Quantifying the Longitudinal Propagation of Aquatic Disturbances From the Hermit’s Peak/Calf Canyon Fire Along the Gallinas Creek-Pecos River Fluvial Network

Wildfires are increasing globally in frequency, severity, and extent, but their impact on fluvial networks, and the resources they provide, remains unclear. Growing evidence suggests that wildfires trigger cascading impacts that propagate across fluvial networks and impact key ecosystem services. These impacts originate in hillslopes and streams within burned areas and affect water quantity and quality over multiple spatiotemporal scales. While we currently map fire areas and their severity with relatively high accuracy using areal and satellite images, we do not have comparable abilities to map the propagation of wildfire disturbances across fluvial networks. Since current fire models consistently predict that the prevalence of wildfire and associated damage will continue to increase due to anthropogenic climate change and forest management practices, we must be able to quantify and predict the propagation of wildfire disturbances. However, to date, we lack data and modeling tools to answer the fundamental questions: How far downstream do wildfire disturbances propagate in fluvial networks and what are the key controlling factors? These knowledge gaps hinder our ability to mitigate wildfire impacts on aquatic ecosystems and to protect their vital services. We monitored the propagation of water quality disturbances generated by the largest wildfire recorded in New Mexico, the Hermit’s Peak/Calf Canyon Fire. For this, we instrumented multiple sites along the Gallinas Creek – Pecos River fluvial network, and at Santa Rosa Lake. We found that burned material became available soon after the monsoon precipitation began and that such disturbances propagated for more than 180 km and were brought into Santa Rosa Lake, which regulated the propagation of sediments and ash. The work presented here is being submitted for peer-reviewed publication led by the graduate students working on the project. We appreciate your respect for their work.