Master thesis Julius Weyer

Julius Weyer (2017)
Geomorphological evaluation of the potential for induced bank filtration in the Jesús Mariá watershed at the Pacific Coast of Costa Rica. Master thesis, Technische Universität Dresden, September 2017

Abstract

River bank filtration (RBF) is a water treatment technique applied in many countries of the world. Yet, the selection on potential suitable sites is often linked to costly, laborious and time-consuming on-site investigations. In this paper, GIS-based analysis methods concerning geomorphological stream features were used to draw inferences about the RBF potential along the Jesús Mariá watershed in Costa Rica. For the analysis, fully automatized methods were developed in ArcGIS and applied for the width and the slope of the river. A partially-automatized method was used for the radius of curvature and manual measures were taken for the wavelength and amplitude at the specific river sections. Trend analyses reveal high correlations between these features at already existing sites in Europe and the USA. Results indicate that suitable sites can be found along the upper and lower reaches of the Jesús Mariá and in the upper reaches of the Machuca river. However, especially sites in the upper reaches are classified as cascade forms which contradict the general suitability assumptions from similar studies. Since the classification was based on a rather limited amount of sites analyzed, the sites classified as unsuitable should not be completely disregarded. In these cases, further, detailed analysis is suggested. Therefore, the proposed scheme should be used as an integrated approach for the selection procedure, rather than be regarded as an isolated method. Nevertheless, findings provided in this paper refine and extent the work done in previous studies and propose a methodology that is easily applicable for other river systems, is time-saving and it requires only a limited amount of readily available data.