River basins located in the Central Sudetes (SW Poland) demonstrate a high vulnerability to flooding. Four mountainous basins and the corresponding outlets have been chosen for modeling the streamflow dynamics using TOPMODEL, a physically based semi-distributed topohydrological model. The model has been calibrated using the Monte Carlo approach—with discharge, rainfall, and evapotranspiration data used to estimate the parameters. The overall performance of the model was judged by interpreting the efficiency measures. TOPMODEL was able to reproduce the main pattern of the hydrograph with acceptable accuracy for two of the investigated catchments. However, it failed to simulate the hydrological response in the remaining two catchments. The best performing data set obtained Nash-Sutcliffe efficiency of 0.78. This data set was chosen to conduct a detailed analysis aiming to estimate the optimal timespan of input data for which TOPMODEL performs best. The best fit was attained for the half-year time span. The model was validated and found to reveal good skills.
Aleja Mickiewicza 24/28, 30-059 Kraków, Poland Abstract: The objective of this paper is to present the concept of a novel system, known as HydroProg, that aims to issue flood warnings in real time on the basis of numerous hydrological predictions computed using various models. The core infrastructure of the system is hosted by the University of Wrocław, Poland. A newly-established computational centre provides in real time, courtesy of the project Partners, various modelling groups, referred to as “project Participants”, with hydrometeorological data. The project Participants, having downloaded the most recent observations, are requested to run their hydrologic models on their machines and to provide the HydroProg system with the most up-to-date prediction of riverflow. The system gathers individual forecasts derived by the Participants and processes them in order to compute the ensemble prediction based on multiple models, following the approach known as multimodelling. The system is implemented in R and, in order to attain the above-mentioned functionality, is equipped with numerous scripts that manipulate PostgreSQL- and MySQL-managed databases and control the data quality as well as the data processing flow. As a result, the Participants are provided with multivariate hydrometeorological time series with sparse outliers and without missing values, and they may use these data to run their models. The first strategic project Partner is the County Office in Kłodzko, Poland, owner of the Local System for Flood Monitoring in Kłodzko County. The experimental implementation of the HydroProg system in the Nysa Kłodzka river basin has been completed, and six hydrologic models are run by scientists or research groups from the University of Wrocław, Poland, who act as Participants. Herein, we shows a single prediction exercise which serves as an example of the HydroProg performance.
The Department of Geoinformatics and Cartography of the University of Wrocław, Poland, is host in¬stitution of a project, financed by the National Science Centre in Poland, whose objective is to predict riverflow in real-time. If inundation is predicted, the problem of the verification of the overbank flow prognosis arises. This verification can be attained by utilizing an unmanned aerial vehicle that may be used for remote sensing applications. The unmanned aerial vehicle in question can take sequential photos with the unprecedented resolution of 3 cm/pix. Both the resolution and the opportunity for frequent flights – due to the low cost of the entire operation – allow us to compare prediction maps showing the forecasted overbank flow during an extreme hydrological event with the true observation obtained from the air. Although such verification is site- and event-specific, it can provide us with an objective technique for checking our system in a spatial domain. The main part of the system, known as HydroProg, produces multimodel ensemble hydrograph predictions and compares single-model prognoses; visualizations of them are then published in a web map service. The spatial predictions, along with the aerial orthophoto images, will also be presented online so that the user is able to observe the functioning of the system. Regular research flights have been carried out in Kłodzko County since 2012. The study areas correspond to sites where our Partner, the County Office in Kłodzko (SW Poland) – owner of the Local System for Flood Monitoring in Kłodzko County – has automatic gauges, and thus spatially reflect the hydrologic observation network. The aforementioned aerial module is experimental and will be incorporated into the entire system.
Przestrzenny charakter antropogenicznych zmian w obrębie koryt rzecznych wymaga zastosowania metod i narzędzi umożliwiających nie tylko jakościową, ale i ilościową ich analizę. Pomiary geodezyjne są bardzo dokładne, lecz kosztowne i czasochłonne, co sprawia, że regularne pomiary, potrzebne do określenia dynamiki form fluwialnych, są trudne do zrealizowania. Tradycyjna fotogrametria lotnicza jest wartościowym źródłem informacji jedynie w przypadku analizy dużych obiektów. Skala, w jakiej najczęściej wykonywane są zdjęcia lotnicze, nie zapewnia wystarczającej szczegółowości do analizy niewielkich form rzeźby. W niniejszej publikacji zaprezentowane zostanie użycie bezzałogowego statku powietrznego (ang. UAV, Unmanned Aerial Vehicle), który wypełnia lukę między pomiarami naziemnymi a tradycyjną fotogrametrią czy analizą obrazów satelitarnych. Ultralekki bezzałogowy statek powietrzny swinglet CAM wyposażony jest w kompaktowy aparat fotograficzny wykonujący sekwencje zdjęć, które po przetworzeniu mogą służyć jako źródło kartometrycznych danych przestrzennych. Zniekształcenia geometryczne zdjęć oraz zniekształcenia spowodowane pochyleniem aparatu i rzeźbą terenu są usuwane w procesie wieloetapowego przetwarzania. Dzięki wysokiej rozdzielczości materiałów obserwacyjnych (do 3 cm px–1), wygenerowane ortofotomapy umożliwiają analizę niewielkich obiektów. Teren badań – Kotlina Kłodzka – jest doskonałym przykładem występowania zmian fluwialnych o podłożu antropogenicznym i – z uwagi na ten fakt – został wybrany jako obszar testowy do prezentacji możliwości bezzałogowego statku powietrznego w zakresie zdalnego wykrywania omawianych form. Wyniki potwierdzają dużą szczegółowość pozyskanych materiałów, co – w połączeniu z niskimi kosztami misji lotniczych oraz łatwością dostosowania parametrów i czasu realizacji lotów – jednoznacznie pokazuje, że zastosowana technologia jest odpowiednim narzędziem do obserwacji antropogenicznych form fluwialnych i może przyczynić się do rozwiązywania wielu problemów badawczych dotyczących ich roli w kształtowaniu procesów hydrologicznych.
EN
Spatial character of anthropogenic fluvial changes requires the use of methods and tools eligible for not only qualitative, but also quantitative analysis. Geodetic surveys are very accurate, but time and cost consuming, what makes repetitive measurements needed for determining the dynamics of fluvial landforms hard to perform. Traditional aerial photogrammetry is a valuable source only for examining features visible in a small cartographic scale. Hence, small fluvial forms cannot be observed using traditional aerial photogrammetry due to its limitations in resolution. Unmanned Aerial Vehicles (UAVs), presented extensively in this paper, serve as the additional source of high-resolution spatial information and thus fill the gap between terrestrial measurements and traditional aerial photogrammetry as well as satellite data. Ultra-light unmanned aircraft swinglet CAM, with consumer – grade camera onboard, provides sequences of pictures, which after geoprocessing can serve as source of spatial data eligible for quantitative measurements. Geometric incorrectness of the acquired pictures and distortions caused by tilt and relief are removed in the process of multistep processing. Due to high resolution of the observational material (up to 3 cm px-1) the generated orthophotomaps are appropriate for the analysis of small fluvial features. The study area – namely Kłodzko County – serves as a great example of assemblages of anthropogenic fluvial changes and – due to this fact – has been chosen as a test area to present potentials of UAV in observing the aforementioned landforms. The results confirm a great accuracy of the collected materials, which – in combination with low cost surveys, ease of parameter adjustment and flight schedule – unequivocally shows that the applied technology is an appropriate tool for observing anthropogenic fluvial forms, and thus may contribute to solutions of numerous research problems related to hydrological processes impacted by human interventions.
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