Assessing future drought conditions under a changing climate: a case study of the Lake Urmia basin in Iran

Abstract This study was conducted to assess the impacts of climate change on drought over the Lake Urmia basin, Iran. Drought events for 2011–2040, 2041–2070, and 2071–2100 were analyzed based on the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI) and were compared with the adopted baseline period (1976–2005). The SPI and SPEI were calculated using the precipitation and temperatures obtained from the second-generation Canadian Earth System Model (CanESM2) under Representative Concentration Pathway (RCP) 2.6 and RCP 8.5 as optimistic and pessimistic scenarios respectively. The results of SPI analyses revealed that under RCP 2.6 the frequency of droughts is almost constant while under RCP 8.5 drought frequency increased especially in the period 2071–2100. The calculated SEPI under both scenarios and during all future periods predict that the frequency and duration of droughts will increase. Generally, the difference between the SPI and SPEI is related to the input to each index. SPI is solely based on precipitation while the SPEI accounts for both precipitation and potential evapotranspiration (PET). Under global warming and changing climate, the significant role of PET was highlighted. It was concluded that the SPEI outperformed the SPI for drought studies under a changing climate.

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Inductive/Deductive Learning by Considering the Role of Gender—A Case Study of Iranian French-Learners

International Education Studies ◽

10.5539/ies.v9n12p254 ◽

2016 ◽

Vol 9 (12) ◽

pp. 254 ◽

Cited By ~ 1

Author(s):

Rouhollah Rahmatian ◽

Fatemeh Zarekar

Keyword(s):

Foreign Language ◽

Learning Styles ◽

Language Learning ◽

Inductive Approach ◽

The Difference ◽

Gender Based

<p class="apa">This article defines the objective of discovering the first preferred styles of Iranian learners of French as a Foreign Language (FFL) as regards inductive or deductive learning; and secondly, the difference between gender-based learning tendencies. Considering these points as target variables, the questionnaire developed by Felder and Silverman in 1988 was applied to form the learning styles and consequently to associate them with inductive and deductive approaches. The results led the team to set the idea which is based on the choice of induction or deduction in language learning and the gender variable that follows different directions. Consequently, in terms of the inductive approach, we find ourselves facing a rather male solicitation. A proportion of the use of this approach is also associated with women whose motivation is seen rather noticeably. Moreover, the significance is relative rather than significant in all the relationships studied in this research: males and inductive (1)/deductive learning (2); females and inductive (3)/deductive learning (4); inductive (5)/deductive (6) among Iranians.</p>

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Combining the standardized precipitation index and climatic water deficit in characterizing droughts: a case study in Romania

Theoretical and Applied Climatology ◽

10.1007/s00704-008-0061-1 ◽

2008 ◽

Vol 97 (3-4) ◽

pp. 219-233 ◽

Cited By ~ 31

Author(s):

Cr. Paltineanu ◽

I. F. Mihailescu ◽

Zoia Prefac ◽

Carmen Dragota ◽

Felicia Vasenciuc ◽

...

Keyword(s):

Water Deficit ◽

Standardized Precipitation Index ◽

Precipitation Index ◽

Climatic Water Deficit ◽

The Standardized Precipitation Index

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Drought monitoring and prediction using SPI, SPEI, and random forest model in various climates of Iran

Journal of Water and Climate Change ◽

10.2166/wcc.2021.287 ◽

2021 ◽

Author(s):

Morteza Lotfirad ◽

Hassan Esmaeili-Gisavandani ◽

Arash Adib

Keyword(s):

Random Forest ◽

Correlation Coefficient ◽

Potential Evapotranspiration ◽

Standardized Precipitation Index ◽

Monthly Precipitation ◽

Model Combination ◽

The North ◽

Drought Prediction ◽

Lag Times ◽

The Standardized Precipitation Index

Abstract The aim of this study is to select the best model (combination of different lag times) for predicting the standardized precipitation index (SPI) and the standardized precipitation and evapotranspiration index (SPEI) in next time. Monthly precipitation and temperature data from 1960 to 2019 were used. In temperate climates, such as the north of Iran, the correlation coefficient of SPI and SPEI was 0.94, 0.95, and 0.81 at the time scales of 3, 12, and 48 months, respectively. Besides, this correlation coefficient was 0.47, 0.35, and 0.44 in arid and hot climates, such as the southwest of Iran because potential evapotranspiration (PET) depends on temperature more than rainfall. Drought was predicted using the random forest (RF) model and applying 1–12 months lag times for next time. By increasing of time scale, the prediction accuracy of SPI and SPEI will improve. The ability of SPEI is more than SPI for drought prediction, because the overall accuracy (OA) of prediction will increase, and the errors (i.e., overestimate (OE) and underestimate (UE)) will reduce. It is recommended for future studies (1) using wavelet analysis for improving accuracy of predictions and (2) using the Penman–Monteith method if ground-based data are available.

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The role of Bayes factors in testing interactions

10.31234/osf.io/qjrg4 ◽

2019 ◽

Author(s):

Bence Palfi ◽

Zoltan Dienes

Keyword(s):

Experimental Manipulation ◽

Bayes Factors ◽

Sufficient Evidence ◽

Frequentist Statistics ◽

Shiny App ◽

Bayesian Evidence ◽

The Difference ◽

Condition B

Psychologists are often interested whether an experimental manipulation has a different effect in condition A than in condition B. To test such a question, one needs to directly compare the conditions (i.e. test the interaction). Yet, many tend to stop when they find a significant test in one condition and a non-significant test in the other condition, and deem it as sufficient evidence for the difference between the two conditions. This tutorial aims to raise awareness of this inferential mistake when Bayes factors are used with conventional cut-offs to draw conclusions. For instance, some might falsely conclude that there must be good enough evidence for the interaction if they find good enough Bayesian evidence for H1 in condition A and good enough Bayesian evidence for H0 in condition B. The introduced case study highlights that ignoring the test of the interaction can lead to unjustified conclusions and demonstrates that the principle that any assertion about the existence of an interaction necessitates the comparison of the conditions is as true for Bayesian as it is for frequentist statistics. We provide an R script of the analyses of the case study and a Shiny App that can be used with a 2x2 design to develop intuitions on the current issue, and we introduce a rule of thumb with which one can estimate the sample size one might need to have a well-powered design.

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Trends of SARS-Cov-2 infection in 67 countries: Role of climate zone, temperature, humidity and curve behavior of cumulative frequency on duplication time

10.1101/2020.04.18.20070920 ◽

2020 ◽

Cited By ~ 4

Author(s):

Jaime Berumen ◽

Max Schmulson ◽

Guadalupe Guerrero ◽

Elizabeth Barrera ◽

Jorge Larriva-Sahd ◽

...

Keyword(s):

Growth Curve ◽

Growth Curves ◽

Cumulative Frequency ◽

Climate Zone ◽

First Case ◽

Containment Measures ◽

The Difference ◽

Lineal Regression

Summary Objective. To analyze the role of temperature, humidity, date of first case diagnosed (DFC) and the behavior of the growth-curve of cumulative frequency (CF) [number of days to rise (DCS) and reach the first 100 cases (D100), and the difference between them (ΔDD)] with the doubling time (Td) of Covid-19 cases in 67 countries grouped by climate zone. Design. Retrospective incident case study. Setting. WHO based register of cumulative incidence of Covid-19 cases. Participants. 1,706,914 subjects diagnosed between 12-29-2019 and 4-15-2020. Exposures. SARS-Cov-2 virus, ambient humidity, temperature and climate areas (temperate, tropical/subtropical). Main outcome measures. Comparison of DCS, D100, ΔDD, DFC, humidity, temperature, Td for the first (Td10) and second (Td20) ten days of the CF growth-curve between countries according to climate zone, and identification of factors involved in Td, as well as predictors of CF using lineal regression models. Results. Td10 and Td20 were ≥3 days longer in tropical/subtropical vs. temperate areas (2.8[plusmn]1.2 vs. 5.7[plusmn]3.4; p=1.41E-05 and 4.6[plusmn]1.8 vs. 8.6[plusmn]4.2; p=9.7E-05, respectively). The factors involved in Td10 (DFC and ΔDD) were different than those in Td20 (Td10 and climate areas). After D100, the fastest growth-curves during the first 10 days, were associated with Td10<2 and Td10<3 in temperate and tropical/subtropical countries, respectively. The fold change Td20/Td10 >2 was associated with earlier flattening of the growth-curve. In multivariate models, Td10, DFC and ambient temperature were negatively related with CF and explained 44.7% (r2 = 0.447) of CF variability at day 20 of the growth-curve, while Td20 and DFC were negatively related with CF and explained 63.8% (r2 = 0.638) of CF variability towards day 30 of the growth-curve. Conclusions. The larger Td in tropical/subtropical countries is positively related to DFC and temperature. Td and environmental factors explain 64% of CF variability in the best of cases. Therefore, other factors, such as pandemic containment measures, would explain the remaining variability.

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An analysis of drought evolution characteristics based on standardized precipitation index: a case study in Southwest Guizhou Autonomous Prefecture, China

Journal of Agrometeorology ◽

10.54386/jam.v21i3.255 ◽

2021 ◽

Vol 21 (3) ◽

pp. 327-335

Author(s):

XU YANG ◽

XIAOHOU SHAO ◽

XINYU MAO ◽

XIUNENG LI ◽

RONGQI LI

Keyword(s):

Drought Resistance ◽

Standardized Precipitation Index ◽

Precipitation Index ◽

Natural Ecosystems ◽

Drought Duration ◽

Agricultural Water Management ◽

Evolution Characteristics ◽

Drought Disaster ◽

The Standardized Precipitation Index

Drought is a worldwide concerned issue which causes huge losses in agriculture, economic and damages in natural ecosystems. The precise assessment of drought evolution characteristics is essential for agricultural water management and drought resistance, while such work is rarely reported. Thus, eight meteorological stations located within the Southwest Guizhou Autonomous Prefecture (SGAP) were selected, and the Standardized Precipitation Index (SPI) was used to assess the drought evolution characteristics. The results revealed that the drought occurrences number in Pu'an station was the largest (23 droughts), and the average drought duration in Xingren station was the longest (48.75 months). Moreover, the drought characteristics of the eight stations have account for the largest proportion under normal conditions, was more than 60%, the frequency of drought disaster occurring in Xingren is the highest (30.05%), followed by Wangmo (23.73%). The results of this study will provide theoretical guidance for drought resistance and agricultural production in Southwest Guizhou Autonomous Prefecture of China.

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Examine The Role of Online Travel Agents to Increase Room Occupancy

10.31219/osf.io/68z4u ◽

2021 ◽

Author(s):

Hary Hermawan ◽

Rudi Wijayanto ◽

Prihatno ◽

Nikasius Jonet Sinangjoyo

Keyword(s):

Case Study Research ◽

Travel Agents ◽

Advantages And Disadvantages ◽

Start Up ◽

The Difference ◽

The Many ◽

Online Reservation ◽

Online Travel

Online Travel Agent (OTA) is an online-based start-up company that serves ticket purchases, hotel room reservations, and tourist attraction ticket purchases. One of the many OTA companies that collaborate with accommodation providers is Traveloka. Balkondes Sakapitu has used OTA, in this case, Traveloka as a partner in selling its products in the form of rooms. This study aims to analyze the role of OTA in increasing room occupancy in Balkondes Sakapitu. This research is qualitative research with a case study research design. This study indicates that OTA plays an essential role in increasing room occupancy at Balkondes Sakapitu. The increase in room occupancy is measured by the number of online reservation levels through Traveloka within three months from October to December 2020. The role of increasing room occupancy, the use of OTA in this case Traveloka includes: showing the position or position of the hotel based on reviews from guests and a forum for promotion and sales. There are advantages and disadvantages of using Traveloka for Balkondes Sakapitu. These advantages include marketing personnel's efficiency, saving operational costs, easy to change prices, and statistical data reports. While the drawbacks: the difference in sales prices, long payment tempo, and needed qualified HR. The strength of this research, when compared with previous research, is that this study reveals the pattern of cooperation between the hotel and OTA, and discusses the distribution of commission amounts that in previous studies not discussed.

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Flash Drought Response to Precipitation and Atmospheric Evaporative Demand in Spain

Atmosphere ◽

10.3390/atmos12020165 ◽

2021 ◽

Vol 12 (2) ◽

pp. 165

Author(s):

Iván Noguera ◽

Fernando Domínguez-Castro ◽

Sergio M. Vicente-Serrano

Keyword(s):

Drought Index ◽

Standardized Precipitation Index ◽

Precipitation Index ◽

Rapid Decline ◽

Spatial And Temporal Patterns ◽

Evaporative Demand ◽

Main Driver ◽

The Standardized Precipitation Index ◽

High Degree

Flash drought is the result of strong precipitation deficits and/or anomalous increases in atmospheric evaporative demand (AED), which triggers a rapid decline in soil moisture and stresses vegetation over short periods of time. However, little is known about the role of precipitation and AED in the development of flash droughts. For this paper, we compared the standardized precipitation index (SPI) based on precipitation, the evaporative demand drought index (EDDI) based on AED, and the standardized evaporation precipitation index (SPEI) based on the differences between precipitation and AED as flash drought indicators for mainland Spain and the Balearic Islands for 1961–2018. The results show large differences in the spatial and temporal patterns of flash droughts between indices. In general, there was a high degree of consistency between the flash drought patterns identified by the SPI and SPEI, with the exception of southern Spain in the summer. The EDDI showed notable spatial and temporal differences from the SPI in winter and summer, while it exhibited great coherence with the SPEI in summer. We also examined the sensitivity of the SPEI to AED in each month of the year to explain its contribution to the possible development of flash droughts. Our findings showed that precipitation is the main driver of flash droughts in Spain, although AED can play a key role in the development of these during periods of low precipitation, especially in the driest areas and in summer.

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Reliability Assessment of Agricultural Reservoirs for Water Supply under Climate Change

Korean Society of Hazard Mitigation ◽

10.9798/kosham.2020.20.1.53 ◽

2020 ◽

Vol 20 (1) ◽

pp. 53-60

Author(s):

Dasang Ko ◽

Yeongcheol Joo ◽

Taesam Lee

Keyword(s):

Climate Change ◽

Standardized Precipitation Index ◽

Precipitation Index ◽

Severe Drought ◽

Water Shortages ◽

The Future ◽

Storage Rate ◽

The Standardized Precipitation Index ◽

Agricultural Areas

Recently, the frequency of drought occurrence and the resulting damage has increased due to climate change. Frequent severe droughts induce water shortages in agricultural reservoirs. The role of drought monitoring and prediction is critical for mitigating the effects of severe drought in agricultural areas. In this study, a compound standardized storage and precipitation index (CSSPI) was developed that adapted the existing drought index-the standardized precipitation index (SPI)-by adding hydrological data on storage rate. Furthermore, the future storage rate was simulated using autoregressive models (AR) to estimate the future CSSPI. A dataset containing records of reservoirs and precipitation at the three areas of Jungbu, Youngnam, and Honam was applied to estimate the current and future status of the CSSPI. The results indicate that the CSSPIs generated accurately present the past pattern of the observed data and that they can be considered as inputs for predicting future drought conditions.

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Past and Future Precipitation Trend Analysis for the City of Niamey (Niger): An Overview

Climate ◽

10.3390/cli6030073 ◽

2018 ◽

Vol 6 (3) ◽

pp. 73 ◽

Cited By ~ 8

Author(s):

Velia Bigi ◽

Alessandro Pezzoli ◽

Maurizio Rosso

Keyword(s):

Standardized Precipitation Index ◽

Positive Trend ◽

Precipitation Trend ◽

Daily Precipitation Data ◽

Rcp 8.5 ◽

Precipitation Analysis ◽

The Republic ◽

The Standardized Precipitation Index ◽

West African Sahel ◽

The City

Despite the interest in detecting the extremes of climate in the West African Sahel, few studies have been specifically conducted on the Republic of Niger. This research focuses on past, present, and future precipitation trends for the city of Niamey through the combined assessment of WMO precipitation indices using RClimDex and the Standardized Precipitation Index. Past daily precipitation data were derived from a 60-year reconstructed meteorological dataset for the Niamey airport station for the period of 1950–2009 and validated through comparison with an observed time series at Niamey airport (1980–2012). Precipitation analysis confirms the literature’s findings, in particular, a decreasing trend in total precipitation over the period of 1950–2009, and a positive trend for data that spans over the period of 1980–2009, suggesting a precipitation recovery after the dry epoch (1968–1985), even if the deficit with the wettest years in the period of 1950–1968 has not been made up. Furthermore, WATCH-Forcing-Data-ERA-Interim projections, elaborated under RCP 4.5 and RCP 8.5 socio-economic conditions, show that precipitation will increase in the future. Therefore, the Nigerien population will benefit from increased rainfall, but will also have to cope with the exacerbation of both flood and drought risks due to a great interannual variability that can positively or negatively influence water availability.

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