title: Sensitivity analysis of a sediment dynamics model applied in a Mediterranean river basin: global change and management implications.
abstract: Climate change and land-use change are major factors influencing sediment dynamics. Models can be used to better understand sediment production and retention by the landscape, although their interpretation is limited by large uncertainties, including model parameter uncertainties. The uncertainties related to parameter selection may be significant and need to be quantified to improve model interpretation for watershed management. In this study, we performed a sensitivity analysis of the InVEST (Integrated Valuation of Environmental Services and Tradeoffs) sediment retention model in order to determine which model parameters had the greatest influence on model outputs, and therefore require special attention during calibration. The estimation of the sediment loads in this model is based on the Universal Soil Loss Equation (USLE). The sensitivity analysis was performed in the Llobregat basin (NE Iberian Peninsula) for exported and retained sediment, which support two different ecosystem service benefits (avoided reservoir sedimentation and improved water quality). Our analysis identified the model parameters related to the natural environment as the most influential for sediment export and retention. Accordingly, small changes in variables such as the magnitude and frequency of extreme rainfall events could cause major changes in sediment dynamics, demonstrating the sensitivity of these dynamics to climate change in Mediterranean basins. Parameters directly related to human activities and decisions (such as cover management factor, C) were also influential, especially for sediment exported. The importance of these human-related parameters in the sediment export process suggests that mitigation measures have the potential to at least partially ameliorate climate-change driven changes in sediment exportation.
authors.affiliation: Universidad Politécnica de Madrid, Escuela Técnica Superior de Ingenieros de Minas, C/Ríos Rosas 21, 28003 Madrid, Spain. Electronic address: mscanales@dmami.upm.es.
authors.forename: M
authors.initials: M
authors.lastname: Sánchez-Canales
authors.affiliation: Universidad Politécnica de Madrid, Escuela Técnica Superior de Ingenieros de Minas, C/Ríos Rosas 21, 28003 Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: López-Benito
authors.affiliation: Institut Català de Recerca de l'Aigua, C/Emili Grahit 101, 17003 Girona, Spain.
authors.forename: V
authors.initials: V
authors.lastname: Acuña
authors.affiliation: School of Geography, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors.forename: G
authors.initials: G
authors.lastname: Ziv
authors.affiliation: The Natural Capital Project, Woods Institute for the Environment, 371 Serra Mall, Stanford, CA 94305-502, USA.
authors.forename: P
authors.initials: P
authors.lastname: Hamel
authors.affiliation: The Natural Capital Project, Woods Institute for the Environment, 371 Serra Mall, Stanford, CA 94305-502, USA.
authors.forename: R
authors.initials: R
authors.lastname: Chaplin-Kramer
authors.affiliation: Universidad Politécnica de Madrid, Escuela Técnica Superior de Ingenieros de Minas, C/Ríos Rosas 21, 28003 Madrid, Spain.
authors.forename: F J
authors.initials: FJ
authors.lastname: Elorza
mesh_terms: D057231:Climate Change; D003247:Conservation of Natural Resources; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods*; D019015:Geologic Sediments / Q000032:analysis*; D019083:Mediterranean Region; D008962:Models, Theoretical; D045483:Rivers / Q000737:chemistry*
keywords: Global change; Mediterranean river basin; Sensitivity analysis; Soil erosion; USLE equation