Due to their size, water construction belongs to the largest and heaviest engineering structures. Ensuring the safe operation of such facilities requires continuous monitoring. Among the basic forms of monitoring in such facilities one should list continuous seasonal piezometric measurements, which are obligatory elements of general control measurements aimed at ensuring safety when using the facility. The latter is directly related to guaranteeing the safety of people living and working in an area exposed to destruction in the event of a possible disaster involving the building. From the perspective of increasing the safety of the hydrotechnical facility, optimal conditions occur when the water levels in piezometers oscillate around a constant value as this signalizes that filtration processes in the body and the surface of a dam are stable. Various factors may disturb measurements of water levels in open piezometers or water pressure in closed piezometers. These factors may take the form of systematic, random or obvious errors. Thus, before analyzing this type of data, the largest errors (outliers) should be removed from the sample as they could significantly affect the outcomes of analysis and lead to a false interpretation. In such a situation, it is necessary to apply respective statistical tests, which allow verification of whether a particular portion of data may be treated as a set of outliers at a given significance level α. In this work the following statistical tests were used to identify and remove outliers: Q-Dixon test, Grubbs test, Hampel test, Rosner test, Iglewicz and Hoaglin test, Tietjen-Moore test and quartile test. The scope of the empirical analysis is focused on piezometric measurements at the Dobczyce dam over the period 2012-2016.

This paper aims to analyze the changes in the trends of water levels in closed piezometers installed in the largest dam in Poland, i.e. Solina Dam located in the Podkarpackie province. The scope of the research includes the analysis of water levels in piezometers in the study period between 2010...

Currently, the problems related to the development of seepage are emerging more and more frequently. For this reason, there is a constant need to improve the existing methods, and to develop new ones, for determining the direction and intensity of the development of seepage processes occurring in earth-fill dams and their foundations. The analysed earth-fill dam is located in Pieczyska in the Kujawy-Pomerania province at 49.115 km from the river mouth of the Brda River. The catchment area is 4.109 km². The article aims to verify the non-invasive, non-subjective method for examining the direction of seepage through earth-fill dams using the modified scalar product approach, which allows to determine the direction and intensity of the seepage process. A proper analysis of this process can greatly reduce the repair costs (injections or other methods of sealing), and significantly increase the safety of the existing earth-fill dams. In the case of the dam in Pieczyska, in 2010–2015, the two piezometers (located on the left abutment of the dam and denoted as P15A and P60) exhibited a direct hydraulic connection with the upstream water level (the scalar product approach). For the study dam, the “source” piezometer (to which all the piezometers in its surrounding exhibited similar changes in water levels) turned out to be the piezometer P15A. This fact was confirmed both by the number of connections between the individual piezometers and the resulting system of equipotential lines for the dam.

Forests are considered one of the most valuable natural areas in metropolitan region landscapes. Considering the sensitivity and ecosystem services provided by trees, the definition of urban forest ecosystems is nowadays based on a comprehensive understanding of the entire urban ecosystem. The effective capturing of particulate matter is one of the ecosystem services provided by urban forests. These ecosystems function as efficient biological filters. Plants accumulate pollutants passively via their leaves. Therefore, another ecosystem service provided by city forests could be the use of tree organs as bioindicators of pollution. This paper aims to estimate differences in trace metal pollution between the wooded urban areas of Vienna and Krakow using leaves of evergreen and deciduous trees as biomonitors. An additional objective of the research was to assess the ability of the applied tree species to act as biomonitors. Plant samples of five species—Norway spruce, Scots pine, European larch, common white birch, and common beech—were collected within both areas, in seven locations: four in the “Wienerwald” Vienna forest (Austria) and three in the “Las Wolski” forest in Krakow (Poland). Concentrations of Cr, Cu, Cd, Pb, and Zn in plant material were determined. Biomonitoring studies with deciduous and coniferous tree leaves showed statistically higher heavy metal contamination in the “Las Wolski” forest compared to the “Wienerwald” forest. Based on the conducted analyses and the literature study, it can be concluded that among the analyzed tree species, only two: European beech and common white birch can be considered potential indicators in environmental studies. These species appear to be suitable bioindicators, as both are widespread in urban woodlands of Central Europe and have shown the highest accumulation levels of trace metals.

Water erosion in mountainous areas is a major problem, especially on steep slopes exposed to intense precipitation. This paper presents the analysis of the topsoil loss using the SWAT (Soil and Water Assessment Tool) model. The SWAT model is a deterministic catchment model with a daily time step. It was designed to anticipate changes taking place in the catchment area, such as climate change and changes in land use and development, including the quantity and quality of water resources, soil erosion and agricultural production. In addition to hydrological and environmental aspects, the SWAT model is used to address socio-economic and demographic issues, such as water supply and food production. This program is integrated with QGIS software. The results were evaluated using the following statistical coefficients: determination (R2), Nash–Sutcliff model efficiency ( NS), and percentage deviation index ( PBIAS). An assessment of modelling results was made in terms of their variation according to different land cover scenarios. In the case of the scenario with no change in use, the average annual loss of topsoil (average upland sediment yield) was found to be 14.3 Mg∙ha –1. The maximum upland sediment yield was 94.6 Mg∙ha –1. On the other hand, there is an accumulation of soil material in the lower part of the catchment (in-stream sediment change), on average 13.27 Mg∙ha –1 per year.

One of the main modes of monitoring the geotechnical conditions of earth dams is piezometric measurement, which measures water levels in an open piezometer or water pressure in a closed piezometer. During piezometric measurements, various types of factors can cause disturbances in these measurements that take the form of systematic, accidental, or obvious mistakes. Before measurements from open or closed piezometers are analyzed, outliers due to coarse errors should be detected and rejected. Such observations may significantly influence the result of the analysis and cause erroneous assessment and interpretation of the phenomenon studied. To do this, statistical tests must be applied so that the doubtful measurement can be accepted or rejected at the assumed significance level. This paper uses five statistical tests for identifying and rejecting outliers: the Q-Dixon test, the Grubbs test, as well as the Hampel test, the Iglewicz and Hoaglin test, and the Rosner test. The aim of this article is to try to identify the most suitable test for periodic piezometric measurements. The scope of the study includes the analysis of piezometric measurements for the Czaniec Dam for the multi-year period 2017–2020.