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Time variant cross correlation to assess residence time of water and implication for hydraulics of a sink‐rise karst system
Author(s) -
BaillyComte V.,
Martin Jonathan B.,
Screaton E. J.
Publication year - 2011
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/2010wr009613
Subject(s) - karst , sinkhole , hydrograph , hydrology (agriculture) , sink (geography) , hydraulics , groundwater , environmental science , geology , hydraulic conductivity , electrical conduit , residence time (fluid dynamics) , soil science , drainage basin , geotechnical engineering , soil water , mechanical engineering , paleontology , cartography , aerospace engineering , geography , engineering
Transport rates and residence time in the subsurface are critical parameters for understanding water‐rock interactions for efficient contaminant remediation. This paper presents a methodology for assessing flow and transit time of water through hydrological systems, with specific applications to karst systems and implication for hydraulics of a conduit system surrounded by a porous and permeable intergranular matrix. A time variant cross‐correlation function analysis is applied to bivariate time series that characterize mass transfer, assuming a stationary system using sliding windows of various sizes. We apply the method to 1 year long temperature records in the Santa Fe River (north central Florida) measured at (1) the River Sink, where all the incoming surface water drains into a sinkhole, (2) Sweetwater Lake, where the river resurges into a 500 m long karst window, and (3) the River Rise, where the water discharges from a first‐magnitude karst spring. Results are compared with those obtained using specific conductivity. Estimated residence time ranges from less than 1 day during floods to more than 15 days during base flow within the 8000 m flow path between the River Sink and the River Rise. Results are used to characterize geometric, hydraulic, and hydrodynamic properties of this sink‐rise system with strong matrix‐conduit interactions. These properties are critical to the chemical and physical behavior of surface water–groundwater mixing. Our results also have direct implications for sampling strategies and hydrograph separation of many karst systems with different degrees and types of matrix porosity and permeability.