scholarly journals 3D Numerical Modelling of Tailings Dam Breach Run Out Flow over Complex Terrain: A Multidisciplinary Procedure

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2538
Author(s):  
Kun Wang ◽  
Peng Yang ◽  
Guangming Yu ◽  
Chao Yang ◽  
Liyi Zhu
Keyword(s):  
Complex Terrain ◽  
Overland Flow ◽  
Safety Management ◽  
Mining Industry ◽  
Small Scale ◽  
Tailings Dam ◽  
Dam Breach ◽  
Mining Sites ◽  
Response Planning ◽  
3D Numerical Modelling

Tailings dams, as essential mining structures, are being built globally for containing the chief waste stream of the mining industry. Catastrophic tailings dam breaches have occurred frequently over the past decade, causing severe impacts on the environment, economy, and human health. The foreknowledge of the tailings dam breach overland flow is crucial for the risk assessment and emergency response planning in order to prevent or minimize possible losses. Using unmanned aerial vehicles (UAV) photogrammetry and smoothed particle hydrodynamics (SPH) numerical method, this study proposed a multidisciplinary procedure for modelling a hypothetical tailings dam breach run out flow over the downstream complex terrain. A case study on a 97-m-height tailings dam in Shandong Province of China was carried out. The proposed procedure was proven applicable to determine the overland tailings flow. The submerged area and flow velocities suggested that the downstream G2 highway would hardly be threatened and more concerns should be paid on the factory plants and workers deployed between the dam toe and the highway. Additionally, the application of UAV photogrammetry in the mining industry as a supplementary surveying method can be further expanded, especially for the numerous small-scale mining sites. The proposed procedure is then recommended for the safety management of the tailings’ storage facilities globally.

scholarly journals SPH modelling of dam breach run out flow for a site planning tailings storage facility

2021 ◽  
Vol 303 ◽  
pp. 01051
Author(s):  
Kun Wang ◽  
Xiaofei Jing ◽  
Fan Feng ◽  
Guangming Yu
Keyword(s):  
Overland Flow ◽  
Safety Management ◽  
Mining Industry ◽  
Guizhou Province ◽  
Community Safety ◽  
Surface Model ◽  
Particle Hydrodynamics ◽  
Site Planning ◽  
Maximum Impact Force ◽  
A Site

Tailings storage facilities (TSFs) are being built globally for containing the chief solid waste stream from mining industry. Catastrophic TSF breach accidents have occurred frequently since the beginning of the 21st century, causing severe impacts on the environment, economy and community safety. The recent example is the 2019 Brumadinho accident in Brazil that released 12 million m3 of tailings and killed more than 249 people. The foreknowledge of the TSF breach run out overland flow can be crucial to prevent or minimize possible losses. Using the Digital Surface Model (DSM) terrain data and the smoothed particle hydrodynamics (SPH) numerical method, this study proposed a procedure to predict the routings of hypothetical TSF breach run out flow over downstream complex terrain. A case study of a planning TSF site in Guizhou Province of China was carried out to evaluate its applicability. The results suggested that the maximum routing distance of the TSF breach run out flow was 1.45 km. At 240 s, the run out flow began to impact the downstream viaduct piers with the maximum submerged depth of 3.3 m and the maximum impact force of 21.8 kPa. Essential protective measures were recommended before the TSF site construction. The proposed procedure is then recommended for the safety management of the TSFs globally.

scholarly journals Sensitivity and Performance Analyses of the Distributed Hydrology–Soil–Vegetation Model Using Geomorphons for Landform Mapping

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2032
Author(s):  
Pâmela A. Melo ◽  
Lívia A. Alvarenga ◽  
Javier Tomasella ◽  
Carlos R. Mello ◽  
Minella A. Martins ◽  
...  
Keyword(s):  
Complex Terrain ◽  
Overland Flow ◽  
Hydrological Model ◽  
Model Performance ◽  
Soil Parameters ◽  
Vegetation Model ◽  
Landform Classification ◽  
Physically Based ◽  
And Performance ◽  
Streamflow Simulation

Landform classification is important for representing soil physical properties varying continuously across the landscape and for understanding many hydrological processes in watersheds. Considering it, this study aims to use a geomorphology map (Geomorphons) as an input to a physically based hydrological model (Distributed Hydrology Soil Vegetation Model (DHSVM)) in a mountainous headwater watershed. A sensitivity analysis of five soil parameters was evaluated for streamflow simulation in each Geomorphons feature. As infiltration and saturation excess overland flow are important mechanisms for streamflow generation in complex terrain watersheds, the model’s input soil parameters were most sensitive in the “slope”, “hollow”, and “valley” features. Thus, the simulated streamflow was compared with observed data for calibration and validation. The model performance was satisfactory and equivalent to previous simulations in the same watershed using pedological survey and moisture zone maps. Therefore, the results from this study indicate that a geomorphologically based map is applicable and representative for spatially distributing hydrological parameters in the DHSVM.

scholarly journals Work-Related Accident Prevention in Norwegian Road and Maritime Transport: Examining the Influence of Different Sector Rules

2021 ◽  
Vol 6 (5) ◽  
pp. 72
Author(s):  
Tor-Olav Nævestad ◽  
Beate Elvebakk ◽  
Karen Ranestad
Keyword(s):  
Safety Management ◽  
Qualitative Interviews ◽  
Road Transport ◽  
Accident Prevention ◽  
Small Scale ◽  
Maritime Transport ◽  
The Road ◽  
Work Related ◽  
Safety Regulations ◽  
Framework Conditions

About 36% of fatal road accidents in Norway involve at least one driver who is “at work”. It has been argued that the implementation of rules clearly defining the responsibility of road transport companies to prevent work related accidents, by implementing safety management systems (SMS), could lead to increased safety. In the present study we tested the validity of this suggestion, by examining the influence of different sector rules on work-related accident prevention in Norwegian road and maritime transport. In contrast to the road sector, the maritime sector has had rules requiring SMS for over 20 years, clearly defining the shipping companies responsibility for prevention of work-related accidents. The aims of the study were to: (1) examine how the different sector rules influence perceptions of whether the responsibility to prevent work-related accidents is clearly defined in each sector; and (2) compare respondents’ perceptions of the quality of their sectors’ efforts to prevent work-related accidents, and factors influencing this. The study was based on a small-scale survey (N = 112) and qualitative interviews with sector experts (N = 17) from companies, authorities, and NGOs in the road and the maritime sectors. Results indicate that respondents in the maritime sector perceive the responsibility to prevent work-related accidents as far more clearly defined, and they rate their sector’s efforts to prevent accidents as higher than respondents in road. Multivariate analyses indicate that this is related to the scope of safety regulations in the sectors studied, controlled for several important framework conditions. Based on the results, we conclude that the implementation of SMS rules focused on transport companies’ responsibility to prevent work-related accidents could improve safety in the road sector. However, due to barriers to SMS implementation in the road sector, we suggest starting with a simplified version of SMS.

Evaluation of Surface Analyses and Forecasts with a Multiscale Ensemble Kalman Filter in Regions of Complex Terrain

2011 ◽  
Vol 139 (6) ◽  
pp. 2008-2024 ◽  
Author(s):  
Brian C. Ancell ◽  
Clifford F. Mass ◽  
Gregory J. Hakim
Keyword(s):  
Kalman Filter ◽  
High Resolution ◽  
Data Assimilation ◽  
Ensemble Kalman Filter ◽  
Complex Terrain ◽  
Error Variance ◽  
Small Scale ◽  
Observation Error ◽  
Grid Spacing ◽  
Background Error

Abstract Previous research suggests that an ensemble Kalman filter (EnKF) data assimilation and modeling system can produce accurate atmospheric analyses and forecasts at 30–50-km grid spacing. This study examines the ability of a mesoscale EnKF system using multiscale (36/12 km) Weather Research and Forecasting (WRF) model simulations to produce high-resolution, accurate, regional surface analyses, and 6-h forecasts. This study takes place over the complex terrain of the Pacific Northwest, where the small-scale features of the near-surface flow field make the region particularly attractive for testing an EnKF and its flow-dependent background error covariances. A variety of EnKF experiments are performed over a 5-week period to test the impact of decreasing the grid spacing from 36 to 12 km and to evaluate new approaches for dealing with representativeness error, lack of surface background variance, and low-level bias. All verification in this study is performed with independent, unassimilated observations. Significant surface analysis and 6-h forecast improvements are found when EnKF grid spacing is reduced from 36 to 12 km. Forecast improvements appear to be a consequence of increased resolution during model integration, whereas analysis improvements also benefit from high-resolution ensemble covariances during data assimilation. On the 12-km domain, additional analysis improvements are found by reducing observation error variance in order to address representativeness error. Removing model surface biases prior to assimilation significantly enhances the analysis. Inflating surface wind and temperature background error variance has large impacts on analyses, but only produces small improvements in analysis RMS errors. Both surface and upper-air 6-h forecasts are nearly unchanged in the 12-km experiments. Last, 12-km WRF EnKF surface analyses and 6-h forecasts are shown to generally outperform those of the Global Forecast System (GFS), North American Model (NAM), and the Rapid Update Cycle (RUC) by about 10%–30%, although these improvements do not extend above the surface. Based on these results, future improvements in multiscale EnKF are suggested.

CDA technical bulletin on tailings dam breach analyses

2019 ◽  
pp. 3484-3498
Author(s):  
V. Martin ◽  
M. Al-Mamun ◽  
A. Small
Keyword(s):  
Tailings Dam ◽  
Dam Breach

scholarly journals Assessment of the Challenges in Policy Implementation in the Small Scale Gold Mining Sector in Ghana – A Case Study

2017 ◽  
Vol 17 (1) ◽  
pp. 54-63 ◽  
Author(s):  
P. Arroja Eshun ◽  
E. Okyere
Keyword(s):  
Policy Implementation ◽  
Gold Mining ◽  
Small Scale ◽  
Mining District ◽  
Test Case ◽  
Mining Sector ◽  
Social Challenges ◽  
Mining Sites ◽  
Adequate Knowledge ◽  
Acquisition Processes

In recent times, stakeholders in the mining sector have expressed concerns about the environmental degradation and the social impacts of uncontrolled Small Scale Mining (SSM) activities in Ghana despite the existence of legislative instruments that define the procedures required for the acquisition of licences and operations of SSM activities in the country. This paper assesses the challenges in policy implementation in the small scale gold mining sector of Ghana by reviewing policies on regularisation and environmental management. It further identifies challenges faced by small scale mining operators in adhering to laid down policies for the smooth operation of the sector and furthermore assesses the views of some principal stakeholders on the benefits and challenges of small scale mining using the Dunkwa mining district as a test case. The methods employed include: field visits to some  small scale mining sites within the Dunkwa mining district; interviews and questionnaire administration; and statistical and content analysis of data. The study reveals the following factors, among others, to have contributed largely to the difficulty in regularisation, environmental and social challenges that have plagued the SSM sector: low level of education of majority of miners; bureaucracies and centralisation of licence acquisition processes; lack of sources of finance for SSM projects; lack of geological information on mineable areas; and lack of adequate knowledge of the laws and regulations on mining and environment. In addressing the challenges the following recommendations are made: decentralisation of the regularisation processes to simplify licence acquisition; adequate geological investigations should be undertaken on SSM blocked-out areas to reduce the try and error mining approach adopted by miners; and continuous education and training of miners on good mining and environmental practices. Keywords: Small Scale Mining, Mineral Policies, Environmental Impact, Regularisation, Challenges

scholarly journals Heavy Metals in the Soils of Placer Small-Scale Gold Mining Sites in Myanmar

2020 ◽  
Vol 10 (27) ◽  
pp. 200911
Author(s):  
Aung Zaw Tun ◽  
Pokkate Wongsasuluk ◽  
Wattasit Siriwong
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Gold Mining ◽  
Soil Samples ◽  
Small Scale ◽  
Mining Activities ◽  
Mining Operations ◽  
Metal Concentrations ◽  
Mining Sites ◽  
Heavy Metal Concentrations

Background. Artisanal and small-scale mining activities are widely practiced globally. Concentrations of heavy metals associated with gold, such as copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb) can increase in the environment as a result of mining activities, leading to environmental pollution and pose toxicity risks to humans and animals. Objectives. The aim of the present study was to investigate soil concentrations of toxic heavy metals in placer small-scale gold mining operations in Myanmar. Methods. Soil samples were collected from three placer small-scale gold mining sites: Site A located in the Hmawbon public protected forest, Site B and Site C, situated in the Nant-Kyin reserved forest around Nar Nant Htun village. At each site, soil samples were collected from four gold mining stages (ore processing, sluicing, panning, and amalgamation). Atomic absorption spectroscopy was utilized to examine the concentrations of As, Cd, Pb, and Hg. Results. The highest heavy metal concentrations were generally found in the amalgamation stages across all the gold mining sites. Across the three mining sites, the maximum heavy metal concentrations in the amalgamation stage were 22.170 mg.kg−1 for As, 3.070 mg.kg−1 for Cd, 77.440 mg.kg−1 for Hg, and 210.000 mg.kg−1 for Pb. Conclusions. The present study examined the concentrations of As, Cd, Hg and Pb in the soil of several small-scale gold mining sites in Banmauk Township, Myanmar. The results demonstrated the presence of high concentrations of heavy metals in the soil of the gold mining sites. Miners in this area work without proper personal protective equipment, and frequent exposure to heavy metals in the soil may cause adverse health effects. The present study provides baseline data for future risk assessment studies of heavy metal contamination in gold mines. Competing Interests. The authors declare no competing financial interests

Erosion and sediment transport models with reference to the needs of small scale

2021 ◽  
Author(s):  
Ahsan Raza ◽  
Thomas Gaiser ◽  
Muhammad Habib-Ur-Rahman ◽  
Hella Ahrends
Keyword(s):  
Soil Erosion ◽  
Overland Flow ◽  
Model Development ◽  
Agroforestry Systems ◽  
Specific Model ◽  
Small Scale ◽  
Field Scale ◽  
Erosion Prediction ◽  
Dynamic Components ◽  
Output Information

<p>Information on field scale soil erosion and related sedimentation process is very important for natural resource management and sustainable farming. Plenty of models are available for study of these processes but only a few are suitable for dynamic small scale soil erosion assessments. The available models vary greatly in terms of their input requirements, analysis capabilities, process [t1] complexities, spatial and temporal scale of their intended use, practicality, the manner they represent the processes, and the type of output information they provide. The study aims in examining, theoretically, 51 models classified as physical, conceptual, and empirical based on their representation of the processes of soil erosion. The literature review shows that there is no specific model available for soil erosion prediction under agroforestry systems.   It is further suggested that models like EPIC, PERFECT, GUEST, EPM, TCRP, SLEMSA, APSIM, RillGrow, and CREAMS can be potentially used for soil erosion assessment at plot/field scale at daily time steps. Most of these models are capable to simulate the soil erosion process at small scale; further model development is needed regarding their limitations with respect to components interaction i.e., rainfall intensity, overland flow, crop cover, and their difficulties in upscaling. The research suggested that SIMPLACE network can provide modules with LintulBiomass, HillFlow, Runoff to develop new dynamic components to simulate overland flow and soil erosion incorporating improved upscaling capabilities</p>

scholarly journals Large-Eddy Simulations of Real-World Episodes in Complex Terrain Based on ERA-Reanalysis and Validated by Ground-Based Remote Sensing Data

2019 ◽  
Vol 147 (12) ◽  
pp. 4325-4343 ◽  
Author(s):  
Cornelius Hald ◽  
Matthias Zeeman ◽  
Patrick Laux ◽  
Matthias Mauder ◽  
Harald Kunstmann
Keyword(s):  
Remote Sensing ◽  
Boundary Conditions ◽  
Complex Terrain ◽  
Computing Time ◽  
Remote Sensing Data ◽  
Large Eddy Simulations ◽  
Small Scale ◽  
Sensing Data ◽  
Large Eddy ◽  
Local Weather

Abstract A computationally efficient and inexpensive approach for using the capabilities of large-eddy simulations (LES) to model small-scale local weather phenomena is presented. The setup uses the LES capabilities of the Weather Research and Forecasting Model (WRF-LES) on a single domain that is directly driven by reanalysis data as boundary conditions. The simulated area is an example for complex terrain, and the employed parameterizations are chosen in a way to represent realistic conditions during two 48-h periods while still keeping the required computing time around 105 CPU hours. We show by evaluating turbulence characteristics that the model results conform to results from typical LES. A comparison with ground-based remote sensing data from a triple Doppler-lidar setup, employed during the “ScaleX” campaigns, shows the grade of adherence of the results to the measured local weather conditions. The representation of mesoscale phenomena, including nocturnal low-level jets, strongly depends on the temporal and spatial resolution of the meteorological boundary conditions used to drive the model. Small-scale meteorological features that are induced by the terrain, such as katabatic flows, are present in the simulated output as well as in the measured data. This result shows that the four-dimensional output of WRF-LES simulations for a real area and real episode can be technically realized, allowing a more comprehensive and detailed view of the micrometeorological conditions than can be achieved with measurements alone.

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