Recurrence of historical drought events over the Iberian Peninsula in different observational datasets and reanalyses

2020 ◽  
Author(s):  
Julia Moemken ◽  
Joaquim G. Pinto
Keyword(s):  
Iberian Peninsula ◽  
Standardized Precipitation Index ◽  
Small Scale ◽  
Special Focus ◽  
Severe Drought ◽  
Topographic Effects ◽  
Physical Mechanisms ◽  
Invading Species ◽  
Expert Team ◽  
Oak Ecosystem

<p>Extreme climate events such as droughts can have very strong impacts both for society and the environment. In particular, the occurrence of severe droughts can endanger the balance of an ecosystem. While intact woodlands, e.g. the Iberian cork-oak ecosystem, are well adapted to withstand single severe drought events, both competition with invading species and recurrent droughts (i.e. droughts in consecutive years) may drive these systems towards critical limits. This is of crucial importance considering that the frequency, intensity and duration of extreme droughts are projected to increase in future decades in various regions all over the world, including the Mediterranean region. <br>We evaluate the occurrence and intensity of historical extreme drought events over the Iberian Peninsula for the past decades. Special focus is given to consecutive/recurrent drought events. Our study compares various indices for the identification of droughts, e.g. the SPEI (Standardized Precipitation Evapotranspiration Index), the SPI (Standardized Precipitation Index) or indices from the “Expert Team on Climate Change Detection and Indices” (ETCCDI). All indices are based on precipitation and/or temperature. We analyse different observational (E-OBS V17, V20, IBERIA01) and reanalysis datasets (ERA-Interim, ERA5) at several spatial resolutions, ranging roughly between 10 km and 25 km. The high resolution of the datasets enables the consideration of small-scale processes and local topographic effects which are relevant for extreme droughts, thus enabling a deeper insight on the physical mechanisms associated with droughts in the study area.</p>

Markets, Distribution and Value Chains in Small-Scale Fisheries: A Special Focus on Europe

2018 ◽  
pp. 141-162 ◽  
Author(s):  
José J. Pascual-Fernández ◽  
Cristina Pita ◽  
Helga Josupeit ◽  
Alicia Said ◽  
João Garcia Rodrigues
Keyword(s):  
Value Chains ◽  
Small Scale ◽  
Special Focus ◽  
Small Scale Fisheries

scholarly journals Impact of Large-Scale Climate Indices on Meteorological Drought of Coastal Ghana

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Martin Addi ◽  
Kofi Asare ◽  
Samuel Kofi Fosuhene ◽  
Theophilus Ansah-Narh ◽  
Kenneth Aidoo ◽  
...  
Keyword(s):  
Water Resource Management ◽  
Stepwise Regression ◽  
Pearson Correlation ◽  
Standardized Precipitation Index ◽  
Climate Indices ◽  
Severe Drought ◽  
Time Lags ◽  
Drought Prediction ◽  
Catchment Areas ◽  
Dry Seasons

The devastating effects of drought on agriculture, water resources, and other socioeconomic activities have severe consequences on food security and water resource management. Understanding the mechanism that drives drought and predicting its variability is important for enhancing early warning and disaster risk management. In this study, meteorological droughts over six coastal synoptic stations were investigated using three-month Standardized Precipitation Index (SPI). The dry seasons of November-December-January (NDJ), December-January-February (DJF), and January-February-March (JFM) were the focal seasons for the study. Trends of dry seasons SPIs were evaluated using seasonal Mann–Kendall test. The relationship between drought SPI and ocean-atmosphere climate indices and their predictive ability were assessed using Pearson correlation and Akaike Information Criterion (AIC) stepwise regression method to select best climate indices at lagged timestep that fit the SPI. The SPI exhibited moderate to severe drought during the dry seasons. Accra exhibited a significant increasing SPI trend in JFM, NDJ, and DJF seasons. Besides, Saltpond during DJF, Tema, and Axim in NDJ season showed significant increasing trend of SPI. In recent years, SPIs in dry seasons are increasing, an indication of weak drought intensity, and the catchment areas are becoming wetter in the traditional dry seasons. Direct (inverse) relationship was established between dry seasons SPIs and Atlantic (equatorial Pacific) ocean's climate indices. The significant climate indices modulating drought SPIs at different time lags are a combination of either Nino 3.4, Nino 4, Nino 3, Nino 1 + 2, TNA, TSA, AMM, or AMO for a given station. The AIC stepwise regression model explained up to 48% of the variance in the drought SPI and indicates Nino 3.4, Nino 4, Nino 3, Nino 1 + 2, TNA, TSA, AMM, and AMO have great potential for seasonal drought prediction over Coastal Ghana.

scholarly journals China as an Emerging Actor in Conflict Management: from Non-Interference in Internal Affairs to “Constructive” Engagement

2019 ◽  
Vol 19 (3) ◽  
pp. 420-431 ◽  
Author(s):  
Alexandra Victorovna Khudaykulova
Keyword(s):  
The United States ◽  
Humanitarian Assistance ◽  
Political Support ◽  
Small Scale ◽  
Special Focus ◽  
National Interests ◽  
Security Environment ◽  
International Pressure ◽  
Internal Affairs ◽  
Constructive Engagement

The need to protect citizens and investments abroad is placing tremendous pressure on China’s traditional foreign policy strategy and noninterference principle. Instability in most of BRI countries form new security conditions, pushing China to be more flexible in engaging in missions it had previously opposed, including political engagement in intrastate conflicts in the developing world. Following the formula “politics is a big economy”, China starts rethinking its security interests. As a result, China has smoothly adopted the transition strategy from non-intervention into internal affairs to a more proactive non-indifference approach, that Chinese academics are describing as “creative” or “constructive” engagement. Many new elements contribute to this new constructive engagement - conceptual narrative, political support, geopolitical competition, growing capacities and new security conditions. The key point of the article is to analyze China’s strategy in defending national interests overseas, including the rescue and peacekeeping operations, mediation, political envoys, etc. The special focus is done on proactive peacekeeping policy of China and its new role in the security environment. Obviously, in future China will follow implementing the overseas missions, including humanitarian assistance and disaster relief, evacuation operations, defense of sea lanes, stabilization operations, peacekeeping and counterterrorism missions. After launching in 2017 its first overseas military base in Djibouti, there is little evidence to predict that in the near future China intends to construct more bases. But nevertheless the geopolitical rivalry with the United States might push China to convert three deep-water ports - Gwadar (Pakistan), Salalah (Oman), and Seychelles ports into naval bases. The degree of the China’s involvement in global security landscape will depend on the level of its responsibility, since Beijing is undergoing through a higher degree of international pressure in order to take more obligations. Responding to overseas security crises through military actions would be mostly shaped by events (case-by-case approach), inspired by political motivations and organized as small-scale and low-intensity missions.

Drought dynamics and variability over Bundelkhand region of central India: Past, Present and Future

2021 ◽  
Author(s):  
Md Saquib Saharwardi ◽  
Aditya Kumar Dubey ◽  
Pankaj Kumar ◽  
Dmitry V. Sein
Keyword(s):  
Climate Model ◽  
Monsoon Season ◽  
Science And Technology ◽  
Regional Climate ◽  
Standardized Precipitation Index ◽  
Central India ◽  
Severe Drought ◽  
Future Projection ◽  
Russian Science ◽  
Regional Drought

<p>In the present study, an evaluation of the past, present, and future variability of droughts in the Bundelkhand region of Central India are analyzed. Bundelkhand is a severe drought-prone region with intense water stress, where in the last five years four were drought. Therefore, understanding the drivers of drought over the region and its future projection is quite crucial for regional water management. The assessment has been made by analyzing the observational dataset from 1951-2018 to understand the regional drought dynamics. The future projection is made using a multi-model ensemble from a regional climate model over the CORDEX South-Asia domain under the highest emission scenario. The Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI) indices are used to understand present drought and its future projection. In addition to this, drought driving parameters like precipitation, temperature, sea-surface temperature wind circulation has been assessed to understand the regional drought dynamics. The composite analysis of drought indicates that the moisture-laden low-level jet from the Arabian Sea branch generally weakened compared to Bay of Bengal branch for monsoon season. Teleconnections of drought over Bundelkhand region shows that nearly half of the droughts are linked to El-Nino events that have become stronger in recent past. The model result reveals that regional climate variability is reasonably captured over the region. In addition, we found increasing drought frequency since the beginning of the 21<sup>st</sup> century. The detailed results from the analysis will be shown briefly in the general assembly.</p><p><strong>Acknowledgement: </strong>This work is jointly supported by the Department of Science and Technology (DST), Govt. of India, grant number DST/INT/RUS/RSF/P-33/G and the Russian Science Foundation (Project No.: 19-47-02015). The first author is also thankful to the Department of Science and Technology (DST), Govt. of India for providing DST INSPIRE fellowship (Grant No. IF160281).</p>

scholarly journals Analysis of Drought in the Northern Region of Bangladesh Using Standardized Precipitation Index (SPI)

2019 ◽  
Vol 11 (1-2) ◽  
pp. 199-216
Author(s):  
R Afrin ◽  
F Hossain ◽  
SA Mamun
Keyword(s):  
Standardized Precipitation Index ◽  
Extended Period ◽  
Northern Region ◽  
Precipitation Index ◽  
Rainfall Data ◽  
Extreme Drought ◽  
Severe Drought ◽  
Drought Analysis ◽  
Dry Conditions ◽  
The Standardized Precipitation Index

Drought is an extended period when a region notes a deficiency in its water supply. The Standardized Precipitation Index (SPI) method was used in this study to analyze drought. Northern region of Bangladesh was the area of study. Monthly rainfall data of northern region of Bangladesh was obtained from the Meteorological Department of Bangladesh. Obtained rainfall data was from 1991 to 2011 and values from 2012 to 2026 were generated using Markov model. Then SPI values from 1991 to 2026 were calculated by using SPI formula for analyzing drought. Analysis with SPI method showed that droughts in northern region of Bangladesh varied from moderately dry to severely dry conditions and it may vary from moderately dry to severely dry conditions normally in future but in some cases extreme drought may also take place. From the study, it is observed that the northern region of Bangladesh has already experienced severe drought in 1991, 1992, 1994, 1995, 1997, 1998, 2000, 2003, 2005, 2007, 2009 and 2010. The region may experience severe drought in 2012, 2015, 2016, 2018, 2019, 2021, 2022, 2023, 2024, 2025 and 2026 and extreme drought in 2012, 2014, 2016, 2023 and 2024. J. Environ. Sci. & Natural Resources, 11(1-2): 199-216 2018

scholarly journals Elucidating Diverse Drought Characteristics from Two Meteorological Drought Indices (SPI and SPEI) in China

2020 ◽  
Vol 21 (7) ◽  
pp. 1513-1530 ◽  
Author(s):  
Lingcheng Li ◽  
Dunxian She ◽  
Hui Zheng ◽  
Peirong Lin ◽  
Zong-Liang Yang
Keyword(s):  
Clustering Algorithm ◽  
Potential Evapotranspiration ◽  
Standardized Precipitation Index ◽  
Three Dimensional ◽  
Meteorological Drought ◽  
Drought Indices ◽  
Drought Severity ◽  
Severe Drought ◽  
Small Areas ◽  
Drought Characteristics

AbstractThis study elucidates drought characteristics in China during 1980–2015 using two commonly used meteorological drought indices: standardized precipitation index (SPI) and standardized precipitation–evapotranspiration index (SPEI). The results show that SPEI characterizes an overall increase in drought severity, area, and frequency during 1998–2015 compared with those during 1980–97, mainly due to the increasing potential evapotranspiration. By contrast, SPI does not reveal this phenomenon since precipitation does not exhibit a significant change overall. We further identify individual drought events using the three-dimensional (i.e., longitude, latitude, and time) clustering algorithm and apply the severity–area–duration (SAD) method to examine the drought spatiotemporal dynamics. Compared to SPI, SPEI identifies a lower drought frequency but with larger total drought areas overall. Additionally, SPEI identifies a greater number of severe drought events but a smaller number of slight drought events than the SPI. Approximately 30% of SPI-detected drought grids are not identified as drought by SPEI, and 40% of SPEI-detected drought grids are not recognized as drought by SPI. Both indices can roughly capture the major drought events, but SPEI-detected drought events are overall more severe than SPI. From the SAD analysis, SPI tends to identify drought as more severe over small areas within 1 million km2 and short durations less than 2 months, whereas SPEI tends to delineate drought as more severe across expansive areas larger than 3 million km2 and periods longer than 3 months. Given the fact that potential evapotranspiration increases in a warming climate, this study suggests SPEI may be more suitable than SPI in monitoring droughts under climate change.

scholarly journals Norway at the Border of EU – Cross-Border Shopping and its Implications

2009 ◽  
Vol 26 (2) ◽  
pp. 205-231 ◽  
Author(s):  
Randi Lavik ◽  
Sturla Nordlund
Keyword(s):  
Small Scale ◽  
Special Focus ◽  
Political Debate ◽  
General Increase ◽  
Cross Border ◽  
Obvious Reason ◽  
The Media ◽  
Price Differences ◽  
Different Sources ◽  
The Eu

Cross-border shopping has for many years been an issue in the political debate in Norway, and it remains so. The focus of the media is mostly on alcohol and tobacco shopping, but shopping for other goods such as meat and other groceries are at least as important. Aim The aim of this article is to present estimates of the total cross-border shopping, especially from Sweden, with a special focus on alcohol and tobacco. Data Data are collected from different sources, mainly from the two research institutes SIFO and SIRUS. Results The total private import by travelers to Norway has increased, and so has special cross-border shopping from Sweden. An obvious reason is the price differences on alcohol, tobacco and meat in particular, which have been increasing since the neighbouring countries Sweden and Finland became members of the EU in 1995. Another reason is the general increase in travelling, especially by airplanes, during later years. People living near the border are, not surprisingly, much more often border-shoppers than people living far away. Border-shopping also has an illegal side, since some people violate the quite restrictive Norwegian quotas on travelers import e.g. of alcohol and tobacco. Around 20 per cent of the of the Norwegian travellers see such “small-scale smuggling” of spirits as a serious crime, and 25 percent had brought too much alcohol. The total private import by travelers, legal as well as illegal, represents a considerable revenue loss to Norway.

scholarly journals Evaluation of temporal drought variation and projection in a tropical river basin of Kerala

2020 ◽  
Vol 11 (S1) ◽  
pp. 115-132 ◽  
Author(s):  
M. A. Jincy Rose ◽  
N. R. Chithra
Keyword(s):  
River Basin ◽  
Standardized Precipitation Index ◽  
Drought Severity ◽  
Climate Projections ◽  
Severe Drought ◽  
Tropical River ◽  
The Past ◽  
Drought Conditions ◽  
The Future ◽  
The Standardized Precipitation Index

Abstract Temperature is an indispensable parameter of climate that triggers evapotranspiration and has vital importance in aggravating drought severity. This paper analyses the existence and persistence of drought conditions which are said to prevail in a tropical river basin which was once perennial. Past observed data and future climate projections of precipitation and temperature were used for this purpose. The assessment and projection of this study employ the Standardized Precipitation Evapotranspiration Index (SPEI) compared with that of the Standardized Precipitation Index (SPI). The results indicate the existence of drought in the past and the drought conditions that may persist in the future according to RCP 4.5 and 8.5 scenarios. The past drought years identified in the study were compared with the drought declared years in the state and were found to be matching. The evaluation of the future scenarios unveils the occurrence of drought in the basin ranging from mild to extreme conditions. It has been noted that the number of moderate and severe drought months has increased based on SPEI compared to SPI, indicating the importance of temperature in drought studies. The study can be considered as a plausible scientific remark helpful in risk management and application decisions.

scholarly journals Application of Markov chains to Standardized Precipitation Index (SPI) in São Francisco River Basin

2019 ◽  
Vol 14 (3) ◽  
pp. 1
Author(s):  
Esdras Adriano Barbosa dos Santos ◽  
Tatijana Stosic ◽  
Ikaro Daniel de Carvalho Barreto ◽  
Laélia Campos ◽  
Antonio Samuel Alves da Silva
Keyword(s):  
Markov Chains ◽  
River Basin ◽  
Arid Region ◽  
Standardized Precipitation Index ◽  
Precipitation Index ◽  
Severe Drought ◽  
Sao Francisco River ◽  
São Francisco River ◽  
Semi Arid Region ◽  
Semi Arid

This work evaluated dry and rainy conditions in the subregions of the São Francisco River Basin (BHSF) using the Standardized Precipitation Index (SPI) and Markov chains. Each subregion of the BHSF has specific physical and climatic characteristics. The data was obtained from the National Water Agency (ANA), collected by four pluviometric stations (representative of each subregion), covering 46 years of data, from 1970 to 2015. The SPI was calculated for the time scales of six and twelve months and transition probabilities were obtained using the Markov chain. Transition matrices showed that, at both scales, if the climate conditions were severe drought or rainy, switching to another class would be unlikely in the short term.  Correlating this information with the probabilities of the stationary distribution, it was possible to find the regions that are most likely to be under rainy or dry weather in the future. The recurrence times calculated for the stations that belong to the semi-arid region were smaller when compared to the value of the return period of the representative station of Upper São Francisco that has higher levels of precipitation, confirming the predisposition of the semi-arid region to present greater chances of future periods of drought.

scholarly journals Sting Jets in Simulations of a Real Cyclone by Two Mesoscale Models

2010 ◽  
Vol 138 (11) ◽  
pp. 4054-4075 ◽  
Author(s):  
Oscar Martínez-Alvarado ◽  
Florian Weidle ◽  
Suzanne L. Gray
Keyword(s):  
Small Scale ◽  
Extratropical Cyclones ◽  
Vertical Resolution ◽  
Mesoscale Models ◽  
Physical Mechanisms ◽  
The United Kingdom ◽  
Scale Modeling ◽  
Surface Measurements ◽  
The Subject ◽  
Comparison Of The Results

Abstract The existence of sting jets as a potential source of damaging surface winds during the passage of extratropical cyclones has recently been recognized. However, there are still very few published studies on the subject. Furthermore, although it is known that other models are capable of reproducing sting jets, in the published literature only one numerical model [the Met Office Unified Model (MetUM)] has been used to numerically analyze these phenomena. This article aims to improve our understanding of the processes that contribute to the development of sting jets and show that model differences affect the evolution of modeled sting jets. A sting jet event during the passage of a cyclone over the United Kingdom on 26 February 2002 has been simulated using two mesoscale models, namely the MetUM and the Consortium for Small Scale Modeling (COSMO) model, to compare their performance. Given the known critical importance of vertical resolution in the simulation of sting jets, the vertical resolution of both models has been enhanced with respect to their operational versions. Both simulations have been verified against surface measurements of maximum gusts, satellite imagery, and Met Office operational synoptic analyses, as well as operational analyses from the ECMWF. It is shown that both models are capable of reproducing sting jets with similar, though not identical, features. Through the comparison of the results from these two models, the relevance of physical mechanisms, such as evaporative cooling and the release of conditional symmetric instability, in the generation and evolution of sting jets is also discussed.

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