Transverse spatiotemporal variability of lowland river properties and effects on metabolic rate estimates

Abstract

[1] Variability of river properties such as temperature, velocity, dissolved oxygen (DO), and light at small scales (centimeters to meters) can play an important role in the local exchanges of energy and mass. We hypothesize that significant transverse cross-sectional DO variation is observable within a river. Such variation may influence conventional singlestation metabolic rate (primary production and respiration) estimates with respect to DO probe location, and reveal important connections between physical and biogeochemical processes and their drivers in rivers. Using a mobile sensor system, we measured river properties across a bend in the lower Merced River in Central California under stationary flow conditions in April and September. Cross-sectional temperature, DO, and chlorophylla concentrations exhibited modest but significant gradients, which varied in magnitude and direction on a diel basis. The spatiotemporal variation was consistent with reach geomorphology and incident light patterns. Gross primary production (GPP), community respiration (CR 24 ), and net ecosystem production (NEP) rates estimates derived from local DO and temperature time series varied by 3-10% over the river cross section, with greater variation in late summer. The presence of transverse metabolic rate gradients in this relatively simple reach implies the existence of substantial gradients in more complex river regimes, such as those spanning distinctively different microhabitats, transient storage zones, and related distributed biogeochemical zones.Citation: Villamizar, S. R., H. Pai, C. A. Butler, and T. C. Harmon (2014), Transverse spatiotemporal variability of lowland river properties and effects on metabolic rate estimates, Water Resour. Res., 50,[482][483][484][485][486][487][488][489][490][491][492][493]

Monitoring turbidity from above: Deploying small unoccupied aerial vehicles to image in‐stream turbidity

“…Our approach may also prove useful for assessing fine‐scale differences and mixing if paired with high‐resolution, mobile, in situ sensor sampling. Studies demonstrating high‐resolution lateral and longitudinal approaches to water quality sampling (e.g., Hensley, Cohen, & Korhnak, ; Pai et al, ; Villamizar, Pai, Butler, & Harmon, ) have elucidated meaningful interactions between water quality and hydrologic processes and captured patterns that would be missed by a single sensor deployed at one point observing water quality through time. Given the relative information that can be extracted from the induced turbidity experiments (Figure ), we believe that this type of approach would be particularly useful for small rivers and lakes, especially those used as water sources (e.g., Effler, Prestigiacomo, Peng, Bulygina, & Smith, ) and adapted to situations where rapid turbidity monitoring is crucial to operations.…”

Estudo Integrado de um Ambiente Lacustre: Laguna La Salada (Província de Buenos Aires, Argentina)

“…Dada su importancia, los ambientes de lagos y lagunas han sido ampliamente estudiados desde diversas perspectivas. Las investigaciones se orientan a la paleolimnología (Velez et al, 2014(Velez et al, , 2018Serna et al, 2016), limnología (Meerhoff et al, 2013;O'Reilly et al, 2015;Rodríguez et al, 2015;Tsai et al, 2016;Woolway et al, 2016;Leach et al, 2017), hidrobiología (Diovisalvi et al, 2015), hidrología (Villamizar et al, 2014;Jepsen et al, 2016), paleoclimatología (Correa-Metrio et al, 2016), variabilidad climática (de Löe & Kreutzwiser, 2000;Stefanidis et al, 2016), riesgo y vulnerabilidad (Lozoya et al, 2015;Hoyos et al, 2017), cambio de usos del suelo (Rodriguez-Gallego et al, 2017), entre otras temáticas.…”