Effects of evaporative enrichment on the stable isotope hydrology of a central Florida (USA) river

Abstract

The d 07 O characteristics of water masses contributing to ~ow in the Econlockhatchee River basin\ a subtropical low!gradient watershed in central Florida\ were monitored to assess the potential for applying hydrograph separation models in the watershed[ Daily sampling for a 1!month period in autumn 0881 revealed ranges in precipitation of −5=53 to −9=06-\ in sur_cial groundwater of −2=18 to −1=89-\ and in river water of −1=57 to −0=30-[ Results indicated that river d 07 O was consistently more enriched than either groundwater or precipitation by about 0-\ prompting the hypothesis that evaporative enrichment signi_cantly altered the d 07 O of river water[ Additional monitoring and mass!balance modelling of the entire basin "519 km 1 # and a subcatchment "69 km 1 # showed that evaporative e}ects could account for the observed enrichment[ Although some enrichment occurred in headwater swamps and wetlands\ the _eld data and modelling results supported the hypothesis that evaporation from the river channel signi_cantly altered the d 07 O of river water[ Enrichment elsewhere in the hydrological cycle\ such as during throughfall or temporary storage in wetlands or stormwater management ponds\ may have contributed to the observed signal of evaporation\ but could not be distinguished from headwater or river evaporation[ It appears that a su.cient isotopic signal exists in central Florida precipitation to apply hydrograph separation models\ but that evaporative isotopic enrichment should be included as a modelling element[ Copyright Þ 1999 John Wiley + Sons\ Ltd[ KEY WORDS oxygen stable isotopes^hydrograph separation^evaporative enrichment^recession analysis

Diet and mobility in Middle Archaic Florida: stable isotopic and faunal evidence from the Harris Creek archaeological site (8Vo24), Tick Island

“…Since imbibed water was likely collected from rivers, we utilized river water d 18 O values ( Fig. 3; after Dutton et al, 2005;Gremillion and Wanielista, 2000). Rivers in regions north of Florida (not shown in Fig.…”

The Global Network of Isotopes in Rivers (GNIR): integration of water isotopes in watershed observation and riverine research

“…McDonnell et al, 1990;Kendall and McDonnell, 1998;Lambs, 2000;Gibson et al, 2005;Liu et al, 2008;Jasechko et al, 2013). Hydrological processes occurring between rainfall input and river discharge modify the stable isotopic composition of rivers and include the isotopic averaging during soil infiltration, runoff, damming (Ogrinc et al, 2008;Koeniger et al, 2009) and seasonally differential fractional inputs of water from surface and groundwater sources (Sklash, 1990;Buttle, 1994;Lambs, 2004); and heavy isotope ( 2 H, 18 O) enrichment due to the effects of watershed evapotranspiration or instream evaporation (Simpson and Herczeg, 1991;Gremillion and Wanielista, 2000;Telmer and Veizer, 2000) and isotopic fractionation of snowmelt (Taylor et al, 2002). All of these processes may result in markedly different average isotopic values in river discharge compared to precipitation, both in space and time (Dutton et al, 2005;Rock and Mayer, 2007).…”

“…The cumulative effect of catchment-scale evapotranspiration and instream evaporative processes may additionally increase δ 18 O and δ 2 H values in the downstream direction. Rivers that are hundreds of kilometres long may therefore have distinctive upstream versus downstream isotopic patterns as they accumulate discharge and integrate various hydrological processes from contributing subcatchments (Simpson and Herczeg, 1991;Gremillion and Wanielista, 2000;Ferguson et al, 2007;Bowen et al, 2011). Alpine or high-latitude rivers may be ephemeral, dominated mostly by isotopically depleted snowmelt events (e.g.…”

Estimating marine resource use by the American crocodile Crocodylus acutus in southern Florida, USA

“…A possible explanation is that some inland alligators may ingest water that is O of precipitation is −2.7 to −2.5 ‰ (Meyers et al 1993, Gremillion & Wanielista 2000. Mean δ…”