Intense rainfall-runoff events and subsequent soil erosion can cause serious damage to the infrastructure in residential areas in Europe countries and all over the world. In the Czech Republic, the Ministry of the Interior has supported an analysis dealing with the risks to residents, infrastructure, and water bodies from flash floods and sediment transport. A total of more than 150,000 risk points were identified by GIS morphology and land-use analysis. The threat, the vulnerability, and the resulting risk category were determined for each of these points. The WaTEM/SEDEM model was used to assess the threat with 10-m data resolution. The summarized vulnerability of real objects on individual runoff trajectories was combined with the threat of sediment transport, resulting in the overall risk represented by a 5-degree scale, from lowest (1) to highest (5). The output of the project lies stored in the WEB application. Nineteen percent of the sites in the Czech Republic, i.e., more than 23,000 sites, have been assigned to categories 4 and 5, with a high level of risk. Thirty-four percent of cadastral units are classified as the high risky (4416 cadasters, with a total area 24,707 km2). Approximately 30% of the population of the Czech Republic lives in high-risk cadastral areas. Four scenarios of protection were modeled. To reduce the high-risk and very high-risk sites (categories 4 and 5), the most effective solution is the implementation of technical measures or conversion to grassland within the contributing watersheds. This could reduce the number of high-risk sites from 23,400 to 3700.Methods of sediment transport modeling and risk evaluation, based on presented USLE input data and documented WaTEM/SEDEM model, can be used worldwide. Especially in post-soviet union countries with shared arable land development and erosion consequences.

• Keywords
• Pluvial flow, Risk, Sediment transport, Soil erosion, USLE, WaTEM/SEDEM,
• MeSH
• Geologic Sediments analysis   MeSH
• Disasters * MeSH
• Environmental Monitoring methods   MeSH
• Water Movements * MeSH
• Soil MeSH
• Risk MeSH
• Floods * MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Czech Republic MeSH
• Names of Substances
• Soil MeSH

This paper presents a newly-derived method for directly determining the amount of transported dissolved phosphorus by water erosion. The results of the method are compared to prediction based on enrichment ratio (as proposed by Sharpley) and average share of dissolved phosphorus (DP) in total transported phosphorus (5%) that is widely used in the Czech Republic. Four study areas (catchments of dozens of sq. kilometer) were chosen for their different characteristics (land use, average slope, average elevation, phosphorus concentration in the soil) which influence their rainfall-runoff behavior. The modeled results are compared with data measured in situ. The two methods provide similar results in intensively agriculturally used regions. Agreement among the methods was observed for three study areas with significant erosion intensity (above 4 t/ha/year). In the catchment with significantly lower erosion intensity (0.5 t/ha/year), the indirect method (Sharpley) underestimates the amount of DP transported in the watercourses. The sum of transports of suspended solids into watercourses and the average available phosphorus content in the soil determined by the Mehlich 3 method (PM3) are the main factors influencing the results provided by the two methods. An analysis of the impact of these factors on the difference between the results of the methods was provided. Transport of suspended solids is related to the method difference (R range from 0.37 to 0.71). However, no significant relationship was found between the difference in the results and the average PM3 content in the soil (R range from 0.15 to 0.36).

• Keywords
• Dissolved phosphorus, Eutrophication potential, Soil erosion,
• MeSH
• Models, Chemical * MeSH
• Phosphorus analysis   MeSH
• Geological Phenomena MeSH
• Soil Pollutants analysis   MeSH
• Water Pollutants analysis   MeSH
• Environmental Monitoring methods   MeSH
• Water Movements MeSH
• Soil MeSH
• Water analysis   MeSH
• Agriculture MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Czech Republic MeSH
• Names of Substances
• Phosphorus MeSH
• Soil Pollutants MeSH
• Water Pollutants MeSH
• Soil MeSH
• Water MeSH