Strength and permeability properties along with microstructural evolution of hardened slurries composed of fly ash from fluidal bed combustion of brown coal and an addition of OPC/BFSC is assessed in this paper. An increase in the amount of fly ash in slurries influences the development of mechanical strength and a decrease of hydraulic conductivity. SEM, XRD, and porosity analyses confirmed formation of watertight microstructures. The structure of slurries is composed of ettringite, C-S-H phase, AFt, and AFm phases. Ettringite crystallises as relatively short needles forming compact clusters or intermixed with the C-S-H phase. The occurring C-S-H phases are mainly of type I – fibrous and type II – honeycomb

The situation when groundwater considerably rises above the “normal” level, water intake, lowering of groundwater levels and other relevant practical tasks require the drainage facilities. The most effective techniques of numerical studies of the corresponding boundary problems at present time are methods of dealing with inverse boundary value problems (conformal and quasi-conformal mappings). As basis of this research we used the case of combining the fictitious domain methods with quasi-conformal mappings of the solution of nonlinear boundary value problems for the calculation of filtra-tion regimes in environments with free boundary areas (depression curves) and zones of “mountainous” areas. This paper reviews the stationary issue of flat-vertical stationary non-pressure liquid filtration to horizontal symmetric drainage. In the paper a practical methodology for solving boundary value problems on conformal mappings is suggested for the calculation of the filtration process in the horizontal symmetrical drainage. The idea of block iterative methods was used during the creation of the corresponding algorithm which is based on the alternating “freeze” of the anticipated conformance parameter, the internal and boundary connections of the curvilinear area. The results of the conducted numerical calculations confirmed the effectiveness of the suggested problem formulations and algorithms of their numerical solution and the possibility of their use in the modelling of nonlinear filtration processesoccurring in horizontal drainage systems, as well as in the design of drainage facilities and optimizing other hydrosystems. Therefore these results are of great importance.

Flood embankments have played an important role in flood protection systems for centuries. Tightness evaluation of water structures should result in determining whether floods may cause seepage incidents, consequently leading to their damage or even destruction. It is assumed that the time of water passage from the river to the protected area under steady-state conditions can be a good indicator of the embankment resistance to long-term water rise. The curve of water passage times shows the values obtained at different ordinates of the dammed water and can be regarded as a characteristic parameter of flood embankment tightness. Determination of the water passage time ( T_p) additionally requires finding the trajectory along which this time is the shortest possible. However, there is no need to analyse the unsteady filtration, which requires the determination of an initial condition and the course of time-dependent boundary conditions. Engineers in practice, often use the time T_pp which elapses from the beginning of flooding to the occurrence of seepage in the protected area. The relationship between the passage time ( T_p) and the seepage onset time ( T_pp) was analysed on a model example. Practical use of the curve of passage times is showed on the example of the reconstruction of the left-bank Warta embankment in the area of Konin.

The Netherlands has a long tradition in water management, mainly stemming from the geography of the country. The ‘struggle with water’ has been organised from medieval times by the water boards (waterschappen), which are the oldest democratic institutions in the Netherlands. Nowa-days the water boards, 27 in the whole of the Netherlands, are not only responsible for flood protec-tion and regulation of water levels, but for water quality management and waste water treatment as well. In the years in which the WFD implementation has been underway in the Netherlands, several issues have arisen. Cooperation between all levels of government is key. This requires as clear as possible divisions of competences between the various parties involved. It also takes much time, es-pecially in a process in which many matters have to be invented ‘on the fly’, such as criteria for des-ignating water bodies, ecological standards, and the formulation of MEP and GEP.

The article discusses the option for the application of the methodology for the solution of boundary value problems on the conformal mapping for the calculation of filtration process in the horizontal systematic drainage, provided that the drain is installed at a different depth. In particular, the case of methods combining fictitious areas and quasiconformal mappings for solving nonlinear boundary conditions problems for calculating filtration regimes in soils with free sections of boundaries (depression curves) and intervals of the “drainage” type. As an example, the authors designed a hydrodynamic flow grid, determined the values of the flows to the drain, established a section line and elicited other process characteristics. The algorithm for the numerical solution of model nonlinear boundary conditions problems of quasiconformal reflection in areas bounded by two equipotential lines and two flow lines, when for one of the sections, the boundary is an unknown (free) curve with fixed and free ends. The conducted numerical calculations prove that the problems and algorithms of their numerical solution, with a relatively small iterations number (k = 141) suggested in the paper, can be applied in the simulation of nonlinear filtration processes that arise in horizontal drainage systems. Total filtration flow obtained Q = 0.9 dm3·s–1; flow for drains Q1 = 0.55 dm3·s–1 and Q2 = 0.35 dm3·s–1 are quite consistent with practically determined values.

This research examines the relationship between urban planning and environmental conditions. As urb-anisation processes increase the density of the built-up tissue of cities, this process puts a lot of pressure on land and natural resources such as rivers and soil. This article aims to verify whether environmental risks (e.g. flooding) and land protection from them is sufficiently addressed in the examined spatial policies and strategies.
This problem can be observed in the Powiśle district of Warsaw where buildings are constructed in the proximity of the unregulated Vistula River and that is why there is the direct risk of flooding. It is done despite the lack of legally binding Master plans which would consider the natural risk.
The literature research on the Municipality-led spatial planning policies and documents was completed with qualitative interviews with key actors in this process (planners: the authors of Master plans under construction, regarding the area of Powiśle South and North). Main designers and team members were asked about the priorities of these plans as well as their dynamics (taking more than ten years to establish those plans).
An environmental analysis was conducted in the GIS mapping system of many databases. The comparison of both aspects of current development, formal urban planning and environmental protection was made in an interdisciplinary approach. The study presents an analysis of the situation for urban planning along with flood maps and other environmental conditions. The results show the lack of necessary alignment of environmental issues with the planning documentation and strategies.

Two-third of the area of the Netherlands is flood prone. Storm surges at the North Sea, floods in the rivers, failure of secondary dikes, as well as heavy rainfall may cause flooding. Most of the flood prone areas rely for their existence on drainage by pumping, because their surface level may be permanently or during floods up to several metres below the surrounding water levels. During the past decades climate change is generally felt as a reason for major concern. However, the impacts of climate change on increase in extreme conditions may be up to 45% per century. If we look at the man-induced changes in land use, due to increase in population and rapid increase in the value of public and private property, then one may observe an increase of 100–1,000% per century. One should therefore wonder what would have to be our major concern.

In the paper the relevant processes are described, based on some characteristic data on water management and flood protection in the Netherlands. It is shown that impacts of climate change on water management and flood protection may be expected, but that such impacts can easily be accommodated during improvement works on water management systems and flood protection provisions that from time to time will be required. It will be much more important to take carefully into account the risk of flooding in the planning of land use development, especially for valuable types of land use like urban and industrial areas, green houses and recreation areas.

A little over a decade ago, a number of legislative changes were made in Polish law dealing with spatial planning in relation to floodplains and water management. More specifically, the amendments were a consequence of the adoption of the relevant Floods Directive by the European Parliament and the European Council in 2007, which was introduced as a countermeasure to the allegedly increasing flood risks associated with the ongoing urbanisation of floodplains. It was recognised that the risks of material and non-material damage associated with increasing urbanisation are so great that appropriate legal provisions must be introduced to reduce them. More than a decade has passed since the introduction of these provisions (the Floods Directive was adopted in Poland in March 2011). Over time, it has become apparent that the implementation of many legislative changes in Poland related to spatial planning in floodplains has been impractical and has had a very negative impact on the spatial and economic development of these areas. In this article we focus on the Lower Bug Valley and show how these new laws have led to a deterioration of the living situation in the floodplains. Indeed, the problem of economic decline in the floodplains and Natura 2000 sites is very serious and affects people who have lived for years in a 2–5 km wide strip in quiet surroundings flood-prone areas and along the river bend. Restrictions on livestock and the decline of agriculture are compounded by the lack of interest in acquiring habitats and land. These areas are becoming an open-air museum with residents living on social benefits and pensions.