Credit: Fotó: Kovács János, 2017


9 May 2023

Hydrology Working Group

Understanding the physical and chemical processes of the hydrologic cycle is indispensable to predict the uncertainties associated with the increasing frequency of weather extremities. We have been studying the water cycle comprehensively with the aid of field monitoring, physical and numeric models.

Specific topics:

  1. Modelling the channel of the Drava River
  2. Hydrological consequences of extreme weather
  3. Mitigation of the ecological impacts of droughts in SW Hungary

Topic 1: Modelling the channel of the Drava River

This project aims at studying the grainsize distribution of the bedload and the suspended load of the Drava River. Sonar measurements provide bathymetric data of the channel bed. Both field monitoring and laboratory analyses were involved in the analyses. Measured and monitored grain size and bathymetric data serve as input for the HEC-RAS 2D hydraulic model. Using simulated data, future scenarios of channel evolution can be predicted. Knowledge on future channel morphology enables the accurate delineation of navigation routes and may contribute to the improvement of the ecological conditions of the river and its floodplain through a better water and oxygen supply of the side branches at low flow.

Side-scan image of the Drava channel at river km 174+000
Side-scan image of the Drava channel at river km 174+000

Physical model experiments are performed in a fully computer-controlled flume. Slopes in the flume are adjustable both along the longitudinal and lateral axes of the flume. The flume is also equipped with lateral push-blades to simulate tectonic control on the surface. These features of the flume enable the modelling of the impact of climate change, variable flow, channel incision and tectonic influence on the morphological evolution of the riverbed.

Bathymetric map of 1 x 1 meter resolution of a reach of the Drava River along the village of Heresznye in SW Hungary
Bathymetric map of 1 x 1 meter resolution of a reach of the Drava River along the village of Heresznye in SW Hungary

Topic 2: Hydrological consequences of extreme weather

In the wake of climate change, the frequency of extreme weather phenomena, both excess runoff and prolonged droughts, has been increasing. On highly impervious surfaces of developed areas, high-intensity rainfalls often generate urban flash floods. The severity of flash floods is influenced by multiple factors, like the shape of the watershed, its morphological and topographical properties, volume of woody debris and land use practices. GIS softwares, rainfall-runoff models and hydraulic models (HEC-RAS) are used to study the spatial distribution of these properties. For the parameterization of the models, a hydrometeorological monitoring system consisting of 16 stations were established for the city of Pécs, SW Hungary. The flash flood vulnerability map for the hilly and low-mountain regions of Hungary has also been developed.

Schematic of the development of a flash flood vulnerability map for Hungary
Schematic of the development of a flash flood vulnerability map for Hungary

Topic 3: Mitigation of the ecological impacts of droughts in SW Hungary

Along with increased excess runoff, a second consequence of climate change is the growing frequency, severity and length of droughts. According to climate models, periods of negative water balance will be probably more common in the coming years. Hence, sustainable adaptation of agriculture to altered climates and water balances is indispensable. It also demands the selection of climate- and soil-specific land use practices. An improper selection of crops and the uneven distribution of hydrologic resources all present global issues. Instead of the fast conveyance of water through the Pannonian Basin, we also need to focus on water retention. Hence, our objectives are the identification and selection of the most adequate land use type for the optimization of local moisture and water dynamics.

Pálfai drought (left) and aridity (right) indices in the summers of 019 and 2022 for a ploughland, a pasture and an orchard located in SE Hungary
Pálfai drought (left) and aridity (right) indices in the summers of 019 and 2022 for a ploughland, a pasture and an orchard located in SE Hungary

Soil moisture values at three study sites in SW Hungary over the summer of 2022
Soil moisture values at three study sites in SW Hungary over the summer of 2022

Selected papers

Czigány, S., Sarkadi, N., Lóczy, D., Cséplő, A., Balogh, R., Fábián, S. Á., Ciglič, R., Mateja F., Pirisi, G., Imre, M., Nagy, G., Pirkhoffer, E. (2023) Impact of Agricultural Land Use Types on Soil Moisture Retention of Loamy Soils. Sustainability 15(6):4925. DOI: 10.3390/su15064925

Sarkadi, N., Pirkhoffer, E., Lóczy, D., Balatonyi, L., Geresdi, I., Fábián, S. Á., Varga, G., Balogh, R., Gradwohl-Valkay, A., Czigány, S. (2022). Generation of a flood susceptibility map of evenly weighted conditioning factors for Hungary. GEOGRAPHICA PANNONICA, 26(3), 200–214. http://doi.org/10.5937/gp26-38969

Schmeller, G., Nagy, G., Sarkadi, N., Cséplő, A., Pirkhoffer, E., Geresdi, I., … Czigány, S. (2022). Trends in extreme precipitation events (SW Hungary) based on a high-density monitoring network. HUNGARIAN GEOGRAPHICAL BULLETIN (2009-), 71(3), 231–247. http://doi.org/10.15201/hungeobull.71.3.2

Víg, B., Fábián, S.Á., Czigány, S., Pirkhoffer, E., Halmai, Á., Kovács, I. P., Varga, G., Dezső, J.; Nagy, G., Lóczy, D. (2022). Morphometric analysis of low mountains for mapping flash flood susceptibility in headwaters. NATURAL HAZARDS 114(3), 3235–3554.

Farics, É., Halász, A., Czigány, S., & Pirkhoffer, E. (2021). Vulnerability mapping of karst springs and its application for the delineation of protection zones (Mecsek Karst, Hungary). ACTA CARSOLOGICA, 50(2–3), 301–315. http://doi.org/10.3986/ac.v50i2-3.8583

Pirkhoffer, E., Halmai, Á., Ficsor, J., Gradwohl‐Valkay, A., Lóczy, D., Nagy, Á., Liptay, Z. Á., Czigány, S. (2021). Bedload entrainment dynamics in a partially channelized river with mixed bedload: A case study of the Drava River, Hungary. River Research and Applications. 37, 699-711. doi: 10.1002/rra.3794

Słowik, M., Kiss, K., Czigány, S., Gradwohl-Valkay, A., Dezső, J., Halmai, Á., Marciniak, A., Tritt, R., Pirkhoffer, E. (2021). The influence of changes in flow regime caused by dam closure on channel planform evolution: insights from flume experiments. Environmental Earth Sciences 80: 4 Paper 165.

Liptay, Z. Á., Czigány, S., Pirkhoffer, E. (2021). River ice and water temperature prediction on the Danube. Hungarian Geographical Bulletin (2009-). 70: 201-214.

Halmai, Á., Gradwohl–Valkay, A., Czigány, S., Ficsor, J., Liptay, Z. Á., Kiss, K.; Lóczy, D., Pirkhoffer, E. (2020). Applicability of a Recreational-Grade Interferometric Sonar for the Bathymetric Survey and Monitoring of the Drava River. ISPRS International Journal of Geoinformation. 9, 149 doi:10.3390/ijgi9030149

Czigány, S., Novák, T. J., Pirkhoffer, E., Nagy, G., Lóczy, D., Dezső, J., Switoniak, M., Charzyński, P. (2020). Application of a topographic pedosequence in the Villány Hills for terroir characterization. Hungarian Geographical Bulletin (2009-), 69(3), 245–261. http://doi.org/10.15201/hungeobull.69.3.2

Nagy, G., Lóczy, D., Czigány, S., Pirkhoffer, E., Fábián, S. Á., Ciglič, R., & Ferk, M. (2020). Soil moisture retention on slopes under different agricultural land uses in hilly regions of Southern Transdanubia. HUNGARIAN GEOGRAPHICAL BULLETIN (2009-), 69(3), 263–280. http://doi.org/10.15201/hungeobull.69.3.3

Dezső, J., Czigány, S., Nagy, G., Pirkhoffer, E., Slowik, M., & Lóczy, D. (2019). Monitoring soil moisture dynamics in multilayered Fluvisols. BULLETIN OF GEOGRAPHY-PHYSICAL GEOGRAPHY SERIES, 16(1), 131–146. http://doi.org/10.2478/bgeo-2019-0009

Liptay, Z. Á., Czigány, S., Pirkhoffer, E., & Hermann, K. (2018). Hydrological modelling of small alpine watersheds with the NAM model. CARPATHIAN JOURNAL OF EARTH AND ENVIRONMENTAL SCIENCES, 13(1), 235–248. http://doi.org/10.26471/cjees/2018/013/021

Hegedüs, P., Czigány S., Pirkhofffer, E., Balatonyi. L., Hickey, R. (2015). Analysis of spatial variability of near-surface soil moisture to increase rainfall-runoff modelling accuracy in SW Hungary. OPEN GEOSCIENCES, 7(1), 126–139. http://doi.org/10.1515/geo-2015-0017

Pirkhoffer, E., Halmai, Á., Czigány, S., Bugya, T., Rábay, A., Bötkös, T., Balassa, B., Anweiler, I. J., Lóczy, D. (2014). New opportunities for experiments in fluvial geomorphology: the flume PTETHYS. HUNGARIAN GEOGRAPHICAL BULLETIN (2009-), 63(4), 425–436. http://doi.org/10.15201/hungeobull.63.4.4

Hegedüs, P., Czigány S., Pirkhoffer, E. Balatonyi, L. & Ronczyk, L. (2013). Estimation of flow rate calculation errors on the example of five rapid response catchments in the Mecsek Hills. HUNGARIAN GEOGRAPHICAL BULLETIN (2009-), 62(4), 331–350.

Hegedüs, P., Czigány S., Balatonyi. L., Pirkhoffer, E. (2013). Analysis of Soil Boundary Conditions of Flash Floods in a Small Basin in SW Hungary. CENTRAL EUROPEAN JOURNAL OF GEOSCIENCES, 5(1), 97–111. http://doi.org/10.2478/s13533-012-0119-6

Czigány, S., Pirkhoffer, E., Nagyváradi, L., Hegedüs, P., Geresdi, I. (2011). Rapid screening of flash flood-affected watersheds in Hungary. ZEITSCHRIFT FÜR GEOMORPHOLOGIE, 55(Suppl. 1), 1–13. http://doi.org/10.1127/0372-8854/2011/0055-0031

Czigány, S., Pirkhoffer, E., Geresdi, I. (2010). Impact of extreme rainfall and soil moisture on flash flood generation. IDŐJÁRÁS / QUARTERLY JOURNAL OF THE HUNGARIAN METEOROLOGICAL SERVICE, 114(1–2), 79–100.

Czigány, S., Pirkhoffer, E., Szebényi, A., Vass, P., Geresdi, I. (2010). Potential areas of flood impoundment in Human environments. GEOMORPHOLOGIE, 3, 301–310.

Czigány, S., Pirkhoffer, E., Geresdi, I. (2009). Impact of rainfall pattern on the occurence of flash floods in Hungary. ZEITSCHRIFT FÜR GEOMORPHOLOGIE, 53(2), 139–157. http://doi.org/10.1127/0372-8854/2009/0053S3-0139

Fábián, S. Á., Görcs, N. L., Kovács, I. P., Radvánszky, B., Varga, G. (2009). Reconstruction of a flash flood event in a small catchment: Nagykónyi, Hungary ZEITSCHRIFT FÜR GEOMORPHOLOGIE 53(2): 123-138.

Members of the research group:

- Dr. Szabolcs Czigány
- Dr. Ervin Pirkhoffer
- Dr. Noémi Sarkadi
- Dr. Dénes Lóczy
- Dr. Szabolcs Ákos Fábián
- Dr. Ákos Halmai
- Richárd Balogh
- Parisa Maleknia
- Alexandra Gradwohl–Valkay

Former members:

- Dr. Gábor Nagy
- Dr. Péter Hegedüs
- Dr. László Balatonyi
- Dr. Zoltán Liptay
- Balázs Víg