Simulation of Leachate Generation from a Waste Rock Dump in Kiruna Using HYDRUS-1D
The percolation of water through waste rock dumps at mine sites can lead to the production of a leachate with high concentrations of dissolved metals, sulfate and nitrogen compounds. It is important to understand how water flows in waste rock dumps in order to predict the environmental impact of thi...
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Uppsala universitet, Institutionen för geovetenskaper
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ftuppsalauniv:oai:DiVA.org:uu-379225 2023-05-15T17:04:10+02:00 Simulation of Leachate Generation from a Waste Rock Dump in Kiruna Using HYDRUS-1D Simulering av lakvattenbildning från gråbergsdeponier i Kiruna med HYDRUS-1D Atmosudirdjo, Aryani 2019 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-379225 eng eng Uppsala universitet, Institutionen för geovetenskaper Examensarbete vid Institutionen för geovetenskaper, 1650-6553 1650-6553 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-379225 info:eu-repo/semantics/openAccess Hydrus-1D matrix flow leachate unsaturated flow waste rock dump Oceanography Hydrology and Water Resources Oceanografi hydrologi och vattenresurser Student thesis info:eu-repo/semantics/bachelorThesis text 2019 ftuppsalauniv 2023-02-23T21:49:28Z The percolation of water through waste rock dumps at mine sites can lead to the production of a leachate with high concentrations of dissolved metals, sulfate and nitrogen compounds. It is important to understand how water flows in waste rock dumps in order to predict the environmental impact of this leachate on recipients. The dynamics of percolation and leachate discharge are controlled by climatological conditions at the site, where relatively large flows in northern Sweden correspond to snowmelt during late Spring. Rock dumps are often tens of meters in height, resulting in an unsaturated water flow system through heterogeneous material. Hence, the simulation of leachate generation requires an accurate representation of the subsurface materials as well as the flow processes, where water flow in waste rock dumps is dominated by matrix flow with macropore flow being of secondary importance. Matrix flow is rather slow and may thus potentially yield relatively high concentrations of contaminants in the leachate, in response to precipitation and snow melt. This study uses Hydrus-1D to predict leachate generation from a small-scale waste rock dump in Kiruna in terms of discharge magnitude and timing. The 3-dimensional geometry of the waste rock dump is approximated by summing simulations from 1225 one-dimensional columns of different length, with a surface area of 1 m2 each. There are four output parameters that are compared between the model results and measured data: snow accumulation, water content, temperature, and discharge. There are some discrepancies between the model results and field measurements, most likely due to uncertainties in the input parameters (especially waste rock properties), limitations in the Hydrus-1D model (i.e. freeze-thaw dynamics), and assumptions that are used in constructing the conceptual model. For better agreement between model results and measured data, a new modelling approach is recommended, potentially using a different program than Hydrus-1D. Bachelor Thesis Kiruna Northern Sweden Uppsala University: Publications (DiVA) Kiruna |
institution |
Open Polar |
collection |
Uppsala University: Publications (DiVA) |
op_collection_id |
ftuppsalauniv |
language |
English |
topic |
Hydrus-1D matrix flow leachate unsaturated flow waste rock dump Oceanography Hydrology and Water Resources Oceanografi hydrologi och vattenresurser |
spellingShingle |
Hydrus-1D matrix flow leachate unsaturated flow waste rock dump Oceanography Hydrology and Water Resources Oceanografi hydrologi och vattenresurser Atmosudirdjo, Aryani Simulation of Leachate Generation from a Waste Rock Dump in Kiruna Using HYDRUS-1D |
topic_facet |
Hydrus-1D matrix flow leachate unsaturated flow waste rock dump Oceanography Hydrology and Water Resources Oceanografi hydrologi och vattenresurser |
description |
The percolation of water through waste rock dumps at mine sites can lead to the production of a leachate with high concentrations of dissolved metals, sulfate and nitrogen compounds. It is important to understand how water flows in waste rock dumps in order to predict the environmental impact of this leachate on recipients. The dynamics of percolation and leachate discharge are controlled by climatological conditions at the site, where relatively large flows in northern Sweden correspond to snowmelt during late Spring. Rock dumps are often tens of meters in height, resulting in an unsaturated water flow system through heterogeneous material. Hence, the simulation of leachate generation requires an accurate representation of the subsurface materials as well as the flow processes, where water flow in waste rock dumps is dominated by matrix flow with macropore flow being of secondary importance. Matrix flow is rather slow and may thus potentially yield relatively high concentrations of contaminants in the leachate, in response to precipitation and snow melt. This study uses Hydrus-1D to predict leachate generation from a small-scale waste rock dump in Kiruna in terms of discharge magnitude and timing. The 3-dimensional geometry of the waste rock dump is approximated by summing simulations from 1225 one-dimensional columns of different length, with a surface area of 1 m2 each. There are four output parameters that are compared between the model results and measured data: snow accumulation, water content, temperature, and discharge. There are some discrepancies between the model results and field measurements, most likely due to uncertainties in the input parameters (especially waste rock properties), limitations in the Hydrus-1D model (i.e. freeze-thaw dynamics), and assumptions that are used in constructing the conceptual model. For better agreement between model results and measured data, a new modelling approach is recommended, potentially using a different program than Hydrus-1D. |
format |
Bachelor Thesis |
author |
Atmosudirdjo, Aryani |
author_facet |
Atmosudirdjo, Aryani |
author_sort |
Atmosudirdjo, Aryani |
title |
Simulation of Leachate Generation from a Waste Rock Dump in Kiruna Using HYDRUS-1D |
title_short |
Simulation of Leachate Generation from a Waste Rock Dump in Kiruna Using HYDRUS-1D |
title_full |
Simulation of Leachate Generation from a Waste Rock Dump in Kiruna Using HYDRUS-1D |
title_fullStr |
Simulation of Leachate Generation from a Waste Rock Dump in Kiruna Using HYDRUS-1D |
title_full_unstemmed |
Simulation of Leachate Generation from a Waste Rock Dump in Kiruna Using HYDRUS-1D |
title_sort |
simulation of leachate generation from a waste rock dump in kiruna using hydrus-1d |
publisher |
Uppsala universitet, Institutionen för geovetenskaper |
publishDate |
2019 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-379225 |
geographic |
Kiruna |
geographic_facet |
Kiruna |
genre |
Kiruna Northern Sweden |
genre_facet |
Kiruna Northern Sweden |
op_relation |
Examensarbete vid Institutionen för geovetenskaper, 1650-6553 1650-6553 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-379225 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766058215097761792 |