Worth of hydraulic and water chemistry observation data in terms of the reliability of surface water-groundwater exchange flux predictions under varied flow conditions

JOURNAL OF HYDROLOGY

卷:590

Article

Partington, Daniel^1,2  Knowling, Matthew J.^3,7  Simmons, Craig T.^1,2  Cook, Peter G.^1,2  Xie, Yueqing^1,2,4  Iwanaga, Takuya⁵  Bouchez, Camille⁶ 

[1] Flinders Univ S Australia, Natl Ctr Groundwater Res & Training, Adelaide, SA, Australia

[2] Flinders Univ S Australia, Coll Sci & Engn, Adelaide, SA, Australia

[3] GNS Sci, Lower Hutt, New Zealand

[4] Nanjing Univ, Sch Earth Sci & Engn, Nanjing, Peoples R China

[5] Australian Natl Univ, Integrated Catchment Assessment & Management iCAM, Fenner Sch Environm & Soc, Canberra, ACT, Australia

[6] Univ Rennes, Geosci Rennes, CNRS, UMR 6118, F-35000 Rennes, France

[7] Univ Adelaide, Sch Civil Environm & Min Engn, Adelaide, SA 5005, Australia

关键词: Data worth;    surface water-groundwater interaction;    surface-subsurface modelling;   

DOI  :  10.1016/j.jhydrol.2020.125441

来源: Elsevier

【 摘 要 】

This study assesses the worth of routinely collected hydraulic data (groundwater head, stream stage and streamflow) and lesser collected water chemistry data (Radon-222, Carbon-14, electrical conductivity (EC)) in the context of making regional-scale surface water-groundwater (SW-GW) exchange flux predictions. Using integrated SW-GW flow and transport numerical models, first-order, second-moment (FOSM) analyses were employed to assess the extent of the uncertainty reduction or lack thereof in SW-GW exchange flux predictions following acquisition of hydraulic and water chemistry observation data. With a case study of the Campaspe River in the Murray-Darling Basin (Australia), we explored the apparent information content of these data during low, regular and high streamflow conditions. Also, a range of spatial and temporal prediction scales were considered: catchment-wide and reach-based spatial scales and annual and monthly temporal scales. Generally, the data worth evaluations showed significant variability across predictions that were dependent on the spatio-temporal scale of the SW-GW exchange, the magnitude and direction of the SW-GW exchange flux and the prevailing streamflow conditions. These dependencies serve to emphasise the importance of prediction specificity with respect to SW-GW exchange. Among existing data, the most worth was found in Radon-222, groundwater hydraulic head, EC, and streamflow data showing average reductions in uncertainty of 41%, 38%, 32%, and 23% respectively. Assessment of type and spatiotemporal locations of potential data showed Radon-222 to be the next most important observation type across many predictions in locations with data paucity of all data types. Hydraulic observation data types were found to inform SW-GW exchange flux best under high- and regular- streamflow conditions when the magnitude of exchange fluxes were largest, whereas the water chemistry data was of highest value for low- and regular-streamflow conditions where groundwater is discharging to the stream.

【 授权许可】

Free