Combination of modified Mann‐Kendall method and Şen innovative trend analysis

Alashan, Sadık

doi:10.1002/eng2.12131

Cited by 69 publications

(36 citation statements)

References 49 publications

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“…Here, a combination of Hamed and Rao modified MK-test and Theil-Sen's Slope Estimator was used to identify the trend and its magnitude, respectively, at different timescales (annual, seasonal, and monthly). Several studies have suggested that the modified MK-test provides consistent results with Sens's slope [68][69][70].…”

Section: Modified Mann-kendall Testmentioning

confidence: 94%

A Response of Snow Cover to the Climate in the Northwest Himalaya (NWH) Using Satellite Products

2021

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The Himalayan region is one of the most crucial mountain systems across the globe, which has significant importance in terms of the largest depository of snow and glaciers for fresh water supply, river runoff, hydropower, rich biodiversity, climate, and many more socioeconomic developments. This region directly or indirectly affects millions of lives and their livelihoods but has been considered one of the most climatically sensitive parts of the world. This study investigates the spatiotemporal variation in maximum extent of snow cover area (SCA) and its response to temperature, precipitation, and elevation over the northwest Himalaya (NWH) during 2000–2019. The analysis uses Moderate Resolution Imaging Spectroradiometer (MODIS)/Terra 8-day composite snow Cover product (MOD10A2), MODIS/Terra/V6 daily land surface temperature product (MOD11A1), Climate Hazards Infrared Precipitation with Station data (CHIRPS) precipitation product, and Shuttle Radar Topography Mission (SRTM) DEM product for the investigation. Modified Mann-Kendall (mMK) test and Spearman’s correlation methods were employed to examine the trends and the interrelationships between SCA and climatic parameters. Results indicate a significant increasing trend in annual mean SCA (663.88 km2/year) between 2000 and 2019. The seasonal and monthly analyses were also carried out for the study region. The Zone-wise analysis showed that the lower Himalaya (184.5 km2/year) and the middle Himalaya (232.1 km2/year) revealed significant increasing mean annual SCA trends. In contrast, the upper Himalaya showed no trend during the study period over the NWH region. Statistically significant negative correlation (−0.81) was observed between annual SCA and temperature, whereas a nonsignificant positive correlation (0.47) existed between annual SCA and precipitation in the past 20 years. It was also noticed that the SCA variability over the past 20 years has mainly been driven by temperature, whereas the influence of precipitation has been limited. A decline in average annual temperature (−0.039 °C/year) and a rise in precipitation (24.56 mm/year) was detected over the region. The results indicate that climate plays a vital role in controlling the SCA over the NWH region. The maximum and minimum snow cover frequency (SCF) was observed during the winter (74.42%) and monsoon (46.01%) season, respectively, while the average SCF was recorded to be 59.11% during the study period. Of the SCA, 54.81% had a SCF above 60% and could be considered as the perennial snow. The elevation-based analysis showed that 84% of the upper Himalaya (UH) experienced perennial snow, while the seasonal snow mostly dominated over the lower Himalaya (LH) and the middle Himalaya (MH).

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Section: Modified Mann-kendall Testmentioning

confidence: 94%

A Response of Snow Cover to the Climate in the Northwest Himalaya (NWH) Using Satellite Products

2021

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“…The Mann-Kendall (MK) test aims to identify trends in time series (Alashan 2020 ) and the test statistic is calculated according to: …”

Section: Methodsmentioning

confidence: 99%

São Paulo’s atmospheric pollution reduction and its social isolation effect, Brazil

Rosse

Pereira

Boari

et al. 2020

Air Qual Atmos Health

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Since January 2020, studies report reductions in air pollution among several countries due to social isolation measures, which have been adopted in order to contain the coronavirus outbreak progress (COVID-19). This study aims to evaluate the change in the atmospheric pollution levels by NO and NO 2 in São Paulo City for the social isolation period. The NO and NO 2 hourly concentrations were obtained through air quality monitoring stations from CETESB, from January 14, 2020 to April 12, 2020. Mann-Kendall and the Pettitt tests were performed in the air pollutant time series. We observed an overall negative trend in all stations, indicating a decreasing temporal pattern in concentrations. Regarding NO, the highest absolute decrease rates were observed in the Congonhas (− 6.39 μg m −3 month −1 ) and Marginal Tietê (− 6.19 μg m −3 month −1 ) stations; regarding NO 2 , the highest rates were observed in the Marginal Tietê (− 4.45 μg m −3 month −1 ) and Cerqueira César (− 4.34 μg m −3 month −1 ) stations. In addition, we identified a turning point in the NO and NO 2 series trends that occurred close to the start date of the social isolation period (March 20, 2020). Moreover, from statistical analysis, it was found that NO 2 is a suitable surrogate for monitoring economic activities during social isolation periods. Thus, we concluded that social isolation measures implemented on March 20, 2020 caused significant changes in the air pollutant concentrations in the city of São Paulo (as high as − 200% in NO 2 levels).

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“…When r 1 falls within the confidence limits, a significant autocorrelation does not exist and the trend is examined using the Mann-Kendall (MK) trend test. On the other hand, if r 1 is found outside of the confidence interval, it indicates the presence of correlation between adjusted observations and the modified Mann-Kendall (MMK) test should be employed to remove the impact of autocorrelation [42]. In this study, both MK and MMK were used when there was independence and serial correlation, respectively, on time series analysis of rainfall and temperature using R software programs [43].…”

Section: Temporal Trend Analyses Of Rainfall and Temperaturementioning

confidence: 99%

Spatial Variability and Temporal Trends of Climate Change in Southwest Ethiopia: Association with Farmers’ Perception and Their Adaptation Strategies

Habte

Mamo

Worku

et al. 2021

Advances in Meteorology

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The impact of climate change is a global threat, and its effect is more pronounced in developing countries. It is vital to link physical data analysis with endogenous knowledge and practices of farmers to strengthen their adaptive capacity. This study was conducted to explore spatial variability and temporal trends of temperature and rainfall in association with farmers’ perceptions and their adaptation strategies in Southwest Ethiopia. Daily rainfall and temperature data of twelve weather stations were collected from the National Meteorological Agency of Ethiopia for the period 1983 to 2016. Farmers’ perceptions about climate change and its impact and their adaptation strategies were assessed through a survey. Spatial variability and temporal trends of rainfall and temperature were analyzed using ArcGIS and R software. Sen’s slope estimator and Mann–Kendall’s trend tests were used to detect the magnitude and statistical significance of changes in rainfall and temperature. Spatial analysis of rainfall showed high variability over the region. There were no consistent and significant temporal trends of annual and seasonal rainfall of the area. Significant and upward trends of annual maximum and minimum temperatures were reported for all stations. Accordingly, annual maximum and minimum temperatures were increased by 0.71 and 0.65°C, respectively, over the period 1983 to 2016. Farmers had a good awareness of climate change and its impact. Adaptation strategies used by farmers included soil and water conservation practices (66.21%), crop diversification (62.16%), modifying planting date (42.56%), agroforestry practices (35.13%), use of drought-tolerant variety (33.95%), use of early maturing crop (27.03%), and livelihood diversification (25.42%). As most of these adaptation strategies were familiarized by a small number of farmers, further effort is needed to identify factors limiting the adoption of these strategies. Furthermore, additional planned strategies and supports that widen available options at the farmers’ disposal should be introduced to strengthen their adaptive capacity.

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Combination of modified Mann‐Kendall method and Şen innovative trend analysis

Cited by 69 publications

References 49 publications

A Response of Snow Cover to the Climate in the Northwest Himalaya (NWH) Using Satellite Products

A Response of Snow Cover to the Climate in the Northwest Himalaya (NWH) Using Satellite Products

São Paulo’s atmospheric pollution reduction and its social isolation effect, Brazil

Spatial Variability and Temporal Trends of Climate Change in Southwest Ethiopia: Association with Farmers’ Perception and Their Adaptation Strategies

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