slope test
Recently Published Documents


TOTAL DOCUMENTS

41
(FIVE YEARS 23)

H-INDEX

5
(FIVE YEARS 1)

Author(s):  
Lia Pervin ◽  
Sabbir Mostafa Khan

Abstract This study was intended to evaluate the variability and trends of climate extremes by incorporating daily data from Chattogram station and from the high-resolution Coordinated Regional Climate Downscaling Experiment (CORDEX) for two different time series. Here, we also focused on evaluating the performance of the selected RCMs (CanESM2, CSIRO, and GFDL from CORDEX) using Taylor diagrams and heat map analysis. Twenty-two extreme climate indices from ETCCDI were computed for 1950–1989 and 1990–2020 periods. Mann–Kendall and Sen's slope test were performed to estimate the trends from the indices from both station and RCMs data. Highly significant increasing trend for the warm days and warm nights’ frequencies were found, whereas, the frequency of cold days and cold nights indicated significantly decreasing trend. On the other hand, mild increasing trend in 1-day and 5-day maximum rainfall was detected. Also, the average annual precipitation has increased by 6% from the 1950–1989 to 1990–2020 period. During the last three decades, the region has experienced more heavier rainfall in the monsoon but increased water stress in the dry season. The two-fold effects of climate change on the local hydrology revealed by this study need to be addressed properly for the sustainable development of this region.


2021 ◽  
Author(s):  
Meseret Bekele Toma ◽  
Mulugeta Dadi Belete ◽  
Mihret Dananto Ulsido

Abstract BackgroundIdentifying hydro-meteorological trends is basic for assessing change in climate and river discharge at watershed level. This study examined the long-term trends of rainfall, temperature, and discharge in the annual, monthly and seasonal time scale of Ajora-Woybo watershed in Ethiopia. The data span of rainfall and temperature is between 1990 and 2020 and that of discharge is between 1990 and 2015. Homogeneity test was performed by using Pettit and SNHT tests. Then Mann-Kendall and Sen's slope test for trend analysis and different variability measures were used. ResultsResults indicate that inhomogeneity was detected in annual rainfall data of Angacha and Areka stations. On annual basis, rainfall and discharge exhibited insignificant trends over time while showing a general decreasing pattern. On monthly basis, February and March were found to have significantly decreasing trend for rainfall. During the Kiremt season, rainfall increases and discharge decreases insignificantly. In contrast, maximum, minimum and mean annual temperatures exhibited significant trends with annual increment of 0.04oC, 0.01oC, and 0.025 oC per year respectively. Correlations of discharge with both temperature and rainfall have found to be weak in this study.ConclusionsThis trend, combined with population growth and increasing demand of water for agricultural activities exacerbates competing demands for water resources. Caution is therefore required when it comes to developing appropriate measures for the planning and sustainable development of the water resources in the watershed.


2021 ◽  
Vol 22 (1) ◽  
pp. 48-51
Author(s):  
GANESH D. KALE

Climate change information at the scale of basin is vital for planning, development and use of water. The Tapi basin is climatically responsive. Hydrological response of a basin is based mainly on rainfall and temperature. Variations in climate at regional scales impacts fundamental features of our life. Thus, in the present work, trend analyses of regional time series (1971-2004) of minimum, mean, maximum temperatures and rainfallis performed for monthly, annual and seasonal scales for the Tapi basin. Correlogram is utilized for evaluation of dependence of data. Mann-Kendall test and Mann-Kendall test with block bootstrapping are applied for the evaluation of trend significance. Sen’s slope test is applied for the evaluation of trend magnitude. Sequential Mann-Kendall test is applied for assessment of beginning and end of the trend. Statistically significant positive trends are detected in regional annual and winter Tmean time series with their beginning in years 1974 and 1972, respectively.


Author(s):  
Deepak Kumar Tiwari ◽  
◽  
Tiwari H. L. ◽  
Raman Nateriya ◽  
◽  
...  

The conceptual and physical mathematical model of rainfall-runoff modeling uses various parameters such as land use land cover, soil type classification, rainfall, atmospheric data such as temperature, evapotranspiration, solar radiation and wind speed, etc. But these data may not be available for developing countries and data scares semi-arid watershed. Also, the problem is even more critical for ungauged catchments and where manual record is maintained of water level and rainfall data. To address this issue, trend analysis is performed using Mann-Kendall test and Sen’s slope test which shows significant trend change stressing the need for new method for runoff prediction for better water resource management. In this study, a total of four models namely nonlinear autoregressive model with exogenous inputs lumped (LNARX), nonlinear autoregressive model with exogenous geomorphometrically processed inputs (GNARX), wavelet nonlinear autoregressive model with exogenous inputs (WLNARX) and nonlinear autoregressive model with exogenous geomorphometrically processed inputs (WGNARX). Ten models with different input combinations were selected based on their performance are analyzed for all the four networks. The best performing model for these networks is model no. 6 with WGNARX network with NSE 0.97 and RMSE 0.97 and with least value of RMSE. This method can be applied to data scarce region where data available are available for shorter duration and helpful for ungauged catchments also.


2021 ◽  
pp. 088626052110234
Author(s):  
Jingyu Geng ◽  
Yuhui Wang ◽  
Hongxia Wang ◽  
Pengcheng Wang ◽  
Li Lei

Although some studies have explored the psychological and behavioral outcomes of social comparison orientation (SCO), few have explored the associations of SCO with cyberbullying perpetration and victimization. The current study aimed to investigate the associations of SCO with cyberbullying perpetration and victimization, and considered envy on social networking sites (SNS) as a mediator and body satisfaction as a moderator in these relations. To test our expectations, 941 adolescents aged between 10 and 16 years ( M = 13.15, SD = 1.18) completed multiple questionnaires, namely the Social Comparison Orientation Scale, the Revised Cyber Bullying Inventory, an envy scale revised for the SNS context, and the Body Areas Satisfaction Scale. Correlation analysis revealed that cyberbullying perpetration and cyberbullying victimization were significantly and positively correlated with SCO and envy on SNS, and significantly and negatively correlated with body satisfaction. The results of structural equation modeling (SEM) revealed that envy on SNS played a mediating role in the associations of SCO with cyberbullying perpetration and victimization. The results of SEM and simple slope test analysis indicated that body satisfaction weakened the direct association of SCO with envy on SNS and further weakened the indirect associations of SCO with cyberbullying perpetration and victimization via envy on SNS. Specifically, individuals with high levels of SCO were more likely to feel envious on SNS, and further tended to bully others and be bullied online when they were dissatisfied with their bodies. In other words, positive body satisfaction protected individuals with high levels of SCO from cyberbullying perpetration and victimization by decreasing their feelings of envy on SNS.


Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 982
Author(s):  
Dawit Ghebreyesus ◽  
Hatim O. Sharif

Precipitation is the main source for replenishing groundwater stored in aquifers for a myriad of beneficial purposes, especially in arid and semi-arid regions. A significant portion of the municipal and agricultural water demand is satisfied through groundwater withdrawals in Texas. These withdrawals have to be monitored and regulated to be in balance with the recharge amount from precipitation in order to ensure water security. The main goal of this study is to understand the spatio-temporal variability of precipitation in the 21st century using high spatial resolution stage-IV radar data over the state of Texas and examine some climatic controls behind this variability. The results will shed light on the trends of precipitation and hence will contribute to improving water resources management strategies and policies. Pettit’s test and Standard Normal Homogeneity Test (SNHT), tools for detecting change-point in the monthly precipitation, suggested change-points have occurred across the state around the years 2013 and 2014. The test for the homogeneity of the data before and after 2013 revealed that, in over 64% of the state, the precipitation means were significantly different. The Panhandle region (northern part) is the only part of the state that did not show a significant difference in the mean precipitation before and after 2013. Theil-Sen’s slope test, Correlated Seasonal Mann-Kendall Test, and Cox and Stuart Trend Test all indicated that there were no significant trends in the monthly precipitation after 2013 in over 98% of the area of the state. Texas precipitation was found to be influenced significantly by the El Niño-Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO). A significant correlation in more than 82% and 60% of the state was found with ENSO at two-month and with PDO at four-month lag, respectively.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zhengqiao Liu ◽  
Yongzhong Jiang ◽  
Zhu Yao ◽  
Xiliang Liu ◽  
Li Zhao ◽  
...  

Purpose Based on self-consistency theory and conservation of resource theory, this study aims to discuss the impact of career calling congruence on employees’ innovation performance (IP) and analyzes the mediating effect of work passion [harmonious passion (HP) and obsessive passion (OP)]. Design/methodology/approach To avoid serious common method biases, data in this paper were collected at three-wave. This paper investigated 381 employees to assess their career calling in time 1, measured their work passion in time 2 and assessed the IP of these employees in time 3. This paper also conducts confirmatory factor analysis, polynomial regression, response surface analysis, bootstrapping test and simple slope test to verify the research hypothesis in this paper. Findings In the career calling congruence case, employees’ HP, OP and IP are higher when both levels of serving oneself career calling and helping others career calling are high than when both are low; In the career calling incongruence case, employees’ HP, OP and IP are higher in the “low serving oneself and high helping others” case than in the “high serving oneself and low helping others” case; The more congruent the “serving oneself” and “helping others” career calling are, the higher the employees’ HP, OP and IP will be; and HP and OP mediate the relationship between career calling congruence and IP. Originality/value This study further clarifies the structure of career calling and find the positive effects of career calling on IP. The results present a deeper understanding of career calling and are universal applicable to the eastern culture context.


Climate ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 149
Author(s):  
Firew Bekele ◽  
Degefa Tolossa ◽  
Teshale Woldeamanuel

This study aimed to appraise the role of local institutions in adaptation to changing climate at the local level in the Bilate Basin Agropastoral Livelihood Zone of Ethiopia. Thirty-one years of climate data were analyzed by employing the Mann–Kendall trend and Sen’s slope test techniques. The survey was conducted on 400 households that were systematically randomized from 7066 households, while community-level data were collected through the participatory rural appraisal (PRA) technique. The entire analysis was framed by a tetragonal model. The results of the analysis indicated that temperature exhibited a significantly increasing trend, while rainfall, which is statistically related to temperature, showed a decreasing trend, resulting in lingering droughts and human and animal diseases. Major livestock declined by 69%. As a response, while Sidama indigenous institutions were well-functioning and nurtured through local knowledge, and the governmental and civic ones were entrenched with various limitations. Contextual fitness and compatibility, interplay, inclusiveness, and sustainability of their operations in temporal and spatial scales were some of their limitations. Therefore, federal and local governments should focus on monitoring, evaluating, and learning aspects of their grand strategies, review general education, farmers’ credit, and civic institutions’ governance policies and strengthen the synergy of civic, government, and indigenous institutions.


2020 ◽  
Vol 11 ◽  
Author(s):  
Xiwei Liu ◽  
Shenggang Yang ◽  
Zhu Yao

The purpose of this paper is to explore the relationship between workplace bullying (WB) and employee silence (ES) as well as its mechanism. This paper collects data from 322 employees of three Chinese enterprises in two waves, with a 2 months interval between the two waves. Moreover, this paper uses confirmatory factor analysis, a bootstrapping mediation test, a simple slope test, and other methods to verify the hypothesis. We find that: (1) WB is positively correlated with ES; (2) psychological safety (PS) and affective commitment mediated the relationship between WB and ES, respectively, and these two variables have a chain mediating effect in the above relationship; and (3) a forgiveness climate moderates this chain mediating effect by weakening the negative impact of WB on PS. Our findings can effectively guide organizations to ultimately adjust their management style, pay attention to employees’ cognitive and emotional resources, and formulate some measures to curb WB in organizations.


Sign in / Sign up

Export Citation Format

Share Document