Nonparametric correlation estimators as the Kendall and Spearman correlation are widely used in the applied sciences. They are often said to be robust, in the sense of being resistant to outlying observations. In this paper we formally study their robustness by means of their influence functions and gross-error sensitivities. Since robustness of an estimator often comes at the price of an incre...

abstract in this study, trends of threshold heavy precipitation were examined on the basis of measurements of 1437 stations (included synoptic, climatic and rain gage stations) in iran for the period of 40 years (1964-2003). for this purpose, the statistical method of nonparametric mann-kendall test is used for analyzinging the thresholds of heavy precipitation and nonparametric sen method for ...

This study aims to investigate the trend of water-level changes in lakes (Lake Tuz and Lake Bey?ehir) sinkholes (Timra? K?zören) Konya Closed Basin located Turkey. Water-level these were investigated along with meteorological parameters (precipitation, temperature, evaporation) groundwater trends that indicate climate region. Several statistical tests can be used determine significance hydrolog...

todays, the world development is facing serious water quality issues. since protect of water quality and ecosystem healthy is an important aspect of ecohydrology. the present research aimed to analyze the temporal trends of water quality parameters of mashin zard river station in order to planning long term management approaches. in this research, trend of some significant factors of water qual...

Airborne particulate matter with a diameter of 2.5 microns or less (PM2.5), as well as slightly bigger particles (PM10), arrive from the westerly direction and collect in the city centre of Tehran, the capital of Iran. The statistical characteristics and daily trend of the air quality index (AQI) in Theran were studied over an 11-year period (2002- 2012). Various statistical analyses were appli...

The Mann-Kendall test is a commonly-used nonparametric test for time trend. However, the standard P-values obtained from it are based on an assumption of independence between observations (since the theory is that of the Kendall correlation). However, observations in time series are often autocorrelated: knowing that one observation is larger than the mean may tell you that the next observation...

This research highlights the precipitation trends and presents the results of the study in temporal and spatial scales. Precise predictions of precipitation trends can play imperative part in economic growth of a state. This study examined precipitation inconsistency for 23 stations at the Dongting Lake, China, over a 52-years study phase (1961–2012). Statistical, nonparametric Mann-Kendall (MK...

in this study, long-term trends and abrupt changes of hydro-climatic variables was investigated in the observed period 1971-2000 for aidoghmoush basin using mann-kendall nonparametric test and cumulative curve of climatic variables-runoff, respectively. results show decrease trends for rainfall and runoff and increase trend for temperature by the mann-kendall test with a confidence level of 99%...

In this paper two nonparametric tests for monotonic trend detection are compared with respect to their power and accuracy. The importance of comparing powers at equal empirical signiicance levels rather than nominal levels, is stressed. Therefore, an appropriate graphical method is presented. The eeect of the sampling frequency is also assessed using a trajectory representation that visualizes ...

Treatment means in factorial experiments are lattice ordered when there is an increase in mean response as the level of any factor is increased while holding the other factors fixed. Such means occur naturally in many experiments. A nonparametric test for lattice-ordered means involving a Kendall-type statistic will be summarized for k-factor factorial experiments. Specifically, the form of the...