2022 CSDMS meeting-062
Modeling icy riverbank erosion into permafrost
Josie Arcuri, (she/her/hers),University of Colorado Boulder Boulder Colorado, United States. Josephine.Arcuri@colorado.edu
Irina Overeem, University of Colorado Boulder Boulder Colorado, United States. firstname.lastname@example.org
Rivers flowing across permafrost limit the residence time of floodplain soil organic carbon (SOC) by transferring riverbank material to the fluvial network. In this way, permafrost riverbank erosion limits production of greenhouse gases (GHG) in a deepening permafrost active layer. Concurrently, arctic riverbanks are laden with permafrost ice wedges and channels themselves are seasonally occupied by ice; these factors are known to affect fluvial potential to erode and remove material from floodplains. However, we do not know how ice impacts rates of riverbank migration through permafrost, especially in small arctic watersheds where observations are limited. We hypothesize that bank migration into permafrost is best described by melting of bank ice but is also described by slumping of the active layer, and fluvial carrying capacity. First, we develop a model of thermal riverbank erosion. Next, we detail plans to incorporate slumping and mechanical erosion into a holistic icy riverbank erosion model. We will characterize riverbanks along the Canning this field season and use or measurements to calibrate our model. Then, we will test which mechanisms are most significant in forming permafrost riverbanks, as well as describe their evolution under warming mean annual air temperatures. This work is also useful for predicting the future contribution of the arctic rivers to their basin-wide carbon budget. This work has immediate importance for people who traverse or depend on arctic landscapes, but especially those who live within them. Arctic landscape response to climate change is just as much a story about the loss of place and vanishing resources as it is about a dynamic earth system.
Mkutano wa CSDMS 2022: Modeling Icy Riverbank Erosion into Permafrost - Josie Arcuri, Chuo Kikuu cha Colorado Boulder, Colorado Josephine Arcuri, Irina O'Reilly, Chuo Kikuu cha Colorado Boulder Mito inayotiririka kupitia permafrost hupunguza muda wa kukaa wa kaboni ya kikaboni ya udongo wa mafuriko kwa kuhamisha nyenzo za ukingo wa mto kwenye mtandao wa mto. Kwa njia hii, erosion ya mto wa permafrost hupunguza uzalishaji wa gesi za chafu (GHG) katika safu ya kazi ya permafrost inayozidi. Matofali ya mto wa Arctic yanajaa barafu ya permafrost na mifereji yenyewe hujazwa barafu kwa majira; mambo haya yanajulikana kuathiri uwezo wa mto wa kuharibika na kuondoa vifaa kutoka kwa mabonde ya mafuriko. Hata hivyo, hatujui jinsi barafu inavyoathiri viwango vya uhamiaji wa ukingo wa mto kupitia permafrost, haswa katika mabwawa madogo ya maji ya Aktiki ambapo uchunguzi ni mdogo. Uhamiaji wa benki katika permafrost huelezwa vizuri na kuyeyuka kwa barafu ya benki, lakini pia huelezwa na kuanguka kwa safu ya kazi na uwezo wa kubeba maji. Kwanza, tunatengeneza mfano wa mmomonyoko wa maji ya mto. Ifuatayo, tunaelezea mipango ya kuingiza kuanguka na mmomonyoko wa mitambo katika mfano wa jumla wa mmomonyoko wa mto wa barafu. Sisi sifa banks mto kando ya Canning msimu huu shamba na kutumia au vipimo kwa calibrate mfano wetu. Kisha, tutajaribu ni utaratibu gani ni muhimu zaidi katika kuunda permafrost mto ukingo, kama vile kuelezea mageuzi yao chini ya joto wastani wa joto la hewa. Kazi hii pia ni muhimu kwa kutabiri mchango wa baadaye wa mito ya Arctic kwa bajeti yao ya kaboni ya bonde lote. Kazi hii ina umuhimu wa haraka kwa watu ambao hupita au hutegemea mandhari za Arctic, lakini haswa wale wanaoishi ndani yao. Mabadiliko ya hali ya hewa ya Arctic ni hadithi ya kupoteza nafasi na rasilimali zinazopotea kama vile ni kuhusu mfumo wa dunia ya nguvu.