scholarly journals Analysis of hydrometeorological variables over the transboundary Komadugu-Yobe basin, West Africa

2019 ◽  
Vol 11 (4) ◽  
pp. 1339-1354 ◽  
Author(s):  
O. E. Adeyeri ◽  
P. Laux ◽  
A. E. Lawin ◽  
S. O. Ige ◽  
H. Kunstmann
Keyword(s):  
Time Scales ◽  
Minimum Temperature ◽  
River Discharge ◽  
Kendall Test ◽  
Mitigation Measures ◽  
Maximum Temperature ◽  
Spatiotemporal Trends ◽  
Increasing Trend ◽  
Temperature Ranges ◽  
Positive Correlations

Abstract Spatiotemporal trends in daily observed precipitation, river discharge, maximum and minimum temperature data were investigated between 1971 and 2013 in the Komadugu-Yobe basin. Significant change points in time series are corrected using Adapted Caussinus-Mestre Algorithm for homogenizing Networks of Temperature series algorithm. Mann–Kendall test and Sen's slope are used to estimate the trend and its magnitude at dry, wet and annual season time scales, respectively. Preliminary results show an increasing trend of the observed variables. There is a latitudinal increase (decrease) in the basin temperature (precipitation) from lower to higher latitudes. The minimum temperature (0.05 °C/year) increases faster than the maximum temperature (0.03 °C/year). Overall, the percentage changes in minimum temperature range between 3 and 10% while that of maximum temperature ranges between 1 and 3%. Due to precipitation dependence on regional characteristics, the highest percentage change was recorded in precipitation with values between −5 and 97%. In all time scales, river discharge and precipitation have strong positive correlations while the correlation between river discharge and temperature is negative. It is imperative to advocate and support positive developmental practices as well as establishing necessary mitigation measures to cope with the effects of climate in the basin.

scholarly journals ASSESSMENT OF LONG TERM CLIMATIC VARIABILITY OF UTTARAKHAND

2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Sujeet Kumar ◽  
Shakti Suryavanshi
Keyword(s):  
Minimum Temperature ◽  
Monsoon Season ◽  
Climatic Variability ◽  
Kendall Test ◽  
Summer Season ◽  
Climatic Variables ◽  
Maximum Temperature ◽  
Mountain Areas ◽  
Mk Test ◽  
Increasing Trend

A trend analysis was performed for historic (1901-2002) climatic variables (Rainfall, Maximum Temperature and Minimum Temperature) of Uttarakhand State located in Northern India. In the serially independent climatic variables, Mann-Kendall test (MK test) was applied to the original sample data. However, in the serially correlated series, prewhitening is utilized before employing the MK test. The results of this study indicated a declining trend of rainfall in monsoon season for seven out of thirteen districts of Uttarakhand state. However, an increasing trend was observed in Haridwar and Udhamsingh Nagar districts for summer season rainfall. For maximum and minimum temperature, a few districts exhibited a declining trend in monsoon season whereas many districts exhibited an increasing trend in winter and summer season. Mountain dominated areas (as Uttarakhand state) are specific ecosystems, distinguished by their diversity, sensitivity and intricacy. Thus the variability of rainfall and temperature has a severe and rapid impact on mountainous ecosystems. Nevertheless, mountains have significant impacts on hydrology, which may further threaten populations living in the mountain areas as well as in adjacent, lowland regions.

scholarly journals Trend Analysis of Precipitation and Temperature over Different Districts of Karnataka: An Aid to Climate Change Detection and Cropping System Option

2020 ◽  
pp. 15-25
Author(s):  
S. Sridhara ◽  
Pradeep Gopakkali ◽  
R. Nandini
Keyword(s):  
Minimum Temperature ◽  
Monsoon Season ◽  
Cropping System ◽  
Weather Conditions ◽  
Kendall Test ◽  
Annual Rainfall ◽  
Maximum Temperature ◽  
Land Preparation ◽  
Mk Test ◽  
Increasing Trend

Aims: To know the rainfall and temperature trend for all the districts of Karnataka state to develop suitable coping mechanisms for changing weather conditions during the cropping season. Study Design: The available daily data of rainfall (1971-2011) and minimum and maximum temperature (1971-2007) for each district was collected from NICRA-ICAR website. A non-parametric model such as the Mann-Kendall (MK) test complemented with Sen’s slope estimator was used to determine the magnitude of the trend. Place and Duration of Study: The rainfall data of 41 years (1971-2011) and temperature data of 37 years (1971-2007) was collected for all 27 districts of Karnataka. Methodology: Basic statistics related to rainfall like mean, standard deviation (SD), the coefficient of variation (CV) and the percentage contribution to annual rainfall were computed for monthly and season-wise. Mann-Kendall test was used to detect trend for rainfall as well as temperature. Results: An increasing trend in rainfall during winter, monsoon and annual basis for all most all the districts of Karnataka and decreasing trend of rainfall during pre and post-monsoon season was noticed. An early cessation of rainfall during September month in all most all the districts of Karnataka was observed. Similarly, monthly mean, maximum and the minimum temperature had shown an increasing trend over the past 37 years for all the districts of Karnataka. Conclusion: The more variation in rainfall during the pre-monsoon season was observed, which is more important for land preparation and other operations. The increasing trend of maximum and minimum temperature throughout the year may often cause a reduction in crop yield. It is necessary to change crops with its short duration varieties in order to avoid late season drought.

scholarly journals Time Series Trend and Variability Analysis of Temperature and Rainfall in West Shewa Zone of Oromia, Ethiopia

2021 ◽  
Author(s):  
Daniel Assefa ◽  
Mesfin Mengistu
Keyword(s):  
Time Series ◽  
Minimum Temperature ◽  
Kendall Test ◽  
Annual Rainfall ◽  
Maximum Temperature ◽  
Variability Analysis ◽  
Increasing Trend ◽  
Systematic Planning ◽  
Temperature Records ◽  
C 30

Abstract BackgroundThe paper focus on time series trend and variability analysis of observed rainfall and temperature records from 16 stations during 1985-2015. ResultsBoth the summer and annual rainfall have an increasing trend but not statistically significant. Regards to variability, low to very high levels of variability were recorded according to the seasons and annual rainfall, whereas, moderate to extremely high levels of variability were observed. The result of the Mann Kendall test portrays that the mean minimum temperature was raised by 0.05 oC, while the maximum temperature was increased rose by 0.03 oC/30 years. The monthly maximum temperature also shows an increasing trend with the lowest record during August (22.05 oC) and the highest in the March (26.49 oC) except in the month of November and December. Similarly, an increasing trend was observed with a mean monthly minimum temperature with the lowest mean of 8.42Co in December and the highest mean of 11.12 oC recorded in April. Besides, a low level of variability was seen both in the case of minimum and maximum temperature were observed in all months. ConclusionsTherefore, since the observed trends of both temperature and total rainfall show abnormal shifts, there is an urgent need for policymakers to design systematic planning and management activities to rain-fed agriculture.

Homogeneity Evaluation of Historical Rainfall and Temperature Series in Mato Grosso

2019 ◽  
pp. 1-7
Author(s):  
Elizangela Selma da Silva ◽  
José Holanda Campelo Júnior ◽  
Francisco De Almeida Lobo ◽  
Ricardo Santos Silva Amorim
Keyword(s):  
Trend Analysis ◽  
Minimum Temperature ◽  
Statistical Tests ◽  
Kendall Test ◽  
Maximum Temperature ◽  
Data Series ◽  
Positive Trend ◽  
Mato Grosso ◽  
Temperature Climate ◽  
Precipitation And Temperature

The homogeneity investigation of a series can be performed through several nonparametric statistical tests, which serve to detect artificial changes or non-homogeneities in climatic variables. The objective of this work was to evaluate two methodologies to verify the homogeneity of the historical climatological series of precipitation and temperature in Mato Grosso state. The series homogeneity evaluation was performed using the following non-parametric tests: Wald-Wolfowitz (for series with one or no interruption), Kruskal-Wallis (for series with two or more interruptions), and Mann-Kendall (for time series trend analysis). The results of the precipitation series homogeneity analysis from the National Waters Agency stations, analyzed by the Kruskal-Wallis and Wald-Wolfowitz tests, presented 61.54% of homogeneous stations, being well distributed throughout Mato Grosso state, whereas those of the trend analysis allowed to identify that 87.57% of the rainfall-gauging stations showed a concentrated positive trend, mainly in the rainy season. Out of the conventional stations of the National Institute of Meteorology of Mato Grosso, seven were homogeneous for the precipitation variable, five for maximum temperature and four stations were homogeneous for minimum temperature. For the trend analysis in the 11 stations, positive trends of random nature were observed, suggesting increasing alterations in the analyzed variables. Therefore, the trend analysis performed by the Mann-Kendall test in the precipitation, and maximum and minimum temperature climate series, indicated that several data series showed increasing trends, suggesting a possible increase in precipitation and temperature values over the years. The results of the Kruskal-Wallis and Wald-Wolfowitz tests for homogeneity presented more than 87% of homogeneous stations.

scholarly journals Effect of climate change and deforestation on vector borne diseases in the North-Eastern Indian state of Mizoram bordering Myanmar

2020 ◽  
Author(s):  
Balasubramani Karuppusamy ◽  
Devojit Kumar Sarma ◽  
Pachuau Lalmalsawma ◽  
Lalfakzuala Pautu ◽  
Krishanpal Karmodiya ◽  
...  
Keyword(s):  
Climate Change ◽  
Minimum Temperature ◽  
Forest Cover ◽  
Kendall Test ◽  
Maximum Temperature ◽  
Monsoon Period ◽  
Vector Borne Diseases ◽  
Sen’S Slope ◽  
Mann Kendall Test ◽  
Vector Borne

Abstract Background Malaria and dengue are the two major vector-borne diseases in Mizoram. Malaria is endemic in Mizoram, and dengue was first reported only in 2012. It is well documented that climate change has a direct influence on the incidence and spread of vector-borne diseases. The study was designed to study the trends and impact of climate variables (temperature, rainfall and humidity) in the monsoon period (May to September) and deforestation on the incidence of dengue and malaria in Mizoram. Methods Temperature, rainfall and humidity data of Mizoram from 1979–2013 were obtained from the National Centers for Environmental Prediction Climate Forecast System Reanalysis and analyzed. Forest cover data of Mizoram was extracted from India State of Forest Report (IFSR) and Land Processes Distributed Active Archive Centre. Percent tree cover datasets of Advanced Very High Resolution Radiometer and Moderate Resolution Imaging Spectroradiometer missions were also used to study the association between deforestation and incidence of vector-borne diseases. The study used non-parametric tests to estimate long-term trends in the climate (temperature, rainfall, humidity) and forest cover variables. The trend and its magnitude are estimated through Mann-Kendall test and Sen's slope method. Year-wise dengue and malaria data were obtained from the State Vector Borne Disease Control Program, Mizoram. Results The Mann-Kendall test indicates that compared to maximum temperature, minimum temperature during the monsoon period is increasing (p < 0.001). The Sen’s slope estimation also shows an average annual 0.020C (0.01–0.03 at 95% CI) monotonic increasing trend of minimum temperature. The residuals of Sen’s estimate show that temperature is increasing at an average of about 0.10C/year after 2007.Trends indicate that both rainfall and humidity are increasing (p <. 0.001); on an average, there is a 20.45 mm increase in monsoon rainfall per year (5.90–34.37 at 95% CI), while there is a 0.08% (0.02–0.18 at 95% CI) increase in relative humidity annually. IFSR data shows that there is an annual average decrease of 162 sq.km (272.81–37.53 at 95% CI, p < 0.001) in the dense forest cover. Mizoram in 2012 was the last state in India to report the incidence of dengue. Malaria transmission continues to be stable in Mizoram; compared to 2007, the cases have increased in 2019. Conclusion Over the study period, there is an ~ 0.80C rise in the minimum temperature in the monsoon season which could have facilitated the establishment of Aedes aegypti, the major dengue vector in Mizoram. In addition, the increase in rainfall and humidity may have also helped the biology of Ae. aegypti. Deforestation could be one of the major factors responsible for the consistently high number of malaria cases in Mizoram.

scholarly journals Spatial and Temporal Variations of Temperature in the Punjab Province, Pakistan

2021 ◽  
Vol 12 (1) ◽  
pp. 67-75
Author(s):  
Sohail Abbas ◽  
Safdar Ali Shirazi ◽  
Nausheen Mazhar ◽  
Kashif Mahmood ◽  
Ashfak Ahmad Khan
Keyword(s):  
Climate Change ◽  
Temperature Change ◽  
Minimum Temperature ◽  
Temporal Variations ◽  
Maximum Temperature ◽  
Punjab Province ◽  
Mean Temperature ◽  
Increasing Trend ◽  
Slope Estimator ◽  
Level Of Significance

Identifying the temperature change at a regional level is one of the essential parameters to determine the intensity of climate change. The current investigation provides an examination of changing trends of temperature in the Punjab province from 1970 to 2019. Sen's slope estimator method is applied to monthly data of mean temperature (Tmean), maximum temperature (Tmax), and minimum temperature (Tmin) to calculate the rate of temperature change. Statistical methods were used to find out the level of significance in terms of negative or positive trends to examine the variability among various weather observatories. Moreover, predicted values have also been observed for a detailed analysis of temperature variability and trends. Significant and pronounced changes in the mean temperature (T mean) are distinguished all over the Punjab regions with an increasing trend from North to South Punjab. In the case of maximum temperature (Tmax), a faster rate of rising in temperature is observed over the Southern and Western regions of Punjab. In contrast, the minimum temperature (Tmin) shows an increasing trend in Central Punjab. The findings provide detailed insight to policymakers for the planning of mitigating efforts and adaptation strategies in response to climate change.

scholarly journals Spatio-Temporal Trends and Variability of Temperature Over Bale Zone, Ethiopia

2019 ◽  
Vol 9 (2) ◽  
pp. 903-916
Keyword(s):  
Minimum Temperature ◽  
Temporal Trends ◽  
Temperature Series ◽  
Spatiotemporal Variability ◽  
Maximum Temperature ◽  
Data Series ◽  
Parametric Test ◽  
Temperature Trends ◽  
Increasing Trend ◽  
Bale Zone

Understanding of temperature trends and their spatiotemporal variability has great significances on making deep insight for planners, managers, professionals and decision makers of water resources and agriculture. Therefore, this research was set with aim to analyze spatiotemporal variability of temperature and their time series trends over Bale Zone. Statistical analysis: Parametric test with regression analysis on the anomalies like deviation from mean and Non-parametric test with Mann-Kendall test together with Sen’s Slope Estimator & Zs statistics has been used for estimation of trends of a historical data series of monthly, seasonal and annually maximum and minimum temperature of selected meteorological stations in Bale Zone. Both tests relatively shows same results for monthly, seasonal and yearly temperature series. The coefficient of variation (CV) was used for variability analysis. Arc GIS 9.3 software was also used to investigate the spatial variability temperature (minimum and maximum) for the period under review. These methodology has shown a significant increasing and decreasing trends at 95% confidence level for certain time scale temperature series: temperature trends (i.e the mean maximum temperature series) showed a significant increasing trend in Robe (Annual, Spring, February, March, April, May, July, and October), Ginir (February, July, September, and December).Mean minimum temperature series showed a substantial increasing trend in Robe (May, July, September, and November) and Hunte (September). It is also observed that Mean seasonal and annually minimum temperature of the stations have shown higher variability than those mean seasonal and annual maximum temperature of the stations.

Principal Component Analysis to Explore Climate variability of Pakistan

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Syed Afrozuddin Ahmed ◽  
Junaid Saghir Siddiqi
Keyword(s):  
Time Series ◽  
Total Variation ◽  
Minimum Temperature ◽  
Principal Component ◽  
Component Analysis ◽  
Maximum Temperature ◽  
P Value ◽  
Annual Data ◽  
Increasing Trend ◽  
Time Series Plot

<p><span>Various studies have reported that global warming causes unstable<br /><span>climate and many serious impact to physical environment and public<br /><span>health. The climatic or environmental structure data was processed<br /><span>by coding, editing, tabulating, recoding, restructuring in terms of retabulating was carried out.Applying different statistical methods,<br /><span>techniques and procedures for the evaluation.To study the global<br /><span>warming effects on overall environmental conditions of Pakistan.<br /><span>Annual data of maximum and minimum temperature of four provincial<br /><span>capitals have been taken from 1947 to 2012. The data isconsideredas<br /><span>representative environmental components, use for further analysis.<br /><span>Time series plot shows difference of behaviors in maximum and<br /><span>minimum temperatures of Karachi and Lahore while bend of Quetta<br /><span>indicates increasing trend and Peshawar shows flat and smooth. The<br /><span>fit of trend line, maximum temperature of Karachi, has significant<br /><span>regression coefficient b = 0.0504 with p-value 0.000 and R<span>2<span>equal to<br /><span>70.2%. The minimum temperature has decreasing trend but it is<br /><span>insignificant. The data of Lahore shows decreasing and increasing<br /><span>trends for maximum and minimum temperatures respectively shows<br /><span>the differences reducing with the passage of time and expected to<br /><span>have cooler weather than the past. Quetta and Peshawar temperatures<br /><span>fit of trend lines and graphs, revealed that both cities getting warmer<br /><span>with the passage of time.Principal component analysis is performed<br /><span>for the purpose of finding if there is/are any general environmental<br /><span>factor/structure which could be considered as Pakistani climate</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span><br /></span></span></span></p><p><span><span><span><br /></span></span></span></p><p><span><span><span><span>The PC1 is constructed by six manifest variables and represent the<br /><span>environmental factor called as “Index of Pakistan weather”. Explain<br /><span>42.74% of the total variation. The time series plot of this index seems<br /><span>to have increasing trend. The PC2 represents the temperature of<br /><span>Karachi, Quetta and Lahore. PC3 is the contrast between of minimum<br /><span>and maximum temperature. PC4 represents complex contrast between<br /><span>maximum and minimum temperature explain 9.0% of total variation of<br /><span>temperature. PC5 represent contrast between Karachi and Peshawar<br /><span>weather and its contribution to the total or overall variation of Pakistani<br /><span>weather is only 3.5%.</span></span></span></span></span></span></span></span></span><br /><br class="Apple-interchange-newline" /></span></span></span></span></p>

scholarly journals Long-Term Trend Analysis in Annual and Seasonal Precipitation, Maximum and Minimum Temperatures in the Southwest United States

Climate ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 142
Author(s):  
Koffi Djaman ◽  
Komlan Koudahe ◽  
Ansoumana Bodian ◽  
Lamine Diop ◽  
Papa Malick Ndiaye
Keyword(s):  
United States ◽  
Trend Analysis ◽  
Minimum Temperature ◽  
Test Method ◽  
Maximum Temperature ◽  
Crop Season ◽  
Southwest United States ◽  
Annual Minimum Temperature ◽  
Increasing Trend

The objective of this study is to perform trend analysis in the historic data sets of annual and crop season [May–September] precipitation and daily maximum and minimum temperatures across the southwest United States. Eighteen ground-based weather stations were considered across the southwest United States for a total period from 1902 to 2017. The non-parametric Mann–Kendall test method was used for the significance of the trend analysis and the Sen’s slope estimator was used to derive the long-term average rates of change in the parameters. The results showed a decreasing trend in annual precipitation at 44.4% of the stations with the Sen’s slopes varying from −1.35 to −0.02 mm/year while the other stations showed an increasing trend. Crop season total precipitation showed non-significant variation at most of the stations except two stations in Arizona. Seventy-five percent of the stations showed increasing trend in annual maximum temperature at the rates that varied from 0.6 to 3.1 °C per century. Air cooling varied from 0.2 to 1.0 °C per century with dominant warming phenomenon at the regional scale of the southwest United States. Average annual minimum temperature had increased at 69% of the stations at the rates that varied from 0.1 to 8 °C over the last century, while the annual temperature amplitude showed a decreasing trend at 63% of stations. Crop season maximum temperature had significant increasing trend at 68.8% of the stations at the rates varying from 0.7 to 3.5 °C per century, while the season minimum temperature had increased at 75% of the stations.

scholarly journals Maximum and Minimum Temperature Trends Variation over Northern and Southern Part of Bangladesh

2015 ◽  
Vol 6 (2) ◽  
pp. 83-88 ◽  
Author(s):  
NM Refat Nasher ◽  
MN Uddin
Keyword(s):  
Minimum Temperature ◽  
Geographical Location ◽  
Kendall Test ◽  
Maximum Temperature ◽  
Coastal City ◽  
Post Monsoon ◽  
Temperature Trends ◽  
Two Cities ◽  
Slope Estimator ◽  
Increasing Trends

Temperature is one of the pivotal climatic variables in our world climate literature. In the present study monthly, seasonal and yearly highest maximum and lowest minimum temperatures of two cities were analyzed. Mann-Kendall test and Sen’s Slope Estimator were used to determine the trend and slope magnitude. Chittagong, as the coastal city and Rajshahi, as Barind track were selected as a study area due to its respective geographical location. Such types of data of 52 years for Chittagong as well as 48 years for Rajshahi were collected from Bangladesh Meteorological Department (BMD). Monthly highest maximum and lowest minimum temperature data from 1950-2002 for Chittagong and 1964-2012 for Rajshahi were used for analysis. In Rajshahi, significant rising trends were found in highest maximum post-monsoon temperature, lowest minimum monsoon temperature and highest maximum temperature from July to October, June and August for lowest minimum temperature. Falling trends were found in annual highest maximum and lowest minimum temperatures, pre-monsoon highest maximum temperature, lowest minimum winter temperature and January lowest minimum temperature. For Chittagong, significant increasing trends found in post-monsoon highest maximum temperature, June to December highest maximum temperature except July and December lowest minimum temperature. No significant decreasing trend was found in Chittagong.DOI: http://dx.doi.org/10.3329/jesnr.v6i2.22101 J. Environ. Sci. & Natural Resources, 6(2): 83-88 2013

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