This paper analyzes the flood that occurred between 11th and 13th of September 2013 in the upper catchment of the river Geru. The flood was simulated using the program Mike by DHI with the Unitary Hydrograph Method. As input data, we used the precipitation measured at the Automated Hydrological Sensor Station Cudalbi and radar precipitations. We analyzed the importance of accuracy for input data on the simulation results and the direct influence of setting the proper time steps in achieving the simulated discharge hydrograph. It appears that radar precipitations used as input data lead to a discharge hydrograph with low errors for amplitude and phase of the runoff peak. The model can be used in the future to reproduce the floods produced in the analyzed catchment and to study the influence of physical and geographical characteristics of the hillslopes.

From previous studies, it was found that the most important pluviometric indicators which characterize the frequency, intensity and spatial distribution of drought in Prut River floodplain are the standardized precipitation index, Hellmann's criterion and Topor aridity index. Standardized precipitation index values between (-1.5) and (-1.0) indicates a high frequency of the moderate-dry periods and very dry ones reached 2.3 %. Autumn shows moderate -dry traits in 13.5% of the years and can be very dry only for 9% of the cases from 1979 until 2013. To forecast drought through the standardized precipitation index, it is estimated that if severe periods occur in autumn, will be extended throughout the winter period and for the whole next (year) growing season. A severe drought which began in autumn of 2011 remained throughout the winter until the next growing season (2012). To strengthen this study, a characterization of months using Hellman's criterion was carried out. The authors laid emphasis on the excessively rainy months and the excessively dry months, the latter had a higher weight. Topor aridity index results showed a dry substance in 1982, 1985, 1986, 1989, 1992, 1997, 2000, 2002, 2003, 2004, 2006, 2008, 2009, 2011 and 2012 respectively. The incidence of droughts in the Moldavian Plain resulted in a sharp decrease in the runoff and the appearance of a drying -up phenomenon in the middle basin of Prut River. Rivers dried up at a frequency of 40 -50 % in river basins with a surface area of 15 -20 km 2 and over 90 % in river basins with areas less than 5 km 2 .

The dam of the non-permanent reservoir Ezer, located on Jijia river is an earth dam with a maximum height of 6.18 m, which provides a global retention to the canopy of 10.330 million cubic meters. The dam founded on weak, muddy soils suffered in the years 1989 and 1992 downstream slope failures of the fillings. It was found that hydrostatic levels were high in the piezometric wells and that consolidation of the foundation soil was reduced. This paper presents a brief history of the dam and aspects regarding the behaviour monitoring of Ezer non-permanent reservoir during the years 2000-2012.

MIKE software created by Danish Institute of Hydraulics can be used to perform mathematical modelling of rainfall-runoff process on the hillslopes, resulting in a runoff hydrograph in the closing section of a catchment. The software includes a unitary hydrograph method - UHM in the hydrological module Rainfall - Runoff. Excess rainfall is routed to the river and transited through unit hydrograph method. The model divides the flood generating precipitation in excess rainfall (net rainfall) and losses (infiltration). This paper analyzes data from the flash flood that occurred between the 11th and 13th of September 2013 in the upper catchment of the river Geru. The catchment chosen for study, is controlled by the hydrometric station located in the village Cudalbi. Simulations of this flash flood were performed with MIKE by DHI –UHM software, alternatively using as input data the precipitations recorded by AHSS (Automated Hydrological Sensor Station) Cudalbi and radar precipitations generated by ROFFG (Romanian Flash Flood Guidance) software system in ArcGIS module for determining the areas affected by flash floods. The Unitary Hydrograph Method - UHM from the hydrological module Rainfall – Runoff calculates excess rainfall and determines infiltration losses by four methods. For each set of input data, the four methods for calculating infiltration losses were subsequently used. The comparison between the results highlights that the amplitude and phase errors for the maximum discharge are smaller when the model uses for simulation radar precipitations as input data, and calculates infiltration losses with the Proportional Loss method. This method reproduces with a better accuracy the peaks of the discharge hydrograph. The model can be used in the future to forecast a discharge hydrograph based on estimated radar precipitations in the catchment

The dam of the reservoir Cuibul Vulturilor, located on the Tutova river is an inhomogeneous earth dam with a maximum height of 15.0 m, with a clayey central core and lateral prisms made of clayey-dusty sands. For tracking the evolution of body dam seepage, 12 piezometers and a drainage pipe with discharge in the downstream connection channel of the bottom outlet are used. The paper presents the characteristic elements of the theoretical infiltration curve in the dam It also shows the hydro isohypses for the dam drawn with SURFER program, using the maximum hydrostatic levels in the piezometers measured in the year 2019. The distribution of the hydro isohypses across the dam is strongly influenced by the location of the piezometers and the other point of measuring the hydraulic head. The pattern circulation of the infiltration water inside the dam body could be studied with increased accuracy, if the dam had been equipped with several piezometers. Even in these conditions, it is clearly observed that the regime of infiltrations through the dam body is similar to the theoretical way of behavior.