Tomasz Kowalczyk

ESTIMTION OF SOIL WATER RETENTION OF URBAN GREEN AREAS UNDER THE CONDITIONS OF PRECIPITATION DEFICIT ON THE EXAMPLE OF THE SZCZYTNICKI PARK IN WROCŁAW

The paper presents a characterisation of water relations and an estimation of the variability pertaining to soil water retention resources in the selected area of the Szczytnicki Park in Wrocław. The estimation was performed on the basis of the measurements of soil moisture performed in the years 2015 and 2016, and the results of monitoring and research conducted in an earlier period. The detailed study was conducted on a fragment of the park with the surface area of about 8.6 ha, situated north of the Japanese Garden, between the Mickiewicza and Kopernika streets. Soil moisture measurements were conducted with the TDR method, at 27 points, within the soil layers of 0–25 cm and 25–50 cm. On the basis of the analysis of spatial distribution of soil moisture it was observed that considerable and long-lasting moisture deficits of the active layer of the soil have occurred during the period under study. Moisture levels below the permanent wilting point (PWP, pF = 4.2) were noted on approximately 36% of the study area, in the layer of 25–50 cm. The reservoir with an area of 1.1 ha, situated centrally in the study area, did not cause any improvement of soil-ground water retention during the period of the study. That was due to the periodic lack of supply of the water system of the park from the intake of Oder river in which the water level decreased as a result of a drought.

ASSESSMENT OF CHANGEABILITY OF SOIL RETENTION RESOURCES IN THE SOUTHERN PARK IN WROCŁAW

STRESZCZENIE W pracy przedstawiono charakterystykę stosunków wodnych i ocenę zmienności zasobów retencji glebowej na terenie Parku Południowego we Wrocławiu. Oceny tej dokonano na podstawie pomiarów uwilgotnienia gleby wykonanych w roku 2012 i 2013 oraz wyników badań prowadzonych na tym terenie w latach wcześniejszych. Pomiary wilgotności przeprowadzono metodą TDR w powierzchniowej warstwie gleby 0–25 cm oraz 25–50 cm, w kilkudziesięciu punktach (ok. 60) na terenie całego parku. Pozwoliło to na wygenerowanie map przestrzennego rozkładu uwilgotnienia gleby. Na ich podstawie stwierdzono, że na powierzchni parku występuje zauważalne zróżnicowanie zasobów retencji gromadzonych w glebie. Wyraźnie wyższe wartości uwilgotnienia obserwowano w pobliżu stawu parkowego. Przeprowadzone badania i analizy wskazują, że nadmierne uwilgotnienie w badanych profilach glebowych na terenie parku występuje zazwyczaj w okresie wiosennym i po nawalnych deszczach. Największy wpływ na kształtowanie zasobów retencji glebowej ma wielkość oraz rozkład opadów atmosferycznych.

EVALUATION OF THE IMPACT OF LAND USE CHANGES ON THE OUTFLOW FORMATION FROM LOCAL MICROCATCHMENT OF THE WUELS ARBORETUM AREA IN PAWŁOWICE

In the paper the impact of land use changes localised in catchment of the Wrocław University of Environmental and Life Sciences (WUELS) arboretum in Pawłowice near Wrocław on outflow from local micro-catchment was analysed. The study results show necessity for solutions that allow increasing the efficiency of rainwater management discharged from the sealed surfaces in the arboretum area. In this study the selected investments that are planning to improve water condition of forest habitat and to decrease flood risk of lower localised area were characterised. The planned investments include the development of various forms of small scale retention taking into account the aspect of improving water quality.