Temat: mann-kendall test - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: The Short-Term and Seasonal Trend Detection of Sediment Discharges in Turkish Rivers
Autorzy:: Burgan, Halil Ibrahim
Powiązania:: https://bibliotekanauki.pl/articles/2174920.pdf
Data publikacji:: 2022
Wydawca:: Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:: innovative trend analysis
ITA
Mann-Kendall test
seasonal Mann-Kendall test
sediment discharge
trend
Turkish rivers
Opis:: Hydrometeorological variables are tested by trend methods to detect trends in river basins. Mann-Kendall and Spearman’s rho tests are widely used as traditional trend methods. Besides, some new trend tests are applied to hydrometeorological variables, such as Innovative Trend Analysis (ITA). Sediment discharge observations are more complicated than other hydrometeorological variables. In general, sediment data are observed on a monthly time scale. Therefore, there are minimal studies on sediment data, especially in Turkey. In this study, Innovative Trend Analysis (ITA), Mann-Kendall, Correlated Mann-Kendall and Seasonal Mann-Kendall trend analyses are applied to sediment discharges in Turkish river basins. According to Mann-Kendall, Correlated Mann-Kendall and Seasonal Mann-Kendall results, positive trends have detected only 8, 2 and 20 gauging stations, respectively. Then, 30 positive and 15 negative trends were detected by ITA methodology. The trend slopes calculated from ITA methodology are categorised because some positive and negative trends are weak. The applied trend methods are evaluated together, considering the climate properties of hydrological regions in Turkey. Increasing trends in sediment data are detected from the rivers in the Mediterranean region of Turkey. The results of the study would help to manage water resources as well as sustainable development in the Turkish river basins.
Źródło:: Rocznik Ochrona Środowiska; 2022, 24; 214--230
1506-218X
Pojawia się w:: Rocznik Ochrona Środowiska
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Trend analysis of changes in soil moisture from the different depths in the Martew Forestry
Autorzy:: Krysztofiak-Kaniewska, A
Miler, A. T.
Urbaniak, M.
Ziemblińska, K.
Wróbel, M.
Powiązania:: https://bibliotekanauki.pl/articles/101526.pdf
Data publikacji:: 2016
Wydawca:: Polska Akademia Nauk. Stowarzyszenie Infrastruktura i Ekologia Terenów Wiejskich PAN
Tematy:: Mann-Kendall test
soil moisture
Martew Forestry
Opis:: The paper presents trends in average annual soil moisture in the area covered by the sixty-year old pine stand. The area of analysis is located in the Tuczno Forest District, the Martew Forestry, in the north-western part of Poland. The calculations were based on the measurements of soil moisture at seven different depths below the ground level. A set of probes was installed for measuring the moisture using TDR method in order to calculate retention changes in the unsaturated zone. Humidity measurements used in this work were carried out at daily intervals throughout the year 2014. Designated trends were analysed using the non-parametric Mann – Kendall test, which is used for detecting trend of hydrological and meteorological parameters. Negative values of the Mann-Kendall statistics point to a declining trend for most – six out of the seven, analysed levels of measurement. The tendency toward dryness was not confirmed by the data set of precipitations. Although precipitations are considered to be the main driver of variations in soil moisture their impact severity seems to be controlled by other characteristics of the catchment area and components of the water balance, such as evapotranspiration.
Źródło:: Infrastruktura i Ekologia Terenów Wiejskich; 2016, IV/1; 1157-1167
1732-5587
Pojawia się w:: Infrastruktura i Ekologia Terenów Wiejskich
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Trends In Groundwater Level Changes in Small Forest Catchments of Wielkopolska
Autorzy:: Stasik, R.
Korytowski, M.
Liberacki, D.
Powiązania:: https://bibliotekanauki.pl/articles/124923.pdf
Data publikacji:: 2016
Wydawca:: Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:: small forest catchment
groundwater
Mann-Kendall test
Opis:: Trends in groundwater level changes in small forest catchments located in Wielkopolska region were analysed on the basis on data collected for many years of groundwater levels observations. The observations were carried out from 2000 to 2010 hydrological year in Marianka Siemiańska and Laski forest district as well as in Puszcza Zielonka. The groundwater levels were measured in soil profiles located in different forest habitats: fresh, moist and swamp forest. Changes in groundwater level determined using the Mann-Kendall test were found to differ significantly between the catchment studied. Statistically insignificant decrease in groundwater levels was observed at all forest sites in the catchment area in Marianka Siemiańska forest district. In the catchment area of the Hutka watercourse the groundwater level showed a statistically significant decreasing tendency in Puszcza Zielonka in swamp and fresh mixed coniferous forest. It may indicate a decrease in water resources and implies the need of groundwater level monitoring. A statistically insignificant increase in groundwater level was observed in the wells in moist mixed broadleaved forest in the area of pond catchment in Laski forest district, this trend was interpreted as a result of the clearcutting made in this area.
Źródło:: Journal of Ecological Engineering; 2016, 17, 4; 99-106
2299-8993
Pojawia się w:: Journal of Ecological Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Trend analysis of flood peaks in lower reaches of Satluj River, Himachal Pradesh, India
Autorzy:: Kumar, S.
Santosh, ---
Powiązania:: https://bibliotekanauki.pl/articles/970628.pdf
Data publikacji:: 2015
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:: flood peaks
mann-kendall test
satluj river basin
regression
trend analysis.
Opis:: Climate change arising from anthropogenic driven emissions of greenhouse gases has emerged as one of the most important environmental issues in the last two decades. One of the most significant potential consequences of climate change may be alteration in regional hydrological cycle and river flow regimes. Increased temperature is expected to increase the peak flows in snowfed rivers of Himalayas. The changing pattern of regional temperature on flood peaks deserves urgent and systematic attention over a basin which provides an insight view of historical trends. Lower reaches of Satluj River is selected for the present study. Testing the significance of observed trends in flood peaks has received a great attention recently, especially in connection with climate change. The data series available was 48 years (1967-2010). The records were subjected to trend analysis by using both non-parametric (Mann-Kendall test) and parametric (linear regression analysis) procedures. For better understanding of the observed trends, flood peaks were computed into standardised flood peak indices (SFPI). These standardised data series were plotted against time and the linear trends observed were represented graphically. The analysis of flood peaks at different observation stations in lower reaches of Satluj River showed a large variability in the trends and magnitudes. The trend analysis results of flood peaks and gauge heights indicate that the flood peaks at all sites i.e. Rampur, Suni and Kasol show increasing but statistically insignificant trends. The trends in gauge height at all sites are also showing increasing trend but Kasol is statistically significant at 95% confidence level. The fast melting of glaciers, incessant monsoon rainfall and the synchronisation of the discharge peaks are the main causes of river floods. The past flood peaks will help us to observe the frequency of occurrence of floods in certain region and to determine whether the flood peaks in the past have been same with that of the present or whether there is any deviation in the trend in relation to climate change. Such studies will help in designing mitigation and adaptation strategies towards extreme hydrological events.
Źródło:: International Letters of Natural Sciences; 2015, 46
2300-9675
Pojawia się w:: International Letters of Natural Sciences
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: On the long-term variability of temperature trends and changes in surface air temperature in Kolkata Weather Observatory, West Bengal, India
Autorzy:: Khan, A.
Chatterjee, S.
Bisai, D.
Powiązania:: https://bibliotekanauki.pl/articles/108500.pdf
Data publikacji:: 2015
Wydawca:: Instytut Meteorologii i Gospodarki Wodnej - Państwowy Instytut Badawczy
Tematy:: temperature
trend analysis
Mann-Kendall test
Sen’s slope estimator
Kolkata
Opis:: The impact of climate change on annual air temperature has received a great deal of attention from climatologists worldwide. Many studies have been conducted to illustrate that changes in temperature are becoming evident on a global scale. Air temperature, one of the most important components of climate parameters, has been widely measured as a starting point towards the apprehension of climate change and variability. The main objective of this study is to analyse the temporal variability of mean monthly temperature for the period of 1941 to 2010 (70 years). To detect the magnitude of trend in mean monthly temperature time series, we have used non-parametric test methods such as The Mann-Kendall test, often combined with the Theil-Sen’s robust estimate of linear trend. Whatever test is used, the user should understand the underlying assumptions of both the technique used to generate the estimates of a trend and the statistical methods used for testing. The results of this analysis reveal that four months – January, February, March and December – indicate a decreasing trend in average temperature, while the remaining eight months have an increasing trend. The magnitude of Mann-Kendall trend statistic Zc for this declining temperature and the magnitude of slope for the months of January, February and December are confirmed at the high significance levels of α = 0.001, 0.01 and 0.1 respectively. Though, the overall trend is positive for monthly as well as seasonally efficient time series.
Źródło:: Meteorology Hydrology and Water Management. Research and Operational Applications; 2015, 3, 2; 9-16
2299-3835
2353-5652
Pojawia się w:: Meteorology Hydrology and Water Management. Research and Operational Applications
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Trend analysis of climatic variables in an arid and semi-arid region of the Ajmer District, Rajasthan, India
Analiza trendu czynników klimatycznych na suchych i półsuchych obszarach dystryktu Ajmer w Radżasthanie, Indie
Autorzy:: Pingale, S. M.
Khare, D.
Jat, M. K.
Adamowski, J.
Powiązania:: https://bibliotekanauki.pl/articles/292780.pdf
Data publikacji:: 2016
Wydawca:: Instytut Technologiczno-Przyrodniczy
Tematy:: Mann–Kendall test
modified Mann–Kendall test
Pettitt–Mann–Whitney test
Rajasthan
Sen’s slope
trends
nachylenie Sena
test Manna–Kendalla (MK)
test Pettitta–Manna–Whitneya (PMW)
trendy
zmodyfikowany test Manna–Kendalla (MMK)
Opis:: In the present study, trends and variations in climatic variables (i.e. rainfall, wet day frequency, surface temperature, diurnal temperature, cloud cover, and reference and potential evapotranspiration) were analyzed on seasonal (monsoon and non-monsoon) and annual time scales for the Ajmer District of Rajasthan, India. This was done using non-parametric statistical techniques, i.e. the Mann–Kendall (MK) and Modified Mann–Kendall (MMK) tests, over a period of 100 years. The MK test with prewhitening (MK–PW) of climatic series was also applied to climatic variables and the results were compared to those obtained through the MK and MMK tests in order to assess the performance of trend detection methods. The Pettitt–Mann–Whitney (PMW) test was applied to detect the temporal shift in climatic series. The trend analysis revealed that annual and seasonal rainfall did not show any statistically significant trend at a 10% significant level. A noticeable trend increase was found in wet day frequency, surface temperature and reference evapotranspiration (ET) during the non-monsoon season from the three non-parametric statistical tests at a 10% significance level. A statistically significant decrease in maximum temperature was found during the non-monsoon season by the MK–PW test alone. This analysis of several climatic variables at the district scale is helpful for the planning and management of water resources and the development of adaptation strategies in adverse climatic conditions.
W pracy analizowano trendy i zmienność czynników klimatycznych (opad, częstotliwość dni wilgotnych, temperaturę powierzchni ziemi, temperaturę dobową, zachmurzenie oraz ewapotranspirację wskaźnikową i potencjalną) w skali sezonowej i rocznej w dystrykcie Ajmer, w Radżasthanie (Indie). Analizę przeprowadzono za pomocą nieparametrycznych technik statystycznych Manna–Kendalla (MK) i zmodyfikowanej techniki MK (MMK) dla 100-letniego okresu. Test MK z eliminacją korelacji serii klimatycznych (prewhitening – MK–PW) zastosowano także do zmiennych klimatycznych, a wyniki porównano z uzyskanymi z użyciem testów MK i MMK, co pozwoliło na ocenę wiarygodności wykrywania trendu zmian w czasie. W celu wykrycia czasowych przesunięć serii klimatycznych zastosowano test Pettitta–Manna–Whitneya (PMW). Na podstawie analizy trendu stwierdzono, że opady roczne i sezonowe nie wykazywały statystycznie istotnego trendu na poziomie istotności 10%. Wykorzystując trzy testy nieparametryczne, stwierdzono rosnący trend w przypadku częstości występowania wilgotnych dni, temperatury powierzchni i ewapotranspiracji wskaźnikowej w okresie pozamonsunowym na poziomie istotności 10%. Statystycznie istotny spadek maksymalnej temperatury w tym okresie stwierdzono jedynie, gdy stosowano test MK–PW. Przedstawiona analiza kilku zmiennych klimatycznych w skali dystryktu może być pomocna w planowaniu i zarządzaniu zasobami wodnymi i w rozwoju strategii adaptacji do niekorzystnych warunków klimatycznych.
Źródło:: Journal of Water and Land Development; 2016, 28; 3-18
1429-7426
2083-4535
Pojawia się w:: Journal of Water and Land Development
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Analyzing trends in reference evapotranspiration in Northwest part of Iran
Autorzy:: Azizzadeh, M.
Javan, K.
Powiązania:: https://bibliotekanauki.pl/articles/124913.pdf
Data publikacji:: 2015
Wydawca:: Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:: reference evapotranspiration
trend
Mann-Kendall test
Sen’s estimator
northwest of Iran
Opis:: Evapotranspiration is one of the most important components of the hydrological cycle. It is essential in all of hydro climatological studies, irrigation and drainage calculations, water balance, and crop water requirements. The aim of this study is to investigate temporal trends of reference evapotranspiration (ETo) in the Northwest part of Iran. For this purpose, the meteorological data from 20 synoptic stations over a 22-year time period (1986–2007) were used. After the calculation of ETo using the Penman-Monteith FAO-56 method, the non-parametric Mann-Kendall test was used to investigate the temporal trends on monthly, seasonal and annual scales. The Sen’s estimator method was used and to calculate the slope of the trend line. The results indicated that the ETo trend was increasing (positive) in various months, except for the Sarab station in December. On a monthly scale, the Maragheh station showed the highest positive slope in August, and the Bijar station showed the highest negative slope in May. 43.34% of the stations showed a significant trend, and 56.66% did not show a significant trend. In seasonal and annual time periods there was not a significant decreasing trend in any of the stations. The analysis of the results shows that in the spring 20%, in the summer 55%, in the fall 70%, in the winter 75%, and on an annual scale 60% of the stations under study showed an increasing trend. For modeling these changes, the spatial distribution of ETo trends (on monthly, seasonal, and annual scales) were mapped in ArcGIS. Final models determine that most stations in this study show an increasing trend on monthly, seasonal and annual scales.
Źródło:: Journal of Ecological Engineering; 2015, 16, 2; 1-12
2299-8993
Pojawia się w:: Journal of Ecological Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Trend analysis of rainfall in Satluj River Basin, Himachal Pradesh, India
Autorzy:: Kumar, Sandeep
Gill, G. S.
Santosh, Santosh
Powiązania:: https://bibliotekanauki.pl/articles/1193980.pdf
Data publikacji:: 2015
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:: Himachal Pradesh
Mann-Kendall test
Rainfall
Regression
Satluj River Basin
Trend analysis
Opis:: attention recently, especially in connection with climate change. The changing pattern of rainfall deserves urgent and systematic attention for planning, development, utilisation and management of water resources. The daily data on variable were converted to monthly and then computed to seasonal and annual series. Annual rainfall (mm/yr) was calculated as the sum of monthly values. The missing values in the data were computed by using average method. The records of rainfall were subjected to trend analysis by using both non-parametric (Mann-Kendall test) and parametric (linear regression analysis) procedures. For better understanding of the observed trends, data were computed into standardised precipitation indices (SPI). These standardised data series were plotted against time and the linear trends observed were represented graphically. Trend analysis results of rainfall show that out of 15 annual trends 6 (40%) are increasing and 9 (60%) are decreasing in nature where 1 (6.6%) is statistically significant (increasing) and 2 (13.3%) are statistically significant (decreasing) at 95% confidence level. Similarly, the changes were investigated for the four seasons: winter (December-March), pre-monsoon (April-June), monsoon (July-September) and post-monsoon (October-November). The analysis of rainfall, annual as well as seasonal, of different gauge stations in Satluj River Basin showed a large variability in the trends and magnitudes from 1984 to 2010. The rainfall shows great temporal and spatial variations, unequal seasonal distribution with frequent departures from normal. Majority of gauge stations have experienced decreasing trends, both on seasonal and annual scales. Some were statistically significant at 95% confidence level. The sensitivity of rainfall variations provides important insight regarding the responses and vulnerability of different areas to climate change. It will further strengthen the formulation of future strategy for management of water resources.
Źródło:: World Scientific News; 2015, 14; 1-55
2392-2192
Pojawia się w:: World Scientific News
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Spatial and temporal precipitation trends of proposed smart cities based on homogeneous monsoon regions across India
Autorzy:: Singh, Lakhwinder
Khare, Deepak
Mishra, Prabhash K.
Pingale, Santosh M.
Thakur, Hitesh P.
Powiązania:: https://bibliotekanauki.pl/articles/1844405.pdf
Data publikacji:: 2020
Wydawca:: Instytut Technologiczno-Przyrodniczy
Tematy:: smart city
trend
modified Mann–Kendall test
MMK
monsoon homogeneous regions
India
Opis:: The conservation of rainwater and augmentation of groundwater reserve is necessary to meet the increased water demands. Precipitation occurring in the smart cities need to be understood for a better water management action plan. Therefore, monotonic precipitation trend analysis was performed for eight smart cities drawn from six monsoon homogeneous regions across India. The precipitation data were investigated for trends using the modified Mann–Kendall (MMK) test and Sen’s slope estimator at annual, seasonal and monthly scales. The trend analysis was carried out over 118 years (from 1901 to 2018) at 95% significance level. The Dehradun city (Northern Himalayan region) showed a significant increasing annual precipitation trend (Z = +3.22). Indore and Bhopal cities from West Central region showed significant increasing annual trend (Z = +2.01) and non-significant decreasing annual trend respectively. Although, Vadodara and Jaipur are lying in the same Northwest region, the trends are opposite in nature. Jaipur city showed a significant increasing annual pre-monsoon trend (Z = +2.44). The winter rainfall in the city of Vadodara is showing a significant decreasing trend (Z = –2.16). The pre-monsoon rainfall in Bhubaneswar (Central Northeast region) and monsoon precipitation in Trivandrum (Peninsular region) are showing significant increasing (Z = +2.56) and decreasing (Z = –2.71) trends, respectively. A non-significant decreasing trend was seen in Guwahati city (Northeast region). The eight smart cities selected for investigation are not truly representing the entire country. However, the study is clearly pointing towards the regional disparity existing in the coun-try. These findings will be helpful for water managers and policymakers in these regions for better water management.
Źródło:: Journal of Water and Land Development; 2020, 47; 150-159
1429-7426
2083-4535
Pojawia się w:: Journal of Water and Land Development
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Water level trends in the ponds of Siemianice Experimental Forest Farm
Autorzy:: Stasik, Rafał
Kęsicka, Barbara
Korytowski, Mariusz
Powiązania:: https://bibliotekanauki.pl/articles/1844421.pdf
Data publikacji:: 2020
Wydawca:: Instytut Technologiczno-Przyrodniczy
Tematy:: forest ponds
long-term monitoring
Mann–Kendall test
multiyear trend
water level
Opis:: The results of a long-term water level monitoring in three forest ponds are presented in the paper. The ponds are located in the Wielisławice and Laski forest districts in South Wielkopolska, Poland. Two of the analysed ponds are natural ones supplied by precipitation and the third now is disused artificial fishpond of throughflow water management. Systematic water level measurements, as well as measurement of basic meteorological conditions – precipitation and air temperature – were carried out in the 2000–2016 hydrological period. The basic statistics as well as the trends in long-time changes in water levels, were determined using the nonparametric Mann–Kendall test were calculated. The results obtained were statistically inconclusive, but they indicated downward trends in water levels in the natural ponds and upward trends in water levels in the artificial pond. Although a statistically significant downward trend was observed in only one natural pond, it may suggest some negative changes occurring in the catchment of ponds in general.
Źródło:: Journal of Water and Land Development; 2020, 47; 169-175
1429-7426
2083-4535
Pojawia się w:: Journal of Water and Land Development
Dostawca treści:: Biblioteka Nauki

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