The paper presents an analysis of the course and frequency of high water stages in selected catchments of the upper Vistula basin in the south of Poland. The following rivers were investigated: the Dunajec–Nowy Targ-Kowaniec cross-section, the Rudawa–Balice cross-section, the Kamienica–Nowy Sącz cross-section, the Wisłok–Tryńcza cross-section and the San–Przemyśl cross-section. Daily flows from the years 1983–2014 were used to determine maximum annual flows and maximum flows per summer and winter half-year. Selected floods were analyzed with reference to the following metrics: POTX (mean size of the flow determined based on high water stages exceeding the assumed threshold value), POT3F (number of high water stages exceeding the threshold value for each hydrological year), WPOT3F (number of high water stages exceeding the threshold value for the winter half-year and), LOPT3F (number of high water stages exceeding the threshold value for the summer half-year). The determined metrics were analyzed for trend (Mann-Kendall test), homogeneity (Kruskal-Wallis test), and heteroscedasticity (Levene test). Additionally, periodograms were used to determine periodicity of time series for maximum annual flows. The resulting computations indicated upward trends in the analyzed flood metrics but they were not significant in any case. Therefore, in the years 1983–2014 no factors were observed that would significantly affect the size and frequency of high water runoff from the investigated catchments.
The objective of this study is to present the approach to assess needs of land consolidation to prepare rural areas for proper water resource management. The study presented links of water management with land consolidation, which is a new approach in rural development planning in Central Europe. The results of this research are presented in the form of a needs assessment matrix for water retention. The matrix includes the main groups of parameters that are related to water resource management systems and rural development planning, which are classified into three groups: (1) water resources and retention, (2) technical systems and water management measures, and (3) information about land space distribution in rural areas. A verification of the proposed matrix was carried out for two sites that differ in terms of factors influencing the retention size; one is located in southern Poland in Lower Silesia—in the village of Mokrzeszów—and the other is located in Strzelce Wielkie—a village located in Lesser Poland. Both sites were evaluated using different needs assessment methods in terms of retention. The main factors influencing a reduced retention potential are related to the insufficient retention capacity of river channels and valleys and the inadequate maintenance of melioration systems. In Strzelce Wielkie, the land consolidation favours longer catchment response on rainfall, which is an advantage to mitigating drought and flood problems. The developed matrix can be applied for an assessment of the retention potential of rural areas based on the relatively accessible data. The method is universal and can be used in different regions. The approach presents practical tools dedicated to authorities to deciding on land consolidation in regards to water resources management; it aims at resolving agricultural land use conflicts and sustainably using space in order to manage water domains.
The aim of the study was to determine the impact of natural and anthropogenic factors on the values of 22 quality indicators of surface waters flowing out of two small catchments differing in physiographic parameters and land use, in particular forest cover and urbanization of the area. The research was carried out in the years 2012–2014 at four measurement-control points located on the Chechło river and the Młoszówka stream (Poland), which are the main tributaries of the retention reservoir. Basic descriptive statistics, statistical tests, as well as cluster analysis and factor analysis were used to interpret the research results. The water that outflowed from the forestry-settlement catchment of the Młoszówka stream contained higher concentrations of total phosphorus, phosphates, nitrite, and nitrate nitrogen and salinity indicators than outflow from the Chechło river. Water from the Młoszówka stream was characterized by more favourable oxygen conditions. Higher oxygen concentration in the catchment influenced a large slope of the watercourse and thus higher water velocity, which is promoted by the mixed process. In the case of the forest catchment of the Chechło river, the water quality was generally better than in the Młoszówka stream, mainly in cases of total suspended solids TSS, total phosphorus TP, phosphates PO43−, total nitrogen TN, nitrite N–NO2−, nitrate N–NO3−, and salinity parameters. Despite it being a short section of the river taken into the study, favourable self-purification processes like mixed, nitrification, and denitrification were observed in its water. The research shows that forest areas have a positive effect on the balance of most substances dissolved in water, and natural factors in many cases shape the quality and utility values of surface waters on an equal footing with anthropogenic factors. In the case of a large number of examined parameters and complex processes occurring in water, the interpretation of the results makes it much easier by applying multivariate statistical methods.
1 January 2015 in Journal of Ecological Engineering
A key parameter for the design of soil drainage and irrigation facilities and for the modelling of surface runoff and erosion phenomena in land-formed areas is the saturated hydraulic conductivity (Ks). There are many methods for determining its value. In situ and laboratory measurements are commonly regarded as the most accurate and direct methods; however, they are costly and time-consuming. Alternatives can be found in the increasingly popular models of pedotransfer functions (PTFs), which can be used for rapid determination of soil hydrophysical parameters. This study presents an analysis of the Ks values obtained from in situ measurements conducted using a double-ring infiltrometer (DRI). The measurements were conducted using a laboratory permeability meter (LPM) and were estimated using five PTFs in the Rosetta program, based on easily accessible input data, i.e., the soil type, content of various grain sizes in %, density, and water content at 2.5 and 4.2 pF, respectively. The degrees of matching between the results from the PTF models and the values obtained from the in situ and laboratory measurements were investigated based on the root-mean-square deviation (RMSD), Nash–Sutcliffe efficiency (NSE), and determination coefficient (R2). The statistical relationships between the tested variables tested were confirmed using Spearman’s rank correlation coefficient (rho). Data analysis showed that in situ measurements of Ks were only significantly correlated with the laboratory tests conducted on intact samples; the values obtained in situ were much higher. The high sensitivity of Ks to biotic and abiotic factors, especially in the upper soil horizons, did not allow for a satisfactory match between the values from the in situ measurements and those obtained from the PTFs. In contrast, the laboratory measurements, showed a significant correlation with the Ks values, as estimated by the models PTF-2 to PTF-5; the best match was found for PTF-2.