scholarly journals Assessment of seasonal and annual rainfall trend in Calabria (southern Italy) with the ITA method

2019 ◽  
Vol 22 (4) ◽  
pp. 738-748 ◽  
Author(s):  
T. Caloiero ◽  
R. Coscarelli ◽  
E. Ferrari
Keyword(s):  
Temporal Variability ◽  
Southern Italy ◽  
Kendall Test ◽  
Climatic Conditions ◽  
Annual Rainfall ◽  
Rainfall Trend ◽  
Entire Study ◽  
Rain Gauges ◽  
Autumn And Winter ◽  
Entire Study Area

Abstract In this paper, an investigation on the temporal variability of seasonal and annual rainfall in the Calabria region (southern Italy) was carried out using a homogeneous and gap-filled monthly rainfall dataset of 129 rain gauges in the period 1951–2006. In particular, possible trends have been assessed by means of the Innovative Trend Analysis (ITA) technique, which allows the identification of a trend in the low, medium and high values of a series. Moreover, the results obtained with the ITA have been compared with the ones obtained with the Mann–Kendall test. These analyses have been performed in five rainfall zones (RZs) of the study area, characterized by different climatic conditions. As a result, both the methods evidenced a negative trend of the annual rainfall in the entire study area. On a seasonal scale, this negative tendency has been confirmed in autumn and winter although with some differences among the several RZs.

scholarly journals Analysis of Monthly Rainfall Trend in Calabria (Southern Italy) through the Application of Statistical and Graphical Techniques

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 629 ◽  
Author(s):  
Tommaso Caloiero ◽  
Roberto Coscarelli ◽  
Ennio Ferrari
Keyword(s):  
Southern Italy ◽  
Water Cycle ◽  
Rainfall Variability ◽  
Kendall Test ◽  
Monthly Rainfall ◽  
Annual Rainfall ◽  
Natural Environments ◽  
Rain Gauges ◽  
Sen’S Method ◽  
Trend Identification

One of the most evident consequences of global atmospheric warming is the modification of the water cycle. Precipitation plays a crucial role in the process and its variations can affect water resources, natural environments and human activities. In this paper, an investigation of the temporal rainfall variability in the Calabria region (southern Italy) has been carried out using a homogeneous and gap-filled monthly rainfall dataset of 129 rain gauges with more than 50 years of observation in the period 1951–2006. Possible trends in monthly and annual rainfall values have been detected by means of the Mann–Kendall test and of a new graphical technique (Şen’s method), which allows the trend identification of the low, medium and high values of a series. As a result, a different behavior of both the highest and the lowest rainfall values emerged among the five Rainfall Zones (RZs) that were considered in the analysis. Moreover, from the comparison of the trend methodologies, different trends results (increasing, decreasing, or trendless time series) have been identified. In particular, this study shows that the Şen’s method could be successfully used in the evaluation of peak and low values of data for the trend analysis of rainfall values.

scholarly journals Rainfall trend analysis

2021 ◽  
Vol 17 (1) ◽  
pp. 121-125
Author(s):  
Virendra N. Barai ◽  
Rohini M. Kalunge
Keyword(s):  
Trend Analysis ◽  
Kendall Test ◽  
River Basins ◽  
Annual Rainfall ◽  
Positive Trend ◽  
Rainfall Trend ◽  
Trend Magnitude ◽  
Increasing Trends ◽  
Multiple Units ◽  
Rainy Days

This article aims to review studies pertaining to trends in rainfall, rainy days over India. Non-parametric tests such as Sen’s Slope were used as estimator of trend magnitude which was supported by Mann-Kendall test. The findings of various studies indicate variance with respect to the rainfall rate, which contributes to an uncertain picture of the rainfall trend. In the study of monsoon of different locations in India some places showed increasing trends however, there is signifying decrease in trend all over India. It was also mentioned that analysis can vary from for a location if done using different source or types of collection of data. Spatial units range from station results and sub-division to sub-basin/river basins for trend analysis. The outcomes of the different experiments vary and a simple and reliable picture of the trend of rainfall has not appeared. While there can be a non-zero slope value for the multiple units (sub-basins or sub-divisions), few values are statistically important. In a basin-wise trend analysis report, some basins had a declining annual rainfall trend; at a 95 per cent confidence stage, only one basin showed a strong decreasing trend. Out of the six basins exhibiting a rising trend saw a major positive trend in one basin. Many of the basins have the same pattern direction on the annual and seasonal scale for rainfall and rainy days.

scholarly journals Long term rainfall variability and trend analysis in lower Shivaliks of Punjab, India

MAUSAM ◽  
2021 ◽  
Vol 72 (3) ◽  
pp. 571-582
Author(s):  
NAVNEET KAUR ◽  
ABRAR YOUSUF ◽  
M. J. SINGH
Keyword(s):  
Trend Analysis ◽  
Monsoon Rainfall ◽  
Rainfall Variability ◽  
Kendall Test ◽  
Annual Rainfall ◽  
Entire Study ◽  
Seasonal Basis ◽  
Normal Rainfall ◽  
Rainy Days

The trend analysis of historical rainfall data on monthly, annual and seasonal basis for three locations in lower Shivaliks of Punjab, viz., Patiala-ki-Rao (1982-2015), Ballowal Saunkhri (1987-2015) and Saleran (1984-2017) has been done in the present study using linear regression model, Mann Kendall test and Sen’s slope. Further, the data for annual and seasonal rainfall and rainy days has also been analyzed on quindecennial basis, i.e., for the period of 1986-2000 and 2001-2015. The analysis of data showed that annual rainfall in the region ranged from 1000 to 1150 mm. The trend analysis of the data shows that the monthly rainfall is decreasing at Patiala-ki-Rao and Saleran, however, the trend was significant for May at Patiala-ki-Rao; and in March and November at Saleran. At Ballowal Saunkhri, the decreasing trend is observed from May to October, however, the trend is significant only in August. The decrease in annual and monsoon rainfall is about 13 to 17 mm and 12 to 13 mm per year respectively at three locations in lower Shivaliks of Punjab. The highest annual (1600-2000 mm) and monsoon (1500-1800 mm) rainfall during the entire study period was recorded in the year 1988 at three locations. The decadal analysis of the data shows below normal rainfall during April to October. The analysis of the rainfall and rainy days on monthly, annual and seasonal averages of 15 year basis showed that both rainfall and rainy days have decreased during the 2001-2015 as compared to 1986-2000 during all the seasons of the year.

scholarly journals Rainfall trend analysis and weather forecast accuracy in selected parts of Khyber Pakhtunkhwa, Pakistan

2021 ◽  
Vol 3 (5) ◽  
Author(s):  
Fakhri Alam ◽  
Muhammad Salam ◽  
Nasir Ahmad Khalil ◽  
Owais khan ◽  
Masaud Khan
Keyword(s):  
Climate Change ◽  
Trend Analysis ◽  
Forecast Accuracy ◽  
Weather Forecast ◽  
Kendall Test ◽  
Annual Rainfall ◽  
Rainfall Trend ◽  
Khyber Pakhtunkhwa ◽  
Temperature Records ◽  
Nonparametric Techniques

AbstractClimate change is a multidimensional phenomenon, which has various effects on people's environmental and socioeconomic conditions. In the agricultural economy that is susceptible to natural changes, its impact is more profound. Therefore, climate change directly affects society in different ways, and society must pay a price. Climate change, especially the changes in annual temperature and rainfall, has attracted widespread attention worldwide. The variability of these factors or the magnitude of fluctuations varies according to location. Therefore, in the context of climate change, especially in countries dominated by rainfed agriculture, studying the trend of meteorological variables is essential to assess climate-induced variations and propose feasible adaptation approaches. Focusing on this fact is the main goal of this research study was to determine the rainfall trend and the accuracy of predicted temperature at three particular stations of Khyber Pakhtunkhwa (Kp) Province, Pakistan. For this purpose, rainfall and temperature data were provided by Pakistan Meteorological Department (PMD), Islamabad, for the period 1960–2020. Two types of nonparametric techniques, Sen’s slope estimate and the Mann–Kendall test, were applied to determine a trend in the average monthly and annual rainfall. The results of the annual rainfall trend analysis showed that Peshawar and Dera Ismail Khan stations showed a positive increasing trend, while the monthly rainfall trend showed a negative decreasing trend for all stations. The trend was statistically significant for Peshawar and Saidu Sharif stations. The accuracy of predicted and actual temperature and rainfall indicated that mostly over-forecast occurred at Saidu Sharif and Peshawar. Most of the precipitation and temperature records showed under forecast for Dera Ismail Khan, but some over-prediction has also occurred. Graphical abstract

scholarly journals Análise da Variação Sazonal e de Tendências na Precipitação Pluviométrica no Município de Juazeiro-BA

2020 ◽  
Vol 13 (6) ◽  
pp. 2641
Author(s):  
Henrique Santos Junqueira ◽  
Luan Moreira Fernandes de Almeida ◽  
Tailan Santos de Souza ◽  
Patricia Dos Santos Nascimento
Keyword(s):  
Agricultural Development ◽  
Kendall Test ◽  
Annual Rainfall ◽  
Rainfall Trend ◽  
Rainy Period ◽  
Precipitation Concentration Index ◽  
A Value ◽  
Daily Series ◽  
Climate Series ◽  
Kendall Method

A cidade de Juazeiro-BA destaca-se por ser um importante polo de desenvolvimento agrícola em bases irrigadas no Nordeste, no qual a distribuição sazonal da precipitação pluviométrica tem influência decisiva no contexto da relação saúde e saneamento em áreas urbanizadas, na agricultura familiar, no abastecimento de água de famílias isoladas e na economia dessa região. Assim, essa pesquisa tem como objetivo avaliar a distribuição das chuvas no município de Juazeiro-BA, analisando uma série diária de 32 anos de dados pluviométricos, calculando os valores anuais e sazonais do Índice de Concentração da Precipitação (ICP) e realizando um estudo de tendência da precipitação pluviométrica, a partir do método de Mann-Kendall. Os resultados revelaram que, em Juazeiro, o período chuvoso é bem definido, com os maiores índices de precipitação entre os meses de dezembro e março. O ICP anual tem o valor de 28,48 %, indicando alta irregularidade na distribuição das chuvas anuais, possibilitando a ocorrência de eventos extremos, tanto de inundações quanto de escassez hídrica. O teste de Mann-Kendall, para o período em estudo, apresentou tendência de diminuição da média pluviométrica anual em 7,51 mm, o que pode aumentar o déficit hídrico na região.Palavras-chave: Chuvas; Séries Climáticas; Concentração Pluviométrica; Mann-Kendall. Seasonal Variation and Trend in Rainfall in the Municipality of Juazeiro-BA A B S T R A C TThe city of Juazeiro-BA stands out for being an important agricultural development hub on irrigated bases in the Northeast, in which the seasonal distribution of pluviometric precipitation has a decisive influence in the context of the health and sanitation relationship in urbanized areas, in family agriculture, in water supplying of isolated families and the economy of that region. Thus, this research aims to assess the distribution of rainfall in the municipality of Juazeiro-BA, analyzing a daily series of 32 years of rainfall data, calculating the annual and seasonal values of the Precipitation Concentration Index (PCI) and conducting a rainfall trend study, using the Mann-Kendall method. The results revealed that, in Juazeiro, the rainy period is well defined, with the highest levels of precipitation between the months of December and March. The annual PCI has a value of 28.48 %, indicating a high irregularity in the distribution of annual rainfall, enabling the occurrence of extreme events, both floods and water scarcity. The Mann-Kendall test, for the period under study, presented tendency decrease of the annual rainfall average by 7.51 mm, which may increase the water deficit in the region.Keywords: Rainfall; Climate Series; Rain Concentration; Mann-Kendall.

scholarly journals Rainfall Trend Analysis in Tehsils of Palghar District, Maharashtra State, India

2021 ◽  
Vol 9 (11) ◽  
pp. 238-253
Author(s):  
Dr. Sumit M. Dhak
Keyword(s):  
Trend Analysis ◽  
Linear Trend ◽  
Daily Rainfall ◽  
Kendall Test ◽  
Rainfall Data ◽  
Annual Rainfall ◽  
Rainfall Trend ◽  
Department Of Agriculture ◽  
Increasing Trend ◽  
Slope Estimator

Abstract: A detailed trend analysis of monthly and annual rainfall for Tehsils of Palghar district were carried out using 22 years (1998-2019) daily rainfall data taken from Department of Agriculture, Maharashtra State. In this study, to analyse the trend, the non-parametric test (Mann-Kendall test) and Sen’s slope estimator were used. For developing a functional relationship between variables, a linear trend of rainfall data for the studied area evaluated using the linear regression. The results showed that the trend analysis of monthly rainfall has a varied trend of rainfall in the rainy months in tehsil of Palghar District. The month of July significant increasing trend was observed at Jawhar (42.91 mm/year), Vikramgad (29.90 mm/year), Wada (24.06 mm/year), Talasari (31.36 mm/year), Palghar (25.299 mm/year), Mokhada (29.96 mm/year) and Dahanu (38.14 mm/year), whereas non-significant increasing trend 2.76 mm/year was observed at Vasai tehsil of Palghar District during 1998-2019. The month of June, August, September and October rainfall did not show any significant trend in tehsil of Palghar District and non significant decreasing as well as non significant increasing trend was observed in tehsil of Palghar District during 1998 – 2019. The result concluded that annual rainfall trend was increased in Jawhar, Vikramgad, Wada, Talasari, Palghar, Mokhada and Dahanu; whereas Vasai tehsil rainfall trend was decreased in tehsil of Palghar District during 1998 -2019. Keywords: Rainfall, Trend Analysis, Mann Kendall’s Test, Sen Slopes, Regression

scholarly journals Extreme rainfall trends over the Mekong Delta under the impacts of climate change

2020 ◽  
Vol 12 (5) ◽  
pp. 639-652 ◽  
Author(s):  
Seung Kyu LEE ◽  
Truong An Dang
Keyword(s):  
Heavy Rainfall ◽  
Mekong Delta ◽  
Kendall Test ◽  
Data Series ◽  
Entire Study ◽  
Content Type ◽  
Slope Estimate ◽  
Increasing Trend ◽  
Entire Study Area

Purpose This study aims to investigate aspects related to the changing trends of the rainfall extremes in the entire Mekong Delta in the period of 32 years (1984-2015) applying rainfall extreme indices. First, the homogeneity tests were applied to assess the quality of observed rainfall data series. The authors, then, investigated three rainfall indices including the number of very heavy rainfall days 20 mm (R20), number of days above 50 mm (R50) and number of days above 100 mm (R100) applying the Mann-Kendall test and Sen’s slope estimate. Design/methodology/approach First, the homogeneity tests were applied to assess the quality of observed rainfall data series. The authors, then, investigated three rainfall indices including the number of very heavy rainfall days 20 mm (R20), number of days above 50 mm (R50) and number of days above 100 mm (R100) applying the Mann-Kendall test and Sen’s slope estimate. Findings The results of R20 pointed out that an insignificant upward tendency was found in the coastal provinces, whereas an insignificant downward tendency was also recorded in the inland provinces. Regarding the number of R50, a similar trend to R20 was recorded with five stations slightly increased and five stations slightly decreased. For the number of R100, the results recorded an absence of significant trends over the entire study area. Approximately 58.5% of stations show a slightly decreasing trend, while 41.5% of the remaining stations recorded a slightly increasing trend. Originality/value For the number of R100, the results recorded an absence of the significant trends over the entire study area. Approximately 58.5% of stations show a slightly decreasing trend, while 41.5% of the remaining stations recorded a slightly increasing trend. Of note is the fact that the number of R100 occurred more frequently in the northern provinces, which means the northern region is facing a high risk of flooding.

scholarly journals Long-Term Rainfall Trends and Their Variability in Mainland Portugal in the Last 106 Years

Climate ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 146
Author(s):  
Maria Manuela Portela ◽  
Luis Angel Espinosa ◽  
Martina Zelenakova
Keyword(s):  
Temporal Variability ◽  
Annual Rainfall ◽  
Small Country ◽  
Rain Gauges ◽  
Mainland Portugal ◽  
Mk Test ◽  
Rainfall Trends ◽  
Slope Estimator ◽  
European Coast

This study addresses the long-term rainfall trends, their temporal variability and uncertainty over mainland Portugal, a small country on the most western European coast. The study was based on monthly, seasonal and annual rainfall series spanning for a period of 106 years, between October 1913 and September 2019 (herein after referred to as global period), at 532 rain gauges evenly distributed over the country (c.a. 6 rain gauges per 1000 km2). To understand the rainfall behavior over time, an initial sub-period with 55 years and a final sub-period with 51 years were also analyzed along with the global period. The trends identification and the assessment of their magnitude were derived using the nonparametric Mann-Kendall (MK) test coupled with the Sen’s slope estimator method. The results showed that after the initial sub-period with prevailing increasing rainfall, the trends were almost exclusively decreasing. They were also so pronounced that they counterbalanced the initial rainfall increase and resulted in equally decreasing trends for the global period. The study also shows that approximately from the late 1960s on, the rainy season pattern has changed, with the last months prior to the dry season showing a sustained decrease of their relative contributions to the annual rainfalls. Overall, the results support the hypothesis of less uncertainty on the pronounced decrease of rainfall over mainland Portugal in recent years, which is expected to continue. They also show that the asymmetry between a less wet North, yet still wet, and an arid South is becoming much more marked.

scholarly journals Assessment of Seasonal and Annual Rainfall Trends and Variability in Sharjah City, UAE

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Tarek Merabtene ◽  
Mohsin Siddique ◽  
Abdallah Shanableh
Keyword(s):  
Climate Change ◽  
Temporal Variability ◽  
Low Frequency ◽  
Annual Rainfall ◽  
Spatial And Temporal Variability ◽  
Rainfall Trend ◽  
Significant Drop ◽  
Statistical Measures ◽  
Rainfall Trends ◽  
The Impact

Although a few studies on rainfall spatial and temporal variability in the UAE have been carried out, evidence of the impact of climate change on rainfall trends has not been reported. This study aims at assessing the significance of long-term rainfall trends and temporal variability at Sharjah City, UAE. Annual rainfall and seasonal rainfall extending over a period of 81 years (1934–2014) recorded at Sharjah International Airport have been analyzed. To this end, several parametric and nonparametric statistical measures have been applied following systematic data quality assessment. The analyses revealed that the annual rainfall trend decreased from −3 mm to −9.4 mm per decade over the study periods. The decreasing annual rainfall trend is mainly driven by the significant drop in winter rainfall, particularly during the period from 1977 to 2014. The results also indicate that high probability extreme events have shifted toward low frequency (12.7 years) with significant variations in monthly rainfall patterns and periodicity. The findings of the present study suggest reevaluating the derivation of design rainfall for infrastructure of Sharjah City and urge developing an integrated framework for its water resources planning and risk under climate change impacts scenarios.

scholarly journals Spatio-temporal Variability and Trends in Rainfall and Temperature in Anger watershed, Southwestern Ethiopia

2021 ◽  
Vol 5 (1) ◽  
pp. 462-472
Author(s):  
Gemechu Yigezu Ofgeha ◽  
Muluneh Woldetsadik Abshire
Keyword(s):  
Temporal Trends ◽  
Kendall Test ◽  
Annual Rainfall ◽  
Small Scale ◽  
Rainfall Trend ◽  
High Rainfall ◽  
Southwestern Ethiopia ◽  
Spatio Temporal ◽  
Small Scale Farmers ◽  
Increasing Trends

Insights to broadly argued research gap on lack of climate studies at micro-scale considering unique features of an area, this paper intended to examine agro-ecological level spatio-temporal trends and variability in rainfall and temperature in Anger watershed of southwestern Ethiopia. The gridded data managed by the Ethiopia National Meteorological Services Agency (NMSA) for 1983-2018 were used. The Mann-Kendall test for trend analysis and different variability measures were used. Questionnaire and FGD data on community perceptions gathered from 214 households and elders were analysed descriptively and qualitatively. The study reveals the consistent increasing trends in temperature; and high variability and insignificant but increasing rainfall trend. The trends and variability show spatio-temporal differences along agro-ecologies. The watershed is characterized by moderate to high rainfall coefficient of variations, significant years of high rainfall concentration, and considerable negative annual rainfall anomalies; that the variability was severe in woinadega followed by kolla agro-ecology. Although, the perceptions on trends, variability and its implications show difference across agro-ecology, the propensity to increased temperature, unclear rainfall trend and significant inter-annual and seasonal variability were witnessed. Unpredictability of rainfall time, concentrations in kiremt, and unexpected rain during harvesting was major challenges resulting multifaceted impacts on the small-scale farmers’ livelihoods.

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