Building permit decisions are one of the most important elements of the investment process in Poland. It should be noted that water reservoirs influence the diversification of landscapes by increasing their attractiveness in both urban and rural areas. The article aimed to verify the relationship between the changes in land-use development and investments related to small retention. Another goal was classifying objects for which building permits have been obtained and registered. Changes in land-use development associated with the introduction of ponds, which blend in with the landscape, are desirable from the perspective of retaining water resources in urban and rural ecosystems. The research methodology was based on spatial data and included statistical analyses in three regions: Mazowieckie, Lodzkie and Swietokrzyskie. Studies carried out in these regions showed a spatial correlation associated with investments in small retention. The research used methods of the global I Moran statistic and local Moran statistics. The data used in the study came from the Register of Applications, Decisions and Notifications, made available by the Main Office of Construction Site. The research indicates clusters of investments in small retention in analysed regions. The majority of investors are residents who invest in earth ponds. The study shows that investment in small retention is connected with ecosystem services.

The construction of dams in rivers can offer many advantages, however the consequences resulting from their failure could result in major damage, including loss of life and property destruction. To mitigate the threats of dam break it is essential to appreciate the characteristics of the potential flood in realistic manner. In this study an approach based on the integration of hydraulic modelling and GIS has been used to assess the risks resulting from a potential failure of Zardezas dam, a concrete dam located in Skikda, in the North East of Algeria. HEC-GeoRAS within GIS was used to extract geometric information from a digital elevation model and then imported into HEC-RAS. Flow simulation of the dam break was performed using HEC-RAS and results were mapped using the GIS. Finally, a flood hazard map based on water depth and flow velocity maps was created in GIS environment. According to this map the potential failure of Zardezas dam will place a large number in people in danger. The present study has shown that Application of Geographical Information System (GIS) techniques in integration with hydraulic modelling can significantly reduce the time and the resources required to forecast potential dam break flood hazard which can play a crucial role in improving both flood disaster management and land use planning downstream of dams.

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.