Ignacy Kardel

Eco-Hydrological Functioning of the Biebrza Wetlands: Lessons for the Conservation and Restoration of Deteriorated Wetlands

Human activities have led to the loss of a large proportion of biodiversity in riverine wetlands in western Europe (Van Urk 1984; Cirujano et al. 1996). In the second half of the twentieth century, many floodplains, fens, and riparian woodlands were cultivated for agricultural purposes. In addition, the remain- ing riverine wetlands lost species due to the impact of human activities (Rich and Woodruff 1996; McCollin et al. 2000). Recently, policy has become more focused on conservation of the remaining wetlands and on rehabilitation of disturbed rivers and floodplains (Jongman 1998). The management and reha- bilitation of wetlands is difficult without adequate knowledge of the hydrolog- ical and ecological processes responsible for the functioning and biodiversity of undisturbed wetlands.

Hydrological modelling of the Vistula and Odra river basins using SWAT

ABSTRACT This paper presents a large-scale application of the SWAT model for water balance and natural streamflow simulation in the entire basins of the Vistula and the Odra, covering most of the territory of Poland. A tailored calibration approach was designed to achieve satisfactory goodness-of-fit across a range of catchment sizes. Model calibration and evaluation driven by high-resolution climate data showed overall good behaviour for 80 benchmark catchments divided into eight clusters, and spatial evaluation for 30 gauges showed that the designed regionalization scheme performed well (median KGE of 0.76). Basin-averaged estimates of blue and green water flow and green water storage estimated using the calibrated model were 185, 517 and 206 mm, respectively. This study provides a basis for future work, such as assessing climate change impacts on hydrology, assessing flow alterations, and water quality simulation. The model output is publicly available through an online research data archive (doi:10.4121/uuid:b8ab4f5f-f692-4c93-a910-2947aea28f42). EDITOR A. Castellarin ASSOCIATE EDITOR G. Thirel

Water regime as a key factor differentiating habitats of spotted eagles Aquila clanga and Aquila pomarina in Biebrza Valley (NE Poland)

Capsule Foraging sites of Aquila clanga compared to Aquila pomarina are characterized by a considerably longer duration of flooding within the year and higher mean and maximum depths of flooding. A. clanga is particularly associated with shallow (approx. 20 cm) spring flooding, lasting at least up to the beginning of May (on average up to 90 days per year). Variation in habitat selection with respect to water regime might be due to different food preferences and adaptation to landscape differences in the ranges of these two species.

CHASE-PL Climate Projection dataset over Poland – bias adjustment of EURO-CORDEX simulations

The paper provides an update of climate projections over Poland by adopting the new generation of concentration pathways and recent developments in climate modelling.It provides a dataset of scenarios of temperature and precipitation developed for nine individual RCM simulations and the ensamble one. For each RCM the bias is firstly assessed and than the scenario is adjusted. The scenarios are prepared on annual and seasonal resolution.

What can we learn from the projections of changes of flow patterns? Results from Polish case studies

River flow projections for two future time horizons and RCP 8.5 scenario, generated by two projects (CHASE-PL and CHIHE) in the Polish-Norwegian Research Programme, were compared. The projects employed different hydrological models over different spatial domains. The semi-distributed, process-based, SWAT model was used in the CHASE-PL project for the entire Vistula and Odra basins area, whilst the lumped, conceptual, HBV model was used in the CHIHE project for eight Polish catchments, for which the comparison study was made. Climate projections in both studies originated from the common EURO-CORDEX dataset, but they were different, e.g. due to different bias correction approaches. Increases in mean annual and seasonal flows were projected in both studies, yet the magnitudes of changes were largely different, in particular for the lowland catchments in the far future. The HBV-based increases were significantly higher in the latter case than the SWAT-based increases in all seasons except winter. Uncertainty in projections is high and creates a problem for practitioners.

Developing an algorithm for enhancement of a digital terrain model for a densely vegetated floodplain wetland

Abstract. Airborne laser scanning survey data were conducted with a scanning density of 4  points/m2 to accurately map the surface of a unique central European complex of wetlands: the lower Biebrza River valley (Poland). A method to correct a degrading effect of vegetation (so-called “vegetation effect”) on digital terrain models (DTMs) was applied utilizing remotely sensed images, real-time kinematic global positioning system elevation measurements, topographical surveys, and vegetation height measurements. Geographic object-based image analysis (GEOBIA) was performed to map vegetation within the study area that was used as categories from which vegetation height information was derived for the DTM correction. The final DTM was compared with a model obtained, where additional correction of the “vegetation effect” was neglected. A comparison between corrected and uncorrected DTMs demonstrated the importance of accurate topography through a simple presentation of the discrepancies arising in features of the flood using various DTM products. An overall map classification accuracy of 80% was attained with the use of GEOBIA. Correction factors developed for various types of the vegetation reached values from 0.08 up to 0.92 m and were dependent on the vegetation type.

Modelling of discharge, nitrate and phosphate loads from the Reda catchment to the Puck Lagoon using SWAT

Abstract Modelling of discharge, nitrate and phosphate loads from the Reda catchment to the Puck Lagoon using SWAT. This study presents an application of the SWAT model (Soil and Water Assessment Tool) in an agricultural, coastal catchment situated in northern Poland, draining an area of 482 km2 (the Reda catchment). The main objective of this study was calibration and validation of the model against daily discharge and water quality parameters (bi-monthly total suspended solids [TSS], nitrate nitrogen [N-NO3] and phosphate phosphorus [P-PO4] loads). Calibration and validation were conducted using the SWAT-CUP program and SUFI-2 (Sequential Uncertainty Fitting Version 2) algorithm. The Nash- -Sutcliffe efficiency, which was set as an objective function in calibration of all variables, was equal for discharge to 0.75 and 0.61 for calibration and validation periods, respectively. For TSS, N-NO3 and P-PO4 loads NSE was equal to 0.56, 0.62 and 0.53 in calibration period, and 0.22, 0.64 and -1.78 in validation period, respectively. For the calibration period all the results are satisfactory or good, while for the validation period the results for TSS and P-PO4 loads are rather poor, which is related mainly to the lack of homogeneity between calibration and validation periods. These results demonstrate that SWAT is an appropriate tool for quantification of nutrient loads in Polish agricultural catchments, in particular for N-NO3. The model can therefore be applied for water resources management, for quantification of scenarios of climate and land use change, and for estimation of the Best Management Practices efficiency

Occurrence of nitrogen cycle bacteria in the Biebrza River

Occurrence of nitrogen cycle bacteria in the Biebrza River This paper of the selected groups of nitrogen cycle bacteria in the Biebrza River was analysed. In the water samples the quantity of ammonifying bacteria, nitrifying bacteria, proteolitic bacteria was estimated and also selected water quality indicators were analysed. Large quantities of proteolitic bacteria and ammonifying bacteria were found while the quantity of nitrifying bacteria was very small. Water quality analyses proved high TOC concentrations and low nitrate as well as nitrite concentrations. It was found, that the mineral forms of nitrogen being the intensive product of organic matter degradation is not released (low concentrations of ammonia), but it is accumulated in microorganisms cells. Low concentrations of ammonia are limiting for the number of nitrifying bacteria. The seasonal character of the occurrence of all analysed bacteria groups was as well found. The analytical procedure used was adjusted for bacteriological research on rivers of low anthropopressure. Występowanie bakterii cyklu azotowego w wodach rzeki Biebrzy W niniejszej pracy zbadano występowanie wybranych grup bakterii cyklu azotowego w rzece Biebrzy. W próbach wody oznaczono liczebność bakterii proteolitycznych, amonifikacyjnych i nitryfikacyjnych. Określono poziom wybranych wskażników jakości chemicznej. Stwierdzono wysoką liczebność bakterii proteolitycznych i amonifikacyjnych oraz bardzo niską bakterii nitryfikacyjnych. Badania chemiczne potwierdziły wysokie stężenia OWO i niskie stężenia azotynów i azotanów. Stwierdzono, że mineralne formy azotu intensywnie powstające w wyniku degradacji materii organicznej nie są uwalniane do środowiska (niskie stężenia amoniaku), a kumulowane w komórkach mikro-organizmów. Niskie stężenia amoniaku działają hamująco na liczebność bakterii nitryfikacyjnych. Stwierdzono ponadto sezonowość występowania wszystkich badanych grup bakterii. Dostosowano procedurę analityczną do wykorzystania w badaniach bakteriologicznych rzek o niskiej antropopresji.

Flood Water Hydrochemistry Patterns Suggest Floodplain Sink Function for Dissolved Solids from the Songkhram Monsoon River (Thailand)

Although important for the eco-hydrological functioning of the floodplain, the interactions between river and floodplain are not well understood, especially for rivers in the tropical monsoon region. To explore the floodplain functioning of a tropical monsoon river system the longitudinal and transverse floodwater hydrochemical characteristics were studied in the Songkhram river (Thailand) and its floodplains. Water samples were taken during the monsoon period from 61 locations in the river and on its floodplain. Analysis of floodwater hydrochemistry revealed a significant decreasing longitudinal trend for most dissolved solids, attributable to geological differences. We also observed a significant decreasing transverse trend from river to floodplain. Nutrient concentrations revealed lower dissolved nitrogen, phosphate, and potassium concentrations on the floodplain than in the river channel, which suggests the floodplain functions as a sink for nutrients and chemical species in the river floodwater. This sink function may be related to the presence of a belt of bamboo separating the river from the floodplain, which seems to acts as a sediment trap and nutrient filter, but this needs to be verified by additional dedicated research.

Processing of airborne laser scanning data to generate accurate DTM for floodplain wetland

Structure of the floodplain, especially its topography and vegetation, influences the overland flow and dynamics of floods which are key factors shaping ecosystems in surface water-fed wetlands. Therefore elaboration of the digital terrain model (DTM) of a high spatial accuracy is crucial in hydrodynamic flow modelling in river valleys. In this study the research was conducted in the unique Central European complex of fens and marshes - the Lower Biebrza river valley. The area is represented mainly by peat ecosystems which according to EU Water Framework Directive (WFD) are called “water-dependent ecosystems”. Development of accurate DTM in these areas which are overgrown by dense wetland vegetation consisting of alder forest, willow shrubs, reed, sedges and grass is very difficult, therefore to represent terrain in high accuracy the airborne laser scanning data (ALS) with scanning density of 4 points/m2 was used and the correction of the “vegetation effect” on DTM was executed. This correction was performed utilizing remotely sensed images, topographical survey using the Real Time Kinematic positioning and vegetation height measurements. In order to classify different types of vegetation within research area the object based image analysis (OBIA) was used. OBIA allowed partitioning remotely sensed imagery into meaningful image-objects, and assessing their characteristics through spatial and spectral scale. The final maps of vegetation patches that include attributes of vegetation height and vegetation spectral properties, utilized both the laser scanning data and the vegetation indices developed on the basis of airborne and satellite imagery. This data was used in process of segmentation, attribution and classification. Several different vegetation indices were tested to distinguish different types of vegetation in wetland area. The OBIA classification allowed correction of the “vegetation effect” on DTM. The final digital terrain model was compared and examined within distinguished land cover classes (formed mainly by natural vegetation of the river valley) with archival height models developed through interpolation of ground points measured with GPS RTK and also with elevation models from the ASTER-GDEM and SRTM programs. The research presented in this paper allowed improving quality of hydrodynamic modelling in the surface water-fed wetlands protected within Biebrza National Park. Additionally, the comparison with other digital terrain models allowed to demonstrate the importance of accurate topography products in such modelling. The ALS data also significantly improved the accuracy and actuality of the river Biebrza course, its tributaries and location of numerous oxbows typical in this part of the river valley in comparison to previously available data. This type of data also helped to refine the river valley cross-sections, designate river banks and to develop the slope map of the research area.