scholarly journals Investigating the Meteorological Drought Using CZI in Nineveh Governorate, Iraq.

2021 ◽  
Vol 28 (4) ◽  
pp. 14-24
Author(s):  
Omar M. A. Mahmood Agha
Keyword(s):  
Time Scale ◽  
Historical Data ◽  
Meteorological Drought ◽  
The Other ◽  
Drought Intensity ◽  
Moderate Drought ◽  
Average Probability ◽  
Mild Drought

This paper deals with the study of drought in the Nineveh region usingthe Chinese Z index (CZI) for a time scale (1 month). Historical data wereused from 1981 to 2018 for Mosul, Sinjar, and Tal Afar stations. Thereturn period and probability event for the moderate drought werecalculated for each month separately. The results indicated that allstations experienced the highest drought intensity in March comparedwith the other months. The average probability of moderate droughtranged between 0-0.31 for all months, and the maximum severity of thedrought was found in December from 2004 to 2008 for all stations. Inaddition, the results showed that the region's climate during the studyperiod was within the mild drought and humidity (closest to normal).This paper is the first study using the Chinese Z-index (CZI) in the studyarea and the Iraq region

scholarly journals Analysis of Agricultural Drought Using Remotely Sensed Evapotranspiration in a Data-Scarce Catchment

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 998 ◽  
Author(s):  
Frank Joseph Wambura ◽  
Ottfried Dietrich
Keyword(s):  
Remote Sensing ◽  
Land Cover ◽  
Land Cover Change ◽  
Remotely Sensed ◽  
Agricultural Drought ◽  
Mitigation Measures ◽  
Drought Intensity ◽  
River Catchment ◽  
Moderate Drought ◽  
Mild Drought

Understanding spatial drought characteristics is vital for planning adaptation and mitigation measures in river catchments. In many parts of the world, spatial drought information is not available due to lack of adequate evenly distributed data for spatial drought analyses. This study elucidates a spatial drought analysis in a data-scarce tropical catchment using remote sensing actual evapotranspiration (ET) and potential evapotranspiration (PET) data. Firstly, the time series of 690 images of remotely sensed ET and PET between the years 2000 and 2014 were spatially analyzed using the evapotranspiration deficit index (ETDI) approach to obtain ETDIs in the Kilombero River catchment (Tanzania). Then, spatio-temporal patterns of ETDIs were used to characterize drought frequency, total drought durations, total drought severity, and drought intensity. The frequency, durations, severity, and intensity of drought increased from the year 2000 towards 2014, causing substantial drought changes in the catchment. However, drought intensity revealed that those changes were mainly from no drought and mild drought to moderate drought. Between the years 2000 and 2014, no-drought areas and mild drought areas declined from 10% to 0% and from 42% to 19%, respectively, whereas moderate drought areas increased from 47% to 81% of the catchment size. Those changes of drought conditions were partly attributed to anthropogenic land cover change, especially in the southwest grasslands, and were partly attributed to meteorological factors in other parts of the catchment. This information is crucial for further land cover change and climate change investigations, as well as planning water and land resources in the Kilombero River catchment. Moreover, the study also demonstrates the potential of using publicly available remote sensing ET products and the ETDI approach for spatially characterizing drought in ungauged regions.

scholarly journals Meteorological drought assessment using standardized precipitation index for different agro-climatic zones of Odisha

MAUSAM ◽  
2021 ◽  
Vol 71 (3) ◽  
pp. 467-480
Author(s):  
PANIGRAHI BALRAM ◽  
LIANSANGPUII FANAI
Keyword(s):  
Standardized Precipitation Index ◽  
Meteorological Drought ◽  
Precipitation Index ◽  
Extreme Drought ◽  
Severe Drought ◽  
Climatic Zones ◽  
Drought Assessment ◽  
Moderate Drought ◽  
The Impact ◽  
Mild Drought

In this paper standardized precipitation index (SPI) is used to assess meteorological drought for all 30 districts covering 10 agro-climatic zones in an eastern Indian state, Odisha. Monthly rainfall data of 115 years (1901-2015) for all 30 districts of Odisha are analyzed using SPI on 1, 3, 6, 9 and 12-month timescale. These timescales reflect the impact of drought on the availability of different water resources. Results indicate that in all the agro-climatic zones of Odisha, mild drought events have the highest frequencies of occurrence followed by moderate drought events for different timescales. Severe and extreme drought frequencies are comparatively lesser than mild and moderate drought frequencies. SPI analysis shows that 32-46 years are affected by mild drought, 4-16 years affected by moderate drought, 1-9 years are affected by severe drought and 1-5 years are affected by extreme drought during study period of 115 years in different agro-climatic zones of Odisha. It is observed 50.3% areas in the state are affected by drought in June out of which chances of occurrence of mild drought is maximum (28.7%). In the months of July, August and September, 51.7, 48.5 and 46.1% areas are affected by droughts. On average 49.15% areas of the entire state is affected by drought of various intensities out of which the share of mild, moderate, severe and extreme drought is 28.38, 13.28, 5.06 and 2.43%, respectively.

scholarly journals Comparison of Nine Meteorological Drought Indices Over Middle Euphrates Region During Period from 1988 To 2017

2018 ◽  
Vol 7 (4.20) ◽  
pp. 602 ◽  
Author(s):  
Imzahim A. Alwan ◽  
Abdul Razzak T. Ziboon ◽  
Alaa G. Khalaf
Keyword(s):  
Correlation Coefficient ◽  
Time Scale ◽  
Pearson Correlation ◽  
Meteorological Drought ◽  
The Other ◽  
Drought Indices ◽  
Annual Time Scale ◽  
Maximum Value ◽  
Seasonal Time Scale ◽  
Annual Time

The aim of this research is compare between nine drought indices and evaluate their performance with respect to predict and monitoring drought over Middle Euphrates region during period from 1988 to 2017.These indices are RDI, Normal SPI, Gamma SPI, Log SPI, CZI, MCZI, RAI, PN, and DI.Season and annual time scale were used to calculate all indices at Dewaniya, Hilla, Karbala, Najaf, and Semawa stations. The Pearson correlation coefficient between nine drought indices were analyzed. Annual and seasonal results illustrated that the maximum value of correlation between RDI and the other indices was noted with Gamma SPI and Log SPI at all stations. In annual time scale, the correlation coefficient reached to (0.99) at all stations except Hilla station, where it reached to (0.98), while in seasonal time scale the correlation coefficient reached to (0.98) at all stations. The RDI, Gamma SPI and Log SPI indices have similarity of classes and frequencies for drought. They also have similarity of frequencies for wet but there are minimum differences between wet classes compared to other indices. The RDI, Gamma SPI and Log SPI are good indices to predict and monitoring drought in study area in comparison to other indices which mentioned above.  

scholarly journals Reservoir Sizing at Draft Level of 75% of Mean Annual Flow Using Drought Magnitude Based Method on Canadian Rivers

Hydrology ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 79
Author(s):  
Tribeni C. Sharma ◽  
Umed S. Panu
Keyword(s):  
Standard Deviation ◽  
Time Scale ◽  
Moving Average ◽  
Flow Data ◽  
Truncation Level ◽  
Drought Intensity ◽  
Error Margin ◽  
Reservoir Volume ◽  
The Mean ◽  
Reservoir Sizing

On a global basis, there is trend that a majority of reservoirs are sized using a draft of 75% of the mean annual flow (0.75 MAF). The reservoir volumes based on the proposed drought magnitude (DM) method and the sequent peak algorithm (SPA) at 0.75 MAF draft were compared at the annual, monthly and weekly scales using the flow sequences of 25 Canadian rivers. In our assessment, the monthly scale is adequate for such analyses. The DM method, although capable of using flow data at any time scale, has been demonstrated using monthly standardized hydrological index (SHI) sequences. The moving average (MA) smoothing of the monthly SHI sequences formed the basis in the DM method for estimating the reservoir volume through the use of the extreme number theorem, and the hypothesis that drought magnitude is equal to the product of the drought intensity and drought length. The truncation level in the SHI sequences was found as SHIo [ = (0.75 ‒ 1) µo/σo], where µo and σo are the overall mean and standard deviation of the monthly flows. The DM-based estimates for the deficit volumes and the SPA-based reservoir volumes were found comparable within an error margin of ±18%.

Juárez, Maximilian, and the French Occupation of Mexico

2021 ◽  
Author(s):  
Michael Hogan
Keyword(s):  
United States ◽  
Historical Data ◽  
The United States ◽  
Working Poor ◽  
The Other ◽  
Reform Movement ◽  
Mexican History ◽  
Basic Facts ◽  
The Republic ◽  
Benito Juarez

A tumultuous period in Mexican history began with the Reform Movement of President Benito Juárez, followed by the French invasion and installation of Maximillian as emperor, the defeat of his troops by the liberal army, and the restoration of the Mexican Republic in 1877. Although most of the basic facts of these events are not in dispute, the narrowness of the lens used to examine them is. Some data have been systematically ignored by national historians, and there are also contradictory interpretations of the published historical data. One common reflection on this period is the depiction of Maximilian as liberal whom some argue contributed in a positive way to Mexico. However, some Mexican scholars dispute this. The other widely held belief is that Benito Juárez can be credited with the restoration of the republic and the betterment of the working poor and indigenous. Although criticism of Juárez is uncommon in official circles, where he is idolized, some Mexican scholars are more skeptical of these claims. The missing or generally ignored data concern the contribution of the United States to the defeat of the French and Austrian armies, which is not mentioned in any survey texts and is minimized in most articles. The fuller inclusion of these data coupled with a closer look at the contributions and failures of both the Maximilian and Juárez regimes provides a clearer picture of the epoch and generates new insights.

Weak Coupling Strategy for Multi-Physics CFD Simulation in Engineering Problems

2011 ◽  
Author(s):  
Makoto Yamamoto ◽  
Masaya Suzuki
Keyword(s):  
Strong Coupling ◽  
Time Scale ◽  
Weak Coupling ◽  
Particle Deposition ◽  
Cfd Simulation ◽  
The Other ◽  
Cfd Simulations ◽  
Sand Erosion ◽  
Coupling Strategy ◽  
The Difference

Multi-Physics CFD Simulation will be one of key technologies in various engineering fields. There are two strategies to simulate a multi-physics phenomenon. One is “Strong Coupling”, and the other is “Weak Coupling”. Each can be employed, based on time-scales of physics embedded in a problem. That is, when a time-scale of one physics is nearly same as that of the other physics, we have to use Strong Coupling to take into account the interaction between two physics. On the other hand, when one time-scale is quite different from the other one, Weak Coupling can be applied. Considering the present computer performance, Strong Coupling is difficult to be used in engineering design processes now. Therefore, we are focusing on Weak Coupling, and it has been applied to a number of multi-physics CFD simulations in engineering. We have successfully simulated sand erosion, ice accretion, particle deposition, electro-chemical machining and so on, with using Weak Coupling method. In the present study, the difference between strong and weak couplings is briefly described, and two examples of our multi-physics CFD simulations are expressed. The numerical results indicate that Weak Coupling strategy is promising in a lot of multi-physics CFD simulations.

scholarly journals Tracers confirm downward mixing of Tyrrhenian Sea upper waters associated with the Eastern Mediterranean Transient

2010 ◽  
Vol 7 (4) ◽  
pp. 1533-1557
Author(s):  
W. Roether ◽  
J. E. Lupton
Keyword(s):  
Deep Water ◽  
Time Scale ◽  
Eastern Mediterranean ◽  
Western Mediterranean ◽  
The Other ◽  
Tyrrhenian Sea ◽  
Convective Mixing ◽  
Deep Waters ◽  
Major Process ◽  
Gibraltar Strait

Abstract. Observations of tritium and 3He in the Tyrrhenian Sea, 1987–2009, confirm the enhanced convective mixing of intermediate waters into the deep waters that has been noted and associated with the Eastern Mediterranean Transient in previous studies. Our evidence for the mixing rests on increasing tracer concentrations in the Tyrrhenian deep waters, accompanied by decreases in the upper waters, which are supplied from the Eastern Mediterranean. The downward transfer is particularly evident between 1987 and 1997. Later on, information partly rests on increasing tritium-3He ages; here we correct the observed 3He for contributions released from the ocean floor. The Tyrrhenian tracer distributions are fully compatible with data upstream of the Sicily Strait and in the Western Mediterranean. The tracer data show that mixing reached to the bottom and confirm a cyclonic nature of the deep water circulation in the Tyrrhenian. They furthermore indicate that horizontal homogenization of the deep waters occurs on a time scale of several years. Various features point to a reduced impact of Western Mediterranean Deep Water (WMDW) in the Tyrrhenian during the enhanced-convection period. This is an important finding because it implies less upward mixing of WMDW, which has been named a major process to enable the WMDW to leave the Mediterranean via the Gibraltar Strait. On the other hand, the TDW outflow for several years represented a major influx of enhanced salinity and density waters into the deep-water range of the Western Mediterranean.

scholarly journals Robust Future Changes in Meteorological Drought in CMIP6 Projections Despite Uncertainty in Precipitation

2021 ◽  
Author(s):  
Anna Ukkola ◽  
Martin De Kauwe ◽  
Michael Roderick ◽  
Gab Abramowitz ◽  
Andy Pitman
Keyword(s):  
Climate Models ◽  
Water Security ◽  
Meteorological Drought ◽  
Resource Planning ◽  
Climate Projections ◽  
Land Area ◽  
Natural Ecosystems ◽  
Drought Duration ◽  
Drought Intensity ◽  
Projected Changes

<p>Understanding how climate change affects droughts guides adaptation planning in agriculture, water security, and ecosystem management. Earlier climate projections have highlighted high uncertainty in future drought projections, hindering effective planning. We use the latest CMIP6 projections and find more robust projections of meteorological drought compared to mean precipitation. We find coherent projected changes in seasonal drought duration and frequency (robust over >45% of the global land area), despite a lack of agreement across models in projected changes in mean precipitation (24% of the land area). Future drought changes are larger and more consistent in CMIP6 compared to CMIP5. We find regionalised increases and decreases in drought duration and frequency that are driven by changes in both precipitation mean and variability. Conversely, drought intensity increases over most regions but is not simulated well historically by the climate models. These more robust projections of meteorological drought in CMIP6 provide clearer direction for water resource planning and the identification of agricultural and natural ecosystems at risk.</p>

scholarly journals The genus Fusicladium (Hyphomycetes) in Poland

2013 ◽  
Vol 41 (2) ◽  
pp. 285-298
Author(s):  
Małgorzata Ruszkiewicz-Michalska ◽  
Ewa Połeć
Keyword(s):  
Historical Data ◽  
The Other ◽  
Distribution Maps ◽  
Central Poland ◽  
The World ◽  
First Time

The paper presents new and historical data on the genus <em>Fusicladium</em> verified on the base of the recently published critical monograph. Fifteen species recorded in Poland under the name <em>Fusicladium</em> and synonymous <em>Pollaccia</em> and <em>Spilocaea</em> are reported; 5 are documented by authors’ materials from Central Poland while the other taxa are supported with literature data only, including three species belonging currently to <em>Fusicladiella</em> and <em>Passalora</em>. Three species, reported here for the first time in Poland: <em>Fusicladium convolvularum</em> Ondřej, <em>F. scribnerianum</em> (Cavara) M. B. Ellis and <em>F. virgaureae</em> Ondřej, are known from a few localities in the world. All the species are provided with the distribution maps and the newly reported ones are illustrated with ink drawings.

Phedimus Aizoon L. Responds to Drought Stress: Growth, Physiological Changes and Mechanism of Drought Resistance

2020 ◽  
Author(s):  
Yuhang Liu ◽  
Zhongqun He ◽  
Yongdong Xie ◽  
Lihong Su ◽  
Ruijie Zhang ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Resistance ◽  
Soluble Sugar ◽  
Severe Drought ◽  
Physiological Changes ◽  
Moderate Drought ◽  
Negative Effect ◽  
Mda Content ◽  
Maximum Water ◽  
Mild Drought

Abstract A pot experiment was conducted to investigate the growth, physiological changes and mechanism of drought resistance of Phedimus aizoon L. under different levels of water content .CK: 75% ~ 80% of the MWHC (maximum water holding capacity), Mild drought: 55% ~ 60%, Moderate drought: 40% ~ 45%, Severe drought: 20% ~ 25%.We observed that the plants grew normally in the first two treatments, even the mild drought promoted the growth of the roots. In the last two treatments, drought stress had a significant negative effect on plant growth, at the same time, Phedimus aizoon L. also made positive physiological response to cope with the drought: The aboveground part of the plant (leaf, plant height, stem diameter) was smaller, the waxy layer of the leaves was thickened, the stomata of the leaves were closed during the day, and only a few stomata were opened at night, which proved that the dark reaction cycle metabolism mode of the plant was transformed from C3 cycle to CAM pathway. The activity of antioxidant enzymes (SOD, POD and CAT) was continuously increased to alleviate the damage caused by drought. To ensure the relative stability of osmotic potential, the contents of osmoregulation substances such as proline, soluble sugar, soluble protein and trehalose increased correspondingly. But plants have limited regulatory power, with aggravation of drought stress degree and extension of stress time, the MDA content and electrolyte leakage of leaves increased continuously. Observed under electron microscope,the morphology of chloroplast and mitochondria changed and the membrane structure was destroyed. The plant's photosynthetic and respiratory mechanisms are destroyed and the plant gradually die.

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