TY - JOUR T1 - Parameterizing an aeolian erosion model for rangelands JF - Aeolian Research Y1 - 2022 A1 - Edwards, B.L. A1 - Webb, N.P. A1 - Galloza, M. A1 - Van Zee, J.W. A1 - Courtright, E.M. A1 - Cooper, B.F. A1 - Metz, L.J. A1 - Herrick, J.E. A1 - Okin, G.S. A1 - Duniway, M.C. A1 - Tatarko, J. A1 - Tedela, N.H. A1 - Moriasi, D.N. A1 - Newingham, B.A. A1 - Pierson, F.B. A1 - Toledo, D. A1 - Van Pelt, R.S. KW - aeolian KW - Assessment KW - Dust emission KW - Indicators KW - Land management KW - monitoring KW - Wind erosion AB -

Aeolian processes are fundamental to arid and semi-arid ecosystems, but modeling approaches are poorly developed for assessing impacts of management and environmental change on sediment transport rates over meaningful spatial and temporal scales. For model estimates to provide value, estimates of sediment flux that encapsulate intra- and inter-annual and spatial variability are needed. Further, it is important to quantify and communicate transparent estimates of model uncertainty to users. Here, we present a wind erosion and dust emission model parameterized for rangelands using a Generalized Likelihood Uncertainty Estimation framework. Modeled horizontal sediment flux was calibrated using data from five diverse grassland and shrubland sites from the USDA National Wind Erosion Research Network. Observations of wind speed, vegetation height, length of gaps between vegetation, and percent bare ground were used as model inputs. Horizontal sediment flux estimates from 10,000 independently selected parameter sets were compared to flux observations from 44 ∼ month-long collection periods to calculate a likelihood measure for each model. Results show good agreement for individual sampling periods across sites with few observations falling outside prediction bounds and a one-to-one relationship between median predictions and observations. Additionally, combined distributions of sediment flux estimates from all sample periods for a given site closely approximated the probability of observing a given flux at that site. These results suggest AERO effectively represents temporal variability in aeolian transport rates at rangeland sites and provides robust assessments suitable for assessing land health and better predicting changes in air quality and the impacts of land management activities.

VL - 54 ER - TY - JOUR T1 - Climate change impacts on wind and water erosion on US rangelands JF - Journal of Soil and Water Conservation Y1 - 2019 A1 - Edwards, B.L. A1 - Webb, N.P. A1 - Brown, D.P. A1 - Elias, E. A1 - Peck, D.E. A1 - Pierson, F.B. A1 - Williams, C.J. A1 - Herrick, J.E. KW - climate change KW - rangeland KW - soil erosion KW - water erosion KW - Wind erosion AB -

Soil erosion by water and wind in US rangelands has serious implications for rangeland health and food security and poses significant hazards to human health and communities. Accordingly, understanding how future climate change may impact soil erosion is critical for developing appropriate management strategies that mitigate negative impacts to the extent practical and potentially build resilience. Here, we review potential impacts of climate change on controls of erosion in US rangelands and discuss potential erosion responses. Projected climate changes are expected to have regionally variable effects on important controls of erosion, especially vegetation cover; community composition; frequency, magnitude, and geographical range of fire disturbance; and high intensity, erosive weather events, all of which have the potential to increase rangeland vulnerability to erosion. We identify knowledge gaps relevant to these controls and discuss management considerations to address climate change impacts to soil erosion concerns for US rangelands. In order to improve resilience and the efficacy of climate change adaptation, we recommend that existing monitoring data be used to create assessments of vulnerability, that soil erosion should be explicitly included in management benchmarks and decision support tools, and that no-regrets management options be implemented in anticipation of future impacts.

VL - 74 ER - TY - Generic T1 - AERO: A wind erosion modeling framework with applications to monitoring data T2 - 73rd Soil and Water Conservation Society Annual Conference Y1 - 2018 A1 - Edwards, B.L. A1 - Nicholas Webb A1 - McCord, S.E. AB -

The Aeolian Erosion Model (AERO) is a versatile aeolian transport and dust emission modeling environment developed to provide a robust interface for fundamental research while also acting as a decision-support tool for land managers. The model simulates size-resolved horizontal and vertical mass flux on the plot scale from user inputs of meteorological, soil and vegetation data. AERO is highly customizable; the model can be run for a single set of conditions, a time series of conditions, conditions over space, or a time series of conditions over space. Drag partitioning, vertical dust emission schemes, and horizontal transport equations are user-selectable. Key variables (e.g., vegetation cover, canopy gap distribution, soil type) can be input as scalars, defined by descriptive statistics, supplied as probability distributions, or, when run spatially, as remote sensing-derived inputs and atmospheric data from the Weather Research and Forecasting (WRF) weather prediction model. As such, the model is adaptable to many research and management applications over a range of site conditions. Here, we detail the model framework and processing options and provide an example of model application to U.S. Bureau of Land Management (BLM) Assessment, Inventory and Monitoring (AIM) plots in New Mexico, USA to assess potential implications of management actions for dust emission rates. The test case demonstrates how the AERO model can leverage emerging large-scale ecological datasets like AIM to provide new opportunities to evaluate aeolian sediment transport responses to land surface conditions, potential interactions with disturbances and ecological change, and impacts of anthropogenic land use and land cover change.

JF - 73rd Soil and Water Conservation Society Annual Conference CY - Albuquerque, USA VL - 29 July – 1 August, 2018 ER - TY - Generic T1 - Vegetation effects on spatiotemporal variability in aeolian mass flux over a range of ecological conditions T2 - 10th International Conference on Aeolian Research (ICAR X) Y1 - 2018 A1 - Edwards, B.L. A1 - Nicholas Webb A1 - Van Zee, J.W. A1 - Chappell, A. AB -

Issues of scale have long been a chief concern in efforts by the aeolian research community to monitor and model aeolian mass flux over spatially large areas. Observations over small sampling scales (< 1 m2) dominate physical descriptions of aeolian transport processes and predictive mass flux equations. Consequently, those descriptions are unlikely to represent the controls of transport over space (>> 1 m2). Loss of process fidelity is compounded as area increases because additional sources of variance are introduced and unknown synergies occur between controlling factors. Uncertainty is further amplified by increasing landscape heterogeneity, but because monitoring efforts are often limited in scope, few data are available to adequately describe spatial variability of transport to produce unbiased areal estimates, particularly in vegetated landscapes. In this paper, we use transport and vegetation data from US National Wind Erosion Research Network (http://winderosionnetwork.org) sites to investigate spatiotemporal variability of transport and its controls for a range of vegetation conditions. For a given site, vegetation characteristics (e.g., canopy height, vegetative cover fraction, and gap size distribution) are recorded seasonally using standardized methods. Transport is measured using a stratified scheme of 27 MWAC collectors randomly located in groups of 3 within 9 cells in a 100 m2 plot. We use regression co-kriging to map monthly transport and investigate how vegetation as a controlling factor drives variability in transport. Results are expected to inform future modeling efforts and improve analyses of wind erosion and dust emission responses to land use and land cover change.

JF - 10th International Conference on Aeolian Research (ICAR X) CY - Bordeaux, France VL - 25-29 June, 2018 ER -