Developing proper algorithm for different studies can have a major impact on research time, by decreasing the necessary manual work. If the algorithm is general on regional scale or with minor changes can be adapted for different locations its importance is even higher. The calculation of the SPI value, characterizing the meteorological drought and excess of humidity, has a standard algorithm which made suitable to develop software which calculates

The snowmelt process has an important role in the runoff mechanism, because the quantity of water resulted has a significant impact on both soil coverage and surface runoff. The surpass of soil saturation limit during the snowmelt period depends on the physical characteristics of the soil and on the snowmelt rate. The study purpose is to develop by GIS techniques an algorithm that would make possible the daily analysis of spatial distribution of

This work presents a methodology of determining the surface runoff hydrograph when the storm characteristics are known. The methodology was automated in a Geographic Information System model that can be sed in any study if the user can input the necesarry parameters. The model, built by implementing some well known hydrologic methods in GIS, consists of four components that address the following requirements: the runoff depth in mm, the runoff coefficient,

The extreme hydrological events to which we refer in this study are water excess and drought, and the analyzed territory is Transylvania. The study does not use two types of magnitudes for the representation of water excess and drought, respectively. Based on the VUB model of the monthly precipitation-runoff relation (Vandewiele et al. 1993), the monthly series of the basin water reserve is calculated, series equivalent to the basin mois-ture index.

In this paper we describe an animated method which may allow for the detection of the trend signal, independently of any subjectivism caused by the length of the time series. The new algorithm decomposes the series into a succession of sequentially tendencies, having the feature of sloped steps, in the biggest having divergence shape related to the horizontal that reflects the global mean of the given data sample and the time flow. The sequential