Ephemeral Hydrology

How low can you go? Widespread challenges in measuring low stream discharge and a path forward

Low flows pose unique challenges for accurately quantifying streamflow. Current field methods are not optimized to measure these conditions, which in turn, limits research and management. In this essay, we argue that the lack of methods for measuring …

Non-perennial stream networks as directed acyclic graphs: The R-package streamDAG

Many conventional stream network metrics are poorly suited to non-perennial streams, which can vary substantially in space and time. To address this issue, we considered non-perennial stream networks as directed acyclic graphs (DAGs). DAG metrics …

Causes, Responses, and Implications of Anthropogenic versus Natural Flow Intermittence in River Networks

Rivers that do not flow year-round are the predominant type of running waters on Earth. Despite a burgeoning literature on natural flow intermittence (NFI), knowledge about the hydrological causes and ecological effects of human-induced, …

Alternative stable states and hydrological regime shifts in a large intermittent river

Non-perennial rivers and streams make up over half the global river network and are becoming more widespread. Transitions from perennial to non-perennial flow are a threshold-type change that can lead to alternative stable states in aquatic …

Assessing placement bias of the global river gauge network

Knowing where and when rivers flow is paramount to managing freshwater ecosystems. Yet stream gauging stations are distributed sparsely across rivers globally and may not capture the diversity of fluvial network properties and anthropogenic …

Identifying Regime Shifts in the Arkansas River Near Larned, Kansas

Characterizing the drivers of flow in non-perennial streams is increasingly important for understanding the effects of variable flow regimes on local communities and ecosystems. Regime shift theory has been used to explain changes in other hydrologic …

Reconceptualizing the hyporheic zone for non-perennial rivers and streams

Nonperennial streams dominate global river networks and are increasing in occurrence across space and time. When surface flow ceases or the surface water dries, flow or moisture can be retained in the subsurface sediments of the hyporheic zone, …

Pervasive changes in stream intermittency across the United States

Non-perennial streams are widespread, critical to ecosystems and society, and the subject of ongoing policy debate. Prior large-scale research on stream intermittency has been based on long-term averages, generally using annually aggregated data to …

The Drying Regimes of Non-Perennial Rivers and Streams

The flow regime paradigm is central to the aquatic sciences, where flow drives critical functions in lotic systems. Non-perennial streams comprise the majority of global river length, thus we extended this paradigm to stream drying. Using 894 USGS …

Characterizing Streamflow Intermittency and Subsurface Heterogeneity in the Middle Arkansas River Basin

Non-perennial streams are widespread but understudied relative to their perennial counterparts. In this study, we investigated the flow and intermittency regimes for the Arkansas River near Larned using historical streamflow, groundwater level, and …