We propose one parametric and one non-parametric method for detection of monotone trends in nutrient concentrations in brackish waters. Both methods take into account that temporal variation in the quality of such waters can be strongly influenced by mixing of salt and fresh water, thus salinity is used as a classification variable in the trend analysis. With the non-parametric approach, Mann-K...

Kendall Rank Correlation Let (X1, Y1), · · · , (Xn, Yn) be a bivariate random sample of size n. The Pearson correlation coefficient provides an optimal measure of the degree of association between the X’s and the Y ’s when the sample is drawn from a bivariate normal distribution. The Pearson correlation coefficient is reasonably robust for many other distributions as well. The Kendall correlati...

the discharge data used for hydrological modeling should be the long-term suitable random data without trend and jump which is followed a specific statistical distribution. in this study, the above mentioned conditions were evaluated for 31 years period (1974-2004) of annual mean discharge data of 10 gauging stations of west azarbaijan province. for this purpose, the non-parametric spearman cor...

abstract the aim of this paper is to investigate annual and seasonal precipitation trends of some selective meteorological stations of central region in iran using non-parametric methods. two non-parametric methods including mann-kendall and sen's estimator slope methods were used here to analyze the seasonal and annual trends of precipitation data. some 48 meteorological stations in centr...

In this paper we develop the theory of parametric polynomial regression in Riemannian manifolds and Lie groups. We show application of Riemannian polynomial regression to shape analysis in Kendall shape space. Results are presented, showing the power of polynomial regression on the classic rat skull growth data of Bookstein as well as the analysis of the shape changes associated with aging of t...

drought is one of the natural phenomena which occurs in all climates in different parts of the world. iran is located in the dry belt of the world. the increase of desertification, drought reoccurrence, and destruction by human in this geographical region needs more studies on spatial and temporal trend of rainfall. in this study, trends of climatic drought during 1975-76/ 2004-05 in seasonal a...

The widely-used hydrological procedures for calculating events with T-year return periods from data that follow a Gumbel distribution assume that the data sequence from which the Gumbel distribution is fitted remains stationary in time. If non-stationarity is suspected, whether as a consequence of changes in land-use practices or climate, it is common practice to test the significance of trend ...