7 The Vulnerability of Water Resources from Eastern Romania …
233
1961–2016 interval, under the management of the National Meteorological Administration). The data on river flow were obtained at 17 hydrometric stations located
on rivers without hydrotechnical intervention (for the 1961–2016 interval). The values regarding groundwater level were provided by 56 hydrogeological wells (for
the 1983–2016 time span, under the management of the Prut-Bârlad Water Basin
Administration).
The determination of trends and their slopes was carried out using the nonparametric Mann-Kendal test and the Sen method, developed by researchers from the
Finnish Meteorological Institute [51]. The methods in question have been described
and widely used to identify the trends of certain climatic and hydrological parameters
[7, 58]. In the present study, in order to ensure statistical significance, a value of 0.5
was chosen for the α coefficient.
The correlations between climatic parameters, river flow and variations in the
phreatic level were established using the Bravais-Pearson linear correlation coefficient. This index was applied both to the seasonal data series and the annual data
series. The pairs of data series were devised based on the minimum distance between
meteorological, hydrological and hydrogeological stations, and the same time span
(1983–2016) was used for the correlation between precipitation and phreatic level.
It was, thus, considered that values of the Bravais-Pearson coefficient of at least 0.5
indicate an acceptable degree of correlation between the data series analyzed, given
the spatial variation of natural conditions (topography, geology etc.).
7.4 The Hydrographic Network, Natural and Artificial
Lakes and Groundwater Bodies
The total surface of the Siret-Prut hydrographic area represents 8.63% of the territory
of Romania. The hydrographic network encompasses 392 streams (according to the
official data published by the National Water Administration on www.rowater.ro) [1],
with a total length of 7.696 km and a mean density of 0.38 km/km
2 . On Romanian
territory, the Siret-Prut hydrographic area comprises the middle and lower basin
of the river Prut, the hydrographic basin of the river Bârlad, and all the left-side
tributaries of the river Siret across the counties of Boto¸ sani, Ias , i, Vaslui, and Gala¸ ti
(see Fig. 7.2).
The Siret-Prut hydrographic area comprises the following categories of surface
water bodies: rivers (natural and highly modified by humans)—with a length of
7.696 km (rivers recorded in official documents). Permanent rivers, with a length of
2.269 km, represent 29.48% of the total of streams, and non-permanent rivers, with
a length of 5.427 km, represent 70.52% of the total of streams. To all this are added:
7 natural lakes with surfaces greater than 0.5 km
2 , and a natural lake that has been
significantly altered anthropically, as well as 72 water accumulations with surfaces
that exceed 0.5 km
2 , and 262 ponds.
233
1961–2016 interval, under the management of the National Meteorological Administration). The data on river flow were obtained at 17 hydrometric stations located
on rivers without hydrotechnical intervention (for the 1961–2016 interval). The values regarding groundwater level were provided by 56 hydrogeological wells (for
the 1983–2016 time span, under the management of the Prut-Bârlad Water Basin
Administration).
The determination of trends and their slopes was carried out using the nonparametric Mann-Kendal test and the Sen method, developed by researchers from the
Finnish Meteorological Institute [51]. The methods in question have been described
and widely used to identify the trends of certain climatic and hydrological parameters
[7, 58]. In the present study, in order to ensure statistical significance, a value of 0.5
was chosen for the α coefficient.
The correlations between climatic parameters, river flow and variations in the
phreatic level were established using the Bravais-Pearson linear correlation coefficient. This index was applied both to the seasonal data series and the annual data
series. The pairs of data series were devised based on the minimum distance between
meteorological, hydrological and hydrogeological stations, and the same time span
(1983–2016) was used for the correlation between precipitation and phreatic level.
It was, thus, considered that values of the Bravais-Pearson coefficient of at least 0.5
indicate an acceptable degree of correlation between the data series analyzed, given
the spatial variation of natural conditions (topography, geology etc.).
7.4 The Hydrographic Network, Natural and Artificial
Lakes and Groundwater Bodies
The total surface of the Siret-Prut hydrographic area represents 8.63% of the territory
of Romania. The hydrographic network encompasses 392 streams (according to the
official data published by the National Water Administration on www.rowater.ro) [1],
with a total length of 7.696 km and a mean density of 0.38 km/km
2 . On Romanian
territory, the Siret-Prut hydrographic area comprises the middle and lower basin
of the river Prut, the hydrographic basin of the river Bârlad, and all the left-side
tributaries of the river Siret across the counties of Boto¸ sani, Ias , i, Vaslui, and Gala¸ ti
(see Fig. 7.2).
The Siret-Prut hydrographic area comprises the following categories of surface
water bodies: rivers (natural and highly modified by humans)—with a length of
7.696 km (rivers recorded in official documents). Permanent rivers, with a length of
2.269 km, represent 29.48% of the total of streams, and non-permanent rivers, with
a length of 5.427 km, represent 70.52% of the total of streams. To all this are added:
7 natural lakes with surfaces greater than 0.5 km
2 , and a natural lake that has been
significantly altered anthropically, as well as 72 water accumulations with surfaces
that exceed 0.5 km
2 , and 262 ponds.