On the definition of droughts

Dracup, John A.; Lee, Kil Seong; Paulson, Edwin G.

doi:10.1029/wr016i002p00297

Cited by 872 publications

(502 citation statements)

References 8 publications

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“…We summarized short-term May-June drought properties of the 1339-1998 reconstruction by runs analysis (Dracup et al, 1980) using an arbitrary drought threshold of 53.55 mm. This threshold is 80% of the 1931-98 mean observed May-June precipitation.…”

Section: Analysis Of Wet and Dry Periodsmentioning

confidence: 99%

Preliminary reconstructions of spring precipitation in southwestern Turkey from tree‐ring width

Touchan

Garfin

Meko

et al. 2003

Intl Journal of Climatology

133

101

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Two reconstructions of spring (May-June) precipitation have been developed for southwestern Turkey. The first reconstruction (1776-1998) was developed from principal components of nine chronologies of Cedrus libani, Juniperus excelsa, Pinus brutia, and Pinus nigra. The second reconstruction (1339-1998) was derived from principal components of three J. excelsa chronologies. Calibration and verification statistics of both reconstructions indicate reasonably accurate reconstruction of spring precipitation for southwestern Turkey, and show clear evidence of multi-year to decadal variations in spring precipitation. The longest period of reconstructed spring drought, defined as consecutive years with less than 80% of normal May-June precipitation, was 4 years (1476-79). Only one drought event of this duration has occurred during the last six centuries. Monte Carlo analysis indicates a less than 33% probability that southwestern Turkey has experienced spring drought longer than 5 years in the past 660 years. Apart from the 1476-79 extended dry period, spring droughts of 3 years in length have only occurred from 1700 to the present. The longest reconstructed wet period, defined as consecutive years with more than 120% of normal May-June precipitation, was 4 years (1532-35). The absence of extended spring drought during the 16th and 17th centuries and the occurrence of extended wet spring periods during these centuries suggest a possible regime shift in climate. Preliminary analysis of links between large-scale climatic variation and these climate reconstructions shows that there is a relationship between extremes in spring precipitation and anomalous atmospheric circulation in the region.

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Section: Analysis Of Wet and Dry Periodsmentioning

confidence: 99%

Preliminary reconstructions of spring precipitation in southwestern Turkey from tree‐ring width

Touchan

Garfin

Meko

et al. 2003

Intl Journal of Climatology

133

101

View full text Add to dashboard Cite

show abstract

“…For example, meteorological droughts are on the basis of precipitation deficits, agricultural droughts on soil moisture deficits, and hydrological droughts on streamflow deficits (Dracup et al, 1980). In general, meteorological droughts develop and end relatively quickly, while the occurrence of agricultural drought is later than that of meteorological drought.…”

Section: Introductionmentioning

confidence: 99%

The response of agricultural drought to meteorological drought and the influencing factors: A case study in the Wei River Basin, China

Huang

Chang

et al. 2015

Agricultural Water Management

131

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The heuristic segmentation method Drought propagation The Budyko hypothesis The Wei River Basin a b s t r a c t It is of importance to investigate the response of agricultural drought to meteorological drought and its influencing factors, which could help better understand drought evolution mechanisms and facilitate agricultural drought monitoring and predictions. As a case study in the Wei River Basin (WRB), China, the heuristic segmentation method was first applied to identify change points of long-term hydrological and metrological conditions for the period of 1960-2007. Then the cross wavelet analysis was utilized to reveal the detailed links between agricultural drought (based on Palmer Drought Severity Index (PDSI)) and meteorological drought (based on Standardized Precipitation Index (SPI)) at the seasonal time scale. The controlling factors governing the agricultural response were then explored through quantitatively examining the corresponding large-scale atmospheric conditions and local-scale land surface characteristics. Results indicate that: (1) the variations of the lag time of agricultural drought in response to meteorological drought is large at the seasonal scale, characterized by fast response in summer and relatively slow response in autumn, and the contrasting response in the time lag is mainly due to the buffering effects of soils; (2) the variations of Arctic Oscillation (AO) was found to have large effects on the lag time, with both positive and negative effects; (3) a negative correlation between the lag time and the parameter w in the Fu' equation within the Budyko framework was found, implying the potential effects of vegetation cover on the drought propagation from meteorological drought to agricultural drought in the WRB.

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“…Afin de caractériser les événements hydrologiques, DRACUP et al (1980a) suggèrent de considérer un ensemble de définitions en fonction de l'unité de mesure des données (jour, mois, an) et du seuil utilisé pour définir l'événement tels que présentées sur la figure 1.…”

Section: -Définitionsunclassified

La modélisation stochastique des étiages: une revue bibliographique

Abi‐Zeid¹,

Bobée²

2005

rseau

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SUMMARYThe increasing pressure on the water resources requires better management of the water déficit situations may it be unusual droughts or yearly recurring low-flows. It is therefore important to model the occurrence of thèse déficit events in order to quantify the related risks. Many approaches exist for the modeling of low-flow/drought events. We présent hère a literature review of the stochastic methods. We start by clarifying the différence between lowflows and droughts, two ternis which are often used interchangeably. We then présent some low-flow and drought indicators.The stochastic approach may be divided into two catégories: Frequency analysis and stochastic processes. Most frequency analysis studies aim to assign to a flow value X a cumulative frequency, either directly using empirical distribution fonctions, or by fitting a theoretical distribution. This allows the computation of a critical flow x T corresponding to a return period T, such that P(X < x T ) = -Thèse studies use mostly the annual minima of daily flows T where the hydrological data is assumed independent and identically distributed. It is also common to analyze Q m , the annual minimum of the m-consecutive days average flow, m being generally 7,10,30, 60, 90, or 120 days, and to adopt as critical flow the m-day average having a return period of T years. The distributions which are used include the Normal, Weibull, Gumbel, Gamma, Log-Normal (2) In conclusion, we remark that frequency analysis does not take into account well the duration aspects and uses simplifying stationarity hypothesis. Séries analysis provides duration distributions for simple flow processes. The advantage of point processes is that they can model complex, dépendent and nonstationary processes. Furthermore, alternating point processes can be used to model déficit durations and generate synthetic data such as occurrences of déficit and surplus events. We argue that the duration of low-flows is an important issue which has not received a lot of attention.

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On the definition of droughts

Cited by 872 publications

References 8 publications

Preliminary reconstructions of spring precipitation in southwestern Turkey from tree‐ring width

Preliminary reconstructions of spring precipitation in southwestern Turkey from tree‐ring width

The response of agricultural drought to meteorological drought and the influencing factors: A case study in the Wei River Basin, China

La modélisation stochastique des étiages: une revue bibliographique

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