scholarly journals Evaluating the Spatiotemporal Characteristics of Agricultural Drought in Bangladesh Using Effective Drought Index

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2437 ◽  
Author(s):  
Mohammad Kamruzzaman ◽  
Syewoon Hwang ◽  
Jaepil Cho ◽  
Min-Won Jang ◽  
Hanseok Jeong
Keyword(s):  
Central Region ◽  
Drought Index ◽  
Regional Analysis ◽  
Mitigation Strategies ◽  
Agricultural Drought ◽  
Monthly Precipitation ◽  
Effective Drought Index ◽  
Spatiotemporal Characteristics ◽  
North Western

This study aims to assess the spatiotemporal characteristics of agricultural droughts in Bangladesh during 1981–2015 using the Effective Drought Index (EDI). Monthly precipitation data for 36 years (1980–2015) obtained from 27 metrological stations, were used in this study. The EDI performance was evaluated for four sub-regions over the country through comparisons with historical drought records identified by regional analysis. Analysis at a regional level showed that EDI could reasonably detect the drought years/events during the study period. The study also presented that the overall drought severity had increased during the past 35 years. The characteristics (severity and duration) of drought were also analyzed in terms of the spatiotemporal evolution of the frequency of drought events. It was found that the western and central regions of the country are comparatively more vulnerable to drought. Moreover, the southwestern region is more prone to extreme drought, whereas the central region is more prone to severe droughts. Besides, the central region was more prone to extra-long-term droughts, while the coastal areas in the southwestern as well as in the central and north-western regions were more prone to long-term droughts. The frequency of droughts in all categories significantly increased during the last quinquennial period (2011 to 2015). The seasonal analysis showed that the north-western areas were prone to extreme droughts during the Kharif (wet) and Rabi (dry) seasons. The central and northern regions were affected by recurring severe droughts in all cropping seasons. Further, the most significant increasing trend of the drought-affected area was observed within the central region, especially during the pre-monsoon (March–May) season. The results of this study can aid policymakers in the development of drought mitigation strategies in the future.

scholarly journals Evaluating the Spatiotemporal Characteristics of Meteorological Drought in Bangladesh Using Effective Drought Index

2019 ◽  
Author(s):  
Mohammad Kamruzzaman ◽  
Syewoon Hwang ◽  
Jaepil Cho ◽  
Min-Won Jang ◽  
Hanseok Jeong
Keyword(s):  
Central Region ◽  
Drought Index ◽  
Regional Scale ◽  
Mitigation Strategies ◽  
Monthly Precipitation ◽  
Effective Drought Index ◽  
Spatiotemporal Characteristics ◽  
Increasing Trend ◽  
North Western

This study aims to assess the spatiotemporal characteristics of meteorological droughts in Bangladesh during 1981–2015 using the Effective Drought Index (EDI). Monthly precipitation data for 36 years (1980-2015) obtained from 27 metrological stations, were used in this study. The EDI performance was evaluated for four sub-regions over the country through comparisons with historical drought records identified at the regional scale. Analysis at a regional level showed that EDI could reasonably detect the drought years/events during the study period. The study also revealed that the overall drought severity had increased during the past 35 y; the most significant increasing trend was observed in the central region. The characteristics (severity and duration) of drought were also analysed in terms of spatiotemporal evolution of the frequency of drought events. It was found that the western and central regions of the country are comparatively more vulnerable to drought. Moreover, the southwestern region is more prone to extreme drought, whereas the central region is more prone to severe droughts. In addition, the central region was more prone to extra-long-term droughts, while the coastal areas in the southwestern as well as in the central and north-western region were more prone to long-term droughts. The frequency of droughts in all categories significantly increased during the last quinquennial period (2011 to 2015). The seasonal analysis showed that the north-western areas were prone to extreme droughts during the Kharif (wet) and Rabi (dry) seasons. The central and northern regions were affected by recurring severe droughts in all cropping seasons. Further, the most significant increasing trend of the drought-affected area was observed within the central region, especially during the pre-monsoon (March-May) season. The results of this study can aid policymakers in the development of drought mitigation strategies in the future.

scholarly journals A revised agricultural drought index in Lithuania

2020 ◽  
Vol 29 (4) ◽  
Author(s):  
Egidijus Rimkus ◽  
Viktorija Maciulyte ◽  
Edvinas Stonevicius ◽  
Donatas Valiukas
Keyword(s):  
Drought Index ◽  
Growing Season ◽  
Agricultural Drought ◽  
Drought Indices ◽  
Study Analysis ◽  
Hydrothermal Coefficient ◽  
Positive Tendency ◽  
Drought Conditions ◽  
Long Term Changes

The objective of this study was to develop the best methodology for determining agricultural droughts in Lithuania. The currently used assessment methods do not always accurately reflect drought conditions in the country, especially in the first half of the growing season. For this purpose, the relevance of the currently used Hydrothermal Coefficient (HTC) and five drought indices widely used in other countries were reassessed. It was found that the methodologies applied in Lithuania and other countries are not completely suitable under current conditions. A new agricultural drought identification methodology using the Temperature–Precipitation Index (TPI) is proposed as a result of this study. Analysis of long-term changes (1961–2019) in reoccurrence of droughts was carried out. It was determined that the largest number of droughts in Lithuania was recorded in the last decade of the 20th century and in the first decade of the 21st century. Despite the fact that there is a positive tendency in reoccurrence of droughts, the changes are not statistically significant.

scholarly journals Spatiotemporal variability and assessment of drought in the Wei River basin of China

2018 ◽  
Vol 379 ◽  
pp. 73-82
Author(s):  
Siyang Cai ◽  
Depeng Zuo ◽  
Zongxue Xu ◽  
Xianming Han ◽  
Xiaoxi Gao
Keyword(s):  
River Basin ◽  
Drought Index ◽  
Standardized Precipitation Index ◽  
Meteorological Drought ◽  
Agricultural Drought ◽  
Spatiotemporal Variability ◽  
Monthly Precipitation ◽  
The Wei River Basin ◽  
Wei River Basin ◽  
Wei River

Abstract. The temporal and spatial variations of drought in the Wei River basin (WRB) were investigated by calculating the meteorological drought Index (Standardized Precipitation Index, SPI) and the agricultural drought index (Vegetation Health Index, VHI). Monthly precipitation and air temperature were from 22 meteorological stations over the region from 1960 to 2015. Monthly Normalized Difference Vegetation Index (NDVI) and 8-days Land Surface Temperature (LST) were provided from the National Aeronautics and Space Administration (NASA) for the period 2000–2015 were also adopted. The results showed that the drought initially increased and then decreased, reaching at the maximum value in 1990s. The spatial pattern of meteorological drought showed that the drought in northern WRB was heavier than that in southern WRB before 1990s, after that, the situation had the opposite. By comparing the agricultural drought index (VHI) with crop yield, it was proved that VHI was applicable in the WRB and could well reflect the fluctuation of agricultural drought. The WRB suffered from serious agricultural drought in 2000, 2001, 2007 and 2008. Through analysis of the historical precipitation and temperature data, it was found that precipitation had a greater contribution to creating agricultural drought conditions than temperature in the Wei River basin.

scholarly journals Spatio-Temporal Assessment of Drought using Effective Drought Index (EDI) and Standardized Precipitation Index (SPI) During Monsoon Months in Cuttack District, Odisha, India

2019 ◽  
Vol 8 (4) ◽  
pp. 9993-10000
Keyword(s):  
Drought Index ◽  
Standardized Precipitation Index ◽  
Rainfall Threshold ◽  
Precipitation Index ◽  
Agricultural Drought ◽  
Drought Analysis ◽  
Effective Drought Index ◽  
Climatic Regions ◽  
Block Based ◽  
June July

Various parts of the World is experiencing frequent droughts due to climatic uncertainties. Drought is the most difficult and least understood natural hazard which can occur virtually in all types of climatic regions. Therefore, improved scientific analysis for forecasting, monitoring and management of drought is required. Effective drought index (EDI) and Standardized Precipitation Index (SPI) is used for drought analysis in this study, as both indices gained popularity as important drought indicators in recent years across space and time. Therefore, EDI 3 Aug (June, July and August), SPI 3 Aug, EDI 3 Sep (July, August and September) and SPI 3 Sep are estimated by utilizing the monthly rainfall data for 30 (1988-2017) years in thirteen blocks of Cuttack District, Odisha, India for characterising drought during monsoon months. The analysis inferred that, highest number of total drought (moderate+severe+extreme) events occurred in Narasighpur block based on EDI 3 Aug and Tangi-Choudwar and Tigiria blocks based on both SPI 3 Aug. Similarly, maximum number of total droughts experienced by Salepur block based on EDI 3 Sep and Cuttack Sadar, Nischintakoili and Tangi-Choudwar blocks as per SPI 3 Sep. Drought maps prepared for the years in decades (1995, 2005 and 2015) to study the variation of drought spatially as well as temporally during monsoon months based on the computed value of drought using EDI and SPI. In the year 1995, no drought events are observed from the drought map based on the drought value of EDI and SPI. Two rainfall threshold values were also estimated for agricultural drought during monsoon months in this study. The threshold limit for agricultural drought varied from 553.9 to 706.3, 516.2 to 722.8, 614.1 to 687.4 and 586.0 to 702.0 mm based on EDI 3 Aug, SPI 3 Aug, EDI 3 Sep and SPI 3 Sep value respectively. This drought analysis will be helpful for implementing various strategies of water management and crop planning for different blocks of Cutttack District.

scholarly journals Drought Model DISS Based on the Fusion of Satellite and Meteorological Data under Variable Climatic Conditions

2020 ◽  
Vol 12 (18) ◽  
pp. 2944
Author(s):  
Katarzyna Dabrowska-Zielinska ◽  
Alicja Malinska ◽  
Zbigniew Bochenek ◽  
Maciej Bartold ◽  
Radoslaw Gurdak ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Land Surface ◽  
Drought Index ◽  
Extreme Values ◽  
Meteorological Data ◽  
Climatic Conditions ◽  
Agricultural Drought ◽  
Drought Monitoring ◽  
Large Area

The use of effective methods for large-area drought monitoring is an important issue; hence, there have been many attempts to solve this problem. In this study, the Drought Information Satellite System (DISS) index is presented, based on the synergistic use of meteorological data and information derived from satellite images. The index allows us to monitor drought phenomena in various climatic and environmental conditions. The approach utilizes two indices for constructing a drought index: (1) the hydrothermal coefficient (HTC), which characterizes meteorological conditions across the study area over a long-term period; and (2) the temperature condition index (TCI) derived from Moderate-resolution Imaging Spectroradiometer (MODIS) data, which refers instantaneous land surface temperature (LST) to long-term extreme values. The model for drought assessment based on the DISS index was applied for generating drought index maps for Poland for the 2001–2019 vegetation seasons. The performance of the index was verified through comparison of the extent of agricultural drought to the reduction in cereal and maize yield. Analysis of variance revealed a significant relationship between the area of drought determined by the drought index and the decrease in cereal yield due to unfavorable growth conditions. The presented study proves that the proposed drought index can be an effective tool for large-area drought monitoring under variable environmental conditions.

scholarly journals Molecular Phenomic Approaches to Deconvolving the Systemic Effects of SARS-CoV-2 Infection and Post-acute COVID-19 Syndrome

Phenomics ◽  
2021 ◽  
Author(s):  
Jeremy K. Nicholson
Keyword(s):  
Molecular Level ◽  
Organ Damage ◽  
Zoonotic Diseases ◽  
Mitigation Strategies ◽  
Health Consequence ◽  
Metabolic Phenotyping ◽  
Persistent Symptoms ◽  
Biological Discovery ◽  
New Biomarkers

AbstractSARS COV-2 infection causes acute and frequently severe respiratory disease with associated multi-organ damage and systemic disturbances in many biochemical pathways. Metabolic phenotyping provides deep insights into the complex immunopathological problems that drive the resulting COVID-19 disease and is also a source of novel metrics for assessing patient recovery. A multiplatform metabolic phenotyping approach to studying the pathology and systemic metabolic sequelae of COVID-19 is considered here, together with a framework for assessing post-acute COVID-19 Syndrome (PACS) that is a major long-term health consequence for many patients. The sudden emergence of the disease presents a biological discovery challenge as we try to understand the pathological mechanisms of the disease and develop effective mitigation strategies. This requires technologies to measure objectively the extent and sub-phenotypes of the disease at the molecular level. Spectroscopic methods can reveal metabolic sub-phenotypes and new biomarkers that can be monitored during the acute disease phase and beyond. This approach is scalable and translatable to other pathologies and provides as an exemplar strategy for the investigation of other emergent zoonotic diseases with complex immunological drivers, multi-system involvements and diverse persistent symptoms.

scholarly journals High coverage COVID-19 mRNA vaccination rapidly controls SARS-CoV-2 transmission in long-term care facilities

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Pablo M. De Salazar ◽  
Nicholas B. Link ◽  
Karuna Lamarca ◽  
Mauricio Santillana
Keyword(s):  
Long Term Care ◽  
Mitigation Strategies ◽  
Key Factors ◽  
Modeling Framework ◽  
High Coverage ◽  
Term Care ◽  
Early Effect ◽  
Care Facilities ◽  
The Relationship

Abstract Background Residents of Long-Term Care Facilities (LTCFs) represent a major share of COVID-19 deaths worldwide. Measuring the vaccine effectiveness among the most vulnerable in these settings is essential to monitor and improve mitigation strategies. Methods We evaluate the early effect of the administration of BNT162b2-mRNA vaccine to individuals older than 64 years residing in LTCFs in Catalonia, Spain. We monitor all the SARS-CoV-2 documented infections and deaths among LTCFs residents once more than 70% of them were fully vaccinated (February–March 2021). We develop a modeling framework based on the relationship between community and LTCFs transmission during the pre-vaccination period (July–December 2020). We compute the total reduction in SARS-CoV-2 documented infections and deaths among residents of LTCFs over time, as well as the reduction in the detected transmission for all the LTCFs. We compare the true observations with the counterfactual predictions. Results We estimate that once more than 70% of the LTCFs population are fully vaccinated, 74% (58–81%, 90% CI) of COVID-19 deaths and 75% (36–86%, 90% CI) of all expected documented infections among LTCFs residents are prevented. Further, detectable transmission among LTCFs residents is reduced up to 90% (76–93%, 90% CI) relative to that expected given transmission in the community. Conclusions Our findings provide evidence that high-coverage vaccination is the most effective intervention to prevent SARS-CoV-2 transmission and death among LTCFs residents. Widespread vaccination could be a feasible avenue to control the COVID-19 pandemic conditional on key factors such as vaccine escape, roll out and coverage.

scholarly journals Different Drought Legacies of Rain-Fed and Irrigated Croplands in a Typical Russian Agricultural Region

2020 ◽  
Vol 12 (11) ◽  
pp. 1700
Author(s):  
Yuanhuizi He ◽  
Fang Chen ◽  
Huicong Jia ◽  
Lei Wang ◽  
Valery G. Bondur
Keyword(s):  
Surface Temperature ◽  
Drought Index ◽  
Growth Period ◽  
Meteorological Drought ◽  
Agricultural Drought ◽  
Drought Monitoring ◽  
Growth Stages ◽  
Drought Conditions ◽  
Irrigated Lands ◽  
Meteorological Droughts

Droughts are one of the primary natural disasters that affect agricultural economies, as well as the fire hazards of territories. Monitoring and researching droughts is of great importance for agricultural disaster prevention and reduction. The research significance of investigating the hysteresis of agricultural to meteorological droughts is to provide an important reference for agricultural drought monitoring and early warnings. Remote sensing drought monitoring indices can be employed for rapid and accurate drought monitoring at regional scales. In this paper, the Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation indices and the surface temperature product are used as the data sources. Calculating the temperature vegetation drought index (TVDI) and constructing a comprehensive drought disaster index (CDDI) based on the crop growth period allowed drought conditions and spatiotemporal evolution patterns in the Volgograd region in 2010 and 2012 to be effectively monitored. The causes of the drought were then analyzed based on the sensitivity of a drought to meteorological factors in rain-fed and irrigated lands. Finally, the lag time of agricultural to meteorological droughts and the hysteresis in different growth periods were analyzed using statistical analyses. The research shows that (1) the main drought patterns in 2010 were spring droughts from April to May and summer droughts from June to August, and the primary drought patterns in 2012 were spring droughts from April to June, with an affected area that reached 3.33% during the growth period; (2) local drought conditions are dominated by the average surface temperature factor. Rain-fed lands are sensitive to the temperature and are therefore prone to summer droughts. Irrigated lands are more sensitive to water shortages in the spring and less sensitive to extremely high temperature conditions; (3) there is a certain lag between meteorological and agricultural droughts during the different growth stages. The strongest lag relationship was found in the planting stage and the weakest one was found in the dormancy stage. Therefore, the meteorological drought index in the growth period has a better predictive ability for agricultural droughts during the appropriately selected growth stages.

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