Interazioni tra acque sotterranee e superficiali e problematiche connesse con la determinazione del deflusso minimo vitale: i casi dei fiumi Marta e Mignone (Lazio)
Author(s)
Baiocchi, Antonella
Date Issued
2007
Type
Doctoral Thesis
Abstract
The research has been focused on the interactions between groundwater and surface
water of two highly representative streams of the minor hydrographic net of Northern
Lazio Region (Italy), with the aim to evaluate the main issues linked to the
determination of the instream flow for fish life. The areas analysed are the drainage
basins of the Marta River, outlet of the Bolsena Lake, and the Mignone River. Both of
them are located in the Lazio volcanic region, characterised by the Vulsino, Sabatino,
Cimino and Vico volcanic activities.
They have been chosen as representative cases for trying to estimate the instream flow
due to human impacts, showed by the exploiting of surface water for hydroelectric,
industrial, civil and agricultural uses. The safeguard of the rivers concerned resulted as a
fundamental tool in the sustainable management of the water resources.
Taking into account both the main methods proposed by the previous literature, and the
particular hydro-geological features and available data, the most suitable methods has
been chosen.
As a consequence, the research implied: i) collection of historical instream flow data,
completed by further updated measurements; ii) analyses of historical climatic data for
the estimation of the water budget; iii) definition of the hydrogeological outline through
data collection of wells and springs. Moreover, through several biological indices
reported in literature, the quality status of the surface water has been addressed. Finally,
it has been underlined the linkages between the streams flow and the temporal and
spatial variability of the surface water quality.
Concerning the Marta River, the results highlight that the stream flow is heavily
influenced by the Bolsena Lake level in the high river course and by groundwater
recharge in the other parts of the hydrograph net. The ecological quality of the surface
water emerges as compromised in the heavily human parts, while it improves where the
stream is gaining.
Conversely, hydrogeological outline of the Mignone River resulted highly influenced by
the structural-geological framework of the area, because of its low-permeable
formations. As a consequence, the quality of the surface water can be considered quite
good, except for few parts affected by local problems.
In conclusion, the evaluation of the instream flow has produced various results
concerning the same river section by applying different methods. Consequently, the
estimation of the instream flow should take into account not only the dynamic of the
river, but also the entire processes of the hydrogeological basin. In particular, the
essential role of the groundwaters and, thus, the necessity to define the relationships
between the river and groundwater, considering both the hydrographic basin and
hydrogeological basin, should not be underestimated. In these regards, the exploitation
of the surface water resource should be planned considering the pre-development water
budget and the quantity and the location of the withdrawals from the aquifer on the
basis of the river hydrogeological framework.
Additional information
Dottorato di ricerca in Ecologia e gestione delle risorse biologiche
File(s)![Thumbnail Image]()
![Thumbnail Image]()
Name
CAP 3-5.pdf
Description
Capitoli 3-5
Size
17.95 MB
Format
Adobe PDF
Checksum (MD5)
da466f841ccdac3b52542b39e64f726b
Name
CAP 1-2.pdf
Description
Capitoli 1-2
Size
12.96 MB
Format
Adobe PDF
Checksum (MD5)
9b0486f572049ae4ae22146fd4de6e7d