Download - The book of abstracts uav4
DETAILED AERIAL MAPPING
AND FLOOD IMPACT MONITORING
IN THE V4 REGION
THE BOOK OF ABSTRACTS
Conference of the project No. 31210058
May 11–12, 2015 Budkovice, CZ
Editor: Andrea Křížová
Mapping and aerial photogrammetry are inseparable part of modern research. Satellite and
aerial photos are expensive and quality of resolution isn’t sufficient for detailed research.
Remote controlled platforms are very popular not only for classic imaging but also for aerial
photogrammetry. Self-made aerial photographs offer to the researchers a maximum
operability. The technical parameters of the capturing device and platform help to the
photographer in determining not only place and time but also viewing angle, image coverage,
spatial resolution and exposure settings.There are many possibilities how to applicate UAS
systems. One of the relevant area of interest is fluvial geomorphology and hydrology.
Rivers are naturally dynamic over time and space and respond to the variability of water and
sediment inputs and to anthropogenic pressures that cause changes to the river's behavior and
form. Abstracts in this publication are focused on UAS systems in hydrology mapping and
these articles present new approaches in fluvial geomorphology and hydrology mapping.
Jakub Miřijovský
CONTENTS
LATERAL EROSION MONITORING ALONG A SOUTHERN SECTION OF SAJÓ (SLANÁ)
RIVER
Bertalan L., Szabó G. .............................................................................................................................. 4
THE AIZM FLOOD MODEL – ACCURACY AND PERSPECTIVE OF FURTHER USE
Caletka M., Koli
M., Šulc Michalková
M. ............................................................................................... 5
STRÁŽNICKÝ MEANDER – SEDIMENTATION AND DEVELOPMENT OF THE CUTOFF
CHANNEL
Holík P., Šulc Michalková M. ................................................................................................................. 6
USING ARCGIS AND R FOR AUTOMATED DEM-BASED CATCHMENT ANALYSES
Józsa E. .................................................................................................................................................... 7
HYDROMORPHOLOGIC MONITORING OF THE ACTUAL EVOLUTION
OF MORAVA RIVER IN LITOVELSKÉ POMORAVÍ AREA
Knot M. ................................................................................................................................................... 8
APPLICATIONS OF UAV TECHNOLOGY IN PHYSICAL GEOGRAPHY
AND METHODOLOGY OF UAV IMAGE PROCESSING
Křížová A. .............................................................................................................................................. 9
APPLICATION OF UAS PHOTOGRAMMETRY FOR ASSESSMENT OF FLOOD DRIVEN
FLUVIAL DYNAMICS OF MONTANE STREAM
Langhammer J., Miřijovský J. ............................................................................................................... 10
FLOODPLAIN DEGRADATION AND POSSIBLE REHABILITATION ALONG
THE HUNGARIAN DRAVA SECTION
Lóczy D.,
Dezső J., Ronczyk
L., Czigány S., Pirkhoffer E., Gyenizse P., Halász A.,
Ajkai-Ortmann A. .................................................................................................................................. 11
DETAILED AERIAL MAPPING AND FLOOD IMPACT MONITORING IN THE V4 REGION
Miřijovský J., Šulc Michalková
M
. ........................................................................................................ 12
EVAPORATION ESTIMATION AND ITS EFFECT ON THE WATER BUDGET OF AN OXBOW
AND ITS RIPARIAN FOREST
Prokos H., Dezső J., Halász A., Tóth G., Lóczy D................................................................................ 13
MONITORING OF CHUTE CUTOFF IN MEANDER BEND (ONDAVA RIVER, STROPKOV)
Sládek J., Rusnák M. ............................................................................................................................ 15
SPATIAL DISTRIBUTION OF HALOBITY IN FLOODPLAIN RELATED TO OM
ACCUMULATION
Tóth G., Halász A., Dezső J., Miřijovský
J., Lóczy
D. .......................................................................... 16
4
LATERAL EROSION MONITORING ALONG A SOUTHERN SECTION OF
SAJÓ (SLANÁ) RIVER
László Bertalan*, Gergely Szabó
Department of Physical Geography and Geoinformatics, University of Debrecen, Debrecen,
Hungary
*Corresponding author’s e-mail: [email protected]
Keywords: UAV, photogrammetry, lateral erosion, bank retreatment, Sajó; Slaná
The aim of our investigations is to analyse meander and river bank development influenced
by natural processes and human activity on the alluvial Sajó (Slaná) River of Hungary.
The rate and pattern of meander development was evaluated by analysing horizontal meander
parameters. Long term morphological changes of Sajó River were evaluated on the basis of
maps aerial photographs (1952, 1956, 1972, 1988, 2000, 2005 and 2011) and the 1:10.000
scale topographic map of Hungary (1980). All resources were geo-corrected by applying the
Hungarian EOV coordinate-system. The horizontal channel parameters which reflect the
morphological metamorphosis of the river were measured and their temporal changes were
evaluated. The determination of these parameters was based on the vectorized bank-lines. In
every investigated periods the bank edges were vectorized in ArcGIS then the centerlines
were calculated as well.
In 4 selected bends and meanders detailed UAV measurements by DJI Phantom 2
quadrocopter were performed between April 2014 and May 2015 to identify bank retreat. The
field measurements were supported by Stonex S9 RTK and D-GPS and Spectra Precision
Focus 8 Total station.
The centerline analysis on the total section of the Hungarian part of Sajó River shows an
outstanding shortening between 1952 and 1980 related to the regulation works performed by
several industrial purposes. After 1980 the centerline-length of Sajó River started to increase
and we suggested that it could be a reason of meander-development along the river.
The ortophotographs and DEMs of the banks for the short-term lateral erosion monitoring
were created in Agisoft Photoscan by using UAV aerial photographs. The development of the
selected bends and meanders supplemented by the UAV monitoring results shows very active
bank retreatment rate as 4,5 meters/year (1952–2014) and in some places about 2,4
meters/month.
5
THE AIZM FLOOD MODEL – ACCURACY AND PERSPECTIVE
OF FURTHER USE
Martin Caletka1)
*, Martin Koli2)
, Monika Šulc Michalková1)2)
1) Faculty of Science, Masaryk University, Brno, Czech Republic
2) Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia
*Corresponding author’s e-mail: [email protected]
Keywords: ArcGIS, flood, hydrological modelling, inundation, Model Builder, UAV
Modelling in hydrology has been developed for many years and a plenty of models various in
purpose and complexity have been available nowadays. The AIZM flood model (riginally in
slovak 'Alternatívny Indikatívny Záplavový Model') is an alternative 'viewer', kapable of
providing flood extends, as well as the field of depths, with minimal demands on the input
data and computing time. The model is based on chaining of several toolsets within the Model
Builder. Despite the availability of flood extends modelled by hydraulic models, many
of river sections in the Czech republic lack the outputs of hydrological models. On the basis
of available hydrological measurements, the AIZM model could be used to generate at least
a rough (but reliable) estimate of potential flood extend.
In order to gain reliable outputs, a comparation of the AIZM outputs with the hydraulic
models‘ outputs is necessary. Therefore, 30 sections of czech rivers were chosen. All of them
were sorted out into 6 categories according to the course of their channels. This way it was
possible to determine which category of stream the AIZM model is suitable for. The
comparison was carried out regarding the imput data of digital model of relief (DMR 4G and
DMR 5G) and for floods with periodicity of 5, 20 and 100 years.
The UAV technology provides a good possibility for the AIZM model from two perspectives.
Firstly, the photogrammetric measurements may provide more accurate data of the digital
model relief which is a crucial input influencing the final output. Secondly, UAV scanning
offers detailed information on real flood extends. Such images, together with measurements
of water stages, may be used for the purpose of verification whether the AIZM model
provides reliable outputs for a particular river section.
The introduced tool is a 'living organism' which is being tested and developed. It is going to
be further modified to be able to generate as accurate and reliable outputs as possible under
assumption that the simplicity of control will remain.
References:
Koli, M. (2013) Alternatívny indikatívny záplavový model. Symposium GIS 2013, Ostrava, Technical University
of Ostrava, ISSN 1213-239X.
6
STRÁŢNICKÝ MEANDER – SEDIMENTATION AND DEVELOPMENT OF THE
CUTOFF CHANNEL
Petr Holík1)*
, Monika Šulc Michalková 1)2)
1) Faculty of Science, Masaryk University, Brno, Czech Republic
2) Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia
*Corresponding author’s e-mail: [email protected]
Keywords: Stráţnický meander, cutoff, sedimentation, abandoned channels,
groundwater, Morava river
We study the cutoff Strážnický meander on the river Morava. Research is mostly based on
continual groundwater level measurement (2013 – present). We focus deeply on this part from
the methodological point of view and specific algorithm is presented, that can be used as an
example for similar research in other localities. We analyze, how often the cutoff meander is
connected to the active river channel and for how long part of a year is the meander connected
at both ends, allowing water to flow freely in the abandoned channel. Due to a relatively dry
period, that was observed in the locality in the last year, this did not happen very often.
Further research was focused on estimating the sedimentation rate by generating
cross-sections from digital surface model in the interval of two years and also generating
cross-sections with other geodetic measurements. The digital surface model was created by
using the UAV technology and standard photogrammetric measurements.. The dominant
process in the Strážnický meander is sedimentation, which however happens selectively,
depending on the location in the meander. By analyzing sedimentary samples, the character of
sedimentation was determined with regard on the specific location in the meander.
Acknowledgements:
This work was supported by Visegrad Fund, project no. 31210158 and also by the Slovak Research and
Development Agency under the contract no. APVV-0625-11.
7
USING ARCGIS AND R FOR AUTOMATED DEM-BASED CATCHMENT
ANALYSES
Edina Józsa*
Faculty of Sciences, University of Pécs, Pécs, Hungary
*Corresponding author’s e-mail: [email protected]
Keywords: fluvial landforms, geomorphometry, digital elevation models, land surface
parameters
The delineation of the landforms and the detailed analysis of local and regional land surface
parameters over the area of interest is a basic step in the DEM based environmental
researches. ArcGIS provides a wide range of geoprocessing tools for geomorphometric
analyses – even with the opportunity to use add-ins developed for specialized tasks –, while R
is a powerful tool to perform statistical analyses and data visualization. The interoperability of
these software packages creates the opportunity to prepare the necessary land-surface
parameter maps, then perform statistical analyses and plot the results using the GUI of the
ArcGIS (Roberts et al., 2010).
The main aim of the study was to automatically create a report in pdf format containing the
information about the characteristics of the examined valley and floodplain (width, depth,
longitudinal profile, etc.). For the delineation of the catchment and automatic generalisation of
stream lines the TauDEM add-in was used (Tarboton and Ames, 2001). The floodplain
extraction was carried out in R, based on the relation between simple land surface variables
(slope, curvature, relative relief) and relative altitude above stream elevations (Demoulin et
al., 2007). The slope and curvature values were previously transformed to achieve better
variance using the Python based script tool of Csillik, O. et al. (2015).
The proposed work was performed using contour-based medium resolution DEMs (10 m)
over the subcatchments of the Vasas-Belvárd stream to analyse the characteristics of the
floodplains. The area is a tectonically reshaped piedmont region of the Eastern Mecsek
Mountains sloping N-NW-S-SE with asymmetric valleys, captures and floodplains of variable
width (Pécsi, 1963).
References:
Csillik, O., I.S. Evans, L. Drăguţ, L. (2015). Transformation (normalization) of slope gradient and surface
curvatures, automated for statistical analyses from DEMs. Geomorphology, vol. 232, pp. 65–77.
Demoulin, A., B. Bovy, G. Rixhon, Y. Cornet. (2007). An automated method to extract fluvial terraces from
digital elevation models: The Vesdre valley, a case study in eastern Belgium. Geomorphology, vol. 91, no. 1–2,
pp. 51–64.
Pécsi, M. (1963). Hegylábi (pediment) felszínek a magyarországi középhegységekben (Pediment surfaces in the
Hungarian mountain ranges). Földrajzi Közlemények, vol. 83, no. 3, pp. 195–212.
Roberts, J. J., B.D. Best, D.C. Dunn, E.A. Treml, P.N. Halpin (2010). Marine Geospatial Ecology Tools: An
integrated framework for ecological geoprocessing with ArcGIS, Python, R, MATLAB, and C++.
Environmental Modelling&Software, vol. 25, pp. 1197–1207.
Tarboton, D. G., D. P. Ames (2001). Advances in the mapping of flow networks from digital elevation data,
World Water and Environmental Resources Congress, Orlando, Florida, May 20-24, ASCE.
8
HYDROMORPHOLOGIC MONITORING OF THE ACTUAL EVOLUTION OF
MORAVA RIVER IN LITOVELSKÉ POMORAVÍ AREA
Martin Knot*
Faculty of Science, Masaryk University, Brno, Czech Republic
*Corresponding author‘s email: [email protected]
Keywords: meander, Morava river, cut-off, alluvial plug, sediment
The issue about meander cut-offs has not been much developed in Czech Republic. That is
why this presentation deals about one of them - Kenický meander. This meander is located on
the Morava river in Litovelské Pomoraví, lying north of Olomouc city. To the end of February
2014 this meander was a part of the active channel of the Morava river. Then the neck of
meander was cracked, which caused cutting-off of this meander. Since this time dominant
accumulation processes have taken place, like creating alluvial plugs and following
sedimentation in the meander. At this time only upstream alluvial plug has developed, the
growth is supported by the large accumulation of woody debris. The downstream alluvial plug
has not developed yet. The aim of this thesis is to characterize sedimentary processes in this
meander by using sedimentary fraction analysis and ERT methods, to characterise evolution
of the shape of this meander by using measurement of transverse profiles, and to define
episodes of activity in this meander. These episodes are studied by measuring water level
elevation related to intake channel (connection point) at the upstream alluvial plug.
Preliminary results of this analysis shows accelerated accumulation on profiles 4, 5 and 7, in
contrast to profile 11, where erosion dominates. Grain size of sediments in meander is
supposed to be finer than sediments in the active channel and episodes of the activity of the
meander will be less frequent, restricted to flood events only. In the future meander will be
disconnected from the active channel in both entrances and the process of aggradation will be
slower and slower.
References:
Constantine, J. A., T. Dunne, H. Piégay, G.M. Kondolf (2010). Controls on the alluviation of oxbow lakes by
bed-material load along the Sacramento River, California. Sedimentology, vol. 57, p. 389–407.
Petyniak, O. (2014). Stav a budoucí vývoj odtrženého meandru v CHKO Litovelské Pomoraví. Diplomová
práce. Olomouc: Přírodovědecká fakulta Univerzity Palackého, 128 p.
9
APPLICATIONS OF UAV TECHNOLOGY IN PHYSICAL GEOGRAPHY
AND METHODOLOGY OF UAV IMAGE PROCESSING
Andrea Kříţová*
Faculty of Science, Masaryk University, Brno, Czech Republic
*Corresponding author’s e-mail: [email protected]
Keywords: UAV, Physical Geography, image, photogrammetry, processing, meander
First part of this contribution summarizes applications of unamanned aerial vehicle (UAV)
technology in research of partial disciplines of Physical Geography. There is a quantitative
summary of current state (till 2014) of knowledge within the scope of this area and then there
are given examples of published case studies using UAVs to obtain data for environmental
hazard research or in meteorology, hydrology, glaciology, vegetation ecology and
geomorphology. Meteorology was the first discipline, which started to use unmanned aerial
device for collecting data, whether in the meaning of aerosonde or the remotely piloted more
sophisticated machine. In meteorology UAVs carry special meteorological measuring device
(collecting data for vertical profiles of the atmosphere), on the contrary to rest of partial
disciplines, where UAVs are used as a carrier of a camera (often non-metric consumer grade)
to acquire images of an observed object or an area of our interest. And this purpose of using
UAVs for visual monitoring scientific objects is still more frequent, alongside it is designed
and carried out new fields of application such as flood impact monitoring.
Collecting visual data is one step of UAV method of monitoring. Next step is processing of
acquired images into orthorectified mosaics and digital elevation model. These products are
used for precise analyses of the object of our interest. Second part of the contribution presents
the methodology of processing of visual data acquired by unmanned aerial vehicle step by
step. This processing has a certain specifics that differ from the traditional aerial
photogrammetry. These UAV images were taken by non-metric camera for which parameters
of the interior orientation are unknown and sometimes also unstable (Miřijovský, 2013);
parameters of exterior orientation cannot be derived from inbuilt GPS because of its relatively
low accuracy compared to a large scale of UAV images – respectively in case of need of
really accurate data (Turner et al., 2012). Whole processing is carried out in the software
program Agisoft PhotoScan, suitable for small-format non-metric UAV images. This software
product performs photogrammetric processing of digital images using Structure from motion
technique based on Scale Invariant Feature Transform (SIFT) algorithm, which can be
applied in UAV imagery processing thanks to its robustness against changes in scale, rotation,
pitch and translation between images (Turner et al., 2012). The methodology of processing is
presented on visual data (owned by Palacký University in Olomouc) of meander in Strážnické
Pomoraví from years 2012, 2013 and 2014.
Acknowledgement: This work was supported by the Visegrad Fund (project No. 31210058).
References:
Miřijovský, J. (2013). Fotogrammetrický přístup při sběru geodat pomocí bezpilotních leteckých zařízení:
Disertační práce. Olomouc: Univerzita Palackého v Olomouci, Přírodovědecká fakulta. 144 l., 8 l. příl. Vedoucí
práce: Vít Voženílek.
Turner, D., A. Lucieer, Ch. Watson (2012). An Automated Technique for Generating Georectified Mosaics from
Ultra-High Resolution Unmanned Aerial Vehicle (UAV) Imagery, Based on Structure from Motion (SfM) Point
Clouds. Remote Sensing, 4, pp. 1392–1410, ISSN 2072–4292.
10
APPLICATION OF UAS PHOTOGRAMMETRY FOR ASSESSMENT OF FLOOD
DRIVEN FLUVIAL DYNAMICS OF MONTANE STREAM
Jakub Langhammer1)
*, Jakub Miřijovský2)
1) Faculty of Science, Charles University in Prague, Prague, Czech Republic
2) Faculty of Science, Palacký University in Olomouc, Olomouc, Czech Republic
*Corresponding author’s e-mail: [email protected]
Keywords: UAS, monitoring, photogrammetry, DMT, fluvial geomorphology
Current progress in hydrology and fluvial geomorphology is largely based on new field
survey and analysis techniques, employing advanced technologies for monitoring the
dynamics of the runoff process, field surveying and for remote monitoring of changes in
riverbeds and of fluvial dynamics. Application of these techniques allows researchers to
obtain information on a significantly higher qualitative level than using traditional methods of
field survey and measurement, either in terms of spatial accuracy and resolution, frequency of
sampling or qualitative characteristics of acquired data. The contribution demonstrates the
potential of Unmanned Aerial Systems (UAS) for analysis of fluvial dynamics of montane
stream, driven by flood in combination with other survey techniques, namely the ground
LiDAR scanning, digital granulometry and automated water level monitoring. The UAS
photogrammetry is employed in the study to acquire high precision DTMs, enabling
reconstruction of riverbed and quantitative analysis of volumetric changes related to initial
flood events. The hexacopter UAS platform has been used to acquire the data for
photogrammetric analysis of complex stretch of stream with historically elevated fluvial
dynamics. The photogrammetric reconstruction enabled to build accurate DTM of riverbed
and floodplain before and after the initial event and to calculate the extent of volumetric
changes. The potential of UAS photogrammetry for fluvio morphological study is in
combination with other monitoring and survey techniques, enabling complex analysis of
fluvial dynamics. The magnitude, duration and hydrological properties of initial flood event
were derived from automated high frequency water level monitoring. The digital
granulometry enabled to analyze the structure of sedimentary material in floodplain. The
results of above mentioned techniques are applied to build hydrodynamic model explaining
threshold conditions for initiation of changes in fluvial morphology of the riverbed in relation
to known and theoretical flood magnitude. The presented study proved the UAS
photogrammetry to be unique source of spatial information, allowing analysis of dynamics of
fluvial systems with unprecedented precision and flexibility. This technique has full potential
to bring spatial information to a new qualitative level and in experimental areas with limited
availability of spatial information. The preliminary results achieved in the study enabled us to
discuss the synergic potential of coupling the UAS photogrammetry, sensor networks and
other hydroinformatic techniques to enhance significantly our knowledge on the dynamics of
fluvial systems.
11
FLOODPLAIN DEGRADATION AND POSSIBLE REHABILITATION ALONG THE
HUNGARIAN DRAVA SECTION
Dénes Lóczy1)
*, József Dezső
1), Levente Ronczyk
1), Szabolcs Czigány
1), Ervin
Pirkhoffer1)
, Péter Gyenizse1)
, Amadé Halász1)
, Adrienne Ajkai-Ortmann2)
1) Institute of Geography, University of Pécs, Pécs, Hungary
2) Institute of Biology, University of Pécs, Pécs, Hungary
* Corresponding author’s e-mail: [email protected]
Keywords: floodplain, human impact, landscape degradation, oxbows, groundwater,
rehabilitation, water replenishment, Drava Plain
The lower sections of the Hungarian catchment of the Drava River, particularly the Drava
Plain has suffered large-scale landscape degradation in recent decades. The negative
influences affected both the physical and socio-economic environment. Along the Hungarian
section differential tectonic movements induced channel incision, lowering groundwater
levels and desiccation, which involved the decline of agriculture and serious employment
problems. Human impact, first of all, peak-time operated hydroelectric plants on the upper
section of the river in Austria, Slovenia and Croatia, resulted in large-scale daily fluctuations
of water level. Bed dredging in Croatia also influenced channel processes in Hungary. To
counter these deleterious processes a comprehensive landscape rehabilitation government
project, the Old Drava Programme, was launched. In the core of the Programme, the water
replenishment scheme focuses on the improvement of water availability of the floodplain
through replenishment indirectly from the main river channel. The scheme is meant to take
advantage of a network of abandoned drainage elements (oxbows, old beds, levee crevasses,
backswamps) in the floodplain. On this basis, an ambitious landscape management project is
designed which has the long-term objective to significantly improve economic (employment),
social (integration of ethnicities) and cultural (preservation of cultural heritage and its
utilization for increasing tourism potential). Rehabilitation potential is used as a measure to
express the extent to which the scope of ecosystem services/landscape functions can be
broadened. Within the frame of out project changes in water availability and the ensuing
landscape transformations are monitored with the purpose of assessing the efficiency of the
core project of the Old Drava Programme (a water transfer scheme) in the test area of the
Cún-Szaporca oxbow. Based on the preliminary findings of monitoring some weak points of
the scheme are highlighted. It is pointed out that, if water losses by seepage to groundwater
and by the evapotranspiration from water surfaces and vegetation are fully taken into account,
water replenishment as it is conceived and now being implemented may prove insufficient to
achieve the rehabilitation goals.
12
DETAILED AERIAL MAPPING AND FLOOD IMPACT MONITORING IN THE V4
REGION
Jakub Miřijovský1)
*, Monika Šulc Michalková2)3)
1) Faculty of Science, Palacký University in Olomouc, Olomouc, Czech Republic
2) Faculty of Science, Masaryk University, Brno, Czech Republic
3) Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia
*Corresponding author’s e-mail: [email protected]
Keywords: aerial mapping, monitoring, flood effect, V4 region
Mapping and aerial photogrammetry are inseparable part of modern research. Satellite and
aerial photos are expensive and quality of resolution isn’t sufficient for detailed research.
Main target of this paper is to show the developing of the common platform aimed on
mapping of floodplains and monitoring the effects of floods in V4 region. Proposed platform
will support integration of V4 in region of Europe. Mainly in area of science, research and
application of high-tech progress. In consequence region V4 will be more competitive in
whole Europe. Paper shows mapping the regions after floods, scanning and monitoring of
landslides, monitoring of slope stability, biomass monitoring, cooperation with demarcation
of border fields, documentation of archeology sites and so on. Nowadays floods events are
common in region of middle Europe. Results of this events are damages on personal goods, in
agriculture and also in infrastructure. Monitoring of areas after flood events must be done as
fast as possible. This monitoring can describe flood effects and impact on landscape.
13
EVAPORATION ESTIMATION AND ITS EFFECT ON THE WATER BUDGET OF
AN OXBOW AND ITS RIPARIAN FOREST
Hedvig Prokos*, József Dezső, Amadé Halász, Gabriella Tóth, Dénes Lóczy
Institute of Geography, University of Pécs, Pécs, Hungary
*Corresponding author’s e-mail: [email protected]
Keywords: evapotranspiration, riparian forest, oxbow, water supply
For floodplain rehabilitation the water budget of the area affected has to be revealed in detail.
Especially it is the case in the regional development projects along the Drava, where large-
scale governmental water management projects are aimed at floodplain rehabilitation. The
water replenishment scheme of the Old Drava project involves ca 15–20 surface water bodies.
The purpose of rehabilitation differs for each water body. In some cases the renewed lakes,
oxbows primarily serve recreational purposes, in other places they are meant to enhance
biodiversity.
Our aim with this work is to get information about the water budget of a randomly chosen
oxbow-system (Cún-Szaporca). In situ measurements were carried out during the last few
years to study the water management characteristics of the soil, hydraulic relationship
between surface and subsurface water bodies and chemical parameters. One of the most
important among the arising issues regarding the raised groundwater level is that what output
factors are responsible for the maintenance of the desired water level.
In the present paper our focus is on the water demands of forested areas next to the oxbow. It
must be considered as it reaches its maximum during the arid–hiperarid periods. For our
estimations on the extra water demand we used forest properties, e.g. age, composition,
canopy closure. As there is no relevant database in this subject for the area, our estimations
are mainly based on literary sources. Our research covers the distance between the forestry
areas and the oxbow-system as well as their role in the surface-groundwater hydraulic system.
Due to the great variations in the evapotranspiration rates of the different forests, our
calculations should be considered as estimations, hence we used intervals in our results.
After studying the datasets of the monitoring stations regarding the soil water management,
our conclusions showed that in the agricultural area the amount of infiltration into
groundwater is insignificant. Its reasons can be found in the relatively deep (-3 to -5 m)
groundwater table and in the inhomogeneity and variable conductivity of alluvial deposits.
Sub-surface water recharge of the oxbow mainly occurs laterally from the higher areas.
Riparian forest zones along the oxbow get the necessary water amounts from groundwater. As
a result of the above mentioned factors, the calculation of the actual water demand and the
water budget is quite difficult. Evapotranspiration calculations are based on Zhang (2001),
Járó (1981) and Shuttleworth (1992) using different equations. Regarding the database of ETI
(Scientific Forestry Institute) Pécs and NEBIH the mean age of the studied riparian stand is 42
(the youngest is 2, the oldest is 94) and it is mainly composed of poplars (white, black, etc. 35
%), White Willow (25%) and Black Locust (23%). Using the above mentioned data and
equations, a stand of 120.8 ha has a potential evapotranspiration of ca 530 mm in the
vegetation period (March to October). From hydrological point of view this demand occurs on
the borderline of groundwater–surface water (oxbow) level, further reducing water supply in
the dry summer periods.
Acknowledgement
Research was financed by the Hungarian National Scientific Research Fund (OTKA, no 104552).
14
References:
Járó, Z. (1981). Water consumption of domestic forests. MTA, AgrártudományiKözlemények, 40 (2–4), 353–
356.
Shuttleworth, W. J. (1992). Evaporation. In: Maidement, D.R. (Ed.), Handbook of Hydrology. McGraw-Hill,
New York, pp. 4.1–4.53.
Zhang, L., W.R. Dawes, G.R. Walker (2001). Response of mean annual evapotranspiration changes at catchment
scale. Water Resources Research, vol. 37, no. 3, pp. 701–708.
15
MONITORING OF CHUTE CUTOFF IN MEANDER BEND
(ONDAVA RIVER, STROPKOV)
Ján Sládek*, Miloš Rusnák
Institute of Geography, Slovak Academy of Sciences, Bratislava, Slovakia
*Corresponding author’s e-mail: [email protected]
Keywords: UAV, photogrammetry, floods, monitoring, geomorphology, the Ondava
River
The contribution presents an evolution monitoring of chute cutoff in meander bend of the
Ondava River based on close range aerial image processing. The first impulse for monitoring
was the meander bend cutoff during the three flood events in 2010 - Qculm 150 m3.s
-1 (17.05.),
220 m3.s
-1 (04.06.) and 150 m
3.s
-1 (29.07.). These events equal 1 – 5 N-years discharge. A
new created channel is active only during the high water levels (old meander bend is still
active in normal discharges). Several hectares of agriculture land located inside a meander
band had been destroyed by meander cutoff and 2,5m high river cliff which divides
agricultural land and floodplain was created. The UAV photogrammetry was chosen for
documentation of channel evolution and agricultural land degradation. The very first attempt
to construct of ortophoto mosaic was in 2012. After technical problems, we were able to
reconstruct only a small fragment of channel. Next two UAV flights were realized in April
and July of 2014 after high water levels. From these flights we reconstructed about 150 m of
channel bank. We used six-rotor platform Hexakopter XL as a camera carrier. Nikon D90
(lens 18-105, f/3,5-5,6G AF-S DX VR ED) and Sony NEX 6 (lens 16-50 mm f/3,5-5,6 SEL
1650) cameras were used for image capturing. Average flight altitude in all three campaigns
was 65 m. Total number of processed images were 78 in June 2012, 259 in April 2014 and
375 in July 2014. From all the three field campaigns we have created digital elevation models
and orthophoto mosaics with 5 cm/px resolution. Three stages of bank erosion in the 2012 –
2014 were reconstructed from collected and processed images. The average regression of cliff
is about 4,5 m in 2012 – 2014 period.
Acknowledgement:
This research was supported by Science Grant Agency (VEGA) of the Ministry of Education of the Slovak
Republic and the Slovak Academy of Science: 2/0020/15.
16
SPATIAL DISTRIBUTION OF HALOBITY IN FLOODPLAIN RELATED TO OM
ACCUMULATION
Gabriella Tóth1) *
, Amadé Halász1)
, József Dezső1)
, Jakub Miřijovský2)
, Dénes Lóczy1)
1) Faculty of Sciences, University of Pécs, Pécs, Hungary
2) Faculty of Science, Palacký University in Olomouc, Olomouc, Czech Republic
*Corresponding author’s e-mail: [email protected]
Keywords: spatial distribution, water quality, organic matter, Drava-basin
The Cún-Szaporca oxbow of 275 hectares area was finally disconnected from the Drava River
channel in 1975, when the main flood defence line was built. Open water surface prevails on
the oxbow over most of the year and is composed of three lakes: Lake Kisinc (20 ha), which
used to be the main channel of the Drava in 1785, Lake Lanka and Lake Szilihát (together
30 ha). Since 1996 this is an important water fowl sanctuary under the Ramsar Agreement. At
present, during high water stages water recharge is possible through the opening of the Kisinc
Sluice from the direction of the Drava channel. However, this is not a satisfactory solution.
Accordingly, in the spring period the necessary total interval for filling up the oxbow to the
91,5 m level is 13–17 days, while for the 92,0 m level it is 22–26 days. The parameters
necessary to fill up the oxbow are the following: in the summer season, assuming 0.2 m3.s
-1
inflow rate, the interval necessary to reach the second (92,0 m) level is 46–50 days. In case
the discharge of the Fekete-víz allows 0,5 m3.s
-1 water transfer, the necessary filling time is
32–33 days.
The planners (Ddkövizig, 2012) set the following critera for the regulation of water level:
Water level fluctuation should not exceed 0,5 m within a year;
Water recharge should take place step by step, in divisions;
In a year water recharge should be implemented by not more than two fillings;
The length of the filling period should remain within two weeks.
Three points in the planning concept and calculations seem to be problematic:
The success of the envisioned implementation of water recharge is rather questionable
since the hydraulic connection between the oxbow bed and the neighbouring
geological structure is not sufficiently clear;
The quality of inflow water is different from that in the oxbow, and even more
substantially differs from that of the one-time natural recharge, from the Drava River;
The water quality parameters are not precisely known from Lake Kisinc.
Alluvial sediment analyses are carried out to estimate the conductivity of the different
horizons/beds and land use and vegetation dynamics are surveyed by remote sensing. The
influence of local rainfall events on the groundwater table is evaluated in the light of
precipitation amount and intensity as well as soil temperature and saturation. Since seepage to
groundwater is a major type of loss in the water budget of the oxbow, the monitoring of
groundwater levels is central to our investigations.
After this rainy summer period water sampling campain were realized. Our aim the
investigation of the daily periodicity of water chemical properties (halobity). Thus every hour
-30 cm from water table and -220 cm (30 cm above pond sediments) were sampled. The
changeable properies such as pH, redox potential, temperature, dissolved oxygen, were
measured in the boat, or on the board. The other componennts ammonium, nitrate, phosphorus
17
forms (total- and orto-phosphorus), KOI in the UNIV Pécs laboratory. From the evaluation
concluded that the most of chemical parameters don’t follow the daily fluctuation of the
environmental parameters (excluding dissolved oxygen in the tangle, next too the board). The
KOI values are extremly high due the accumulation of organic material on the mud. We
suppose, that after the artificial water recharge, which count only one meter plus water
column, this disadvantageous parameters will not change in a right direction.
Acknowledgement:
Authors wish to thank the Hungarian National Scientific Research Fund (OTKA) for the financial support
(contract K 104552) and gratefully acknowledge the support by the Visegrad Fund (project No. 31210058).
References:
Ddkövizig (2012). Revitalization of the Cún-Szaporca oxbow system. Manuscript. Final Master Plan. South-
Transdanubian Environment and Water Directorate, Pécs. 100 p.