Embed Size (px)
Citation preview
Marco Materazzi
Università di Camerino
Scuola di Scienze Ambientali
Tel: 0737-402603
E-mail: [email protected]
Materazzi M. - Corso “Idrogeologia”: Lezione 2 – Interazione acque superficiali-falde
Materazzi M. - Corso “Idrogeologia”: Lezione 2 – Interazione acque superficiali-falde
Materazzi M. - Corso “Idrogeologia”: Lezione 2 – Interazione acque superficiali-falde
Gaining streams receive water from the ground-water system (A) This can be determined from
Losing streams lose water to the ground-watersystem (A). This can be determined from water-water system (A). This can be determined from
water-table contour maps because the contourlines point in the upstream direction where theycross the stream (B).
syste ( ) s ca be dete ed o atetable contour maps because the contour linespoint in the downstream direction where theycross the stream (B).
Materazzi M. - Corso “Idrogeologia”: Lezione 2 – Interazione acque superficiali-falde
Disconnected streams areseparated from the ground-watersystem by an unsaturated zone.
If stream levels rise higher thanadjacent ground-water levels,adjacent ground water levels,stream water moves into thestreambanks as bank storage.
Materazzi M. - Corso “Idrogeologia”: Lezione 2 – Interazione acque superficiali-falde
If stream levels rise higher than theirstreambanks (C), the floodwaters rechargeground water throughout the flooded areas.
Materazzi M. - Corso “Idrogeologia”: Lezione 2 – Interazione acque superficiali-falde
The location where perennialstreamflow begins in a channelcan vary depending on thedistribution of recharge inheadwaters areas. Following dry
i d (A) h fperiods (A), the start ofstreamflow will move up-channelduring wet periods as the ground-water system becomes more
t t d (B)saturated (B).
Materazzi M. - Corso “Idrogeologia”: Lezione 2 – Interazione acque superficiali-falde
Esempio di “gaining stream”
Materazzi M. - Corso “Idrogeologia”: Lezione 2 – Interazione acque superficiali-falde
Esempio di “losing stream”
Materazzi M. - Corso “Idrogeologia”: Lezione 2 – Interazione acque superficiali-falde
Surface-water exchange with ground water in the hyporheic zone is associated withb t h i t b d l (A) d ith t d (B)abrupt changes in streambed slope (A) and with stream meanders (B).
Materazzi M. - Corso “Idrogeologia”: Lezione 2 – Interazione acque superficiali-falde
Streambeds and banks are unique environments because they are where ground waterthat drains much of the subsurface of landscapes interacts with surface water that drainsmuch of the surface of landscapes.
Materazzi M. - Corso “Idrogeologia”: Lezione 2 – Interazione acque superficiali-falde
In a schematic hydrologic setting where ground water discharges to a stream under natural conditions (A) placement of aIn a schematic hydrologic setting where ground water discharges to a stream under natural conditions (A), placement of a well pumping at a rate (Q1) near the stream will intercept part of the ground water that would have discharged to the stream(B). If the well is pumped at an even greater rate (Q2), it can intercept additional water that would have discharged to the stream in the vicinity of the well and can draw water from the stream to the well (C).
