Browsing by Author "Contreras López, Manuel"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Coastal erosion in sandy beaches along a tectonically active coast: The Chile study case
    (2021) Martínez Reyes, Carolina Del Pilar; Winckler Grez, Patricio; Agredano Martin, Roberto; Esparza Acuña, Cesar Antonio; Torres Torres, Iván Fernando; Contreras López, Manuel
    Coastal erosion in 45 sandy beaches covering nearly 2000 km along the tectonically active Chilean coast is assessed during the last four decades. The historical analysis is based on the assessment of decadal changes of the shoreline position extracted from topographic surveys, aerial photographs, satellite images and survey maps using the DSAS software. Results show that 80% of the sites presented erosion rates (>-0.2 m/y), 7% beaches accreted (>0.2 m/y) while 13% remained stable. Eroded beaches include headland bay beaches, embayed and pocket beaches. A discussion on the possible causes explaining these results is conducted. While changes in offshore wave climate are spatially smooth within the region, relative mean sea level changes are highly variable and modulated by tectonic activity; the reduction of the sediment supply explains erosion rates in few cases.
  • Thumbnail Image
    Item
    Impacts in ports on a tectonically active coast for climate-driven projections under the RCP 8.5 scenario: 7 Chilean ports under scrutiny
    (2022) Winckler, Patricio; Esparza Acuña, César Antonio; Mora, Javiera; Melo Contreras, Óscar; Bambach, Nicolás; Contreras López, Manuel; Sactic, María Isabel
    Economic costs due to operational downtime and wave overtopping under the RCP 8.5 scenario are evaluated at 7 Chilean ports. Wave statistics for a historical period (1985–2004), mid-century (2026–2045), and end-of-century projections (2081–2100) are computed with a Pacific-wide model, forced by wind fields from six General Circulation Models. Offshore waves are then downscaled to each port, where a proxy of downtime is computed by comparing wave heights with vessel berthing criteria. The difference in downtime between the historical and future projections is attributed to climate change. Results show that some ports would reduce and others increase downtime for mid-century projections due to local effects. However, by the end-of-century, all ports would experience a reduction in downtime. Additionally, by mid-century, overtopping would increase in northern ports as a combination of extreme waves and sea-level rise (SLR), while in southern ports, it is expected to be slightly reduced. By the end-of century, overtopping would increase in the whole region, mainly driven by SLR. However, overtopping is significantly altered by coseismic uplift/subsidence that may occur during the design-life of coastal works. Finally, a few practical suggestions aimed atimproving infrastructure management and operational conditions at the analyzed ports are outlined.