Results

WP1 – Climate review and projections

Tasks within this work-package have been aimed at reviewing and recording previous extreme weather events in the mining industry and reviewing historic climate trends in mining regions around Europe and calculating projections of future climate changes for European mining regions for different emission scenarios. All planned works were finished.

Short summary of main results from specific tasks are described below:

Task 1.1 – Identification and analysis of climatic conditions affecting the mining industry

Significant climate-related events, mainly in Europe were identified and documented, with the focus on project partners countries (Greece, Czechia, Poland, Germany, Spain and United Kingdom) that impacted mining activity and contributed lessons from each country represented in the project. The principal cause for mining-affecting incidents was extreme precipitation – specifically extreme rainfall or snowfall. Furthermore, a database of these events was created and maintained throughout the Project.

Short summary of deliverable D1.1. Report on analysis of most important climatic conditions including past extreme weather events affecting the mining industry is available here

The updated database of mining incidents related to extreme weather event can be downloaded here

Task 1.2 – Establishment of baseline climatic conditions in European mining regions

A climate baseline was created to describe the regions’ current climate conditions that can serve as a reference baseline to assess climate changes. Partners have collected at minimum temperature and precipitation data from their countries and other crucial factors for local regions.

Short summary of deliverable D1.2 Baseline climate report for regions is available here

Task 1.3 – Development of climate projections for regions

A combination of Global Climate Models (GCMs) and downscaled Regional Climate Models (RCMs) were used by project partners to present data in the form of maps and time plots. The CORDEX (Coordinated Regional climate Downscaling Experiment) project used for the majority of the projections developed in this Task, downscaled GCMs using both statistical techniques and dynamical techniques from several different RCMs. A time of emergence i.e. 2050, chosen by partners for projections, is a date at which a climatic change trend emerges from natural climate variability. The world climate will have fundamentally changed by 2047 if nothing is done to reduce GHG emissions. Similarly, temperature increases in all areas, but precipitation trends vary.

Short summary of deliverable D1.3. Regional climate change projections is available here

WP2 – Climate impact identification

The objectives of this work-package are (1) to identify based on modelled projections, how future climate scenarios could impact on closed, abandoned and operating mines within regions and (2) to identify, quantify and evaluate those impacts brought about by changes in precipitation, temperature and sudden changes in atmospheric pressure. A methodical approach was agreed upon and implemented by individual partners.

Following tasks have been carried out within WP2:

Task 2.1 – Identification of physical and chemical impacts due to changes in precipitation

Based on the climate projections, works in Task 2.1. have been focused on the results of changing precipitation, coupled with changes in evaporation – especially how it affects surface run off water & water quality, groundwater recharge, stream flow and changes in composition of mine water. Works in task 2.1 have been divided into three sub-tasks regarding stability issues in both surface features (such as slopes, and tailings dams) as well as old underground workings.

Conclusions so far had identified negative physical impacts caused by changes in precipitation. The physical impacts affecting stability of mine workings and surface structures due to precipitation and floods are mainly related to: overtopping during heavy rainfall events, affecting the stability of the dam; slope stability threatened by fast floodwaters; surface loading caused by extreme flooding over an underground mine; rainstorms and floods cause the phreatic line in the tailings dam to rise which in turn induces seepage damage, producing piping effect by changing the material properties; increased contraction-expansion cycles caused by more extreme wet-dry events.

The physical impacts affecting stability of mine workings and surface structures due to drought which may cause an important indirect impacts. Having a maximum capacity of water stored on site for mining works can increase the risks associated with sudden floods. Correlation between the drought periods and those with higher frequency of sinkhole occurrence. Unstable landforms with insufficient vegetation cover, erosion and mass movement risks occur onsite and sedimentation offsite. Erosion and undermining of the toe of a slope can cause rock falls, landslips or debris flows that can create additional damage.

Short summary of deliverable D2.1. Report on physical and chemical impacts due to changes in precipitation is available here

Task 2.2 – Identification of physical impacts due to changes in temperature

Within this task, following aspects and impacts of change (increase) of temperature are under examination and relate to the effectiveness of rehabilitation of closed and abandoned mines (i),medium/long term changes in biodiversity (ii), potential for vector disease shift (iii), and gas emissions (iv). The impact on efforts to rehabilitated closed and abandoned mines was investigated.

Short summary of deliverable D2.2. Report on physical impacts due to changes in temperature is available here

Task 2.3 – Identification of physical and chemical impacts due to changes in atmospheric pressure

Investigations into the impact of barometric pressure changes have been concerned with the emission of gasses from mines. The work has been carried out in conjunction with the work into the effect of temperature changes on gas emissions. Data from abandoned shafts have been collected on CO₂, and/or CH₄ and O₂ concentrations, and correlated with atmospheric pressure and temperature variations. Local changes in air pressure should be considered as very small differences between very large values. In practice, the baric topography in general (represented by the value dp av.) is the basis for more detailed analysis of pressure variations. The results will be later used to determine the distance from the abandoned, empty shaft where the presence of emitted gases can be detected.

Short summary of deliverable D2.3. Report on physical and chemical impacts associated with changes in atmospheric pressure is available here

WP 3 – Quantitative modeling of climate impacts

The work in WP3 aims to use models to investigate the influence of various facilities or legacies of mining through climate-related changes and to identify the relevant factors. The activities focused on determining the study sites, selecting the model tools and setup the models including compilation of the required input data.

Task 3.1 – Modeling and simulation of environment impacts on mine water quantity & quality

Model works on the influences of climate and water on mine-specific facilities have been carried out with regard to deep mine water, near-surface groundwater and runoff from heaps. The Boxmodel software used to calculate water rise, quantity and quality of deep mine water required modifications in order to be able to take into account climatic influences and their changes in a suitable manner. Existing models were updated, new models were compiled and the test carried out.

The focus of the work was the interface between climatic phenomena (temperature, precipitation, etc.) and the water flowing into the mines. This would be solved by a transient calculation of the formation of the groundwater on the basis of daily data. This makes it possible to calculate the inflows into mines depending on the climate. However, the method requires a complex database that is currently only available for one of the intended test sites (3 in Germany; 2 in Poland and 1 in Spain). The methodological investigations therefore concentrated on this location.

Using a Visual MODFLOW model for the dump and the aquifer the influence of a coal mine dump in Poland has been considered. The potential locations for modeling the impact of precipitation on water flow from spoil tips with respect to flooding potential in UK were selected. In addition to that, gathering the data necessary for carrying out modelling exercises on specific sites has been delayed due to the impact of COVID-19 because visiting spoil heaps to obtain data on issues such as ground conditions and vegetation has not been possible.

Short summary of deliverable D3.1. Individual partner reports on developed numerical models relating to mine water issues is available here

Task 3.2 – Modelling and simulation of impacts on surface stability

Works within Task 3.2 have aimed to model the environmental impacts identified in WP2 on surface stability. Two types of numerical models of mining pits and tailings dams are currently being developed for heavy rain leading to a rise in groundwater level and flooding of excavations.

Moreover, the impact of rainfall infiltration on typical open-pit slopes’ stability has been studied. The influence of several geotechnical and geometrical factors was examined. Additionally, all existing data regarding slope of Lake Most, i.e. the area’s hydrology and geology, were gathered and studied. A pilot installation for slope protection, located at the mine waste dumps of the Janina mine site in Libiąż, Poland, was analyzed and presented with consideration of measurements and observations of erosion and stability due to drought occurrence and heavy rains. Preparatory works at a pilot site have been carried out to implement slope preservation of the mine waste dumps against the impact of extreme weather events (such as extreme rainfalls 77,8 mm/day) and extreme drought with duration of more than 4 months with maximum temperature 39oC. This scenario bases on a constant increase of average temperature and annual precipitation in GZW (USCB) area as it was identified in WP1. A technical design for the liquidation of a shaft was prepared, with use of selected backfilling material in terms to predicted mine water inflows due to changes in precipitation. The behaviour of rock mass and the stability of old shafts affected by increased water inflow was numerically simulated and examined. As the work is still ongoing, the results are not expected until end of this year.

Short summary of deliverable D3.2. Individual partner reports on developed numerical models relating to mine water issues is available here

Task 3.3 – Modelling and simulation of environmental impacts on mine gases

Two numerical models, in Ansys Fluent and FDS, showing the relationship between the rate of change of atmospheric pressure, temperature and gas emissions from their data collated from the shafts in Task 2.3 were studied. Analysing the negative change in temperature, it has been indicated that the advection of the cool air mass is a factor that causes air to flow into underground voids. Thus, in the case of a dominant downward trend in atmospheric pressure, such a case will slightly inhibit gas emissions. Moreover, to check variations of gas concentrations at the surface Pyrosim software were applied.

Short summary of deliverable D3.3. Report on developed numerical models relating to mine gas emissions is available here

WP 4 – Risk and impact mitigation and adaptation

The main purposes of WP4 is to develop effective adaptation strategies and monitoring solutions to reduce the impact and vulnerability of sites to climate change, and in turn enhance the sustainability credentials of mining activities, especially when related to mine closure and mine closure planning, and an integrated risk management tool as well as to apply in pilot scale the remedial measures for stabilisation of sealed shaft and mine spoil dump in case of extreme weather events occurrence. Works in WP4 started earlier than planned.

Task 4.1. Identification and application of impact and risk mitigation/adaptation methods

An in-depth overview of climate change remedial measures in mining was provided. The presented measures related to different forms and types of mining and post-mining facilities, also take into account the important areas of the project focus – minewater, emissions, surface and structure and mine rehabilitation. It has been demonstrated that identified measures are effective from an early stage in avoiding risks resulting from climate change. The remedial measures are also given a gradation of significance that allows them to be used in operations depending on the life stage of the mining facility. Presented remedial measures refer to practice. Reference are made to existing and ongoing pilot sites, risk identification and selection of solutions, etc. Also the relationship of the designed countermeasures to the modelling process carried out in WP3 is demonstrated.

The report includes a very important element from the implementation point of view, namely the pilot installations that were carried out at the Janina Mine Waste Heap and the Głowacki Shaft. These installations are an example of the process of securing mining facilities in such a way that they become resistant to climate change.

Short summary of deliverable D4.1. Report on Remedial Actions is available here

Task 4.2. Development of risk management and monitoring strategies

Various monitoring strategies have been studied to evaluate the continuing effectiveness of the remedial measures developed in Task 4.1 under a future climate change scenario. A tool that has been used for some categories of risk is the Trigger Action Response Plan (TARP), which defines a range of trigger levels and the associated responses to be initiated in the event that a trigger level is reached. An analysis of the various risks that can arise in mining was carried out. Also an assessment is presented of the technical and scientific challenges that are still to be addressed, in future decades, in order to validate or correct the climate change impact evaluation made in this project, and to identify any further remediation actions that may become necessary.

Short summary of deliverable D4.2. Risk management and monitoring strategies is available here

Task 4.3. An integrated risk management tool

Based on all the specific studies within the project, an innovative integrated risk management tool was developed that links the environmental impact, associated risks and mitigation methods caused by extreme weather events. The tool will utilize the results of Tasks 4.1 and 4.2. and provide a “user friendly” roadmap to identify the optimum solution(s) from the point of view of all relevant, identified impacts, helping to decide which management strategy should be chosen to achieve the best results. The use of the SWIFT technique used for the tool development allowed the identification and description of risks. Also an risk assessment is provided and some mitigation strategies are provided.

Short summary of deliverable D4.3. An integrated risk management tool is available here

The integrated risk management tool with User’s Guide can be downloaded here

WP 5 – Outreach and dissemination

WP 5 covers the actions that are undertaken in order to consult and disseminate project results among project stakeholders. The main aims of this WP are:

to produce a “best practice” handbook for the assessment and remediation of the impact of climate change on closed and abandoned mines that will also benefit existing mines in preparing for mine closure.
to ensure thorough dissemination of the project results through workshops, presentations and publications.

TEXMIN Handbook A Guide to Managing the Risks Posed to Working and Abandoned Mining Facilities, and to the Surrounding Environment, Caused by Climate Change can be downloaded here

All publications, both scientific and non-scientific, of TEXMIN project partners are available here

The Virtual Special Collection of articles published in regular issues of the Journal of Sustainable Mining called Climate change impacts on the mining industry (2021) is available here

Pilot installations

Description of pilot installation – the remedial measures for stabilization of sealed shaft in situation of extreme weather events occurrence – is available here.

Description of pilot installation – the remedial measures for stabilization of mine spoil dump in situation of extreme weather events occurrence – is available here.