Environmental Engineering

Several bridge crossings proposed for the Red River Floodway expansion project were recently constructed using vertical sand drains to accelerate excess pore-water pressure dissipation and settlement caused by embankment fill loading. With limited local data regarding the performance of sand drains, the calibrated model presented here addresses the need to optimize the design of sand drain configurations, maximize cost savings, and minimize construction delays for future structures. This study presents a coupled finite element embankment consolidation model calibrated against measured pore-water pressure and settlement data from the Salter Street Bridge embankment fill construction, which used vertical sand drains to dissipate excess pore-water pressures. A hydraulic conductivity modification procedure was used to simulate the axisymmetric flow conditions with a plane-strain model neglecting well resistance but incorporating the effects of a smear zone. A sensitivity analysis was pe...

In 1999, after a period of extensive rainfall, two shallow slope failures developed in the right-of-way of Provincial Road 259 near Virden, Manitoba. The rainfall caused dissipation of soil suction in the near-surface soil, thereby reducing shear resistance and triggering failure. A research project was initiated between the Geotechnical Group at the University of Manitoba and the Manitoba Department of Highways and Transportation to assess the mechanism of failure. The project included a field investigation program, laboratory testing program, and advanced numerical modeling to identify the cause of failure. The results demonstrate that the rainfall resulted in dissipation of the suction in the soil slope, resulting in a reduction in the soil shear strength that triggered shallow failures. The dissipation of the soil suction has been modeled using a time-dependent seepage model that accounts for the flux boundary condition that existed at the ground surface.Key words: slope stabili...

In this study the wastes both solid and liquid from the various stage in the production of wet blue from wet salted goatskin were observed. Then the various types of parameter related to the environmental pollution during this production was determined. The parameters are pH, color, odour, solid wastes, total solids, suspended solids, dissolved solids, total acidity, free mineral acidity, strong alkali, total Kjeldahl nitrogen, sulphates, sulphides, chlorides, chromium, basicity, BOD, COD etc. In case of pH of soaking effluent is closer to the standard value but during liming and pickling or chrome tanning they exceed the limit. More interestingly, bad odour and colour to the receiving effluents are the common pollution. Surprisingly, suspended solid in soak liquor is much higher than that of other liquors. Additionally, the BOD and COD values of different effluents are extremely higher than tolerable limit causing a great threat to our environment. The results show that every param...

The study purpose to know the physical, chemical and environmental parameter of glue manufacture in Bangladesh The existing management system of tannery solid wastes and its consequences were investigated through field survey with structured and unstructured questionnaire; the tannery workers, technologists, officials were interviewed during 2009-2011. The maximum amount of solid wastes generated was measured in the peak season (October-December) in the year 2011 through developed formula and found 443 metric ton solid wastes were generated in a day from tannery at Hazaribagh, Dhaka. It was also observed that 90% of the trimmers, (tannery workers) were directly affected by those solid wastes, the surrounding environment became polluted and soil of dumping ground was contaminated with organic carbon (7.97% ±0.170), organic matter (13.70% ±0.292), TKN (1.54% ±0.137), Chloride (0.247% ±0.0284) and Chromium (2.28 ±0.0291). Keyword: Physical, Chemical, Environmental, Glue manufacture, Ba...

The continuous expansion of the Water Distribution Network (WDN) makes its design a dynamic process performed within many planning horizons. An appropriate planning horizon is important to save costs and avoid over-design. Typically, a master plan is practiced around every 20 years. The complexity of WDN and computational demands have prevented a full network study of the impact of planning horizons on system cost and efficiency. In this paper, a dynamic network model was employed to simulate the growth of WDN under different growth patterns (exponential and linear) and planning horizons to explore the optimum planning horizon under different interest rates. It is found that the choice of the optimum (i.e. least costly) planning horizon is sensitive to the interest rate. For both growth patterns, a shorter planning horizon is favored with higher annual interest rates while a longer planning horizon is favored with lower rates. With the same interest rate, exponential growth pattern ...

ABSTRACTThis article presents a climatology of total cloud cover (TCC) in the area of the three inland Eurasian seas (Black, Caspian, and Aral Sea). Analyses are performed on the basis of 20 years of data (1991–2010), collected from almost 200 ground stations. Average TCC is 49%, with broad spatial and seasonal variability: minimum TCC values are found in summer and to the southeast, whereas maximum values correspond to winter and to the northwest. For the whole area, linear trend analyses show that TCC did not vary during the study period. We only detected a statistically significant positive trend (+1.2% decade−1) in autumn. We obtained different results for the regions delimited by means of a principal component analysis: a clear decrease, both for the annual, spring, and summer series, was detected for the south of Black Sea, while increasing TCC was found for the annual, autumn, and winter series in the north Caucasus and the west and north of Black Sea. We also analysed the TC...

Aquifers are porous media with various physical criteria and hydraulic conditions that largely affect the quality of water they contain. When an aquifer is a sedimentary rock, its depositional environment draws along with its present recharge condition and the footprint of its groundwater quality. The geologic setting of Iraq consists of a sedimentary cover 4 – 13 km thick with a sequence of alternating pervious and impervious sedimentary rock beds of coarse clastics and fractured carbonates with fine clastics and hard rock carbonate. This succession has developed a successive multi aquifer systems. The present study has recognized the major formations that so far have been explored and sampled using available data to identify the probability of their water quality which might be obtained when drilling a well through any of the formations. From among tens of thousands of wells drilled to produce water from whatever horizons they encounter, only those wells which penetrate a single f...

A fully coupled atmospheric‐biospheric regional climate model, GEMRAMS, was used to evaluate potential effects of land‐use/land‐cover changes (LULCC) on near‐surface atmosphere over a southern South American domain at seasonal time scales. In GEMRAMS, leaf area index and canopy conductance are computed based on modelled temperature, solar radiation, and the water status of the soil and air, allowing a two‐way interaction between canopy and atmosphere. Several austral spring‐early summer simulations were conducted using land cover representing current (i.e. agricultural landscape), natural (i.e. before European settlement), and afforestation scenarios for three periods associated with El Niño‐Southern Oscillation (ENSO) conditions. The shift to agriculture resulted in a generalized increase in albedo, reducing the available energy at the near‐surface. (Correction added on 21 September 2011 after original online publication: in the preceding sentence the word ‘decrease’ was corrected ...

ABSTRACTLand cover changes (LCCs) play an important role in the climate system. Research over recent decades highlights the impacts of these changes on atmospheric temperature, humidity, cloud cover, circulation, and precipitation. These impacts range from the local‐ and regional‐scale to sub‐continental and global‐scale. It has been found that the impacts of regional‐scale LCC in one area may also be manifested in other parts of the world as a climatic teleconnection. In light of these findings, this article provides an overview and synthesis of some of the most notable types of LCC and their impacts on climate. These LCC types include agriculture, deforestation and afforestation, desertification, and urbanization. In addition, this article provides a discussion on challenges to, and future research directions in, assessing the climatic impacts of LCC.