A Numerical Approach to Predict Water Levels in Ungauged Regions—Case Study of the Meghna River Estuary, Bangladesh

Iron-related clogging of boreholes, pumps and dripper lines is a significant and costly problem for irrigators worldwide. The primary cause of iron-related clogging is still debated. Previous studies have described complex interactions between biological clogging and inorganic iron/manganese oxide precipitation. This case study examined groundwater bores used for viticulture irrigation in the Limestone Coast region, a highly productive wine growing area in the SE of South Australia. Iron clogging of bore screens, pumps and dripper systems has been a persistent problem in the region and the issue is perceived to be growing, with irrigators suggesting the widespread introduction of iron-related bacteria (IRB) through drilling equipment to be the root cause of the problem. Analysis of the groundwater microbiology and inorganic chemistry found no apparent correlation between the presence of IRB and the clogging status of wells. In fact, IRB proved to be widespread throughout the limestone aquifer. However, a clear correlation could be found between clogging affected bores and the redox potential of the groundwater with the most severely affected bores strongly oversaturated in respect to iron oxide minerals. Elevated dissolved concentrations of Fe(II) thereby tended to be found in deeper bores, which also were generally more recently drilled. Following decades of less than average rainfall, a tendency to deepen bores in response to widespread declines in water levels has been documented for the SE of South Australia. The gradually widening clogging problem in the region is postulated to be related to the changes in climate in the region, with irrigators increasingly driven to rely on deeper, anoxic iron-rich groundwater resources.

Download Full-text

Rainfall Threshold for Flash Flood Warning Based on Model Output of Soil Moisture: Case Study Wernersbach, Germany

Water ◽

10.3390/w13081061 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1061

Author(s):

Thanh Thi Luong ◽

Judith Pöschmann ◽

Rico Kronenberg ◽

Christian Bernhofer

Keyword(s):

Soil Moisture ◽

Flash Flood ◽

Rainfall Threshold ◽

Probability Of Detection ◽

Water Levels ◽

Critical Success ◽

Flood Warning ◽

Critical Discharge ◽

Critical Success Index

Convective rainfall can cause dangerous flash floods within less than six hours. Thus, simple approaches are required for issuing quick warnings. The flash flood guidance (FFG) approach pre-calculates rainfall levels (thresholds) potentially causing critical water levels for a specific catchment. Afterwards, only rainfall and soil moisture information are required to issue warnings. This study applied the principle of FFG to the Wernersbach Catchment (Germany) with excellent data coverage using the BROOK90 water budget model. The rainfall thresholds were determined for durations of 1 to 24 h, by running BROOK90 in “inverse” mode, identifying rainfall values for each duration that led to exceedance of critical discharge (fixed value). After calibrating the model based on its runoff, we ran it in hourly mode with four precipitation types and various levels of initial soil moisture for the period 1996–2010. The rainfall threshold curves showed a very high probability of detection (POD) of 91% for the 40 extracted flash flood events in the study period, however, the false alarm rate (FAR) of 56% and the critical success index (CSI) of 42% should be improved in further studies. The proposed adjusted FFG approach has the potential to provide reliable support in flash flood forecasting.

Download Full-text

Milling Curves Influence in Ring Rolling Processes

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.622-623.956 ◽

2014 ◽

Vol 622-623 ◽

pp. 956-963 ◽

Cited By ~ 4

Author(s):

Luca Giorleo ◽

Elisabetta Ceretti ◽

Claudio Giardini

Keyword(s):

Numerical Approach ◽

The Other ◽

Ring Rolling ◽

Roll Speed ◽

Forming Process ◽

Industrial Case Study ◽

Industrial Environment ◽

Ring Shape ◽

Deformation Processes

Ring Rolling is a complex hot forming process used for the production of shaped rings, seamless and axis symmetrical workpieces. The main advantage of workpieces produced by ring rolling, compared to other technological processes, is given by the size and orientation of grains, especially on the worked surface which give to the final product excellent mechanical properties. In this process different rolls (Idle, Axial, Guide and Driver) are involved in generating the desired ring shape. Since each roll is characterized by a speed law that can be set independently by the speed law imposed to the other rolls, an optimization is more critical compared with other deformation processes. Usually, in industrial environment, a milling curve is introduced in order to correlate the Idle and Axial roll displacement, however it must be underlined that different milling curves lead to different loads and energy for ring realization. In this work an industrial case study was modeled by a numerical approach: different milling curves characterized by different Idle and Axial roll speed laws (linearly decreasing, constant, linearly increasing) were designed and simulated. The results were compared in order to identify the best milling curve that guarantees a good quality ring (higher diameter, lower fishtail) with lower loads and energy required for manufacturing.

Download Full-text

Impacts, Perceptions, and Management of Shoreline Hazards and Water Levels on a Fluctuating Reservoir: A Case Study of the Winnebago System, Wisconsin

Lake and Reservoir Management ◽

10.1080/07438140409354244 ◽

2004 ◽

Vol 20 (3) ◽

pp. 197-210 ◽

Cited By ~ 3

Author(s):

Anthony O. Gabriel

Keyword(s):

Water Levels

Download Full-text

Chloride contamination in construction aggregates due to periodic saline water intrusion: a case study in the Kaluganga River Estuary, Sri Lanka

Environmental Earth Sciences ◽

10.1007/s12665-012-2077-1 ◽

2012 ◽

Vol 69 (8) ◽

pp. 2529-2540 ◽

Cited By ~ 3

Author(s):

N. P. Ratnayake ◽

K. B. A. Silva ◽

I. G. I. K. Kumara

Keyword(s):

Sri Lanka ◽

Saline Water ◽

River Estuary ◽

Saline Water Intrusion ◽

Water Intrusion

Download Full-text

Optimal Design Strategy of a Solar Reflector Combining Photovoltaic Panels to Improve Electricity Output: A Case Study in Calgary, Canada

Sustainability ◽

10.3390/su13116115 ◽

2021 ◽

Vol 13 (11) ◽

pp. 6115

Author(s):

Moon Keun Kim ◽

Khalid Osman Abdulkadir ◽

Jiying Liu ◽

Joon-Ho Choi ◽

Huiqing Wen

Keyword(s):

Solar Radiation ◽

Electricity Generation ◽

Low Cost ◽

Design Strategy ◽

Numerical Approach ◽

Optimal Shape ◽

Energy Technology ◽

Experimental Database ◽

Pv Panel

This study explores the combination of photovoltaic (PV) panels with a reflector mounted on a building to improve electricity generation. Globally, PV panels have been widely used as a renewable energy technology. In order to obtain more solar irradiance and improve electricity output, this study presents an advanced strategy of a reflector combining PV panels mounted on a building in Calgary, Canada. Based on an experimental database of solar irradiances, the simulation presents an optimal shape designed and tilt angles of the reflector and consequently improves solar radiation gain and electricity outputs. Polished aluminum is selected as the reflector material, and the shape and angle are designed to minimize the interruption of direct solar radiation. The numerical approach demonstrates the improvement in performance using a PV panel tilted at 30°, 45°, 60°, and 75° and a reflector, tilted at 15.5° or allowed to be tilted flexibly. A reflector tilted at 15.5° can improve solar radiation gains, of the panel, by nearly 5.5–9.2% at lower tilt angles and 14.1–21.1% at higher tilt angles. Furthermore, the flexibly adjusted reflector can improve solar radiation gains on the PV panel, by nearly 12–15.6% at lower tilt angles and 20–26.5% at higher tilt angles. A reflector tilted at 15.5° improves the panel’s output electricity on average by 4–8% with the PV panel tilted at 30° and 45° respectively and 12–19 % with the PV panel tilted at 60° and 75°, annually. Moreover, a reflector that can be flexibly tilted improves electricity output on average by 9–12% with the PV panel tilted at 30° and 45° and 17–23% with the PV panel tilted at 60° and 75°. Therefore, the utilization of a reflector improves the performance of the PV panel while incurring a relatively low cost.

Download Full-text

COMPUTATION OF KARL PEARSON'S COEFFICIENT OF SKEWNESS AND BOWLEY'S COEFFICIENT OF SKEWNESS BETWEEN RAINFALLAND GROUND WATER LEVELS - A CASE STUDY

10.36106/ijsr/3734167 ◽

2021 ◽

pp. 13-14

Author(s):

Raju Sake

Keyword(s):

Ground Water ◽

Water Levels ◽

Coefficient Of Skewness

Present paper deals with the Computation of Karl Pearson's Coefcient of Skewness (SK ) and Bowley's Coefcient of Skewness (SK ) to analyze P B Rainfall (RF) and Ground Water Levels (GWLs) in Anantapuramu district based on the data collected from January 2007 to December 2016. For the purpose of analysis the district is divided into ve Zones or Revenue Divisions (RD) namely, 1. Anantapuramu RD 2. Penukonda RD 3. Kadiri RD 4. Kalyandurg RD 5. Dharmavaram RD. I have calculated for the Karl Pearson's Coefcient of Skewness (SK ) and Bowley's Coefcient of P Skewness (SK ) between Rainfall and Ground Water Levels and compared among them by using the data.

Download Full-text