A Hydrometric and Hydrological Approach Test at Microscale

Abstract

The objectives of this article were: to test the hydrometric accuracy of some water level variation measuring and recording devices using a metal measuring tank with weir, and to automatically determine runoff intensities and elements. These field tests were performed in order to ensure high accuracy and low uncertainty of studies at hydrological micro-scale (plot scale). Hydrometric tests targeted two level measurement conditions: (i) rise and storage - without overflowing, volumetric measurement V= f (H); and (ii) rise and overflowing, weir measurement Q = f (H). Hydrometric accuracy was evaluated by comparing the measured and recorded level using three instruments with a tell-tale level. This field experiment was conducted in Voineşti Experimental Basin, belonging to the National Institute of Hydrology and Water Management. Levels series data were processed with the software application ParExp v1, in order to automatically convert them into discharges (Q). Hydrometric and hydrological test results highlighted certain aspects. The accuracy estimated for water fluctuation measurement and recording instruments in a weir water tank, for both level measurement conditions revealed accuracy errors (insufficient accuracy) when the runoff hydraulics was changed (storage Qacum ÷ overflowing Qdev). To remedy such instrumental deficiencies, a metrological control shall be performed under specific operational conditions (e.g., water tank) in order to meet increasing needs for high quality hydrological data. The hydrological data processing using the ParExp v1 software application, at the junction of specific “rise and storage” and “rise and overflowing” flows indicated a temporal error (delay). The user may remedy this error by eliminating data from the Qacum-Qdev junction range until reaching the maximum/stabilized level.Finally, we estimate that through the improvement of some technical elements, hydrological data obtained at a micro-scale level can be used for hydrological models of calibration.