Dissolved Inorganic Geogenic Phosphorus Load to a Groundwater-Fed Lake : Implications of Terrestrial Phosphorus Cycling by Groundwater

Show full item record



Permalink

http://hdl.handle.net/10138/312110

Citation

Nisbeth , C S , Kidmose , J , Weckstrom , K , Reitzel , K , Odgaard , B V , Bennike , O , Thorling , L , McGowan , S , Schomacker , A , Kristensen , D L J & Jessen , S 2019 , ' Dissolved Inorganic Geogenic Phosphorus Load to a Groundwater-Fed Lake : Implications of Terrestrial Phosphorus Cycling by Groundwater ' , Water , vol. 11 , no. 11 , 2213 . https://doi.org/10.3390/w11112213

Title: Dissolved Inorganic Geogenic Phosphorus Load to a Groundwater-Fed Lake : Implications of Terrestrial Phosphorus Cycling by Groundwater
Author: Nisbeth, Catharina Simone; Kidmose, Jacob; Weckstrom, Kaarina; Reitzel, Kasper; Odgaard, Bent Vad; Bennike, Ole; Thorling, Laerke; McGowan, Suzanne; Schomacker, Anders; Kristensen, David Lajer Juul; Jessen, Soren
Contributor: University of Helsinki, Ecosystems and Environment Research Programme
Date: 2019-11
Language: eng
Number of pages: 23
Belongs to series: Water
ISSN: 0310-0367
URI: http://hdl.handle.net/10138/312110
Abstract: The general perception has long been that lake eutrophication is driven by anthropogenic sources of phosphorus (P) and that P is immobile in the subsurface and in aquifers. Combined investigation of the current water and P budgets of a 70 ha lake (Nørresø, Fyn, Denmark) in a clayey till-dominated landscape and of the lake’s Holocene trophic history demonstrates a potential significance of geogenic (natural) groundwater-borne P. Nørresø receives water from nine streams, a groundwater-fed spring located on a small island, and precipitation. The lake loses water by evaporation and via a single outlet. Monthly measurements of stream, spring, and outlet discharge, and of tracers in the form of temperature, δ18O and δ2H of water, and water chemistry were conducted. The tracers indicated that the lake receives groundwater from an underlying regional confined glaciofluvial sand aquifer via the spring and one of the streams. In addition, the lake receives a direct groundwater input (estimated as the water balance residual) via the lake bed, as supported by the artesian conditions of underlying strata observed in piezometers installed along the lake shore and in wells tapping the regional confined aquifer. The groundwater in the regional confined aquifer was anoxic, ferrous, and contained 4–5 µmol/L dissolved inorganic orthophosphate (DIP). Altogether, the data indicated that groundwater contributes from 64% of the water-borne external DIP loading to the lake, and up to 90% if the DIP concentration of the spring, as representative for the average DIP of the regional confined aquifer, is assigned to the estimated groundwater input. In support, paleolimnological data retrieved from sediment cores indicated that Nørresø was never P-poor, even before the introduction of agriculture at 6000 years before present. Accordingly, groundwater-borne geogenic phosphorus can have an important influence on the trophic state of recipient surface water ecosystems, and groundwater-borne P can be a potentially important component of the terrestrial P cycle.
Subject: 1172 Environmental sciences
Rights:


Files in this item

Total number of downloads: Loading...

Files Size Format View
water_11_02213.pdf 4.277Mb PDF View/Open

This item appears in the following Collection(s)

Show full item record