scholarly journals Extreme droughts and human responses to them: the Czech Lands in the pre-instrumental period

2019 ◽  
Vol 15 (1) ◽  
pp. 1-24 ◽  
Author(s):  
Rudolf Brázdil ◽  
Petr Dobrovolný ◽  
Miroslav Trnka ◽  
Ladislava Řezníčková ◽  
Lukáš Dolák ◽  
...  
Keyword(s):  
Return Period ◽  
Social Life ◽  
Standardized Precipitation Index ◽  
Drought Indices ◽  
Documentary Evidence ◽  
Sea Level Pressure ◽  
Documentary Sources ◽  
Summer Half ◽  
Instrumental Period ◽  
Czech Lands

Abstract. The Czech Lands are particularly rich in documentary sources that help elucidate droughts in the pre-instrumental period (12th–18th centuries), together with descriptions of human responses to them. Although droughts appear less frequently before 1501, the documentary evidence has enabled the creation of a series of seasonal and summer half-year drought indices (Standardized Precipitation Index, SPI; Standardized Precipitation Evapotranspiration Index, SPEI; Z index) for the Czech Lands for the 1501–2017 period. Based on the calculation of return period for series of drought indices, extreme droughts were selected for inclusion herein if all three indices indicated a return period of ≥20 years. For further analysis, only those from the pre-instrumental period (before 1804) were used. The extreme droughts selected are characterized by significantly lower values of drought indices, higher temperatures and lower precipitation totals compared to other years. The sea-level pressure patterns typically associated with extreme droughts include significantly higher pressure over Europe and significantly lower pressure over parts of the Atlantic Ocean. Extreme droughts with a return period ≥ 50 years are described in detail on the basis of Czech documentary evidence. A number of selected extreme droughts are reflected in other central European reconstructions derived from documentary data or tree rings. Impacts on social life and responses to extreme droughts are summarized; analysis of fluctuations in grain prices with respect to drought receives particular attention. Finally, extreme droughts from the pre-instrumental and instrumental periods are discussed.

scholarly journals Extreme droughts and human responses to them: the Czech Lands in the pre-instrumental period

2018 ◽  
Author(s):  
Rudolf Brázdil ◽  
Petr Dobrovolný ◽  
Miroslav Trnka ◽  
Ladislava Řezníčková ◽  
Lukáš Dolák ◽  
...  
Keyword(s):  
Return Period ◽  
Social Life ◽  
Drought Indices ◽  
Documentary Evidence ◽  
Sea Level Pressure ◽  
Central European ◽  
Documentary Sources ◽  
Summer Half ◽  
Instrumental Period ◽  
Czech Lands

Abstract. The Czech Lands are particularly rich in documentary sources that help elucidate droughts in the pre-instrumental period (12th–18th centuries), together with descriptions of human responses to them. Although droughts appear less frequently before AD 1501, the documentary evidence has enabled the creation of series of seasonal and summer half-year drought indices (SPI, SPEI and Z-index) for the Czech Lands for the 1501–2017 period. Based on calculation of return period for series of drought indices, extreme droughts were selected for inclusion herein if all three indices indicated a return period of ≥ 20 years. For further analysis, only those from the pre-instrumental period (before AD 1804) were used. The extreme droughts selected are characterised by significantly lower values of drought indices, higher temperatures and lower precipitation totals compared to other years. The sea-level pressure patterns typically associated with extreme droughts include significantly higher pressure over Europe and significantly lower pressure over parts of the Atlantic Ocean. Extreme droughts with a return period ≥ 50 years are described in detail on the basis of Czech documentary evidence. A number of selected extreme droughts are reflected in other central European reconstructions derived from documentary data or tree-rings. Impacts on social life and responses to extreme droughts are summarised; analysis of fluctuations in grain prices with respect to drought receives particular attention. Finally, extreme droughts from the pre-instrumental and instrumental periods are discussed.

scholarly journals Droughts in the Czech Lands, 1090–2012 AD

2013 ◽  
Vol 9 (4) ◽  
pp. 1985-2002 ◽  
Author(s):  
R. Brázdil ◽  
P. Dobrovolný ◽  
M. Trnka ◽  
O. Kotyza ◽  
L. Řezníčková ◽  
...  
Keyword(s):  
Drought Indices ◽  
Documentary Evidence ◽  
Documentary Sources ◽  
Recurrence Intervals ◽  
Southern Moravia ◽  
Instrumental Period ◽  
Instrumental Records ◽  
Czech Lands ◽  
Selection Of

Abstract. This paper addresses droughts in the Czech Lands in the 1090–2012 AD period, basing its findings on documentary evidence and instrumental records. Various documentary sources were employed for the selection of drought events, which were then interpreted at a monthly level. While the data on droughts before 1500 AD are scarce, the analysis concentrated mainly on droughts after this time. A dry year in 1501–1804 period (i.e. pre-instrumental times) was defined as a calendar year in the course of which dry patterns occurred on at least two consecutive months. Using this definition, 129 dry years were identified (an average of one drought per 2.4 yr). From the 16th to the 18th centuries these figures become 41, 36 and 49 yr respectively, with the prevailing occurrence of dry months from April to September (73.7%). Drought indices – SPEI-1, Z-index and PDSI – calculated for the Czech Lands for April–September describe drought patterns between 1805 and 2012 (the instrumental period). N-year recurrence intervals were calculated for each of the three indices. Using N ≥ 5 yr, SPEI-1 indicates 40 drought years, Z-index 39 yr and PDSI 47 yr. SPEI-1 and Z-index recorded 100 yr drought in 1834, 1842, 1868, 1947 and 2003 (50 yr drought in 1992). PDSI as an indicator of long-term drought disclosed two important drought periods: 1863–1874 and 2004–2012. The first period was related to a lack of precipitation, the other may be attributed to recent temperature increases without significant changes in precipitation. Droughts from the pre-instrumental and instrumental period were used to compile a long-term chronology for the Czech Lands. The number of years with drought has fluctuated between 26 in 1951–2000 and 16 in 1651–1700. Only nine drought years were recorded between 1641 and 1680, while between 1981 and 2012 the figure was 22 yr. A number of past severe droughts are described in detail: in 1540, 1590, 1616, 1718 and 1719. A discussion of the results centres around the uncertainty problem, the spatial variability of droughts, comparison with tree-ring reconstructions from southern Moravia, and the broader central European context.

scholarly journals Droughts in the Czech Lands, 1090–2012 AD

2013 ◽  
Vol 9 (3) ◽  
pp. 2423-2470 ◽  
Author(s):  
R. Brázdil ◽  
P. Dobrovolný ◽  
M. Trnka ◽  
O. Kotyza ◽  
L. Řezníčková ◽  
...  
Keyword(s):  
Drought Indices ◽  
Documentary Evidence ◽  
Documentary Sources ◽  
Recurrence Intervals ◽  
Southern Moravia ◽  
Instrumental Period ◽  
Instrumental Records ◽  
Czech Lands ◽  
Selection Of

Abstract. This paper addresses droughts in the Czech Lands in the 1090–2012 AD period, basing its findings on documentary evidence and instrumental records. Various documentary sources were employed for the selection of drought events, which were then interpreted at a monthly level. While the data on droughts before 1500 AD are scarce, the analysis concentrated mainly on droughts after this time. A dry year in 1501–1804 period (i.e. pre-instrumental times) was defined as a calendar year in the course of which dry patterns occurred on at least two consecutive months. Using this definition, 129 dry years were identified (an average of one drought per 2.4 yr). From the 16th to the 18th centuries these figures become 41, 36 and 49 yr, respectively, with the prevailing occurrence of dry months from April to September (73.7%). Drought indices – SPEI-1, Z-index and PDSI – calculated for the Czech Lands for April–September describe drought patterns between 1805 and 2012 (the instrumental period). N year recurrence intervals were calculated for each of the three indices. Using N ≥ 5 yr, SPEI-1 indicates 40 drought years, Z-index 39 yr and PDSI 47 yr. SPEI-1 and Z-index recorded 100 yr drought in 1834, 1842, 1868, 1947 and 2003 (50 yr drought in 1992). PDSI as an indicator of long-term drought disclosed two important drought periods: 1863–1874 and 2004–2012. The first period was related to a lack of precipitation, the other may be attributed to recent temperature increases without significant changes in precipitation. Droughts from the pre-instrumental and instrumental period were used to compile a long-term chronology for the Czech Lands. The number of years with drought has fluctuated between 26 in 1951–2000 and 16 in 1651–1700. Only nine drought years were recorded between 1641 and 1680, while between 1981 and 2012 the figure was 22 yr. A number of past severe droughts are described in detail: in 1540, 1590, 1616, 1718 and 1719. A discussion of the results centres around the uncertainty problem, the spatial variability of droughts, comparison with tree-ring reconstructions from southern Moravia, and the broader Central European context.

scholarly journals Rogation ceremonies: a key to understanding past drought variability in northeastern Spain since 1650

2019 ◽  
Vol 15 (5) ◽  
pp. 1647-1664 ◽  
Author(s):  
Ernesto Tejedor ◽  
Martín de Luis ◽  
Mariano Barriendos ◽  
José María Cuadrat ◽  
Jürg Luterbacher ◽  
...  
Keyword(s):  
18Th Century ◽  
Standardized Precipitation Index ◽  
Extreme Drought ◽  
Drought Indices ◽  
Independent Evidence ◽  
Superposed Epoch Analysis ◽  
Drought Variability ◽  
Instrumental Period ◽  
Epoch Analysis ◽  
The Standardized Precipitation Index

Abstract. In the northeast of the Iberian Peninsula, few studies have reconstructed drought occurrence and variability for the pre-instrumental period using documentary evidence and natural proxies. In this study, we compiled a unique dataset of rogation ceremonies – religious acts asking God for rain – from 13 cities in the northeast of Spain and investigated the annual drought variability from 1650 to 1899 CE. Three regionally different coherent areas (Mediterranean, Ebro Valley, and Mountain) were detected. Both the Barcelona and the regional Mediterranean drought indices were compared with the instrumental series of Barcelona for the overlapping period (1787–1899), where we discovered a highly significant and stable correlation with the Standardized Precipitation Index of May with a 4-month lag (r=-0.46 and r=-0.53; p<0.001, respectively). We found common periods with prolonged droughts (during the mid and late 18th century) and extreme drought years (1775, 1798, 1753, 1691, and 1817) associated with more atmospheric blocking situations. A superposed epoch analysis (SEA) was performed showing a significant decrease in drought events 1 year after the volcanic events, which might be explained by the decrease in evapotranspiration due to reduction in surface temperatures and, consequently, the higher availability of water that increases soil moisture. In addition, we discovered a common and significant drought response in the three regional drought indices 2 years after the Tambora volcanic eruption. Our study suggests that documented information on rogation ceremonies contains important independent evidence to reconstruct extreme drought events in areas and periods for which instrumental information and other proxies are scarce. However, drought index for the mountainous areas (denoted Mountain later in the text) presents various limitations and its interpretation must be treated with caution.

scholarly journals Multivariate drought risk analysis based on copula functions: a case study

2020 ◽  
Vol 20 (6) ◽  
pp. 2375-2388
Author(s):  
Mohammadreza Seyedabadi ◽  
Mohammadreza Kavianpour ◽  
Saber Moazami
Keyword(s):  
Return Period ◽  
Drought Index ◽  
Human Life ◽  
Standardized Precipitation Index ◽  
Drought Indices ◽  
Drought Risk ◽  
Severe Drought ◽  
Copula Functions ◽  
Drought Characteristics ◽  
Multiple Variables

Abstract Drought is asserted as a natural disaster that encompasses vast territories for a long time and affects human life. Indicators are powerful tools for understanding this phenomenon. However, in order to get more information about the drought, multivariate indices were introduced for simultaneous evaluation of multiple variables. In this study, a combined drought index (CDI) based on three drought indices, the Standardized Precipitation Index (SPI), Streamflow Drought Index (SDI), and Standardized Water-level Index (SWI), is defined. Then, the Entropy method is used to determine the weight of each indicator. Among the calculated weights, SDI and SPI had the highest and lowest weight, respectively. The CDI is utilized to identify drought characteristics, such as duration and severity. In addition, the joint distribution function of drought characteristics is formed by copula functions and consequently the probability of different droughts is calculated. For the study area, data and information from eight regions located in Golestan province in the northern part of Iran are used to evaluate the performance of the proposed index. Four categories of drought were defined and their return period calculated. The shortest return period of severe drought was observed in the east and then in the west. In the south and center, the return period of severe drought was longer. Over the course of 30 years, all parts of the province experienced all drought categories.

Chronology of strong winds based on documentary evidence in the Czech Republic from AD 1510

2020 ◽  
Author(s):  
Lukáš Dolák ◽  
Rudolf Brázdil ◽  
Petr Dobrovolný ◽  
Hubert Valášek ◽  
Ladislava Řezníčková ◽  
...  
Keyword(s):  
Czech Republic ◽  
Spatiotemporal Variability ◽  
Documentary Evidence ◽  
Convective Storms ◽  
Scientific Papers ◽  
Strong Winds ◽  
Instrumental Period ◽  
Czech Lands ◽  
Wind Speed Measurement

&lt;p&gt;To develop an understanding of recent variability in strong winds, it is necessary to analyse their past behaviour. While relatively short series of wind-speed measurement in the Czech Lands (recent Czech Republic) started mostly in the first half of the 20&lt;sup&gt;th&lt;/sup&gt; century, documentary evidence represents a valuable source of information helping extend the knowledge of strong winds to the pre-instrumental period. In this study, we analyse strong winds on the basis of chronicles, weather diaries, early journalism, economic and financial sources, as well as old academic journals, newspapers, professional papers and recent scientific papers. The created dataset presents a chronology of strong winds in the Czech Lands from AD 1510 to present. The dataset contains more than 5000 events, which are classified on duration, location, extent, severity and type of damage on squalls (convective storms), tornadoes, blizzards, gales and windstorms. Gales, often accompanied by loss of human lives, damage to buildings and forests (windthrows), are the most frequently recorded type of strong winds (44%), followed by blizzards (26%), squalls (18%), and tornadoes (7%). Strong winds detected are concentrated 1820s to late-1840s, 1900s to late-1930s and in the 2000s. Seasonal distribution of strong winds is relatively equal throughout the chronology with the highest frequency in July (10.0%), January (8.6%), and December (8.1%). Uncertainties in results emerge from a different spatiotemporal density of documentary data and from the ambiguous nature of some records in determining the classification of strong winds or attribution of damage caused to particular events. Our results highlight the importance of documentary evidence in the analysis of strong winds and contribute to a better understanding of their spatiotemporal variability in the past.&lt;/p&gt;

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

2019 ◽  
Vol 15 (2) ◽  
pp. 827-847 ◽  
Author(s):  
Jiří Mikšovský ◽  
Rudolf Brázdil ◽  
Miroslav Trnka ◽  
Petr Pišoft
Keyword(s):  
Climate Variability ◽  
Volcanic Activity ◽  
Temporal Variability ◽  
Southern Oscillation ◽  
Standardized Precipitation Index ◽  
Drought Indices ◽  
Drought Severity ◽  
External Forcings ◽  
Czech Lands

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.

A Hydroclimatological Assessment of Regional Drought Vulnerability: A Case Study of Indiana Droughts

2011 ◽  
Vol 15 (26) ◽  
pp. 1-65 ◽  
Author(s):  
Umarporn Charusombat ◽  
Dev Niyogi
Keyword(s):  
Return Period ◽  
Regional Scale ◽  
Management Strategies ◽  
Standardized Precipitation Index ◽  
Water Shortage ◽  
Drought Indices ◽  
Climatic Data ◽  
Drought Vulnerability ◽  
Worst Case ◽  
Drought Variability

Abstract Characterizing and developing drought climatology continues to be a challenging problem. As decision makers seek guidance on water management strategies, there is a need for assessing the performance of drought indices. This requires the adaptation of appropriate drought indices that aid in monitoring droughts and hydrological vulnerability on a regional scale. This study aims to assist the process of developing a statewide water shortage and assessment plan (WSP) for the state of Indiana by conducting a focused hydroclimatological assessment of drought variability. Drought climatology was assessed using in situ observations and regional reanalysis data. A summary of precipitation and evaporation trends, estimated drought variability, worst-case drought scenarios, drought return period, and frequency and duration was undertaken, using multiple drought indices and streamflow analysis. Results indicated a regional and local variability in drought susceptibility. The worst-case (200-yr return period) prediction showed that Indiana has a 0.5% probability of receiving 45% of normal precipitation over a 12-month drought in any year. Consistent with other studies, the standardized precipitation index (SPI) was found to be appropriate for detecting short-term drought conditions over Indiana. This recommendation has now been incorporated in the 2009 Indiana water shortage plan. This study also highlights the difficulties in identifying past droughts from available climatic data, and the authors’ results suggest a persistent, high degree of uncertainty in making drought predictions using future climatic projections.

scholarly journals Documentary data and the study of past droughts: a global state of the art

2018 ◽  
Vol 14 (12) ◽  
pp. 1915-1960 ◽  
Author(s):  
Rudolf Brázdil ◽  
Andrea Kiss ◽  
Jürg Luterbacher ◽  
David J. Nash ◽  
Ladislava Řezníčková
Keyword(s):  
Large Scale ◽  
State Of The Art ◽  
Drought Indices ◽  
Documentary Evidence ◽  
Climatic Trends ◽  
Instrumental Observations ◽  
Spatio Temporal ◽  
Epigraphic Evidence ◽  
Administrative Evidence

Abstract. The use of documentary evidence to investigate past climatic trends and events has become a recognised approach in recent decades. This contribution presents the state of the art in its application to droughts. The range of documentary evidence is very wide, including general annals, chronicles, memoirs and diaries kept by missionaries, travellers and those specifically interested in the weather; records kept by administrators tasked with keeping accounts and other financial and economic records; legal-administrative evidence; religious sources; letters; songs; newspapers and journals; pictographic evidence; chronograms; epigraphic evidence; early instrumental observations; society commentaries; and compilations and books. These are available from many parts of the world. This variety of documentary information is evaluated with respect to the reconstruction of hydroclimatic conditions (precipitation, drought frequency and drought indices). Documentary-based drought reconstructions are then addressed in terms of long-term spatio-temporal fluctuations, major drought events, relationships with external forcing and large-scale climate drivers, socio-economic impacts and human responses. Documentary-based drought series are also considered from the viewpoint of spatio-temporal variability for certain continents, and their employment together with hydroclimate reconstructions from other proxies (in particular tree rings) is discussed. Finally, conclusions are drawn, and challenges for the future use of documentary evidence in the study of droughts are presented.

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

Water ◽  
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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