Reports

The U.S. Geological Survey has developed a high-resolution inset groundwater-flow model in the Mississippi Delta as part of an interdisciplinary collaboration coordinated by the Mississippi Alluvial Plain project to provide a tool that stakeholders can use to support water-resource management decisions. Groundwater withdrawals from the Mississippi River Valley alluvial (MRVA) aquifer...

Introduction Western California is home to a variety of volcanic rocks. The locations, ages, and chemical compositions of these volcanic rocks help tell part of the fascinating story of California’s plate tectonic evolution over the past 40 million years. These volcanic rocks are a product of multiple tectonic processes, including subduction of divergent and transform plate boundaries...

The Los Planes watershed of Baja California Sur, Mexico, and its underlying aquifer are experiencing groundwater decline owing to low average annual rainfall (28.1 centimeters per year) and rising water demand from population growth and agricultural activities. This decline in water availability can lead to desertification—a process that changes arable land to desert by degrading soil...

This report describes a modeling investigation by the U.S. Geological Survey (USGS) of hazards in the Toutle and Cowlitz River valleys posed by hypothetical outburst floods from Spirit Lake, Washington. A massive debris avalanche resulting from the collapse of Mount St. Helens’ north flank during the May 18, 1980, eruption blocked Spirit Lake’s natural outlet into the North Fork Toutle...

Seven potential sources of water, consisting of free-flowing discharge from abandoned coal mines at six locations and one abandoned flooded underground coal mine air shaft, were sampled for chemical analysis to assess the quality of the groundwater emanating from the seven mine sources. The six free-flowing mine discharge sources were also assessed for discharge by current-meter...

The lands and waters of the Chesapeake Bay watershed provide more than $100 billion in economic benefits- an amount that is expected to increase by achieving the region’s clean-water goals. Achieving those goals requires accurate and timely information about the health of the watershed’s rivers and streams. The Chesapeake Bay nontidal monitoring network (NTN), a partnership of local...

Introduction Massachusetts extends from the mountains of the Appalachian system in the west of the State to the sandy beaches and rocky shorelines of the Atlantic coast in the east. Inland topographic data support a wide range of important activities, including geologic mapping, transportation planning, forest and wildlife management, quantifying ecological services, water supply...

The five islands comprising Channel Islands National Park (CHIS) experience natural gradients in temperature and moisture driven by ocean currents. Additionally, the islands were used as ranchlands and military land before becoming a national park, resulting in widespread erosion and vegetation change. As a result, CHIS spans gradients in climate as well as ranching duration and time...

As the population of New Jersey increases, supplying adequate drinking water to meet demand remains a high priority. To better understand potential streamflow trends over time, the U.S. Geological Survey completed a study comparing low flows at continuous- and partial-record streamgages in New Jersey between a historical period (1950–79) and a current period (1990–2019). Fourteen...

We provide an update to the recently published population viability analysis for North Atlantic right whales (Eubalaena glacialis). The update includes improvements to the reproduction modeling and also shares additional context given evidence of reduced mortality indicated by recent population monitoring. Projections from the analysis are used to quantify simulated population sizes...

No abstract available.

Ambient stream water temperatures affect salmonid movement and survival with fish actively seeking thermal refugia from warming waters. This study sought to investigate the potential role of water temperature in the perceived decline in native Brook Trout Salvelinus fontinalis and non-native Brown Trout Salmo trutta populations in the North Branch Au Sable River by fishers and reported...