Trend Analysis of Temperature and Rainfall of Rajasthan, India

Trend analysis of streamflow provides practical information for better management of water resources on the eve of climate change. Thus, the objective of this study is to evaluate the presence of possible trends in the annual, seasonal, maximum, and minimum flow of Yangtze River at Cuntan and Zhutuo stations in China for the period 1980 to 2015. The assessment was carried out using the Mann–Kendall trend test, and the innovative trend analysis, while Sen’s slope is used to estimate the magnitude of the changes. The results of the study revealed that there were increasing and decreasing trends at Cuntan and Zhutuo stations in different months. The mean annual flow was found to decrease at a rate of −26.76 m3/s and −17.37 m3/s at both stations. The minimum flow was found to significantly increase at a rate of 30.57 m3/s and 16.37 m3/s, at a 95% level of confidence. Maximum annual flows showed an increasing trend in both regions of the Yangtze River. On the seasonal scale, the results showed that stations are more sensitive to seasonal flow variability suggesting a probable flooding aggravation. The winter season showed an increasing flow trend, while summer showed a decreasing trend. The spring flow was found to have an increasing trend by the Mann–Kendall test at both stations, but in the Zhutuo Station, a decreasing trend was found by way of the innovative trend analysis method. However, the autumn flow indicated a decreasing trend over the region by the Mann–Kendall (MK) test at both stations while it had an increasing trend in Cuntan by the innovative trend analysis method. The result showed nonstationary increasing and decreasing flow trends over the region. Innovative trend analysis method has the advantage of detecting the sub-trends in the flow time series because of its ability to present the results in graphical format. The results of the study indicate that decreasing trends may create water scarcity if proper adaptation measures are not taken.

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Time series analysis of observed maximum and minimum air temperature at four urban cities of India during 1951-2015

MAUSAM ◽

10.54302/mausam.v71i1.6 ◽

2021 ◽

Vol 71 (1) ◽

pp. 57-68

Author(s):

PRAMANIK SAIKAT ◽

SIL SOURAV ◽

MANDAL SAMIRAN

Keyword(s):

Time Series ◽

Power Spectrum ◽

Air Temperature ◽

India Meteorological Department ◽

Wavelet Power Spectrum ◽

Maximum Temperature ◽

Coastal Cities ◽

Increasing Trend ◽

Two Peaks ◽

Minimum Air Temperature

A sixty - five year (1951-2015) long data for monthly minimum temperature (TMIN) and maximum temperature (TMAX), observed by the India Meteorological Department (IMD), is statistically analyzed at four urban stations namely Bhubaneswar, Delhi, Mumbai and Chennai of India. A bimodal nature in seasonality is noticed for TMAX and TMIN at all locations. Two peaks for TMAX and TMIN are observed in May and September. Exceptionally, Mumbai shows TMAX peaks during May and November and Delhi shows TMIN peaks during June and September. Higher standard deviations (SD) for TMAX is noted at Delhi with a maximum in March (1.78 °C), while for Chennai, the SD for TMIN is lesser compared to other cities. Two different periods 1951-1980 (P1, the first half of the study period) and 1981-2015 (P2, the second half of the study period) were identified from the time series of both TMAX and TMIN. A higher increasing trend is observed during P2 than P1 in all the cities except in TMIN at Mumbai. The highest increasing trend (0.040 °C/year) is observed for TMIN in Mumbai during P1 time, but the trend is almost constant (0.001 °C/year) during P2 time. The highest increasing trend for TMIN at Mumbai is mainly contributed by the increasing trend in post-monsoon and winter months in P1. Surprisingly, in both P1 and P2, the trends are less during monsoon months for all the cities. A consistent 5-year (3-year) band is observed throughout the wavelet power spectrum at the coastal cities Bhubaneswar, Mumbai (Chennai). However, the 5-year signal is not consistent at Delhi and it is observed only during the year 1975-1980. The global wavelet power spectrum showed that TMIN at Chennai has less power (0.6 °C2) corresponding to 3-year signal and Mumbai has highest power (12 °C2) corresponding to the 5-year signal in comparison to other cities.

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ASSESSMENT OF LONG TERM CLIMATIC VARIABILITY OF UTTARAKHAND

Natural Resources Conservation and Research ◽

10.24294/nrcr.v1i4.744 ◽

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.

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

International Journal of Environment and Climate Change ◽

10.9734/ijecc/2020/v10i330184 ◽

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.

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Spatio -Temporal Long-Term Variability and Trend Analysis of Precipitation and Temperature Series in the Ghataprabha (K3) Sub basin of Krishna Basin

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.k1814.0981119 ◽

2019 ◽

Vol 8 (11) ◽

pp. 2547-2552

Keyword(s):

India Meteorological Department ◽

Well Being ◽

Annual Rainfall ◽

Maximum Temperature ◽

Study Region ◽

Changing Climate ◽

Increasing Trend ◽

Precipitation And Temperature ◽

Krishna Basin

Changing Climate is one of the most significant ecological issue, with the implications for agricultural production, water resource, energy and some other aspects of human well-being. Analysis of changing climate is important to assess climate-induced changes through the analysis of variability of climatic parameters such as temperature, precipitation, runoff and groundwater to suggest feasible adaptation strategies. This paper aims the long-term variability of rainfall and temperature using gridded daily data obtained from India Meteorological Department with 0.250 resolution from 1901-2016 for precipitation and 10 resolution from 1969-2005 for temperature (re-gridded to IMD 0.250 gridded location) in Ghataprabha sub basin (K3) of Krishna basin. The analysis of variability and trend in precipitation and temperature carried out by using coefficient of variation (CV), rainfall and temperature anomaly and also Mann-Kendall (MK) test was used to detect the time series trend. Statistical analysis of variability and trend in annual, Indian Summer Monsoon (ISMR) rainfall and temperature observed that i) there is an intra and inter annual variability of precipitation in the sub basin ii) test results revealed that the annual and ISMR trend appears to be increased by 0.12 & 0.14, iii) the Mann-Kendal trend test also analysed for annual minimum, mean and maximum temperature over the K3 sub basin (1969-2005) shows increasing trend by 0.06, 0.21 and 0.40. This analysis revealed that, there is an increasing trend in annual rainfall and temperature observed over the study region.

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

Climate ◽

10.3390/cli8120142 ◽

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.

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Rainfall and Temperature Trend Analysis by Mann–Kendall Test and Significance for Rainfed Cereal Yields in Northern Togo

Sci ◽

10.3390/sci3010017 ◽

2021 ◽

Vol 3 (1) ◽

pp. 17

Author(s):

Agossou Gadedjisso-Tossou ◽

Komlavi II Adjegan ◽

Armand Ketcha Malan Kablan

Keyword(s):

Regression Analysis ◽

Multiple Regression Analysis ◽

Multiple Regression ◽

Maize Yield ◽

Temperature Variability ◽

Annual Rainfall ◽

Maximum Temperature ◽

Mk Test ◽

Increasing Trend ◽

Negative Effect

This study investigates the trend in monthly and annual rainfall, minimum and maximum temperature (Tmin and Tmax) using the Mann–Kendall (MK) test and Sen’s slope (SS) method and evaluates the significance of their variability for maize, sorghum and millet yields in northern Togo employing multiple regression analysis. The historical data of Kara, Niamtougou, Mango and Dapaong weather stations from 1977 to 2012 were used. Four non-parametric methods—Alexandersson’s Standard Normal Homogeneity Test (SNHT), Buishand’s Range Test (BRT), Pettitt’s Test (PT) and Von Neumann’s Ratio Test (VNRT)—were applied to detect homogeneity in the data. For the data which were serially correlated, a modified version of the MK test (pre-whitening) was utilised. Results showed an increasing trend in the annual rainfall in all four locations. However, this trend was only significant at Dapaong (p < 0.1). There was an increasing trend in Tmax at Kara, Mango and Niamtougou, unlike Dapaong where Tmax revealed a significant decreasing trend (p < 0.01). Similarly, there was an increasing trend in Tmin at Kara, Mango and Dapaong, unlike Niamtougou where Tmin showed a non-significant decreasing trend (p > 0.05). Rainfall in Dapaong was found to have increased (7.79 mm/year) more than the other locations such as Kara (2.20 mm/year), Niamtougou (4.57 mm/year) and Mango (0.67 mm). Tmax increased by 0.13, 0.13 and 0.32 °C per decade at Kara, Niamtougou and Mango, respectively, and decreased by 0.20 per decade in Dapaong. Likewise, Tmin increased by 0.07, 0.20 and 0.02 °C per decade at Kara, Mango and Dapaong, respectively, and decreased by 0.01 °C per decade at Niamtougou. Results of multiple regression analysis revealed nonlinear yield responses to changes in rainfall and temperature. Rainfall and temperature variability affects rainfed cereal crops production, but the effects vary across crops. The temperature has a positive effect on maize yield in Kara, Niamtougou and Mango but a negative effect on sorghum in Niamtougou and millet in Dapaong, while rainfall has a negative effect on maize yield in Niamtougou and Dapaong and millet yield in Mango. In all locations, rainfall and temperature variability has a significant effect on the cereal crop yields. There is, therefore, a need to adopt some adaptation strategies for sustainable agricultural production in northern Togo.

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Rainfall and Temperature Trend Analysis by Mann–Kendall Test and Significance for Rainfed Cereal Yields in Northern Togo

Sci ◽

10.3390/sci2040074 ◽

2020 ◽

Vol 2 (4) ◽

pp. 74

Author(s):

Agossou Gadedjisso-Tossou ◽

Komlavi II Adjegan ◽

Armand Ketcha Malan Kablan

Keyword(s):

Regression Analysis ◽

Multiple Regression Analysis ◽

Multiple Regression ◽

Maize Yield ◽

Temperature Variability ◽

Annual Rainfall ◽

Maximum Temperature ◽

Mk Test ◽

Increasing Trend ◽

Negative Effect

This study investigates the trend in monthly and annual rainfall, minimum and maximum temperature (Tmin and Tmax) using the Mann–Kendall (MK) test and Sen’s slope (SS) method and evaluates the significance of their variability for maize, sorghum and millet yields in northern Togo employing multiple regression analysis. The historical data of Kara, Niamtougou, Mango and Dapaong weather stations from 1977 to 2012 were used. Four non-parametric methods—Alexandersson’s Standard Normal Homogeneity Test (SNHT), Buishand’s Range Test (BRT), Pettitt’s Test (PT) and Von Neumann’s Ratio Test (VNRT)—were applied to detect homogeneity in the data. For the data which were serially correlated, a modified version of the MK test (pre-whitening) was utilised. Results showed an increasing trend in the annual rainfall in all four locations. However, this trend was only significant at Dapaong (p < 0.1). There was an increasing trend in Tmax at Kara, Mango and Niamtougou, unlike Dapaong where Tmax revealed a significant decreasing trend (p < 0.01). Similarly, there was an increasing trend in Tmin at Kara, Mango and Dapaong, unlike Niamtougou where Tmin showed a non-significant decreasing trend (p > 0.05). Rainfall in Dapaong was found to have increased (7.79 mm/year) more than the other locations such as Kara (2.20 mm/year), Niamtougou (4.57 mm/year) and Mango (0.67 mm). Tmax increased by 0.13, 0.13 and 0.32 °C per decade at Kara, Niamtougou and Mango, respectively, and decreased by 0.20 per decade in Dapaong. Likewise, Tmin increased by 0.07, 0.20 and 0.02 °C per decade at Kara, Mango and Dapaong, respectively, and decreased by 0.01 °C per decade at Niamtougou. Results of multiple regression analysis revealed nonlinear yield responses to changes in rainfall and temperature. Rainfall and temperature variability affects rainfed cereal crops production, but the effects vary across crops. The temperature has a positive effect on maize yield in Kara, Niamtougou and Mango but a negative effect on sorghum in Niamtougou and millet in Dapaong, while rainfall has a negative effect on maize yield in Niamtougou and Dapaong and millet yield in Mango. In all locations, rainfall and temperature variability has a significant effect on the cereal crop yields. There is, therefore, a need to adopt some adaptation strategies for sustainable agricultural production in northern Togo.

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Trend Analysis of Observed Precipitation, Temperature and Streamflow for Hadejia – Nguru Wetlands Catchment, Nigeria

10.21203/rs.3.rs-650459/v1 ◽

2021 ◽

Author(s):

Salisu Dan'azumi ◽

Usman Abdullahi Ibrahim

Keyword(s):

Water Resources ◽

Trend Analysis ◽

Maximum Temperature ◽

Mean Annual Precipitation ◽

Trend Test ◽

Data Series ◽

Monthly Precipitation ◽

Climate Data ◽

Annual Streamflow ◽

Increasing Trend

Abstract This study investigated trends in hydro-climate data (precipitation, maximum/minimum temperatures, and streamflow) for the period 1980–2016 in a semi-arid Hadejia-Nguru Wetlands (HNWs) catchment, Nigeria. Four meteorological stations (Bauchi, Hadejia, Kano and Nguru) and three streamflow gauge stations (Gashua, Hadejia and Katagum on Rivers Yobe, Hadejia and Jama’are respectively) covers the HNWs catchment. Anderson-Darling and Shapiro-Wilk normality tests were applied on the monthly hydro-climate data series to determine their class of distribution. A non-parametric Pettit’s test for homogeneity was employed to detect change points in the data series. An absolute homogenization method using RHtestsV4 software was applied to homogenize and (as needed) pre-whitened the data series. Trend analysis was carried out using modified Mann–Kendall trend test (trend free pre-whitening approach), while Sen’s slope was used to estimate the magnitude of the changes. Results of the study revealed that there was an increasing positive trends at all the stations for monthly minimum, average annual minimum, average annual maximum, and annual average temperature data series. While monthly maximum temperature series of Bauchi and Kano stations indicated the presence of an increasing trend with magnitude 0.00350C and 0.00190C; and no trend was detected for Hadejia and Nguru stations. For monthly precipitation, no trends was detected at all stations. However, an increasing trend was detected at Bauchi, Hadejia and Nguru stations for mean annual precipitation with magnitude 7.7960mm/yr, 8.1766mm/yr and 5.7214mm/yr respectively. A decreasing trend was detected for monthly and annual streamflow series at Hadejia gauge station with magnitude − 0.0115m3/s/month and − 3.7037m3/s/year respectively; and no trend was detected for monthly and annual streamflow series at Gashua and Katagum gauge stations. The trend analysis may be helpful to water resources managers for planning and management of water resources in the HNWs catchment and the Hadejia Jama’are Komadugu Yobe Basin at large.

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Trend analysis of seasonal rainfall and temperature pattern in Damota Gale districts of Wolaita Zone, Ethiopia

10.21203/rs.3.rs-454366/v1 ◽

2021 ◽

Author(s):

Elias Bojago ◽

Dalga YaYa

Keyword(s):

Trend Analysis ◽

Meteorological Data ◽

Statistical Significance ◽

Kendall Test ◽

Maximum Temperature ◽

Temperature Pattern ◽

Positive Trend ◽

Annual Minimum Temperature ◽

Increasing Trend ◽

Mann Kendall Test

Abstract This paper investigated the recent trends of precipitation and temperature on Damota Gale districts of Wolaita Zone. This study used the observed historical meteorological data from 1987 to 2019 to analyze the trends. The magnitude of the variability or fluctuations of the factors varies according to locations. Hence, examining the spatiotemporal dynamics of meteorological variables in the context of changing climate, particularly in countries where rain-fed agriculture is predominant, is vital to assess climate-induced changes and suggest feasible adaptation strategies. Both rainfall and temperature data for a period of 1987 to 2019 were analyzed in this study. Statistical trend analysis techniques namely Mann–Kendall test and Sen's slope estimator were used to examine and analyze the problems. The long-term trend of rainfall and temperature was evaluated by linear regression and Mann–Kendall test. The temperature was shown a positive trend for both annual and seasonal periods and had a statistical significance of 95%. This study concluded that there was a declining rainfall in the three seasons; spring, summer and winter but in autumn it shows increasing trends and rapid warming, especially in the last 32 years. The detailed analysis of the data for 32 years indicate that the annual maximum temperature and annual minimum temperature have shown an increasing trend, whereas the Damota Gale seasonal maximum and minimum temperatures have shown an increasing trend. The findings of this study will serve as a reference for climate researchers, policy and decision-makers.

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