Detecting and quantifying hydromorphology changes in a chilean river after 50 years of dam operation

Alcayaga, Hernán; Palma, Sebastián; Caamaño, Diego; Mao, Luca; Soto-Alvarez, Marco

doi:10.1016/j.jsames.2019.04.018

Cited by 13 publications

(2 citation statements)

References 45 publications

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“…Though there are no large dams in the basin, expanding croplands, growing population and a changing climate (Webb et al, 2020) have reduced the river flow and sediment inflow to the beach, which shows erosional rates (−0.75 m/yr) within the analyzed period. Further south, the construction of Rapel dam in 1968 (Alcayaga et al, 2019) is presumably one of the sources of beach erosion (−1.73 m/yr) in Santo Domingo – El Yali (Contreras-López et al, 2014). This hypothesis is based on the similar sediment characteristics found in the river and the beach (Vergara, 2014).…”

Section: Discussionmentioning

confidence: 99%

Coastal erosion in sandy beaches along a tectonically active coast: The Chile study case

Martı́nez

Winckler

Martín

et al. 2021

Progress in Physical Geography: Earth and Environment

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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.

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Section: Discussionmentioning

confidence: 99%

Coastal erosion in sandy beaches along a tectonically active coast: The Chile study case

Martı́nez

Winckler

Martín

et al. 2021

Progress in Physical Geography: Earth and Environment

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“…River dynamics are highly non‐linear, making it very challenging to disentangle the relative role of several sources of impacts on their morphological response. In Chile, only some rivers have been studied in these terms, and these studies generally consider a single source of alteration such as dam closure, gravel mining, or climate change (Alcayaga et al, 2019; Arróspide et al, 2019; Bañales‐Seguel et al, 2020; Batalla et al, 2018; Iroumé et al, 2019; Pacheco et al, 2022; Tranmer et al, 2018; Tranmer et al, 2020). Difficulties arise from the wide range of space and time scales, the duration and temporality of the disturbances, the complexity of acquiring the necessary quality and quantity of input data required for predictive models (Alcayaga et al, 2018), the varying responses of rivers to disturbances based on the system's sensitivity (Fryirs, 2017), and their historical context (Khan & Fryirs, 2020).…”

Section: Introductionmentioning

confidence: 99%

Synergistic process interactions and morphological change in a river reach subject to multiple disturbances, the Laja River, Chile

Barahona,

Alcayaga,

Caamaño

et al. 2024

Earth Surf Processes Landf

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This work studies the multiple sources of impacts and disturbances in the Laja River (Central Chile) and evaluates the changes in water and sediment flows and planimetric geomorphic changes.The disturbances sources correspond to hydroelectric plants, water withdrawals for irrigation and the sustained decrease trend in rainfall in the basin. The changes in the plan‐view shape of the river reach were quantified using remote sensing techniques, through a supervised classification of Landsat 5 TM and 8 OLI satellite images, identified Water (W), Islands and Riverine Vegetation (IRV) and Bars and Banks Without Vegetation (BBWV), obtained a Kappa index>0,83 for a period of 15 years (2006–2021).Compared with historical records, the period of analysis shows a decrease in annual rainfall by 17.5%. In addition, water withdrawals for irrigation have contributed to a 64% decrease in monthly stream discharge during the dry season. As a consequence of the decrease in annual rainfall and water withdrawals for irrigation, the sediment transport capacity has also decreased by 10.5%.The changes in morphological driving variables (stream flows and sediment transport regimes) have manifested themselves in morphological changes, where it was possible to establish that a change in the channel form occurred in the last 15 years, going from a river with a single channel to a braided one. An important vegetation establishment has accompanied this morphological change on both riverbanks and the central bars. The colonizing vegetation corresponds to fast‐growing non‐native species (Salix spp., Populus spp. and Alnus spp). A stabilization of the channel form is expected, consolidating itself as a braided section with alternating vegetated bars.

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Evaluation of water quality and its driving forces in the Shaying River Basin with the grey relational analysis based on combination weighting

Tao

Sun

Cao

et al. 2021

Environ Sci Pollut Res

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Detecting and quantifying hydromorphology changes in a chilean river after 50 years of dam operation

Cited by 13 publications

References 45 publications

Coastal erosion in sandy beaches along a tectonically active coast: The Chile study case

Coastal erosion in sandy beaches along a tectonically active coast: The Chile study case

Synergistic process interactions and morphological change in a river reach subject to multiple disturbances, the Laja River, Chile

Evaluation of water quality and its driving forces in the Shaying River Basin with the grey relational analysis based on combination weighting

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