Aspects regarding the trend of the average annual, seasonal and monthly drainage of river water from the Căliman Mountains in the period 1950-2010

Abstract

The Căliman Mountains are the highest volcanic mountains in Romania, being positioned on the western side of the Eastern Carpathians, between their central strip (north and east), south – the Harghita Mountains, and west – the Transylvanian Depression. This positioning gives special features of the water drainage, with both spatial and temporal differentiations. This paper analyzed the trend of average drainage from rivers in the studied group for the period 1950-2010, both multi-annually and seasonally and in the extreme months; the months taken into account being those with the lowest flows (January), respectively the largest (May). To evaluate the mentioned parameters, we used the help of Excel MAKESENS (Mann-Kendall test for trend and Sen’s slope estimates), which identified the type of drainage trend (positive or negative), and using the Sen nonparametric method to estimate the slope of the trend. Based on the type of trend obtained, 9 trend classes were obtained, and with the help of the slope, the net change rate was obtained.