Dynamic Hillslope Soil Moisture in a Mediterranean Montane Watershed

Water Resources Research, Journal Year: 2021, Volume and Issue: 57(11)

Published: Nov. 1, 2021

Abstract Variations in hillslope soil moisture control forest hydrologic fluxes and storage pools, yet sparse observations combined with the complexity heterogeneity of water movement vadose zone can make temporal spatial patterns processes difficult to predict. We used two years field volumetric at three depths (15, 30, 100 cm) across five topographic positions (riparian, toeslope, sideslope, shoulder, ridge) along transects better understand how changes position through time. As expected, we found higher values all riparian toeslope positions. Unexpectedly, that ridges were particularly wet during winter months dried quickly summer months, indicating topography alone cannot account for mean season our Mediterranean climate site. The variability was greatest when soils dry decreased under conditions; this remained high deeper horizons, regardless season. Lastly, event analysis suggests response early rainfall highly variable hillslopes likely dominated by localized controls such as microtopography vegetation well texture, antecedent conditions, characteristics. Our results suggest drivers dynamics vary a do not always follow controls.

Language: Английский

---

Drivers of drought-induced shifts in the water balance through a Budyko approach

Hydrology and earth system sciences, Journal Year: 2022, Volume and Issue: 26(3), P. 589 - 607

Published: Feb. 7, 2022

Abstract. An inconsistent relationship between precipitation and runoff has been observed drought non-drought periods, with less usually during droughts than would be expected based solely on deficit. Predictability of these shifts in the precipitation–runoff is still challenging, largely because underlying hydrologic mechanisms are poorly constrained. Using 30 years data for 14 basins California, we show how Budyko framework can leveraged to decompose versus into “regime” shifts, which result from changes aridity index along same curve, “partitioning shifts”, imply a change parameter ω thus among water balance components that governs partitioning available water. Regime primarily due measurable interannual or temperature, making them predictable conditions. Partitioning involve further nonlinear indirect catchment feedbacks conditions harder predict priori. We regime dominate absolute but gains losses significant. Low aridity, high baseflow, shift snow rain, resilience high-elevation correlate higher annual predicted by ratio years. Differentiating using approach will help resource managers, particularly arid, drought-prone regions, better project magnitudes climate and, furthermore, understand under what circumstances extent their forecasts may reliable basin–climate feedbacks.

Language: Английский

---

The salmonid and the subsurface: Hillslope storage capacity determines the quality and distribution of fish habitat

Ecosphere, Journal Year: 2023, Volume and Issue: 14(2)

Published: Feb. 1, 2023

Abstract Water in rivers is delivered via the critical zone (CZ)—the living skin of Earth, extending from top vegetation canopy through soil and down to fresh bedrock bottom significantly active groundwater. Consequently, success stream‐rearing salmonids depends on structure resulting water storage release processes this zone. Physical below land surface (the subsurface component CZ) ultimately determine how landscapes “filter” climate manifest ecologically significant streamflow temperature regimes. Subsurface capacity CZ has emerged as a key hydrologic variable that integrates many these processes, helping explain flow regimes terrestrial plant community composition. Here, we investigate controls flow, temperature, energetic matter for salmonids. We illustrate explanatory power broadly applicable, storage‐based frameworks across lithological gradient spans Eel River watershed California. Study sites are climatically similar but differ their geologies consequent dictates dynamics, leading dramatically different hydrographs, riparian regimes—with consequences every aspect salmonid life history. Lithological development properties like suggest heretofore unexplored link between geology, adding rich literature highlights various fluvial geomorphic influences diversity distribution. Rapidly advancing methods estimating observing dynamics at large scales present new opportunities more clearly identifying landscape features constrain distributions abundances organisms, including salmonids, scales.

Language: Английский

---

Chytrid infections exhibit historical spread and contemporary seasonality in a declining stream-breeding frog

Royal Society Open Science, Journal Year: 2024, Volume and Issue: 11(1)

Published: Jan. 1, 2024

Species with extensive geographical ranges pose special challenges to assessing drivers of wildlife disease, necessitating collaborative and large-scale analyses. The imperilled foothill yellow-legged frog ( Rana boylii ) inhabits a wide range variable conditions in rivers California Oregon (USA), is considered threatened by the pathogen Batrachochytrium dendrobatidis (Bd). To assess Bd infections over time space, we compiled 2000 datapoints from R. museum specimens (collected 1897–2005) field samples (2005–2021) spanning 9° latitude. We observed south-to-north spread detections beginning 1940s increase prevalence 1970s, coinciding extirpation southern latitudes. detected eight high-prevalence clusters through that span species' range. Field-sampled male exhibited highest prevalence, juveniles sampled autumn loads. infection risk was lower elevation rain-dominated watersheds, cool temperatures low stream-flow at end dry season. Through holistic assessment relationships between risk, context time, identify locations periods where mitigation monitoring will be critical for conservation this species.

Language: Английский

---

Quantifying Dynamic Water Storage in Unsaturated Bedrock with Borehole Nuclear Magnetic Resonance

Geophysical Research Letters, Journal Year: 2020, Volume and Issue: 47(22)

Published: Nov. 3, 2020

Abstract Quantifying the volume of water that is stored in subsurface critical to studies availability ecosystems, slope stability, and water‐rock interactions. In a variety settings, fractured weathered bedrock as rock moisture. However, few techniques are available measure moisture unsaturated rock, making direct estimates storage dynamics difficult obtain. Here, we use borehole nuclear magnetic resonance (NMR) at two sites seasonally dry California quantify dynamic storage. We show strong agreement between NMR derived from neutron logging mass balance techniques. The depths up 9 m likely reflect depth extent root uptake. To our knowledge, these data first vadose zone via NMR.

Language: Английский

---