title: Drought planning and management: using high spatial resolution as part of the solution.
abstract: Water scarcity is intensified by drought, a phenomenon that impacts many sectors of society and affects virtually all climate zones. The Palmer drought indices are widely used by scientists and policy makers to understand drought and model its components. Despite the spatial heterogeneity and variability in variables required by the Palmer model, regional index values are most commonly used for real-time drought assessment. Local stakeholders charged with developing flexible and tailored water management policies have articulated the need for drought indices calculated at finer spatial resolutions than a regional scale. We use the Pacific Northwest United States (U.S.) as a study area to demonstrate the differences between drought indices calculated for U.S. climate divisions with those calculated at a 0.5° by 0.5° latitude/longitude resolution. Our results indicate that regional values of the two cumulative Palmer drought indices do not represent finer-resolution values well. For half of the study area, the pictures of drought (as determined by regional and finer-resolution values) are drastically different more than 30% of the time. Thus, quite often water managers do not have a clear understanding of the relative severity of drought in their area, which can have serious implications for drought mitigation and adaptation.
authors.affiliation: Vanderbilt Institute for Energy and the Environment, Vanderbilt University , PMB 407702, 2301 Vanderbilt Place, Nashville, Tennessee 37240-7702, United States.
authors.forename: Leslie Lyons
authors.initials: LL
authors.lastname: Duncan
authors.forename: Debra
authors.initials: D
authors.lastname: Perrone
authors.forename: John H
authors.initials: JH
authors.lastname: Jacobi
authors.forename: George M
authors.initials: GM
authors.lastname: Hornberger
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D002980:Climate; D004189:Disaster Planning; D055864:Droughts; D006801:Humans; D008962:Models, Theoretical; D015205:Northwestern United States