Short- and long-term responses of nourishments: Barra-Vagueira coastal stretch, Portugal Bárbara Marinho 1 & Carlos Coelho 1 & Magnus Larson 2 & Hans Hanson 2 Received: 22 December 2016 /Revised: 1 June 2017 /Accepted: 10 July 2017 # Springer Science+Business Media B.V. 2017 Abstract Dredged material resulting from deepening and maintenance activities of the Aveiro Harbor inlet channel, northwestern coast of Portugal, has been used to mitigate the erosion trend recorded on nearby beaches (from Barra to Costa Nova Beach) through direct placement of sand by using standard dredge equipment. The disposal activities of dredged material have been undertaken at two main sites: between the south breakwater and the 1st groin of Costa Nova (dumping area 1, DA1) and between the 3rd and the 5th groin of Costa Nova (dumping area 2, DA2).The sand was placed in the nearshore, between the -2 and -7 m Chart Datum, CD, contours. In this study, short- and long-term coastal morphologic changes in the sea bottom, in response to several nourishment operations and to the incoming waves, within the dumping area boundaries are investigated based on a data set of hydro- graphic surveys collected annually, just before and after the nourishments, between 2009 and 2015. Preliminary results describing the main morphologic changes, evolution trends, sediment budget variations, and nourishments performance are discussed using mainly Geographic Information System techniques. Overall, the analysis demonstrates that the short- term losses in the dumping areas (one month of interval) can reach 50% of the nourished volume, revealing a significant movement of the fill material towards offshore. Seasonal var- iations promoting cross-shore material exchange can also pre- vail and misrepresent the sediment balances, if the monitoring area is not comprehensive. Furthermore, some bathymetric analysis suggested that longshore transport gradients have moved the fill material from Barra beach to downdrift areas. All the obtained results contribute to the ongoing discussion about the effectiveness of nearshore sand placements especial- ly in context of an energetic environment. Keywords Dredging . Artificial nourishment . Morphodynamic . GIS . Monitoring Introduction With the increasing urban pressure over the coastal areas, eco- nomic growth, sea level rise and recurrent storm-induced beach erosion events, a demand for adaptive coastal management strat- egies, able not only to provide coastal protection but also create areas for nature and recreation, has been intensely encouraged during the latest decade. In this respect, sand nourishments are typically considered as a soft coastal protection strategy since its pure concept does not involve the construction of hard-struc- tures. This type of solution is becoming popular between coastal engineers and managers due to the several benefits that they can offer (not only environmental but also socials) to mitigate ero- sion, ensure flood safety and increase beach width. Recently, as a way to explore the positive attributes from such projects, sev- eral innovative coastal maintenance approaches have been emerging. An international example is the well-known pilot * Bárbara Marinho barbaramarinho@ua.pt Carlos Coelho ccoelho@ua.pt Magnus Larson magnus.larson@tvrl.lth.se Hans Hanson hans.hanson@tvrl.lth.se 1 RISCO & Civil Engineering Department, Aveiro University, Aveiro, Portugal 2 Department of Water Resources Engineering, Lund University, Lund, Sweden J Coast Conserv DOI 10.1007/s11852-017-0533-5