Classification of fires in coal waste dumps based on Landsat,Aster thermal bands and thermal camera in Polish and Ukrainian mining regions

A self-heating intensity index(SHII)based on the highest(pixel max.)and lowest(pixel min.)values taken from satellite thermal maps of burning coal waste dumps are proposed.The index enables the classification of such fires in Ukrainian-and Polish coal waste dumps.Both in Ukraine and in Poland,varying thermal intensities during 1985–2019 are revealed,using the SHII and following thermal intensity threshold values,namely,extreme thermal activity([7),advanced(3–7),moderate(3–1.5),initial(1.5–1),no activity(<1).The SHII shows decreasing thermal activity in the selected Ukrainian coal waste dumps during 2017–2019.It aids in reconstructing the thermal history of the dumps.Analysis of satellite images revealed a large number of burning coal waste dumps in the Donetsk Coal Basin(Ukraine)with high thermal activity.Such burning likely reflects large amounts of organic matter and sulphides in the dumped material subjected to self-heating and self-burning processes,lack of compaction of the coal waste and/or high methane contents.Comparison of SHII values calculated from satellite-and drone thermal-camera images were compared to show that SHII from drone thermal images have much higher values than those from satellite images;the former have better resolution.Thus,SHII from Landsat-and drone images should be used separately in dump heating studies.

Selected ions and major and trace elements as contaminants in coal-waste dump water from the Lower and Upper Silesian Coal Basins(Poland)

Many temporary and permanent reservoirs of water occur on or near coal-waste dumps in the Lower-and Upper Silesian Coal Basins(Poland).Little or nothing is known of the degree to which their water chemistry might reflect(i)reservoir type,i.e.,whether permanent or temporary,(ii)level of coal-waste thermal activity,i.e.,whether inactive or self-heating or burnt-out or(iii)region,i.e.,whether the dumps are in Upper-or Lower Silesia.To provide some answers,concentrations of selected ions(NH_(4)^(+),HCO_(3)^(-),F^(-),Cl^(-),Br^(-),NO_(2)^(-),NO_(3)^(-),PO_(4)^(3-),SO_(4)^(2-))were determined by ion chromatography and of nineteen elements(Al,B,Ba,Ca,Cd,Cr,Cu,Fe,K,Li,Mg,Mn,Na,P,Pb,S,Si,Sr,Zn)by inductively coupled plasma mass spectrometry(ICP-MS).The data allow a number of the following observations.When permanent reservoirs are considered,there is a clear relationship between concentrations of ions and major and trace elements and dump thermal activity.The highest concentrations occur where the thermal activity is high as inorganic components are transformed into more water-soluble forms.As dump thermal activity shows a regional pattern,it follows also that elemental and ion concentrations in the dump waters show significant regional differences.In temporary reservoirs,concentrations of ions and major and trace elements are much lower and any correlations between components less significant than in the permanent reservoirs;these reservoirs exist for too short a time for any balance between coal waste-and water components to be established.