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Fiche 1,  Justifications,  Anglais

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... a soil/duff drought index [developed by Keetch and Byram (1968]) that ranges from 0 (no drought) to 800 (extreme drought) and is based on soil capacity of 8 inches of water. Factors in the index are maximum daily temperature, daily precipitation, antecedent precipitation, and annual precipitation.  4, fiche 1, Anglais, - Keetch%2DByram%20drought%20index

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The Keetch Byram Drought Index (KBDI) provides a daily measure of soil dryness, which, in turn, gives an indication of water stress in plants. The KBDI represents the net effect of precipitation and evapotranspiration in producing cumulative moisture deficiency in deep duff or upper soil layers. The KBDI has a range from 0 (no drought or soil moisture deficiency, i.e. soil at field capacity) to 2000 (extreme drought, maximum soil moisture deficiency possible). The index can be viewed as the amount of rain needed to bring the soil back to saturation, with one mm of rain reducing the index by 10 points. The 0-2000 point scale is divided into three drought classes: 0-999 = Low; 1000-1499 = Moderate; 1500 - 2000 = High. The KBDI is simple to calculate as it uses only two, daily weather observations - maximum temperature and 24-hour rainfall. The system functions in a book-keeping fashion where estimates of daily evapo-transpiration and measurements of precipitation increase or decrease the value of yesterdays index. The KBDI by itself is not a Fire Danger Rating System as it gives no indicate of the ease of ignition of the vegetation, or of the rate of fire spread, fire intensity and difficulty of control. It does however serve as a useful measure of drought occurrence.  7, fiche 1, Anglais, - Keetch%2DByram%20drought%20index

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Keetch-Byram Drought Index (KBDI): ... 0 - 200: Soil moisture and large class fuel moistures are high and do not contribute much to fire intensity. Typical of spring dormant season following winter precipitation. 200 - 400: Typical of late spring, early growing season. Lower litter and duff layers are drying and beginning to contribute to fire intensity. 400 - 600: Typical of late summer, early fall. Lower litter and duff layers actively contribute to fire intensity and will burn actively. 600 - 800: Often associated with more severe drought with increased wildfire occurrence. Intense, deep burning fires with significant downwind spotting can be expected. Live fuels can also be expected to burn actively at these levels.  9, fiche 1, Anglais, - Keetch%2DByram%20drought%20index

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... the Palmer Drought Index (PDI) and the Keetch-Byram Drought Index (KBDI) ... were [both] developed by John Keetch and George Byram, and originally were developed as aids for agriculture. The ... KBDI is used extensively in the eastern states and also in some parts of the west.  10, fiche 1, Anglais, - Keetch%2DByram%20drought%20index

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In the metric system the value of the index is usually assumed to range from 0 to 200 mm (even though 800 points actually corresponds to 204 mm).  3, fiche 1, Anglais, - Keetch%2DByram%20drought%20index

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Keetch-Byram Drought Index [is] a commonly-used drought index adapted for fire management applications ...  11, fiche 1, Anglais, - Keetch%2DByram%20drought%20index

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"Duff" is ... an important term in the fire weather program of the US Forest Service, used to describe the partially decayed organic matter on the forest floor which can become highly combustible during drought periods and contribute to the longevity and spread of forest fires. ... the Keetch-Byram Drought Index is sometimes referred to as the soil/duff drought index because it is a measure of how dry the soil and duff layers are.  6, fiche 1, Anglais, - Keetch%2DByram%20drought%20index

Fiche 1,  Justifications,  Français

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On écrirait mieux «sècheresse».  2, fiche 1, Français, - indice%20de%20s%C3%A9cheresse%20Keetch%2DByram

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sècheresse : Cette graphie, puisée des Rectifications de l'orthographe recommandées par le Conseil supérieur de la langue française, est attestée dans le Petit Robert (2006).  3, fiche 1, Français, - indice%20de%20s%C3%A9cheresse%20Keetch%2DByram

Fiche 1,  Justifications,  Espagnol