Evaluation of the sediment load in Apulia watersheds

Soil erosion is a natural physical phenomenon associated to changes in surface earth morphology. It usually develops quite slowly, even if it is often accelerated because of anthropic actions. Erosion depends on many different connected factors, such as climatic conditions, soil type, morphology, hydrology, vegetation, crops and agricultural techniques. Erosion processes can be described both in a qualitative and a quantitative way, and referring to many different spatial and temporal scales of analysis. In this paper, an analysis of erosion and transport dynamics in watersheds in Puglia, Southern Italy, is proposed, with the aim of investigating the most influential parameters in the development of these phenomena on wider scales. Integrating a modeling activity with the analysis of field data, many different relationships are proposed, particularly to relate the solid transport with climate, morphology, hydrological and hydraulic characteristics of the sampling area. This could be particularly useful to evaluate quantitatively and qualitatively the entity of erosion processes in ungauged watersheds. Moreover, the effects of erosion are also related to some parameters which are strictly connected with the characteristics of the investigated region, such as area and index flood. Furthermore, considering the fundamental mechanisms of flow generation, the relationship between sediment transport rate and areas contributing to runoff are analyzed. Finally, once detected the most influential parameters, some multiple regressions are performed and the results are here critically interpreted.