Possible land use scenario for the Reda catchment case study and its impact on water management and marine water

Tomasz Walczykiewicz, Ewa Jakusik, Urszula Opial-Gałuszka, Paweł Przygrodzki, Magdalena Skonieczna, Łukasz Woźniak

 

Institute of Meteorology and Water Management – National Research Institute, Poland

 

Due to the fact that water management responds to changing natural and socio-economic conditions its future perspective, depending on multiple and variable factors, is difficult to predict future using traditional prognostic methods. The scenario development process is a useful method for long-term strategic planning in the water management sector. The paper analyzes the possible scenario of land use development in Reda catchment area and its impact on water management and marine water. Scenario building uses mainly analysis of land use trends and analysis of planning documents of different sectors for this area. Reda river is situated in the northern part of Poland in Pomeranian Province next to Tricity (Gdansk, Gdynia, Sopot) metropolitan area. Area of Reda catchment is approximately 486 km2. Currently land use is dominated by agriculture areas (arable land, heterogeneous agricultural areas and pastures) and forest. The shares of agriculture and forest in the Reda catchment are 51% and 44%, respectively. Agricultural areas are dominated in the upper reaches of river and its estuary. Area of artificial surfaces is 4 %. Other types of land use like wetlands and water bodies are insignificant.

Currently one of the main problems in the catchment Reda is a danger of flooding. The river is characterized by high water levels in the winter and early spring. With an average state of the river water reaches an average width of 10-12 meters. In the past Reda river was used for floatable transport, today it is used almost exclusively by kayakers in the sport and tourist. The intensive housing development is continuously implemented. The cause of the increasing flood risk in the catchment Reda is mainly spatial planning.  Polish planning system is not hierarchical. National Spatial Development Plan (NSDP) and zoning plans provinces are indicative only for public administration respectively at governmental level and regional level. In practice, the NSDP translates, however, for the management of space at the regional level, less at the level of local (municipal), while zoning plans provinces have some impact on land use in the municipalities, at least in the field of directions, priorities and concepts, to a lesser extent on specific decisions and solutions. They contain objectives and principles formulated in general and hence poorly translate into actions having a direct impact on changes in space and their consequences.

The elaborated scenario assumes that the development of residential buildings outside the Tricity will continue. The inhabitants of Tricity will choose as a place to live outside of the center. This will affect the intensification of surface runoff and, consequently, the threat of flood and marine pollution. Therefore, the importance of rainwater management will increase. Thus, development of the water management sector should, in the future, concentrate more on specific local catchment areas where application of the IWRM principles and adaptation to climate changes will be easier and possible to merge with local spatial planning. Activities for adaption to climate changes should, above all, be undertaken by parties which will directly experience the change effects, i.e. by citizens, large and small enterprises and service providers.