Avulsaµes de rios - inundaa§aµes catastra³ficas desencadeadas quando um rio traz um novo caminho para o mar - podem ocorrer com mais frequência nos rios conforme oníveldo mar sobe
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)
Acima: Vista de satanãlite de uma avulsão de um rio, em que o rio mudou abrupta e catastroficamente seu curso para o oceano. Este delta éencontrado em East Aceh, Sumatra. Crédito: imagem de base cortesia de Sentinel 2, Vamsi Ganti e Sam Brooke.
O aumento doníveldo mar devido a mudança climática estãoprestes a mudar a maneira como os rios trazm naturalmente seu caminho atéa costa. A natureza dessa mudança dependera¡ tanto da taxa de aumento doníveldo mar quanto da carga de sedimentos transportada pelo rio, de acordo com novos modelos de pesquisadores do Caltech e seus colegas.
Periodicamente, um rio muda seu curso para o mar, formando um novo caminho por meio de um processo denominado avulsão do rio. As avulsaµes de rios são uma parte natural da vida de um rio e são responsa¡veis ​​pela construção de novas terras e pela nutrição dos ecossistemas de pa¢ntanos com a¡gua, nutrientes e sedimentos. No entanto, as avulsaµes de rios também são perigos naturais catastra³ficos. Eles foram responsa¡veis ​​por algumas das enchentes mais mortais da história da humanidade, incluindo as enchentes do Rio Amarelo em 1887 e as enchentes na China de 1931, que juntas custaram cerca de seis milhões de vidas. Em alguns rios, como o Mississippi, os engenheiros construaram canais e diques para contornar os perigos da avulsão do rio.
Vista de satanãlite do delta do Rio Amarelo, China. O Rio Amarelo, como
outros rios em todo o mundo, muda repetidamente seu curso
no delta para depositar sedimentos e construir novas terras.
Crédito: imagem de base cortesia do Google Earth
"A avulsão de um rio éuma inundação catastra³fica que também écrucial para sustentar terras costeiras", disse Austin Chadwick , principal autor de um artigo sobre o novo modelo publicado pela Proceedings of the National Academy of Science em 13 de julho. "Mas a questãoanã: como a elevação doníveldo mar afetara¡ essas inundações catastra³ficas? " Chadwick trabalhou nesta pesquisa como estudante de doutorado na Caltech com o Professor de Geologia Michael Lamb e Vamsi Ganti da UC Santa Barbara.
Oníveldo mar tem subido em geral desde o inicio do século 20, e em um ritmo acelerado. Em 2014, o Painel Intergovernamental sobre Mudanças Clima¡ticas (IPCC) projetou que oníveldo mar poderia subir atéum metro atéo final deste século. Os cientistas da Terra tem mantido um debate sobre como isso poderia afetar as avulsaµes de rios em deltas, as paisagens fanãrteis criadas onde um rio encontra um oceano ou lago - uma questãocratica, dado que as paisagens deltaicas hospedam cerca de 10% da população humana.
“Avulsaµes são terremotos de riosâ€, diz Lamb. “Sa£o eventos naturais repentinos e a s vezes catastra³ficos que ocorrem com regularidade estatastica, mudando a direção dos grandes rios. Estamos tentando entender onde e quando ocorrera£o as próximas avulsaµesâ€. Lamb, Chadwick e Ganti combinaram teoria, modelagem numanãrica e observações de campo para explicar com que frequência as avulsaµes de rios ocorreriam e como sua frequência responderia a um clima em mudança.
Eles descobriram que a ocorraªncia de futuras avulsaµes depende principalmente de dois fatores: a taxa de aumento doníveldo mar e a quantidade de lama e areia carregada por um rio.
Vista de satanãlite do Delta do Rio Mississippi. Em deltas como o Mississippi,
a elevação doníveldo mar não são causara¡ a perda de terras costeiras, mas
também fara¡ com que as avulsaµes de rios ocorram com mais
frequência e mais para o interior do que historicamente.
Crédito: imagem de base cortesia do Google Earth
Na maioria dos deltas, incluindo o delta do rio Mississippi, o aumento doníveldo mar deve causar avulsaµes catastra³ficas mais frequentes. Isso porque, a medida que oníveldo mar sobe, os rios respondem depositando mais sedimentos no canal, o que aumenta o leito do rio em relação a s terras vizinhas, tornando o rio insta¡vel. Eventualmente, uma violação do dique forçara¡ o rio a encontrar um caminho mais curto e angreme para o mar. Avulsaµes mais frequentes podem inundar comunidades costeiras como Nova Orleans, Louisiana, que já são vulnera¡veis ​​a inundações pela elevação doníveldo mar.
A elevação doníveldo mar pode afetar não apenas quando, mas também onde, ocorrera£o futuras avulsaµes do rio. “Se oníveldo mar subir mais rápido do que os rios podem depositar sedimentos, a zona de deposição e avulsão se deslocara¡ rio acima, introduzindo novos riscos de avulsão nas comunidades rio acimaâ€, disse Chadwick. Em tal cena¡rio, a infraestrutura de gestãodo rio existente (barragens e diques) poderia se tornar obsoleta, e os custosos esforços de avulsão-mitigação precisariam ser deslocados rio acima.
Chadwick, Lamb e Ganti esperam que este trabalho possa ajudar a orientar o gerenciamento de rios em deltas densamente povoados, oferecendo-lhes uma estrutura para calcular o que esperar nas próximas décadas.
O artigo éintitulado "Freqa¼aªncia de avulsão acelerada do rio em deltas das planacies devido ao aumento doníveldo mar." O trabalho foi financiado pela National Science Foundation e pelo Resnick Sustainability Institute da Caltech.