UNIQUE HYDROLOGICAL RECLAMATION LOCALITY OF OPENCAST MINE
PIT
, Ing. Milena Vágnerová1, Ing. Petr Svoboda, CSc.1, Ing. Jan Brejcha1
1
Výzkumný ústav pro hnědé uhlí a.s., tř. Budovatelů 2830/3, 434 01 Most, brejcha@vuhu,cz
Abstract
The opencast mines in the region of the North-Bohemian basin are and will be in the close
future ( in the next 20 – 30 years) step wisely closed. The planned and realized reclamation
procedure in the foot of the Krušné hory (the Ore mountains) is based on the constitution of
the artificial lakes dedicated mainly to the recreation purposes. The hydrological reclamation
represents considerable impact into the landscape, which will influences changes of
microclimate, ecosystem and fresh-air quality. The complex impact of the old opencast mine
reclamation on these factors has never been studied in the Czech Republic. The article gives
overall information about the project TAČR No. TA01020592 “Impacts of a hydrological
open-cast mine reclamation on the microclimate, fresh-air quality, water and soil ecosystems”
solved in the frame of the ALFA programme. Brief description of the project objectives, its
methodology and expected results is described. In addition the article deals with the partial
results obtained within the first two years of the project.
Keywords: opencast mine reclamation, hydrologic reclamation, fresh-air quality,
microclimate, ecosystems, Most Lake.
INTRODUCTION
Comprehensive effect of reclamation of the original brown-coal open-cast mine on the microclimate, ecosystem and on air quality in the Czech Republic so far has not been studied. For
this reason it was processed in 2010 and from 2011 carried out within the framework of the
programme ALFA Technology Agency of the Czech Republic the four-year project, which is
aimed at a comprehensive evaluation of the impact of reclamation on microclimate, water
ecosystem water and soil and air quality around the Lake.
Reclamation is an interdisciplinary activity that can be solved successfully only in close
cooperation of science dealing with the atmosphere, the biosphere, geography, and geology,
as well as technical and economic sciences. Therefore, the project is solved by specialists
involved in the field of air quality, microclimates and environment of the institutions VÚHU
a.s. (Research Institute of brown coal, a.s.), ÚFA AV ČR (Institute of atmospheric physics AS
CR, v.v.i.) and UJEP (University of J.E. Purkyně in Ústí nad Labem).
The locality of the Lake Most was therefore selected for the implementation of the project.
The reason for this selection was quite a large area of the surface of the Lake and the
proximity of the permanent meteorological station of Kopisty Observatory, where the climatic
measurements have been carried out since 1970 in a wide range of variables. A cemented
strengthened banks are already built around the Lake together with a circumferential
communication of the length 9 815 m, which is connected to a network of service access
roads. The site is located in the central part of the North Bohemian lignite basin.
So far 2 reclamations have been implemented in the North Bohemian coal basin - residual
pits of the open cast mine Chabařovice and Most-Ležáky. The filling of the residual pit of the
open-cast mine Chabařovice (Lake Chabařovice) was initiated on 15.06.2001 and ended on
08. 08.2010 at the achievement of the planned operational water level on 145,7 m above sea
level, the filling of the residual pit of the open-cast mine Most–Ležáky (Lake Most) has not
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been completed yet. After the completion of filling, the area of the Lake Most (311,0 ha) will
be greater than the Máchovo jezero (296,0 ha) and also much deeper (75.0 m Lake Most,
Mácha's Lake just up to 12 m). The construction of such a large reservoir without the natural
outflow is so far unique in the Czech Republic.
Table no. 1
Parameters
Area
PARAMETERS OF CHABAŘOVICE AND MOST LAKE
LAKE CHABAŘOVICE
Situation on
Planned final values
08.08.2010
252,2 ha
Water amount 35,601 mil. m
252,2 ha
3
35,601 mil. m
LAKE MOST
Situation on
Planned final values
01.06.2012
296,68 ha
3
Water level
145,70 m n.m.
145,70 m n.m.
Max. depth
24,70 m
24,70 m
311,0 ha
3
70,5 mil. m3
197,91 m n.m.
199,0 m n.m.
69,311 mil. m
74,06 m
75,0 m
Source: Palivový kombinát Ústí, s.p.
Project methodology
The project solution is divided into five thematic areas, which share data and results:
1. determination of influence of Lake on microclimate change
2. determination of influence of Lake on air quality in the vicinity
3. determination of the impact of Lake on the ecosystem of water in the lake
4. determination of influence of Lake on the creation of ecosystem of coastal zone of the
lake and the surrounding areas
5. Pedological study of soils
Determination of influence of Lake on microclimate change
The influence of the artificial lake on microclimate is studied in order to find a simple
mathematical model quantitatively describing the influence of large water areas on local
precipitation, temperature, humidity and other weather variables. The existing and future
measurements of the atmosphere, which will be affected by the water surface, of two
professional weather stations Kopisty and Milešovka operated by ÚFA AV ČR, will be used
to formulate the model.
The Kopisty Observatory station is located approximately 1 km from the future shore of the
Lake on the edge of the town Most. The station is equipped with an automatic weather station
and 80 m high meteorological pole. The climate measurements and evaluations have been
carried out on the station since 1970. The basic weather variables are measured and observed
at the station (temperature and humidity at 2 m, air pressure, wind direction and speed,
duration of sunshine, horizontal visibility, soil temperatures in 5, 10, 20, 50 and 100 cm,
rainfall, weather condition, condition of the soil, snow, cloud coverage and the height of the
cloud bottom base). The pole measurements are carried out at height of 20, 40, 60 and 80 m.
The Milešovka station, which is located at an altitude of 836 m on the top of the hill with the
same name, is situated about 20 km in the air from Kopisty. The climate observations have
been made here since 1905. The same basic meteorological parameters (see station Kopisty)
are measured and observed at the station. From the perspective of the project research, the
station of Kopisty Observatory measures the local microclimate in the locality of the Lake. On
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the contrary, the Milešovka station due to its location measures characteristics of the free
atmosphere, which should be affected by the creation of the Lake in the minimal extend.
The results of measurements obtained on the station Kopisty will be compared with the values
from the Observatory on Milešovka to investigate the difference among them before and after
the formation of the Lake. In this way it will be possible to significantly reduce the influence
of variability of meteorological data for each year. The data from Milešovka will be used as
reference data, as well as objective analysis and predictions from the European Centre for
medium-term weather forecasts (ECMWF). ÚFA AV ČR has the free access to this data.
The numerical model COSMO is used to describe the influence of the Lake on atmospheric
elements and their impact on the local weather. To detect more details of microclimate
changes and to verify the model COSMO, two other temporary meteorological stations
located near Lake – "Celio Most" and "Airport Most" were added to the existing weather
stations. In addition an automatic measuring station was installed on the water surface of the
Lake measuring the temperature of the water in the Lake and the basic meteorological
parameters.
The final result will consist of maps of influence of water area on the meteorological elements
in the surrounding countryside. Simultaneously simple empirically-statistical models will be
created for application and estimation of the impact of water reservoirs of future lakes in other
locations.
Determination of influence of Lake on air quality in the vicinity
The project solutions in the field of air quality is focused on the identification of the
significance of changes in air quality in the close vicinity of the Lake, which will occur as a
result of changes to the microclimate of area of interest. The measurements are carried out to
obtain a set of data for the evaluation of trends in air quality in the context of the time and
spatial changes in microclimates. Monitored pollutants are characteristic for the monitored
locality. The measurements are carried out in two zones and on the one reference point.
The close neighbourhood of the Lake is the first zone. The second zone covers the more
distant vicinity of the Lake. Eight monitoring stations is installed in the first zone near the
shore of the Lake approximately in the octants of the wind rose to carry out the passive
sampling of SO2, NO2, BTX, VOC, NH3, H2S, O3 and dust fallout. The second zone
consists of 3 other stations - Kopisty, Most-VÚHU and Braňany. The reference station is
located on the top of Milešovka. In addition to the passive sampling same as in the first zone,
the continual measurement of concentrations of total TSP and PM10 fractions is obtained in
these points. The station Most-VÚHU performs additional continual measurement of SO2,
NO2, O3, VOC, CO and the concentration of the faction PM1. The reference station is located
on the top of Milešovka.
The passive sampling of gaseous components is carried out using the diffusive method
(System Radiello) The determination of the sampled analytes is performed by extraction and
subsequent analyses by spectrophotometry, ion chromatography and gas chromatography.
Dust fallout is determined by sedimentation into open containers with the subsequent
gravimetric differential weighing. Metals in the samples of dust fallout (As, Pb, Ni, Cd, Hg,
Mn, Cr, Zn, V, Sr) are determined using atomic absorption spectrometry (AAS). The
continual measurement of concentrations of gaseous substances is carried out using the
HORIBA type series AP 350 instrument. The aerosol particles are measured by the beta-dust
meters FH62IR or FH62IN.
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In order to determine the significance of the difference between the levels of pollution in the
vicinity of the Lake and in the surrounding region, the data obtained in the first zone, in the
second zone and in the reference station and the surrounding automatic state measuring
network AIM will be compared. The results will be presented in tables and graphically in
charts and specialized maps. The meteorological and climatic parameters, their seasonality
and seasonality of operation of combustion sources will be comprised in the assessment as
well.
Determination of the impact of Lake on the ecosystem of water in the lake
The monitoring of fytobentos is carried out to assess the ecological status of the Lake in
accordance with the directive of the European Parliament and Council establishing a
framework for Community action in the field of water policy (2000/60/EC). Fytobentos
(perifyton) is an important component of aquatic ecosystems. The knowledge of its
composition, present on the biotope, may provide useful information about the status of this
biotope (habitat) and eventually may help to design and evaluate appropriate management
strategies. To discover the nature of the biological recovery in the monitored systems the
following parameters are monitored - microscopic picture, perifyton, saprobe index S,
quantity of macro-algae and phytoplankton. The measurement is carried out on 5 selected
locations on the shore of the Lake. The sampling is carried out in the period March to
November with the frequency 14 days. The samples are analysed and evaluated in the
hydrobiological laboratory of the Faculty of environment, J.E. Purkyně University in Ústí
nad Labem.
Determination of influence of Lake on the creation of ecosystem of coastal zone of the
lake and the surrounding areas
The botanical monitoring takes place in selected squares of coastal slopes of the Lake and in
the vicinity of the Lake. The list of herbs and woody plants and their changes during the
lifetime of the project will be the result. The aim of botanical surveys is, above all, a)
monitoring of the natural succession (spontaneous penetration of each species on an empty
area and subsequent changes in vegetation) with a focus on aquatic and riparian plants, b) the
evaluation of differences in vegetation on surfaces used with different extent (or with unequal
intensity) for recreation and other activities, c) the evaluation of the impact of plantations,
technical or other modifications of the land and their use for the occurrence and spread of
expansion, invasive or, conversely, rare species of plants. The frequency of monitoring is
every 14 days during the growing season (March to October).
The zoological monitoring is focused on the occurrence and nesting of birds and the
determination their species. At the beginning of the project, the neighbourhood of the Lake
was mapped and the places of regular observation were selected. The frequency of
observation is 14 days. The results of the above observation will be drawn up in the map of
botanical and zoological species. The evolution of the ecosystem will be evaluated and
subsequently the "ecological status" of the site will be defined..
Pedological study of soils
The pedological studies of soils in the shore lines and close vicinity of the Lake will provide
substantial information about the suitability of this environment for fauna and vegetation.
Therefore, they are an important part of a complex research area.
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The aim of pedological research is to create a soil survey maps of the area of interest – the
lake shore lines and the close vicinity of the Lake, then the analysis of pedological parameters
of the identified types of soils and their reclamation usability and finally the proposal of the
optimal use of each area consisting of a certain type of soil (maintaining the natural
succession of different reclamation measures, etc.)
Results – outcomes of the project
The project aims to develop procedures for the evaluation of the impact of the hydric
reclamation of the residual pits of the surface open-cast mines on microclimate, ecosystems of
water and soil and air quality. Procedures will be usable, and above all, applicable to the next
hydric reclamation of the closed lignite open–cast mines in the Czech Republic and
eventually abroad (Germany) thanks to the fact that such a comprehensive monitoring,
measuring, mapping and quantitative evaluation of the development and the impact of this
method of reclamation of the closed coal mine on microclimate ecosystems, water and soil
and air quality has not yet been studied in the Czech Republic or in Germany in this range.
The results will be used either by the organisations carrying out the reclamation of the closed
excavated surface mines or for specific planning of utilisation of the Lake Most and its
surroundings by the statutory city of Most.
Summary
The article informs about the research of the impact of hydric reclamation of residual pits of
the open coal mines on the microclimate, air quality, water and soil ecosystems. Research is
carried out in the central part of the North Bohemian coal basin in the vicinity of the Lake
Most, which was created after the flooding of the residual pit of the mine Most–Ležáky. The
goal of the four-year project is to develop procedures for the evaluation of the impact of the
hydric reclamation of open surface mines on microclimate ecosystems, water and soil and air
quality. Procedures will be usable and above all applicable to the next hydric reclamation of
lignite open cast mines in the Czech Republic and abroad.
ACKNOWLEDGEMENT
This research is carried out within the framework of the project research and development no.
TA 1020592 "Impacts on microclimate, air quality, water and soil ecosystems under hydric
reclamation of open cast lignite mines", which is supported by the Technology Agency of the
Czech Republic.
Researchers also expressed thanks to the Palivový kombinát Ústí, s.p., which implements a
comprehensive revitalization of the landscape affected by mining activities; i.e.. hydrological
rehabilitation (lake creation) in the area of the residual pit of the mine Most-Ležáky and
which enabled and allows partners to carry out research of the Lake Most.
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