Rivers and Streams

Hydrologic models are used throughout the world to forecast and simulate streamflow, inform water management, municipal planning, and ecosystem conservation, and investigate potential effects of climate and land-use change on hydrology. The USGS Modeling of Watershed Systems (MoWS) group is currently developing the infrastructure for a National Hydrologic Model (NHM) to support...

Human impacts occurring throughout the DOI Northeast Climate Science Center, including urbanization, agriculture, and dams, have multiple effects on streams in the region which support economically valuable stream fishes. Changes in climate are expected to lead to additional impacts in stream habitats and fish assemblages in multiple ways, including changing stream water temperatures. To...

The eulachon is a small fish that is both highly nutritious and culturally significant to the Chilkat and Chilkoot peoples of the Tlingit Nation in Southeast Alaska, for whom it is a traditional food. Tribal members are increasingly concerned about how climate change might stress the health and abundance of eulachon populations, which are already perceived as being low. In order to...

The Red River Basin is a vital source of water in the South Central U.S., supporting ecosystems, drinking water, agriculture, tourism and recreation, and cultural ceremonies. Stretching from the High Plains of New Mexico eastward to the Mississippi River, the Red River Basin encompasses parts of five states – New Mexico, Texas, Oklahoma, Arkansas, and Louisiana. Further, 74% of the...

The Colorado River is the dominant water source for the southwestern United States, crossing through seven states before reaching Mexico. The river supplies water to approximately 36 million people, irrigates nearly six million acres of farmland within and beyond the basin, and contributes an estimated 26 billion dollars each year to the region’s recreational economy. Yet the Colorado...

There is growing evidence that headwater stream ecosystems are especially vulnerable to changing climate and land use, but managers are challenged by the need to address these threats at a landscape scale, often through coordination with multiple management agencies and landowners. This project sought to provide an example of cooperative landscape decision-making by addressing the...

Drought poses a major threat to New Mexico’s state fish, the Rio Grande cutthroat trout. This southernmost subspecies of cutthroat trout, found only in New Mexico and Colorado, has already been restricted to an estimated 12% of its former range. Now climate change, in the form of lower winter snowpack and reduced precipitation, challenges its long-term persistence. This trout tends to...

In California, increased wildfire activity has been linked to decreasing snowpack and earlier snowmelt. Not only has this translated into a longer fire season, but reduced snowpack has cascading effects that impact streamflow, water supplies, agricultural productivity, and ecosystems. California receives 80% of its precipitation during the winter, so mountain snowpack plays a critical...

Natural climate variability can obscure or enhance long-term trends in experienced weather due to climate change. This can happen temporarily on timescales of a season to several years to a decade or two. Natural variability is poorly described and attributed to specific causes, contributing to uncertainty and misunderstandings about the nature of climate change that stakeholders and...

This project links climate, hydrological, and ecological changes over the next 30 years in a Great Basin watershed. In recent years, climate variability on annual and decadal time scales has been recognized as greater than commonly perceived with increasing impacts on ecosystems and available water resources. Changes in vegetation distribution, composition and productivity resulting from...

Currently, maintaining appropriate flows to support biological integrity is difficult for larger riverine ecosystems. Climate change, through increased temperature, reduced rainfall, and increased rainfall intensity, is expected to reduce water availability and exacerbate the maintenance of ecological flows in the Arkansas-Red River basin. Understanding the nexus among climate change...

To date, hydrological and ecological models have been developed independently from each other, making their application particularly challenging for interdisciplinary studies. The objective of this project was to synthesize and evaluate prevailing hydrological and ecological models in the South-Central U.S., particularly the southern Great Plains region. This analysis aimed to identify...