Risk map for the runoff of the total suspended solids and total phosphorus for Southwestern Finland.

Abstract

Coastal waters are those most affected by terrestrial runoff, and they can be considered hot spots of carbon and nutrient enrichment as well. However, despite nutrient loading is a popular topic for research, there are not enough studies that are dealing with the sources of nutrient loading and coastal filter function. The aim of my bachelor’s thesis was to create a map based on the model for non point source pollution analysis for Raseborg, Hanko and Inkoo areas. The map shows areas that are important for water quality and may be considered as requiring increased attention from environmental managers. The model that was used in risk map production is a simplified USLE (universal soil loss equation) model. It is possible to use it, because the hydrological processes for erosion and the transportation of water pollutants/sediments are basically the same. The model is designed to predict the total suspended solids (TSS) and total phosphorus (TP) loads and highlight the areas on land, runoff from which is critical for the water quality. All the data for the risk map production was taken from publicly open sources. ArcGIS Pro was used for processing data and model implementation. The final map shows us good results in identifying risk areas and proving that the model is valid. The resulting map can already be used by environmental management, however, with updated coefficients for land use, especially for forestry, the identification of risk areas could be even more precise.