Abstract


This thesis deals with the development of erosion, transport and sedimentation model in a catchment scale.

The main questions arise from the review of knowledge in landscape evolution models, more specifically erosion models. Subsequently, it is studied the way these questions have been approached, based either on the state of art as well as on the experience gained in the application of hydrological and sedimentological models.

The model is formulated based on these theoretical and practical backgrounds, from which a source code is developed considering the assumptions of the hypothesis. Thus, the model can be seen as a sum of concepts and techniques coherently integrated, such that it allows the user to include all the knowledge available to solve a particular problem.  The model is based on a hydrological model, the TETIS model, developed in the Departamento de Ingeniería Hidráulica y Medio Ambiente of  Universidad Politécnica de Valencia and the sedimentological approach is based on the CASC2D-SED model developed in the Engineering Research Center of Colorado State University.

The model is tested in a natural catchment in order to validate the hypothesis. The analyzed catchment is Goodwin Creek, in Mississippi, USA, from which there is information available about rainfall, liquid and solid discharge, topography, soils and soil uses. Through this test, the limitations and potential applications of the model can be realized.

The model takes advantage of the knowledge about physical conditions, for instance the topological structure of the river network, and avoids aspects less known and more difficult to parameterize, for instance the random structure of slope rill network. From this perspective, the model is robust and parsimonious, particularly in the sedimetological behavior, which requires just one calibration element.

The model improves the way a catchment is conceptualized, and hence the response to a rainfall event can be better predicted. Moreover, it defines in which regions of the catchment occur the different components of runoff and relate these regions with concrete elements (slope for the runoff, gully for the interflow and river for base flow) from parameters easily identified in a natural catchment.

From the model itself, it is possible to study the hydrological and sedimentological dynamics of the catchment. On the other hand, from the programming tool it is possible to perform analysis to elucidate environmental and anthropogenic changes in the dynamics. Thus, there is not just a scientific applicability, such as knowledge and understanding of natural processes, but also a practical one, Duch as the improvement of engineering design, the territory planning and the analysis of natural hazards.