Modeling the hydrologic impacts of widespread land cover change from the Mountain Pine Beetle in the Rocky Mountain West
Geology and Geological Engineering
Changing climate in the Rocky Mountain West and worldwide has led to insect infestation and resultant tree mortality at epidemic levels. By the end of 2012, the mountain pine beetle has killed over four million acres of evergreen forest in Colorado alone. This unprecedented change in land cover is known to affect tree-scale hydrologic processes in infested forests; however watershed scale impacts are highly variable due to differences in climate and landscape. Complex integrated model simulations are therefore needed to understand how the loss of forest cover over large spatial and temporal extent will impact important mountain headwater resources. To accomplish this task, we use ParFlow, an integrated, parallel watershed model that makes use of high-performance computing to simulate surface and subsurface fluid flow, coupled with the common land model (CLM) to simulate land surface processes. In addition, a particle tracking code called SLIM-FAST will be used to model resulting changes in flow path partitioning and geochemical transport. Model simulations will investigate the effects of widespread changes in land cover across scales ranging from a single watershed, the Big Thompson, to a regional scale model of the entire state of Colorado. As the pine beetle infestation is an ongoing concern, multi-decadal simulations will be run for both domains.