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Sherburne County Multi -Hazard Mitigation Plan, 2020 <br />Figure 20. Seauence of drought occurrence and imvacts for commonly accevted c <br />Natural Climate Variability <br />Pracrpiialion deficiency H-gh temperature, high winds. low <br />i:amou4nt.. intensity, timing] relatlye humidity, greater <br />R <br />surishIne, leas cl6ud cover <br />V _ <br />� <br />f7 CA <br />Reduced infiltration, runoff- <br />o v <br />deep percolation, and Increased evaporataon <br />WO <br />ground water recharge and transpir <br />W <br />i <br />- - - - - - - _ - - - - - - - - - - - - - - - - - - - - <br />- - <br />i:. <br />soil water deficiency <br />ftl <br />3 <br />7 7 <br />'0 <br />Plant water Stress, reduced <br />u 4� <br />biomass and yield <br />�Ay1 <br />j' <br />------------ <br />Reduced streamftaw, inflow to <br />m <br />reservoirs, lakes, and ponds; <br />reduced wettands, <br />7 <br />wildltfs habitat <br />o fs <br />Econnmic Im L Svcia+l Imposts Envrrorrrrmerrta0 ifmpach <br />Source: (National Drought Mitigation Center, 2018) <br />xought types <br />Meteorological drought is qualified by any significant deficit of precipitation. Hydrological drought is <br />manifest in noticeably reduced river and stream flow and critically low groundwater tables. The term <br />agricultural drought indicates an extended dry period that results in crop stress and harvest reduction. <br />Socioeconomic drought refers to the situation that occurs when water shortages begin to affect people <br />and their lives. It associates economic goods with the elements of meteorological, agricultural and <br />hydrological drought. Many supplies of economic goods (e.g., water, food grains, and hydroelectric <br />power) are greatly dependent on the weather. <br />Quantifying Drought Conditions <br />There are numerous approaches to assessing drought conditions. The current gold standard for <br />accurate drought conditions in the United States is the United States Drought Monitor (USDM) Map. <br />Established by the National Drought Mitigation Center (NDMC) in iggg, the Drought Monitor is a <br />weekly map that depicts drought conditions in all 50 states and Puerto Rico. Each weekly map is <br />produced by a NDMC assigned author. Though drought map authors utilize a broad domain of <br />geospatial, climatic data and drought indices that cover every aspect of drought, perhaps their most <br />valuable resource is the input they receive each week from hundreds of drought experts throughout the <br />country. The drought monitor map is thus a collective synthesis of the best quantitative and the most <br />reliable qualitative information available (The National Drought Mitigation Center, 2oi8). Figure 21 <br />displays an example map and statistics table prepared by the U.S. Drought Monitor for Minnesota on <br />November 20, 2012. In total, there are four drought categories: moderate (Di), severe (D2), extreme <br />(D3), and exceptional (D4). A fifth category, abnormally dry (Do) is used to depict areas that are <br />Page175 <br />