years of operation (2015–2016, 2016–2017) and accurately predicts the system performance.     

Modeling and problem solving of building defects using point clouds and enhanced case-based reasoning

Many factors, including improper maintenance and material aging, may lead to the occurrence of defects during the operation of the various functions of buildings. Building defect information is normally stored in a discrete and unstructured way, and for this reason, building a case-based reasoning framework regarding building defects to enhance the level of building maintenance management has become an important field in the related research. At present, there is limited research available on the integration of geometric data models that are built by means of scanning and multi-attribute selection strategies. This study proposes an integrated information management framework for superficial defects in buildings, which is compatible with a point clouds model as a central data source. It features the attributes of defects used in multi-criteria decision analysis. A CBR (case-based reasoning) approach that considers case-based distance is used to enhance the performance of similarity calculations and case retrieval. A case-based distance model is utilized for the data processing stage and concentrates on a smaller case set that contains best alternatives. The potential benefit offered by this approach is that more efficient results can be obtained from classified cases during the retrieval phase process. A comparison of a CBR query with ungrouped sample data is performed to establish patterns to verify the effectiveness of the calculation method of determining case similarity, which is supported by the pre-processing of classified information about the building defects. The analytical results show that the proposed method performs well in solving the multi-attribute classification of building defects and avoiding ambiguous answers retrieved from unrelated subsets. This approach might be capable of investigating the practical problems involved in building maintenance in the AEC domains.     

福州市琴亭人工湖水量及水质保持设计

琴亭湖是一座集防洪滞洪和城市景观公园功能的综合工程,通过对水体水量来源与损耗进行分析计算,确定人工湖以文山里引水工程的水为补给水源。人工湖水质保持采用外源污染控制与引水活水工程的综合性方案。其设计经验在类似工程水量及水质保持系统的建设中具有参考价值。     

Achievable working range for solid all-desiccant air-conditioning systems under specific space comfort requirements

Solid desiccant air-conditioning systems present a promising solution, in terms of performance level and environmental protection, pointing out their potential to be coupled with thermal solar or waste heat energy source. Nevertheless, these systems are characterized by constraints to the load they can satisfy, through the trade-off between the dehumidification cooling capacity and the latent load of the conditioned space. On that level, one has to note that, for steady environmental conditions, the conditioned space does not present unique value of load, but range of load, corresponding to an array of acceptable temperature and (usually relative) humidity values. In this work a methodology is proposed for the definition of the system's achievable working range under specific set of space (comfort) requirements. Through this approach, the systems present greater potential for covering the space requirements, thus presenting more possibilities on a design basis, and more flexible control strategies, as well. The proposed methodology is presented and discussed through the case study of a solar desiccant air-conditioning system coupled to a typical residential building.     

Dynamic and real-time simulation of BMS and air-conditioning system as a ‘living’ environment for learning/training

Dynamic and real-time simulation models are developed to simulate the thermal, hydraulic, mechanical, environmental and energy performance of building a variable air volume (VAV) air-conditioning system and its building management system (BMS). On-line direct digital control (DDC) and supervisory strategies of the BMS controlling the dynamic air-conditioning system are simulated. A window-based users interface is developed to simulate the man–machine interface of a BMS, through which users can monitor the on-line operation, tune the local control loops, and reset the supervisory control strategies. This paper presents models, simulation software, and examples that users practice on the simulated on-line BMS and air-conditioning system using the software.     

Combined approach of poroelastic and earthquake nucleation applied to the reservoir-induced seismic activity in the Val d'Agri area,Italy

In this work,an approach is developed to study the seismicity associated with the impoundment and level changes of a water reservoir(reservoir induced seismicity-RIS).The proposed methodology features a combination of a semi-analytical poroelastic model with an earthquake nucleation approach based on rate-and-state frictional law.The combined approach was applied to the case of the Pertusillo Lake,located in the Val d'Agri area(Italy),whose large seasonal water level changes are believed to induce protracted micro-seismicity(local magnitude M_L 3).Results show that the lake impoundment in 1962 could have produced up to 0.5 bar(1 bar=100 kPa) changes in Coulomb failure stress(△CFS),while the seasonal water level variation is responsible for variation up to 0.05 bar.Modeling results of the seismicity rates in 2001-2014 show that the observed earthquakes are well correlated with the modeled△CFS.Finally,the reason that the seismicity is only observed at southwest of the Pertusillo Lake is provided,which is likely attributed to different rock lithologies and depletion caused by significant hydrocarbon exploitation in the northeastern sector of the lake.     

Heavy metals in Lake Balaton: water column, suspended matter, sediment and biota

During the period 1999-2002, five sampling cruises have been carried out on Lake Balaton to assess trace metal distribution in the lake and to identify major sources. Eighteen elements, including Cr, Co, Ni, Cu, Zn, Cd, Pb (trace metals) and Al, Ba, Ca, Fe, K, Mg, Mn, Na, P, S, Sr (major metals), were determined in one or more of the lake's compartments. Lower trace metal concentrations in rainwater were observed in June and February 2000, while much higher levels were present in September 2001 (during a storm event) and in snow (February 2000). In the Northern and Western parts of the lake, especially at the inflow of river Zala and the locations of the yacht harbours, metal concentrations were higher in almost all compartments. Because the lake is very shallow, storm conditions also change significantly the metal distributions in the dissolved and particulate phases. The Kis-Balaton protection system located on Zala river functions very efficiently for retaining suspended particulate matter (SPM; 72% retention) and associated metals. Metal concentrations in surface sediments of the lake showed a high variability. After normalisation for the fine sediment fraction, only a few stations including Zala mouth appeared to be enriched in trace metals. In zooplankton, Zn seemed to be much more elevated compared to the other trace metals. Based on the molar ratios of the trace metals in the various compartments and input flows of the lake, several trends could be deduced. For example, molar ratios of the trace metals in the dissolved and solid (suspended particulate matter and sediments) phases in the lake are fairly similar to those in Zala River.     

A method for the reduction of lake model prediction error

Recent work on methods of error analysis to accompany the application of lake models has not enjoyed great acceptance in part because of the magnitude of the error term. For the models that have undergone a rigorous error analysis (generally the single equation cross-sectional regression models), prediction errors for various water quality variables are often ± 30% or more. A procedure is proposed herein for the reduction of the error associated with the prediction of lake phosphorus concentration from land use and hydrologic data. Existing lake quality data are used in the prediction, and the model is employed only to project changes from the present state. This obviates the need to project all land use impacts with the model: only those proposed to change are projected. The result is a substantial reduction in prediction error for many planning scenarios.     

夏热冬暖地区湖水源热泵系统方案的可行性研究

以某五星级酒店项目为例,介绍了该工程湖水源热泵的技术方案,分别从初投资、运行费用两个方面分析证明了采用湖水源热泵系统的可行性。分析认为：虽然湖水源热泵系统相对于传统空调系统初投资比较大,但是运行费用低,可在半年内回收增加的成本,并且可以减少大气污染物的排放;随着耗电费费率的提高及运行时间的增长,湖水源热泵系统的经济效益更加可观。因此,在夏热冬暖地区可以推广湖水源热泵系统的应用。     

The Interior Northwest Landscape Analysis System: A step toward understanding integrated landscape analysis

The Interior Northwest Landscape Analysis System (INLAS) project demonstrated a method for assembling teams of scientists to conduct integrated landscape analyses at the mid- or subbasin scale in the interior Northwestern United States. A state and transition modeling system (STM) with transition probabilities calibrated by using a stand-level silvicultural model to estimate rates of vegetative change was used as a central vegetative “modeling engine.” It connected to a variety of resource-related models including: wildlife habitat quantity, insect activity, grazing by ungulates, timber management, and wood utilization potential. Where appropriate, the study team examined other vegetation modeling approaches including an optimization approach based on heuristic methods and modifications to an existing stand-level projection tool, which was integrated with existing fire and insect behavior models. The STM approach provided a relatively simple interface for most resource models. These were connected to examine the influence of vegetative succession, natural disturbances, and management over a 100–200-year horizon under three management scenarios: (1) background natural disturbance, (2) fire suppression only, and (3) active fuel management. Taken all together, the results suggest to us: (1) maintaining abundant large-tree multistoried structure in cool, moist forest conditions is likely to be difficult, (2) both active fuel treatment and passive management scenarios increased the proportion of large-tree single-story forests in dry forest conditions, and (3) fire suppression only was least effective in producing and maintaining these “legacy” structures in either dry or moist forest conditions.     

Modeling and optimization of HVAC systems using artificial neural network and genetic algorithm

Intelligent energy management and control system (EMCS) in buildings offers an excellent means of reducing energy consumptions in HVAC systems while maintaining or improving indoor environmental conditions. This can be achieved through the use of computational intelligence and optimization. The paper thus proposes and evaluates a model-based optimization process for HVAC systems using evolutionary algorithm for optimization and artificial neural networks for modeling. The process can be integrated into the EMCS to perform several intelligent functions and achieve optimal whole-system performance. The proposed models and the optimization process are tested using data collected from an existing HVAC system. The testing results show that the models can capture very well the system performance, and the optimization process can reduce cooling energy consumption by about 11% when compared to the traditional operating strategies applied.     

A suite of multi-segment fugacity models describing the fate of organic contaminants in aquatic systems: application to the Rihand Reservoir,India

The fugacity-based quantitative water-air-sediment interaction (QWASI) model is described which can be used to establish a mass balance for an organic or metallic contaminant in a lake ecosystem consisting of water, suspended matter, bottom sediments and the atmosphere. A suite of such models is described and discussed with various degrees of complexity including versions treating equilibrium and non-equilibrium situations, steady-state and dynamic conditions with either single or multiple segments. It is suggested that when seeking to apply a mass balance model to a specific lake and contaminant situation, it is desirable to start with a simple model and increase the complexity as circumstances dictate. This approach is illustrated by application of QWASI models to the Rihand Reservoir in India for lindane and benzo(a)pyrene. The roles are discussed by which such models can contribute to improved management of chemicals that may adversely affect aquatic systems, especially in developing regions.     

Relationship between apparent optical properties and photosynthetic pigments in the sub-alpine Lake Iseo

The aim of the present study was the evaluation of methods for estimating the content of bio-physical parameters in lake water on the basis of spectral reflectance measured above water surface, in particular the estimation of chlorophyll-a (chl-a) concentrations. Data sets considered refer to some sampling point located in the sub-alpine meso-eutrophic Lake Iseo, surveyed six times over the period March-July and once in November 1998, as these months were very important for the characterization of the springtime algal bloom, which affect the lake waters yearly. At each point station, limnological observations (chlorophyll, total suspended solids, Secchi disk depth) were conducted simultaneously with optical measurements. The latter consisted of water leaving radiance measured by means of a spectroradiometer above the water surface; moreover, a standard reflector radiance was also measured to obtain the water reflectance. Reflectance spectra were transformed according to two well-documented models and correlated to water quality parameters, to investigate their performances as retrieval algorithms under different conditions and referring to different analytical methods. Results outline the sensitivity of the models to chl-a concentrations, different phytoplankton composition, and the sampling depth.