Long-term variability of drought indices in the Czech Lands and effects of external forcings and large-scale climate variability modes

Abstract. While a considerable number of records document the temporal variability of droughts for central Europe, the understanding of its underlying causes remains limited. In this contribution, time series of three drought indices (Standardized Precipitation Index – SPI; Standardized Precipitation Evapotranspiration Index – SPEI; Palmer Drought Severity Index – PDSI) are analyzed with regard to mid- to long-term drought variability in the Czech Lands and its potential links to external forcings and internal climate variability modes over the 1501–2006 period. Employing instrumental and proxy-based data characterizing the external climate forcings (solar and volcanic activity, greenhouse gases) in parallel with series representing the activity of selected climate variability modes (El Niño–Southern Oscillation – ENSO; Atlantic Multidecadal Oscillation – AMO; Pacific Decadal Oscillation – PDO; North Atlantic Oscillation – NAO), regression and wavelet analyses were deployed to identify and quantify the temporal variability patterns of drought indices and similarity between individual signals. Aside from a strong connection to the NAO, temperatures in the AMO and (particularly) PDO regions were disclosed as one of the possible drivers of inter-decadal variability in the Czech drought regime. Colder and wetter episodes were found to coincide with increased volcanic activity, especially in summer, while no clear signature of solar activity was found. In addition to identification of the links themselves, their temporal stability and structure of their shared periodicities were investigated. The oscillations at periods of approximately 60–100 years were found to be potentially relevant in establishing the teleconnections affecting the long-term variability of central European droughts.

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Long-term variability of droughts in the Czech Lands and large-scale climate drivers

10.5194/cp-2018-61 ◽

2018 ◽

Cited By ~ 1

Author(s):

Jiří Mikšovský ◽

Rudolf Brázdil ◽

Miroslav Trnka ◽

Petr Pišoft

Keyword(s):

Volcanic Activity ◽

Temporal Variability ◽

Radiative Forcing ◽

Large Scale ◽

Decadal Variability ◽

Southern Oscillation ◽

Drought Indices ◽

Climate Forcings ◽

Czech Lands

Abstract. While a considerable number of records document the temporal variability of droughts for central Europe, understanding of its underlying causes remains limited. In this contribution, time series of three drought indices (SPI, SPEI, PDSI) that may be used to characterize the long-term drought regime of the Czech Lands are analyzed with regard to their mid-to-long-term variability and potential links to external and internal climate forcings over the 1501–2006 period. Employing instrumental and proxy-based data characterizing the external climate forcings (solar and volcanic activity, concentration of greenhouse gases) in parallel with series that correspond to the activity of climate variability modes with pronounced inter-annual to inter-decadal variability (El Niño–Southern Oscillation – ENSO, Atlantic Multidecadal Oscillation – AMO, Pacific Decadal Oscillation – PDO), regression and wavelet analysis were deployed to identify and quantify the temporal variability patterns of drought indices and similarity between individual signals. Aside from the long-term trend that correlates with anthropogenic radiative forcing, temperatures in the AMO and PDO regions were disclosed as one of the possible drivers of inter-decadal variability in the Czech drought regime. Colder and wetter episodes were found to coincide with increased volcanic activity, while no clear signature of solar activity was found. In addition to identification of the links themselves, their temporal stability and coherence were investigated. The oscillations at periods of approximately 60–100 years were found to be potentially relevant in establishing the teleconnections affecting the long-term variability of central European droughts.

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Long-Term, Gridded Standardized Precipitation Index for Hawai‘i

Data ◽

10.3390/data5040109 ◽

2020 ◽

Vol 5 (4) ◽

pp. 109

Author(s):

Matthew P. Lucas ◽

Clay Trauernicht ◽

Abby G. Frazier ◽

Tomoaki Miura

Keyword(s):

High Spatial Resolution ◽

Standardized Precipitation Index ◽

Precipitation Index ◽

Drought Indices ◽

Drought Severity ◽

Spatially Explicit ◽

Historical Period ◽

The Standardized Precipitation Index ◽

Climatic Information

Spatially explicit, wall-to-wall rainfall data provide foundational climatic information but alone are inadequate for characterizing meteorological, hydrological, agricultural, or ecological drought. The Standardized Precipitation Index (SPI) is one of the most widely used indicators of drought and defines localized conditions of both drought and excess rainfall based on period-specific (e.g., 1-month, 6-month, 12-month) accumulated precipitation relative to multi-year averages. A 93-year (1920–2012), high-resolution (250 m) gridded dataset of monthly rainfall available for the State of Hawai‘i was used to derive gridded, monthly SPI values for 1-, 3-, 6-, 9-, 12-, 24-, 36-, 48-, and 60-month intervals. Gridded SPI data were validated against independent, station-based calculations of SPI provided by the National Weather Service. The gridded SPI product was also compared with the U.S. Drought Monitor during the overlapping period. This SPI product provides several advantages over currently available drought indices for Hawai‘i in that it has statewide coverage over a long historical period at high spatial resolution to capture fine-scale climatic gradients and monitor changes in local drought severity.

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Performance of Drought Indices in Trichy Region, Tamil Nadu

Current Journal of Applied Science and Technology ◽

10.9734/cjast/2019/v38i530385 ◽

2019 ◽

pp. 1-10

Author(s):

L. Sathya ◽

R. Lalitha

Keyword(s):

Tamil Nadu ◽

Standardized Precipitation Index ◽

Synthetic Data ◽

Meteorological Drought ◽

Severity Index ◽

Rainfall Anomaly ◽

Drought Indices ◽

Drought Severity ◽

Data Series

Droughts are regional phenomena, which are considered as one of the major natural environmental hazards and severely affect the water resources. Climate variability may result in harmful drought periods in semiarid regions. Meteorological drought indices are considered as important tools for drought monitoring, they are embedded with different theoretical and experimental structures. This study compares the performance of three indices of Standardized Precipitation Index (SPI), Rainfall Anomaly Index (RAI) End Palmer Drought Severity Index (PNPI) to predict long-term drought events using the Thomas-Feiring Model and historical data. For studies of areal drought extent, the 61 years (1951-2011) historical rainfall data of Trichy District were utilized to generate 58 years (2012-2070) synthetic data series so that the characteristics of long-term drought might be determined and the performance of those three indices might be analyzed and compared. The results show that SPI and PNPI perform similarly with regard to drought identification and detailed analysis to determine the characteristics of long-term drought. Finally, the RAI indicated significant deviations from normalized natural processes.

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The use of multiple dendrochronological techniques to develop a 200-year drought record for subtropical Southeast Queensland, Australia

10.5194/egusphere-egu2020-11768 ◽

2020 ◽

Author(s):

Heather A Haines ◽

Jonathan G Palmer ◽

Nathan B English ◽

Quan Hua ◽

Patricia S Gadd ◽

...

Keyword(s):

Tree Ring ◽

Southern Oscillation ◽

Ring Width ◽

Drought Indices ◽

Drought Severity ◽

Age Validation ◽

Climate Reconstructions ◽

Drought Conditions ◽

Southeast Queensland

In Australia the majority of tropical and subtropical regions lack any long-term (multi-decadal to centennial scale) instrumental climate records highlighting a need for alternatives such as proxy climate reconstructions. Despite this need, only a limited number of terrestrial proxy sources are available. Tree-rings provide one of the few options for climate reconstructions yet very little dendrochronological investigation has been undertaken as early assessments of tropical Australian species in the 1970s and 1980s indicated most species had short life-spans, poorly preserved timbers, or were compromised by having many ring anomalies. There has also been limited effort into understanding the growth-climate relationships of these trees with only a few studies undertaken targeting specific species that have unfortunately been heavily cleared from the region (eg. Toona ciliata). One exception noted in the early species assessment suggested that trees in the Araucariaceae family, a common tree family along the tropical Australian east coast, is longer lived than many other species in the region, contains growth rings which are annual in nature, and grows in response to climatic conditions.Here we describe the results from a stand of Araucaria cunninghamii trees located in Lamington National Park, a World Heritage listed rainforest in subtropical Southeast Queensland, Australia (a region known for experiencing extreme hydroclimatic events). Our assessment discovered the presence of false, faint, locally absent, and pinching rings. By combining traditional dendrochronological analysis (eg. crossdating) with more recent techniques such as age validation by bomb-pulse radiocarbon dating and tree-ring density analysis, a robust ring-width chronology from 1805-2014 was developed. Dendrometers installed on four trees at the Lamington site confirmed that tree growth was annual and that moisture sensitivity was driving growth. Further growth-climate analysis indicated that the strongest correlation to the tree-ring chronology was specifically related to drought conditions in the region. The strength of this response was compared to both local and regional spatial areas and to drought indices such as the self-calibrating Palmer Drought Severity Index (scPDSI), the Standardized Precipitation Evaporation Index (SPEI), and the long-term drought conditions shown by the Australian and New Zealand Drought Atlas (ANZDA). The combined analysis led to the development of a 200-year drought reconstruction for the region and demonstrates influences from both the El Ni&#241;o Southern Oscillation (ENSO) and the Interdecadal Pacific Oscillation (IPO).

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Drought severity–duration–frequency curves: a foundation for risk assessment and planning tool for ecosystem establishment in post-mining landscapes

Hydrology and Earth System Sciences ◽

10.5194/hess-19-1069-2015 ◽

2015 ◽

Vol 19 (2) ◽

pp. 1069-1091 ◽

Cited By ~ 32

Author(s):

D. Halwatura ◽

A. M. Lechner ◽

S. Arnold

Keyword(s):

Standardized Precipitation Index ◽

Bivariate Distribution ◽

Distribution Functions ◽

Drought Indices ◽

Drought Severity ◽

Minor Role ◽

Short Term ◽

Eastern Australia ◽

Recurrence Intervals

Abstract. Eastern Australia has considerable mineral and energy resources, with areas of high biodiversity value co-occurring over a broad range of agro-climatic environments. Lack of water is the primary abiotic stressor for (agro)ecosystems in many parts of eastern Australia. In the context of mined land rehabilitation quantifying the severity–duration–frequency (SDF) of droughts is crucial for successful ecosystem rehabilitation to overcome challenges of early vegetation establishment and long-term ecosystem resilience. The objective of this study was to quantify the SDF of short-term and long-term drought events of 11 selected locations across a broad range of agro-climatic environments in eastern Australia by using three drought indices at different timescales: the Standardized Precipitation Index (SPI), the Reconnaissance Drought Index (RDI), and the Standardized Precipitation-Evapotranspiration Index (SPEI). Based on the indices we derived bivariate distribution functions of drought severity and duration, and estimated the recurrence intervals of drought events at different timescales. The correlation between the simple SPI and the more complex SPEI or RDI was stronger for the tropical and temperate locations than for the arid locations, indicating that SPEI or RDI can be replaced by SPI if evaporation plays a minor role for plant available water (tropics). Both short-term and long-term droughts were most severe and prolonged, and recurred most frequently in arid regions, but were relatively rare in tropical and temperate regions. Our approach is similar to intensity–duration–frequency (IDF) analyses of rainfall, which are crucial for the design of hydraulic infrastructure. In this regard, we propose to apply SDF analyses of droughts to design ecosystem components in post-mining landscapes. Together with design rainfalls, design droughts should be used to assess rehabilitation strategies and ecological management using drought recurrence intervals, thereby minimising the risk of failure of initial ecosystem establishment due to ignorance of fundamental abiotic and site-specific environmental barriers, such as flood and drought events.

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Long-term drought variability and trends in Barcelona (1787-2014)

Cuadernos de Investigación Geográfica ◽

10.18172/cig.2927 ◽

2016 ◽

Vol 42 (1) ◽

pp. 29 ◽

Cited By ~ 5

Author(s):

J. R. Coll ◽

E. Aguilar ◽

M. Prohom ◽

J. Sigro

Keyword(s):

20Th Century ◽

Standardized Precipitation Index ◽

Drought Indices ◽

Drought Severity ◽

Large Temperature ◽

Evaporative Demand ◽

Drought Variability ◽

Seasonal Scale ◽

Drying Trend

Long-term drought variability and trends were assessed in Barcelona at annual and seasonal scale for the period 1787-2014 and sub-periods 1851-2014, 1901-2014 and 1951-2014 to identify changes in drought patterns across time. High quality and adjusted monthly temperature and precipitation series were required for this purpose. The Standardized Precipitation Index (SPI), based on precipitation, and the Standardized Precipitation Evapotranspiration Index (SPEI), based on the difference between precipitation and reference evapotranspiration (ET0), were calculated to describe temporal drought fluctuations. Therefore, major droughts and wet events were identified and an accurate analysis of drought severity, magnitude and duration were also carried out.Both drought indices provided similar results related to drought variability and trends in Barcelona across time, although the SPEI showed larger drought severity than SPI especially during the second half of the 20th century. Trends analysis revealed a significant drying trend at annual scale according to the SPEI since mid-19th century while the SPI did not show changes in drought patterns. At seasonal scale, both the SPI and SPEI found a clear drying trend only for summer (JJA) during the current period (1951-2014), although the SPEI was indicating the trend towards drier conditions for the whole period (1787-2014). Drought severity in SPEI series increased 13% during the second half of the 20th century compared with the whole period under study while drought magnitude and duration did not present significant changes in both the SPI and SPEI series. The increasing atmospheric evaporative demand associated to the large temperature rising experienced in Barcelona during the last decades could have played a substantial role in explaining the increase of drought severity and trends found in the SPEI series.

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An analysis of rainfall variability and drought over Barmer District of Rajasthan: Northwest India

Water Science & Technology Water Supply ◽

10.2166/ws.2021.053 ◽

2021 ◽

Author(s):

Darshan Mehta ◽

S. M. Yadav

Keyword(s):

Climate Variability ◽

Trend Analysis ◽

Arid Zone ◽

Rainfall Variability ◽

Standardized Precipitation Index ◽

Annual Rainfall ◽

Drought Indices ◽

Drought Severity ◽

Study Region ◽

Ground Water Recharge

Abstract Climate variability mainly the annual air temperature and precipitation have received great attention worldwide. The magnitude of these climate variability changes with the variation in locations. Rajasthan comes under the arid and semi-arid zone of India in which monsoon is a principal element of water resource. Due to erratic and scanty rainfall in this zone, agriculture is totally dependent on the monsoon. The objective of the present study is to assess the meteorological drought characteristics using Drought Indices Calculator DrinC from the historical rainfall records of the Barmer district of Rajasthan state by employing the criterion of percentage departure (D%), rainfall Anomaly index (RAI) and standardized precipitation index (SPI). Trend analysis of seasonal and extreme annual monthly rainfall was carried out for the Barmer district of Rajasthan state using the data period between 1900 and 2002 at the 5% level of significance. Sen's slope estimator was also applied to identify the trend. Temporal analysis is useful to predict and identify the possible drought severity and its duration in the study region. It also helps to understand its effect on ground water recharge and increasing the risk of water shortage. Trend analysis of rainfall over 102 years shows an increasing trend in pre-monsoon, post monsoon, southwest monsoon and annual rainfall and decreasing trend in winter rainfall. Through this study, policy makers and local administrators will be benefitted which will help them in taking proactive drought relief decision in the drought-hit regions.

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Assessment of the Dissimilarities of EDI and SPI Measures for Drought Determination in South Africa

Water ◽

10.3390/w13010082 ◽

2021 ◽

Vol 13 (1) ◽

pp. 82

Author(s):

Omolola M. Adisa ◽

Muthoni Masinde ◽

Joel O. Botai

Keyword(s):

South Africa ◽

South African ◽

Correlation Coefficient ◽

Pearson Correlation ◽

Standardized Precipitation Index ◽

Drought Monitoring ◽

Drought Indices ◽

Drought Severity ◽

Pearson Correlation Coefficient ◽

Drought Duration

This study examines the (dis)similarity of two commonly used indices Standardized Precipitation Index (SPI) computed over accumulation periods 1-month, 3-month, 6-month, and 12-month (hereafter SPI-1, SPI-3, SPI-6, and SPI-12, respectively) and Effective Drought Index (EDI). The analysis is based on two drought monitoring indicators (derived from SPI and EDI), namely, the Drought Duration (DD) and Drought Severity (DS) across the 93 South African Weather Service’s delineated rainfall districts over South Africa from 1980 to 2019. In the study, the Pearson correlation coefficient dissimilarity and periodogram dissimilarity estimates were used. The results indicate a positive correlation for the Pearson correlation coefficient dissimilarity and a positive value for periodogram of dissimilarity in both the DD and DS. With the Pearson correlation coefficient dissimilarity, the study demonstrates that the values of the SPI-1/EDI pair and the SPI-3/EDI pair exhibit the highest similar values for DD, while the SPI-6/EDI pair shows the highest similar values for DS. Moreover, dissimilarities are more obvious in SPI-12/EDI pair for DD and DS. When a periodogram of dissimilarity is used, the values of the SPI-1/EDI pair and SPI-6/EDI pair exhibit the highest similar values for DD, while SPI-1/EDI displayed the highest similar values for DS. Overall, the two measures show that the highest similarity is obtained in the SPI-1/EDI pair for DS. The results obtainable in this study contribute towards an in-depth knowledge of deviation between the EDI and SPI values for South Africa, depicting that these two drought indices values are replaceable in some rainfall districts of South Africa for drought monitoring and prediction, and this is a step towards the selection of the appropriate drought indices.

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Climate variability in West Antarctica derived from annual accumulation-rate records from ITASE firn/ice cores

Annals of Glaciology ◽

10.3189/172756404781814447 ◽

2004 ◽

Vol 39 ◽

pp. 585-594 ◽

Cited By ~ 69

Author(s):

Susan Kaspari ◽

Paul A. Mayewski ◽

Daniel A. Dixon ◽

Vandy Blue Spikes ◽

Sharon B. Sneed ◽

...

Keyword(s):

Climate Variability ◽

Moisture Transport ◽

Southern Oscillation ◽

Accumulation Rate ◽

Drainage System ◽

Ice Cores ◽

Cyclonic Activity ◽

West Antarctica ◽

Sea Level Pressure

AbstractThirteen annually resolved accumulation-rate records covering the last ~200 years from the Pine Island–Thwaites and Ross drainage systems and the South Pole are used to examine climate variability over West Antarctica. Accumulation is controlled spatially by the topography of the ice sheet, and temporally by changes in moisture transport and cyclonic activity. A comparison of mean accumulation since 1970 at each site to the long-term mean indicates an increase in accumulation for sites located in the western sector of the Pine Island–Thwaites drainage system. Accumulation is negatively associated with the Southern Oscillation Index (SOI) for sites near the ice divide, and periods of sustained negative SOI (1940–42, 1991–95) correspond to above-mean accumulation at most sites. Correlations of the accumulation-rate records with sea-level pressure (SLP) and the SOI suggest that accumulation near the ice divide and in the Ross drainage system may be associated with the mid-latitudes. The post-1970 increase in accumulation coupled with strong SLP–accumulation-rate correlations near the coast suggests recent intensification of cyclonic activity in the Pine Island– Thwaites drainage system.

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A novel index for ecological drought monitoring based on ecological water deficit: a case study of Northwestern China

10.5194/egusphere-egu21-5439 ◽

2021 ◽

Author(s):

Tianliang Jiang ◽

Xiaoling Su

Keyword(s):

Water Deficit ◽

Time Scales ◽

Drought Index ◽

Vegetation Index ◽

Standardized Precipitation Index ◽

Northwestern China ◽

Drought Monitoring ◽

Drought Indices ◽

Drought Severity ◽

Different Time Scales

Although the concept of ecological drought was first defined by the Science for Nature and People Partnership (SNAPP) in 2016, there remains no widely accepted drought index for monitoring ecological drought. Therefore, this study constructed a new ecological drought monitoring index, the standardized ecological water deficit index (SEWDI). The SEWDI is based on the difference between ecological water requirements and consumption, referred to as the standardized precipitation index (SPI) method, which was used to monitor ecological drought in Northwestern China (NWRC). The performances of the SEWDI and four widely-used drought indices [standardized root soil moisture index (SSI), self-calibrated Palmer drought index (scPDSI), standardized precipitation-evaporation drought index (SPEI), and SPI) in monitoring ecological drought were evaluated through comparing the Pearson correlations between these indices and the standardized normalized difference vegetation index (SNDVI) under different time scales, wetness, and water use efficiencies (WUEs) of vegetation. Finally, the rotational empirical orthogonal function (REOF) was used to decompose the SEWDI at a 12-month scale in the NWRC during 1982&#8211;2015 to obtain five ecological drought regions. The characteristics of ecological drought in the NWRC, including intensity, duration, and frequency, were extracted using run theory. The results showed that the performance of the SEWDI in monitoring ecological drought was highest among the commonly-used drought indices evaluated under different time scales [average correlation coefficient values (r) between SNDVI and drought indices: SEWDI= 0.34, SSI= 0.24, scPDSI= 0.23, SPI= 0.20, SPEI= 0.18), and the 12-month-scale SEWDI was largely unaffected by wetness and WUE. In addition, the results of the monitoring indicated that serious ecological droughts in the NWRC mainly occurred in 1982&#8211;1986, 1990&#8211;1996, and 2005&#8211;2010, primarily in regions I, II, and V, regions II, and IV, and in region III, IV, and V, respectively. This study provides a robust approach for quantifying ecological drought severity across natural vegetation areas and scientific evidence for governmental decision makers.

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