Possibilities of Identification of Localities, Endangered by Surface Runoff and Sediment Transport for Purposes of Landscape Planning
Abstract: Surface runoff and water erosion are natural phenomenon, and historically they acted as important drivers in forming of morphology of our landscape. Negative connotation it got during last decades, due to rising conflicts with human activities, as result of climate changes and improper land use practices. The evidence itself would not be that problematic, as increasing damages, which correspond to rising value structures located in improper localities or on the other hand, rising number of localities endangered by surface runoff due to miss-land use. One should always respect, most of natural processes within the landscape are relatively simply predictable (at least in its basic forms) and their neglecting might lead to high damages or high costs related to construction of control and compensation measures and structures. There are especially risky locating structures within the landscape into waterways, building structures, creating obstacles to water flow or increasing proportion of sealed surfaces within appropriate compensation of rainwater retention. Normal floods, regardless if standard ones or flash floods caused by storm event on small water courses, are relatively well mapped concerning of their occurrence, prediction and also possibilities of control strategies. However, so called pluvial floods (sheet and later concentrated surface runoff out of stream channels) has still not been included into legislation concerning neither its control strategies, nor detection methods. These extreme runoff events are often very risky and dangerous, as they coma very fast and there is mostly no chance to install any protective measures or structures. Damages caused are usually mainly due to loads of sediment from agricultural land, deposited at the structures. Analysis of surface runoff accumulation, including its quantification and assessment of massive development of soil erosion processes and related sediment transport and deposition is technically possible and relatively easy. Using advanced GIS techniques and analysis of DEM, detailed land use and land cover maps and soil conditions maps, landscape can be analyzed and critical points of conflicts between landscape and urban planning versus surface runoff and sediment transport. In case of existing infrastructure such information can lead to design and implementation of control measures or changes in land use. In case of newly planned structures or urbanization, the most effective is to avoid risky spots, as installation of any control measures brings unavoidable risk of their failure – with much higher consequent damages. Such localities can preferably be used for non-conflict use such as recreation, sport grounds or natural zones.
