Ongoing sea-level rise has brought renewed focus on terrestrial sediment supply to the coast because of its strong influence on whether and how long beaches, marshes and other coastal landforms may persist into the future. Here, we summarise findings of sediment discharge from several coastal rivers, revealing that infrequent, large-magnitude events have disproportionate influence on the morphodynamics of coastal landforms and littoral cells. These event-dominated effects are most pronounced for small, steep mountainous rivers that supply beach and wetland sediment along the world ’ s active tectonic margins, although infrequent events are important drivers of sediment discharge for rivers worldwide. Additionally, extreme events (recurrence intervals of decades to centuries) that follow wildfires, earthquakes, volcanic eruptions, extreme precipitation or – most notably – combinations of these factors can redefine coastal sediment budgets and morphology. Some of these extreme events (e.g., wildfires plus rainfall) are increasing in magnitude and frequency under modern climate warming, with the likely result of increasing sediment flux to affected coastlines. Climate change is also altering watershed processes in both high latitudes and high altitudes, resulting in increased sediment supply to downstream catchments. We conclude that sediment inputs to coastal systems are highly variable with time, and that the variability and trends in sediment input are as important to characterise as long-term averages.
{"title":"Fires, Floods, and Other Extreme Events — How Watershed Processes Under Climate Change Will Shape Our Coastlines","authors":"J. Warrick, A. East, Helen W. Dow","doi":"10.1017/cft.2022.1","DOIUrl":"https://doi.org/10.1017/cft.2022.1","url":null,"abstract":"Ongoing sea-level rise has brought renewed focus on terrestrial sediment supply to the coast because of its strong influence on whether and how long beaches, marshes and other coastal landforms may persist into the future. Here, we summarise findings of sediment discharge from several coastal rivers, revealing that infrequent, large-magnitude events have disproportionate influence on the morphodynamics of coastal landforms and littoral cells. These event-dominated effects are most pronounced for small, steep mountainous rivers that supply beach and wetland sediment along the world ’ s active tectonic margins, although infrequent events are important drivers of sediment discharge for rivers worldwide. Additionally, extreme events (recurrence intervals of decades to centuries) that follow wildfires, earthquakes, volcanic eruptions, extreme precipitation or – most notably – combinations of these factors can redefine coastal sediment budgets and morphology. Some of these extreme events (e.g., wildfires plus rainfall) are increasing in magnitude and frequency under modern climate warming, with the likely result of increasing sediment flux to affected coastlines. Climate change is also altering watershed processes in both high latitudes and high altitudes, resulting in increased sediment supply to downstream catchments. We conclude that sediment inputs to coastal systems are highly variable with time, and that the variability and trends in sediment input are as important to characterise as long-term averages.","PeriodicalId":340199,"journal":{"name":"Cambridge Prisms: Coastal Futures","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123169592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Long-term in situ monitoring of beach morphology is indispensable for capturing the processes of foreshore morphological changes, and thus many beach monitoring campaigns have been conducted globally. Here, we review the various foreshore beach processes attributable to cross-shore sediment transport, which have been elucidated through long-term beach monitoring. Historical in situ beach monitoring has revealed many daily–annual-scale cyclic foreshore beach morphological changes and shoreline changes; however, many shorter- and longer-term processes remain unresolved, for example, the short-term response to tidal fluctuations and the long-term response to sea level rise. The cost per area surveyed of state-of-the-art equipment will gradually decrease over time, and the accuracy, resolution, and volume of information obtained from the monitoring methods, which are still in the early stages of development, will improve as research progresses. Continued long-term monitoring and acquisition of previously unmeasured monitoring data through the development of monitoring methods are expected to help elucidate unresolved beach processes.
{"title":"What can long-term in situ monitoring data tell us about our coastlines?","authors":"M. Banno","doi":"10.1017/cft.2022.9","DOIUrl":"https://doi.org/10.1017/cft.2022.9","url":null,"abstract":"\u0000 Long-term in situ monitoring of beach morphology is indispensable for capturing the processes of foreshore morphological changes, and thus many beach monitoring campaigns have been conducted globally. Here, we review the various foreshore beach processes attributable to cross-shore sediment transport, which have been elucidated through long-term beach monitoring. Historical in situ beach monitoring has revealed many daily–annual-scale cyclic foreshore beach morphological changes and shoreline changes; however, many shorter- and longer-term processes remain unresolved, for example, the short-term response to tidal fluctuations and the long-term response to sea level rise. The cost per area surveyed of state-of-the-art equipment will gradually decrease over time, and the accuracy, resolution, and volume of information obtained from the monitoring methods, which are still in the early stages of development, will improve as research progresses. Continued long-term monitoring and acquisition of previously unmeasured monitoring data through the development of monitoring methods are expected to help elucidate unresolved beach processes.","PeriodicalId":340199,"journal":{"name":"Cambridge Prisms: Coastal Futures","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128194831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：