The relationship between catchment structure and runoff characteristics is poorly understood. In steep headwater catchments with shallow soils the accumulation of hillslope area (upslope accumulated (UAA)) a hypothesized first‐order control on distribution soil water groundwater. Hillslope‐riparian table connectivity represents linkage dominant landscape elements (hillslopes riparian zones) channel network. Hydrologic hillslope‐riparian‐stream (HRS) heterogeneous in space often temporally...

Previously regarded as the passive drains of watersheds, over past 50 years, rivers have progressively been recognized being actively connected with off-channel environments. These connections prolong physical storage and enhance reactive processing to alter water chemistry downstream transport materials energy. Here we propose river corridor science a concept that integrates lateral vertical exchange across interfaces. Thus, corridor, rather than wetted channel itself, is an increasingly...

Stream restoration needs to consider the hyporheic zone just as much surface and benthic regions.

ABSTRACT Microbial communities in extreme environments often have low diversity and specialized physiologies suggesting a limited resistance to change. The McMurdo Dry Valleys (MDV) are microbially dominated, ecosystem currently undergoing climate change-induced disturbances, including the melting of massive buried ice, cutting through permafrost by streams, warming events. These processes increasing moisture across landscape, altering conditions for soil mobilizing nutrients salts...

The hydrologic and biogeochemical responses of forested watersheds to inputs rainfall snowmelt can be an indicator internal watershed function. In this study, we assess how the quantity quality, both chemical spectroscopic, stream water DOC changes in response a 6‐day storm event during wet season 2003 three small (<1 km 2 ) basins H. J. Andrews Experimental Forest, Oregon. included one old‐growth (WS02) two previously logged (WS01 WS10). Prestorm concentrations ranged from 1.5 2.2 mg C L...

Permafrost is a defining characteristic of the Arctic environment. However, climate warming thawing permafrost in many areas leading to failures soil structure called thermokarst. An extensive survey 600 km 2 area and around Toolik Lake Natural Research Area (TLNRA) revealed at least 34 thermokarst features, two thirds which were new since ∼1980 when high resolution aerial was done. Most these features associated with headwater streams or lakes. We have measured significantly increased...

Hydrologic connectivity between catchment upland and near stream areas is essential for the transmission of water, solutes, nutrients to streams. However, our current understanding role riparian zones in mediating landscape hydrologic scale export water solutes limited. We tested relationship duration hillslope‐riparian‐stream (HRS) rate degree shallow groundwater turnover along four HRS well transects within a set nested mountain catchments (Tenderfoot Creek Experimental Forest, MT)....

Channel water balances of contiguous reaches along streams represent a poorly understood scale stream‐subsurface interaction. We measured reach headwater stream in Montana, United States, during summer base flow recessions. Reach were estimated from series tracer tests 13 consecutive delineated evenly 2.6 km valley segment. For each reach, we net change discharge, gross hydrologic loss, and gain dilution mass recovery. Four performed relatively high, intermediate, low conditions. The...

Abstract Stream temperature, an important measure of ecosystem health, is expected to be altered by future changes in climate and land use, potentially leading shifts habitat distribution for aquatic organisms dependent on particular temperature regimes. To assess the sensitivity stream change a region where such shift has potential occur, we examine variability controls direct relationship between air water across state Pennsylvania. We characterized via linear nonlinear regression 57 sites...

Studies of hyporheic exchange flows have identified physical features channels that control flow at the channel unit scale, namely slope breaks in longitudinal profile streams generate subsurface head distributions. We recently completed a field study suggested spacing stream profiles can be used to predict between zones upwelling (flux water into stream) and downwelling zone) beds mountain streams. Here, we use two-dimensional groundwater particle tracking models simulate vertical along...

Hyporheic hydrodynamics are a control on stream ecosystems, yet we lack thorough understanding of catchment controls these flow paths, including valley constraint and hydraulic gradients in the bottom. We performed four whole‐stream solute tracer injections under steady state conditions at H. J. Andrews Experimental Forest (Oregon, United States) collected electrical resistivity (ER) imaging to directly quantify 2‐D spatial extent hyporheic exchange through seasonal base recession. ER images...

Application of transient storage models has become popular for characterizing hydrologic and biogeochemical processes in streams. The typical model represents exchange between the main channel a single zone, essentially lumping together different processes. Here we present method to inform that accounts two zones (2‐SZ) discriminate surface (STS) with hyporheic (HTS). This requires that, addition tracer breakthrough curves from channel, cross‐sectional stream velocity distributions...

Although surface water and groundwater are increasingly referred to as one resource, there remain environmental ecosystem needs study the 10 m 1 km reach scale hydrologic system. Streams gain lose over a range of spatial temporal scales. Large scales (kilometers) have traditionally been recognized studied river‐aquifer connections. Over last 25 years hyporheic exchange flows (1–10 m) extensively. Often transient storage model has used quantify physical solute transport setting in which...

Abstract There is a growing recognition of the importance connections between streams and adjacent alluvial aquifers. The exchange water, mass, energy these locations influences stream ecosystem structure function by facilitating nutrient cycling, respiration, temperature buffering, survival macroinvertebrates. Near‐surface aquifers that interact with surface water have been termed ‘hyporheic zones’, yet there are several accepted definitions this term (biological, geochemical, hydrological...

Research Article| November 01, 2011 Water tracks and permafrost in Taylor Valley, Antarctica: Extensive shallow groundwater connectivity a cold desert ecosystem Joseph S. Levy; Levy † 1Department of Geology, Portland State University, Portland, Oregon 97210, USA †E-mail: jlevy@pdx.edu Search for other works by this author on: GSW Google Scholar Andrew G. Fountain; Fountain Michael N. Gooseff; Gooseff 2Department Civil Environmental Engineering, Pennsylvania University Park, 16802, Kathy A....

Abstract Instream and floodplain wood can provide many benefits to river ecosystems, but also create hazards for inhabitants, infrastructure, property, recreational users in the corridor. We propose a decision process managing large wood, particularly assessing relative associated with individual pieces accumulations of wood. This be applied at varying levels effort, from relatively cursory visual assessment more detailed numerical modeling. Decisions retain, remove, or modify channel on are...

Understanding controls over the distribution of soil bacteria is a fundamental step toward describing ecosystems, understanding their functional capabilities, and predicting responses to environmental change. This study investigated on biomass, species richness, community structure composition bacterial communities in McMurdo Dry Valleys, Antarctica, at local regional scales. The goals were describe relationships between abiotic characteristics this unique, microbially dominated environment,...

Groundwater–surface-water (GW-SW) interactions in streams are difficult to quantify because of heterogeneity hydraulic and reactive processes across a range spatial temporal scales. The challenge quantifying these has led the development several techniques, from centimeter-scale probes whole-system tracers, including chemical, thermal, electrical methods. We co-applied conservative smart solute-tracer tests, measurement heads, distributed temperature sensing, vertical profiles solute tracer...

In the McMurdo Dry Valleys, Antarctica, dilute glacial meltwater flows down well‐established streambeds to closed basin lakes during austral summer. During 6–12 week flow season, a hyporheic zone develops in saturated sediment adjacent streams. Longer Valley streams have higher concentrations of major ions than shorter The longitudinal increases Si and K suggest that primary weathering contributes downstream solute increase. hypothesis reactions control stream chemistry was tested by...

Transient storage processes are important to biogeochemical cycling in many streams and depend greatly upon stream fluvial structure. Fluvial geomorphic structure establishes patterns of surface water subsurface head distributions, often driving hyporheic exchange through steps, riffles, meanders, controls the potential for in‐channel dead zone side pools, eddies, etc. We performed tracer experiments geomorphological assessments (topographic thalweg surveys, channel dimension measurement,...