scholarly journals Meteorological Drought Events and Their Evolution from 1960 to 2015 Using the Daily SWAP Index in Chongqing, China

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1887
Author(s):  
Bo Liu ◽  
Yubing Liu ◽  
Wenpeng Wang ◽  
Chunlei Li
Keyword(s):  
Spatial Variation ◽  
Linear Trend ◽  
Weighted Average ◽  
Meteorological Drought ◽  
Economic Losses ◽  
Trend Test ◽  
Drought Risk ◽  
Significant Linear Trend ◽  
Annual Frequency ◽  
Meteorological Droughts

Meteorological droughts are natural disasters that have been linked to economic losses and casualties. Decision-makers need to understand the temporal and spatial variation of meteorological drought events at a daily to weekly scale to develop a more elaborate framework for drought risk management. The present study used the standardized weighted average of precipitation index (SWAP) as an indicator of meteorological droughts, computed from the daily precipitation dataset (1960–2015) of 34 meteorological stations in Chongqing, China. The multi-threshold run theory was applied to identify drought events. Variation of drought characteristics was estimated by the modified Sen’s trend test. The results suggested the following findings: (1) the onset, duration, and severity of drought events identified by the SWAP index are in good agreement with the real local records; (2) there was no significant linear trend and abrupt change in annual duration and severity of drought events, but the decadal variation was obvious. From a decadal perspective, the annual frequency, duration, and severity of drought events showed a steady decreasing trend before the 1990s, and then fluctuated upward; (3) the spatial variation of the duration and severity of ordinary drought events was quite inconsistent at different periods. The annual drought days and severity increased from 1960 to 2015 but decreased after 1990. From 1960 to 2015, the duration days and severity of persistent, long persistent, severe, and extreme drought events declined insignificantly in most parts of the middle and southeast regions but increased in the western and northeast regions. The drought situation in Chongqing shows a large range of variation and obvious spatial heterogeneity. The SWAP index is an effective tool to identify the evolution of daily scale meteorological drought events.

scholarly journals Estimation of Vulnerability and Risk to Meteorological Drought in Mexico

2016 ◽  
Vol 8 (2) ◽  
pp. 95-110 ◽  
Author(s):  
Carolina Neri ◽  
Víctor Magaña
Keyword(s):  
Water Productivity ◽  
Management Strategies ◽  
Meteorological Drought ◽  
Economic Losses ◽  
Drought Risk ◽  
Vulnerability Factors ◽  
Drought Vulnerability ◽  
Risk Management Strategies ◽  
Hydraulic Infrastructure ◽  
Impact Data

Abstract Prolonged droughts severely affect the economic, social, and environmental sectors in Mexico. The interest in reducing the costs of drought is now focused on prevention by means of vulnerability reduction. The present study proposes a methodology to estimate vulnerability and risk to drought, considering the physical, economical, and social factors that make regions of Mexico prone to experiencing hydrological and agricultural droughts. Recognizing that there is no universally accepted way to describe vulnerability, the proposed method defines the object under study, the natural hazard, and vulnerability factors by means of indicators. The vulnerability factors are related to water infrastructure, the condition of aquifers or water reservoirs, the levels of wastewater treatment, water productivity in agriculture, hydraulic infrastructure, and water tariffs. A drought vulnerability model for each Hydrological Administrative Region (RHA) in Mexico is obtained by combining the vulnerability indicators. The product of vulnerability and hazard results in risk estimates that are compared with impact data to validate the approach. Information on agricultural or hydrological drought is used as impact data. The validation process is an important step in the methodology, since it allows examination of the causes of disasters by the vulnerability factors and leads to risk management strategies. It is found that although vulnerability to meteorological drought in the agricultural and hydrological sectors in Mexico has decreased in recent years, the drought risk is still high and results in severe economic losses, such as those registered in central and northern Mexico during the 2011–12 prolonged drought.

scholarly journals Thirty-Nine-Year Wave Hindcast, Storm Activity, and Probability Analysis of Storm Waves in the Kara Sea, Russia

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 648
Author(s):  
Stanislav Myslenkov ◽  
Vladimir Platonov ◽  
Alexander Kislov ◽  
Ksenia Silvestrova ◽  
Igor Medvedev
Keyword(s):  
Climate Change ◽  
Pareto Distribution ◽  
Linear Trend ◽  
Wind Waves ◽  
Kara Sea ◽  
The Arctic ◽  
Storm Events ◽  
Storm Activity ◽  
Significant Linear Trend ◽  
The Impact

The recurrence of extreme wind waves in the Kara Sea strongly influences the Arctic climate change. The period 2000–2010 is characterized by significant climate warming, a reduction of the sea ice in the Arctic. The main motivation of this research to assess the impact of climate change on storm activity over the past 39 years in the Kara Sea. The paper presents the analysis of wave climate and storm activity in the Kara Sea based on the results of numerical modeling. A wave model WAVEWATCH III is used to reconstruct wind wave fields for the period from 1979 to 2017. The maximum significant wave height (SWH) for the whole period amounts to 9.9 m. The average long-term SWH for the ice-free period does not exceed 1.3 m. A significant linear trend shows an increase in the storm wave frequency for the period from 1979 to 2017. It is shown that trends in the storm activity of the Kara Sea are primarily regulated by the ice. Analysis of the extreme storm events showed that the Pareto distribution is in the best agreement with the data. However, the extreme events with an SWH more than 6‒7 m deviate from the Pareto distribution.

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.

Cylindrocarpon and Fusarium root colonization of Douglas-fir seedlings from British Columbia reforestation sites

1998 ◽  
Vol 28 (8) ◽  
pp. 1198-1206 ◽  
Author(s):  
Paige E Axelrood ◽  
William K Chapman ◽  
Keith A Seifert ◽  
David B Trotter ◽  
Gwen Shrimpton
Keyword(s):  
British Columbia ◽  
Pseudotsuga Menziesii ◽  
Root Colonization ◽  
Linear Trend ◽  
Poor Performance ◽  
Douglas Fir ◽  
Root Infection ◽  
Significant Linear Trend ◽  
Conifer Seedlings ◽  
Cylindrocarpon Destructans

Poor performance of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) plantations established in 1987 has occurred in southwestern British Columbia. Affected sites were planted with 1-year-old container stock that exhibited some root dieback in the nursery. A study was initiated in 1991 to assess Cylindrocarpon and Fusarium root infection in planted and naturally regenerating (natural) Douglas-fir seedlings from seven affected plantations. Percentages of seedlings harboring Cylindrocarpon spp.and percent root colonization were significantly greater for planted seedlings compared with natural seedlings. A significant linear trend in Cylindrocarpon root colonization was observed for planted seedlings with colonization levels being highest for roots closest to the remnants of the root plug and decreasing at distances greater than 10cm from that region. This trend in Cylindrocarpon colonization was not observed for natural seedlings. Cylindrocarpon destructans (Zins.) Scholten var. destructans and C.cylindroides Wollenw. var. cylindroides were the only species isolated from planted and natural conifer seedlings. For most sites, percentage of seedlings harboring Fusarium spp.and percent Fusarium root colonization were less than for Cylindrocarpon. Recovery of Fusarium spp.from seedlings and root colonization levels were not significantly different for planted and natural seedlings from all sites.

Hydro-meteorological drought risk assessment using linear and nonlinear multivariate methods

2021 ◽  
pp. 103046
Author(s):  
Zahra Azhdari ◽  
Ommolbanin Bazrafshan ◽  
Hossein Zamani ◽  
Marzieh Shekari ◽  
Vijay P. Singh
Keyword(s):  
Risk Assessment ◽  
Meteorological Drought ◽  
Drought Risk ◽  
Multivariate Methods ◽  
Linear And Nonlinear

Learning as a Function of Subliminal Reinforcements

1963 ◽  
Vol 12 (2) ◽  
pp. 387-398
Author(s):  
Austin Jones ◽  
Melvin Manis ◽  
Bernard Weiner
Keyword(s):  
Relative Frequency ◽  
Probability Learning ◽  
Linear Trend ◽  
Stimulus Category ◽  
Time Intervals ◽  
Significant Linear Trend ◽  
Tachistoscopic Presentation ◽  
Stimulus Classes ◽  
Learning Trials ◽  
Correct Discrimination

Three studies were conducted to assess the effects of subliminal reinforcements on learning. In the first two, Ss were given a discrimination task in which five geometric forms, repeated over 100 trials, were to be assigned to one of two categories. The categories were unbalanced; four geometric forms comprised one category, the remaining form the other. Response was required on each trial. Immediately after each response, the appropriate reinforcing word, “Right” or “Wrong,” was flashed at a subliminal brightness-contrast In Exp. I, under low motivation (without money incentives), Ss showed no learning of the correct discrimination, nor any evidence of probability learning with respect to relative frequency of stimulus categories. In Exp. II, the above procedure was replicated with money as the incentive. There again was no evidence of discrimination learning, i.e., acquisition of the correct response. There was, however, a significant linear trend ( p < .05) in the proportion of responses made to the more frequent stimulus category; Ss showed an increasing tendency to “match” the relative frequency of their two classes of response with the corresponding two stimulus classes. In Exp. III, Ss who were motivated by a money incentive attempted to guess whether E was thinking of an odd or an even number. Following each response, Ss were reinforced by tachistoscopic presentation of the word “Right” or “Wrong,” at time intervals which were too brief to permit recognition; half of the Ss were positively reinforced for emitting the response “Odd,” and half for the response “Even.” After 100 learning trials had been completed, the reinforcement contingencies were switched for an additional 20 trials, e.g., Ss who had been reinforced for “Odd” were now reinforced for “Even.” Ss in Exp. III showed no evidence of probability learning. Some possible explanations for the conflicting results of Exps. II and III were discussed.

scholarly journals Minor psychiatric disorders and their associations in family caregivers of people with mental disorders

2017 ◽  
Vol 22 (11) ◽  
pp. 3567-3578 ◽  
Author(s):  
Carlos Alberto dos Santos Treichel ◽  
Vanda Maria da Rosa Jardim ◽  
Luciane Prado Kantorski ◽  
Aline dos Santos Neutzling ◽  
Michele Mandagará de Oliveira ◽  
...  
Keyword(s):  
Mental Disorders ◽  
Psychiatric Disorders ◽  
Family Caregivers ◽  
Linear Trend ◽  
Trend Test ◽  
P Value ◽  
Test Statistic ◽  
Cross Sectional ◽  
Self Reporting Questionnaire ◽  
Minor Psychiatric Disorders

Abstract This study aims to analyze the occurrence of minor psychiatric disorder and their associations in relatives of people with mental disorders. This is a cross-sectional study of 1164 relatives. For the tracking of minor psychiatric disorders the Self-Reporting Questionnaire Scale (SRQ20) was used, adopting 6/8 as cut-off point. Bivariate analyzes were conducted using Chi-squared test. Trends among strata of independent variables were investigated in relation to the outcome using nonparametric linear trend test. Statistic significance was defined as p-value < 0.05. Crude and adjusted binary logistic regressions were conducted using as a basis the hierarchical model developed through a systematic literature review. It was observed in the population a prevalence of 46.9% for minor psychiatric disorders. Higher prevalence of minor psychiatric disorders were strongly associated with the female gender, older age, first degree family ties, not having a paid work, lower education level, lower income, health problems, lower quality of life and feeling of burden. Many factors are related to the emotional and mental illness of family caregivers, demanding health services to be prepared to recognize and intervene in these situations.

scholarly journals Direct and indirect economic impacts of drought in the agri-food sector in the Ebro River basin (Spain)

2013 ◽  
Vol 13 (10) ◽  
pp. 2679-2694 ◽  
Author(s):  
M. Gil ◽  
A. Garrido ◽  
N. Hernández-Mora
Keyword(s):  
Water Scarcity ◽  
Agricultural Sector ◽  
Economic Impacts ◽  
Economic Loss ◽  
Mitigation Strategies ◽  
Economic Losses ◽  
Drought Risk ◽  
Drought Event ◽  
Drought Impacts ◽  
Indirect Impacts

Abstract. The economic evaluation of drought impacts is essential in order to define efficient and sustainable management and mitigation strategies. The aim of this study is to evaluate the economic impacts of a drought event on the agricultural sector and measure how they are transmitted from primary production to industrial output and related employment. We fit econometric models to determine the magnitude of the economic loss attributable to water storage. The direct impacts of drought on agricultural productivity are measured through a direct attribution model. Indirect impacts on agricultural employment and the agri-food industry are evaluated through a nested indirect attribution model. The transmission of water scarcity effects from agricultural production to macroeconomic variables is measured through chained elasticities. The models allow for differentiating the impacts deriving from water scarcity from other sources of economic losses. Results show that the importance of drought impacts are less relevant at the macroeconomic level, but are more significant for those activities directly dependent on water abstractions and precipitation. From a management perspective, implications of these findings are important to develop effective mitigation strategies to reduce drought risk exposure.

scholarly journals Impact of climate change on hydro-meteorological drought over the Be River Basin, Viet Nam

2021 ◽  
Author(s):  
Dao Nguyen Khoi ◽  
Truong Thao Sam ◽  
Pham Thi Loi ◽  
Bui Viet Hung ◽  
Van Thinh Nguyen
Keyword(s):  
Climate Change ◽  
River Basin ◽  
General Circulation ◽  
Southern Oscillation ◽  
Meteorological Drought ◽  
Climate Projections ◽  
Research Station ◽  
Climate Change Scenarios ◽  
Study Region ◽  
Meteorological Droughts

Abstract In this paper, the responses of hydro-meteorological drought to changing climate in the Be River Basin located in Southern Vietnam are investigated. Climate change scenarios for the study area were statistically downscaled using the Long Ashton Research Station Weather Generator tool, which incorporates climate projections from Coupled Model Intercomparison Project 5 (CMIP5) based on an ensemble of five general circulation models (Can-ESM2, CNRM-CM5, HadGEM2-AO, IPSL-CM5A-LR, and MPI-ESM-MR) under two Representative Concentration Pathway (RCP) scenarios (RCP4.5 and RCP8.5). The Soil and Water Assessment Tool model was employed to simulate streamflow for the baseline time period and three consecutive future 20 year periods of 2030s (2021–2040), 2050s (2041–2060), and 2070s (2061–2080). Based on the simulation results, the Standardized Precipitation Index and Standardized Discharge Index were estimated to evaluate the features of hydro-meteorological droughts. The hydrological drought has 1-month lag time from the meteorological drought and the hydro-meteorological droughts have negative correlations with the El Niño Southern Oscillation and Pacific Decadal Oscillation. Under the climate changing impacts, the trends of drought severity will decrease in the future; while the trends of drought frequency will increase in the near future period (2030s), but decrease in the following future periods (2050 and 2070s). The findings of this study can provide useful information to the policy and decisionmakers for a better future planning and management of water resources in the study region.

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