Buffered, lagged, or cooled? Disentangling hyporheic influences on temperature cycles in stream channels

Abstract

[1] We monitored summertime base flow water temperatures of hyporheic discharge to surface water in main, side, and spring channels located within the bank-full scour zone of the gravel-and cobble-bedded Umatilla River, Oregon, USA. Diel temperature cycles in hyporheic discharge were common, but spatially variable. Relative to the main channel's diel cycle, hyporheic discharge locations typically had similar daily mean temperatures, but smaller diel ranges (compressed by 2 to 6°C) and desynchronized phases (offset by 0 to 6 h). In spring channels (which received only hyporheic discharge), surface water diel cycles were also compressed (by 2 to 6°C) and desynchronized (by À4 to 6 h) relative to the main channel, creating diverse daytime and nighttime mosaics of surface water temperatures across main, side, and spring channels, despite only minor differences (<1°C) in daily mean temperatures among the channels. The river's hyporheic zone received and stored heat from the channel, yet hyporheic return flows carried heat back to the channel minutes to months after removal. Associated surface water temperature dynamics were therefore complex. Hyporheic discharge was not simply ''cooler'' or ''warmer'' than main channel water. Instead, instantaneous temperature differences between channel water and hyporheic discharge typically arose from diel temperature cycles in hyporheic discharge that were buffered and lagged relative to diel cycles in the main channel.

Variation in reach-scale hydraulic conductivity of streambeds

“…The HZ is a unique ecotone that supports a variety of hydrological, ecological and biogeochemical processes essential to river ecosystem function (Gibert et al, 1990;Boulton et al, 2010). By regulating the transfer of heat and mass across the sediment-water interface, the HZs play a critical role in temperature buffering (Arrigoni et al, 2008) and biogeochemical cycling (Mulholland and Webster, 2010). They are also permanent habitats for many microbes and invertebrates (Brunke and Gonser, 1999), provide refugia for surface invertebrates or fish (Dole-Olivier, 2011; Kawanishi et al, 2013), and are used by some fish for spawning (Geist et al, 2002).…”

Effects of stream morphodynamics on hyporheic zone thermal regime

“…The daily mean hyporheic water temperature is equal to the mean in-stream water temperature in all cases as observed in the field studies of Arrigoni et al [2008]. The signal of the upwelling water temperature is characterized by a time lag, the lagged effect in Arrigoni et al [2008], and an attenuation defined as the buffered effect in Arrigoni et al [2008]. These effects relate directly with the dimension of the stream and consequently with the hyporheic residence time.…”

“…Figure 9 shows the in-stream temperature and the hyporheic temperature averaged over the upwelling areas for both small steep-gradient, medium moderate-gradient, and large low-gradient streams (Test 1, Test 10, and Test 18 of Table 2, respectively). The daily mean hyporheic water temperature is equal to the mean in-stream water temperature in all cases as observed in the field studies of Arrigoni et al [2008]. The signal of the upwelling water temperature is characterized by a time lag, the lagged effect in Arrigoni et al [2008], and an attenuation defined as the buffered effect in Arrigoni et al [2008].…”

“…Consequently, we hypothesize a complex three-dimensional hyporheic temperature distribution in gravel bed rivers with pool-riffle morphology, which reflects the flow pattern. To test this hypothesis, we develop a novel threedimensional semianalytical process-based model, which accounts for advection, diffusion, and conduction, for predicting the thermal regime within the hyporheic zone [Anderson, 2005;Hohen and Cirpka, 2006;Cardenas and Wilson, 2007;Arrigoni et al, 2008]. We focus our investigation on pool-riffle bed form because of its ubiquity and ecological importance Buffington and Tonina, 2009).…”

Disruptions of stream sediment size and stability by lakes in mountain watersheds: potential effects on periphyton biomass

“…These patterns of connectivity control water mixing from various sources, each of which has its own distinct characteristics, including turbidity (Mertes 1997), temperature (Arrigoni et al 2008), and composition of dissolved constituents (Dent et al 2001). Any of such characteristics can influence the ecological processes occurring within a parcel of water on a floodplain.…”