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

http://www.sciencedirect.com/science/article/pii/S0341816214003580#gts0010

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


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)




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.

http://www.jtpunion.org/spip/article.php3?id_article=19

7

USING ARCGIS AND R FOR AUTOMATED DEM-BASED CATCHMENT

ANALYSES

Edina Józsa*

Faculty of Sciences, University of Pécs, Pécs, Hungary


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


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.

http://www.sciencedirect.com/science/article/pii/S0341816214003580#gts0010

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


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)





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


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).

mailto:[email protected]

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


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



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.