Environment
Mohammad Hadi Salehzadeh; Hadi Farhadian; Saeed Yousefi; Mohammad Dehju
Abstract
This study aims to assess the environmental impacts of coal mining in the Eastern Alborz region, focusing on coal mines from 2013 to 2021, using remote sensing techniques. Landsat 8 satellite images were digitized based on key environmental indices, including NDVI, NDWI, NDSI, and NDBI, and subsequent ...
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This study aims to assess the environmental impacts of coal mining in the Eastern Alborz region, focusing on coal mines from 2013 to 2021, using remote sensing techniques. Landsat 8 satellite images were digitized based on key environmental indices, including NDVI, NDWI, NDSI, and NDBI, and subsequent statistical analyses and evaluations were conducted for the study areas. To distinguish the effects of mining from those of climate change, the results were compared with a reference area located within a natural resource block (baseline area), and the outcomes were thoroughly analyzed. The findings indicate that the combined impacts of mining and climate change have caused significant environmental degradation in the region. In particular, vegetation cover has experienced a sharp decline in recent years, while soil erosion has increased at a slower rate. Projections of mining impacts on vegetation and soil were made by calculating the average NDVI and NDSI indices for 2030 and 2050 in the studied areas. These projections suggest that NDVI is expected to decrease by 0.25 by 2030 and by 0.72 by 2050, indicating further vegetation loss in the coming decades. In contrast, analysis of the NDWI index reveals no clear trend in soil moisture changes over the study period. Given the climatic conditions of the selected areas, it is essential to monitor, manage, and mitigate environmental risk factors to prevent the expansion of drought into northern forests, highlighting the need for appropriate intervention measures.
R. Morla; Sh. Karekal; A. Godbole
Abstract
Diesel-operated Load Haul Dumper (LHD) vehicles are commonly used in underground coal mines. Despite their value as utility vehicles, the main drawback of these vehicles is that they generate diesel particulate matter (DPM), a known carcinogenic agent. In this work, an attempt is made to model DPM flows ...
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Diesel-operated Load Haul Dumper (LHD) vehicles are commonly used in underground coal mines. Despite their value as utility vehicles, the main drawback of these vehicles is that they generate diesel particulate matter (DPM), a known carcinogenic agent. In this work, an attempt is made to model DPM flows generated by LHDs in an underground coal mine environment for different DPM flow and intake air flow directions. The field experiments are conducted and used to validate the computational fluid dynamics (CFD) models and used to map the DPM flow patterns. The results obtained show that if DPM and the intake air co-flow (flow in the same direction), DPM is confined predominantly in the middle of the roadway. To the contrary, if the DPM and intake air counter-flow (flow in the opposite directions), the DPM spread occurs throughout the entire cross-section of the roadway. In the latter case, the operator will be more susceptible to exposure to high concentrations of DPM. Overall, the DPM concentration decreases with an increase in the intake air velocities. For co-flow for intake air velocities of 2 m/s, 3 m/s, and 4 m/s, the DPM concentrations at 50 m downstream of the vehicles are 39 µg/m3, 23 µg/m3, and 19 µg/ m3, respectively. The DPM concentration is also influenced by the DPM temperature at the source. For the DPM temperatures of 30 oC, 40 oC, 50 oC, and 60 oC, the DPM concentrations at 50 m downstream of the source are 43 µg/m3, 34 µg/m3, 12 µg/m3, and 9 µg/m3, respectively.
Rock Mechanics
R. Rafiee; A. Azarfar
Abstract
One of the main concerns of an underground coal mining engineer is the safety and stability of the mine. One way that the safety and stability can be ensured is to know and understand the coal mine geology and how it reacts to the mining process. One technique that has shown a lot of success in the coal ...
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One of the main concerns of an underground coal mining engineer is the safety and stability of the mine. One way that the safety and stability can be ensured is to know and understand the coal mine geology and how it reacts to the mining process. One technique that has shown a lot of success in the coal mining industry for geologic technical evaluation purposes is the coal mine roof rating (CMRR). The CMRR classification is based on geotechnical data taken from the immediate roof layers within the mine. Since the uncertainty exists in geotechnical data, and CMRR process depends on the expert’s idea implicitly, the final value may be inaccurate. In this paper, the fuzzy type 2 is used to overcome this uncertainty. To design the fuzzy system for calculating the CMRR, only quantitative variables (UCS, spacing, and persistence) are considered as fuzzy inputs. Finally, the scores of CMRR and FCMRR for four units of Riccall mine are compared.
