LANDIS-II Wildfire and Vegetation Simulation Outputs ==================================================== ========================================================================================================== Overview ========================================================================================================== LANDIS-II (the second generation of the Landscape Disturbance and Succession Model) is a spatially explicit, process-based vegetation model. It simulates how climate, vegetation, and wildfire interact through time. LANDIS-II generates its own fires based on algorithms using daily weather data and models the feedback between vegetation and wildfire dynamics internally. The LANDIS-II modeling work supports projections of wildfire behavior and vegetation change under different climate and vegetation management scenarios across California. ========================================================================================================== Model Outputs ========================================================================================================== The LANDIS-II model output includes: - Detailed records of individual fire events - Burn probability maps when multiple iterations are considered - Projected changes in vegetation type resulting from the combined effects of climate and wildfire Each climate simulation is run under two vegetation management scenarios: - Business-as-Usual (BAU): continues vegetation management practices consistent with the 2010-2019 period (~150,000-180,000 acres treated per year) - High Ambition: models a management goal of treating one million acres per year, consistent with the 2018 Executive Order and the 2021 California Wildfire and Forest Resilience Action Plan, focusing on reducing fuels in “high” or “very high” wildfire hazard areas ========================================================================================================== Model Iterations and Data Status ========================================================================================================== For each scenario and climate simulation, LANDIS-II will be run for two (or more) iterations (“replicates”) for each management scenario and climate projection to generate statistics on fire probability. Currently, the repository includes sample outputs from a single replicate for each WRF model and both vegetation management scenarios. Replicates ---------- Each replicate is identified by a numeric ID that encodes both the compute system on which the simulation was run and the batch of the High Ambition scenario implementation. The numbering following this convention: Compute system (hundreds digit): - 1-99: Simulations run on Ungoliant (UC Merced) - 100-199: Simulations run on SIG infrastructure - 200-299: Simulations run on Azaghal High ambition scenario batch (ones digit): - Replicates ending in 0-9 (first batch, e.g., 110-114, 210-214): High Ambition vegetation management implemented through 2045 only - Replicates ending in 20 (second batch, e.g., 120-122, 220-222): High Ambition vegetation management implemented across the full simulation period through 2100, reflecting an updated management parameterization Note: The second batch of High Ambition replicates (those in the 20s within each system range) represents a revised scenario in which high-ambition treatment levels are sustained for the entire simulation period rather than tapering after 2045. BAU replicates are not subject to this distinction. Data Organization ----------------- - Temporal resolution: Annual - Spatial resolution: 150 meters - Temporal span: 2001 - 2100 - Iterations available: One sample replicate per WRF model (for each vegetation management scenario) Data are stored as raster files (.tif) with metadata encoded within raster headers. The directory structure organizes data by: - Climate model - Relative humidity bias adjustment (synthetic RH settings, where applicable) - Vegetation management scenario (BAU or HighAmbition) ========================================================================================================== Input Climate Models ========================================================================================================== Dynamically Downscaled Climate Data (WRF - UCLA) ------------------------------------------------ LANDIS-II uses dynamically downscaled climate data from the Weather Research and Forecasting (WRF) model provided by UCLA. These datasets provide fine-scale representations of historical and projected climate conditions relevant for simulating fire and vegetation dynamics. The LANDIS-II wildfire modeling effort uses the post bias-adjusted WRF datasets. Model Scenario Ensemble Member CESM2 SSP3-7.0 r11i1p1f1 CNRM-ESM2-1 SSP3-7.0 r1i1p1f2 EC-Earth3-Veg SSP3-7.0 r1i1p1f1 FGOALS-g3 SSP3-7.0 r1i1p1f1 Statistically Downscaled Climate Data (LOCA2 - Scripps) ------------------------------------------------------- LANDIS-II also uses statistically downscaled climate data called the Localized Construct Analogs (LOCA2-Hybrid) provided by the Scripps Institution of Oceanography for 2000-2100, which include multiple scenarios and ensemble configurations. Model Scenario(s) Ensemble Member(s) ACCESS-CM2 SSP2-4.5, SSP5-8.5 r1i1p1f1 CNRM-ESM2-1 SSP5-8.5 r1i1p1f2 EC-Earth3-Veg SSP2-4.5, SSP3-7.0, SSP5-8.5 r5i1p1f1, r4i1p1f1 HadGEM3-GC31-LL SSP5-8.5 r3i1p1f3, r1i1p1f3 INM-CM5-0 SSP2-4.5 r1i1p1f1 MPI-ESM1-2-HR SSP2-4.5 r1i1p1f1 MRI-ESM2-0 SSP370 r4i1p1f1 ========================================================================================================== Variables ========================================================================================================== - AG_NPP: Annual aboveground net primary productivity in grams per square meter totaled across the calendar year - ANEE_proc: Annual net ecosystem exchange in grams per square meter totaled across the calendar year - TotalC: Total carbon density of landscape in grams per square meter - bda_insects: Area affected by type of biological disease agent - biomass-removed: Aboveground biomass removed by management activities in grams per square meter - TotalBiomass: Aboveground biomass in grams per square meter - CWHR_fortype: Categorical classification of species or species mixture into a forest type - fire severity: Categorical fire severity - prescripts: Categorical map of broad management activity type ========================================================================================================== Citation and Acknowledgments ========================================================================================================== LANDIS-II modeling and data processing were conducted as part of the California Energy Commission-funded research on wildfire probability and vegetation-climate interactions by the Pyregence consortium (pyregence.org).