WMOD00384

• Title: Weather Scenarios for Western River Basins Under Changed Climate Conditions
• Date: 1/13/1991
• Weather Modification - Doc Type: Report

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This paper is on pages 59 to 62 inclusive of the Preprint Volume for the American
Meteorological Society's Second Symposium on Global Change Studies, New Orleans, January
13-18, 1991.

WEATHER SCENARIOS FOR WESTERN RIVER BASINS
UNDER CHANGED CLIMATE CONDITIONS

A. S. Dennis

U. S. Bureau of Reclamation
Denver, Colorado

1. INTRODUCTION

The primary mission of the Bureau of Reclamation (Reclamation) is management of water
resources in the semiarid western United States. Reclamation needs to identify the potential
impacts of global climate change on western river basins and develop strategies to deal with
those impacts. To fulftl that need, Reclamation has established the Global Climate Change
Response Program (GCCRP).

The OCCRP consists of projects in three broad categories: research, operations, and joint
studies. According to a recent Reclamation bulletin, "Research projects determine the river
basins and water supplies most likely to be at risk, and develop scenarios identifying the
nature and extent of global climate change impacts on water demands and water resources.
Operations projects determine the impacts of global climate change on river systems
operations and project management, and develop strategies and responses to deal with those
impacts. Joint studies are research and operations projects that are performed in conjunction
with the Environmental Protection Agency, Geological Survey, and other agencies,
universities, and organizations."

One joint project with the Geological Survey (GS), the Western Basins Study, is concerned
with the impacts of global climate change on several western basins, including the Gunnison
in southwestern Colorado and the American and Carson-Truckee basins in California and
Nevada. As part of the Western Basins Study, a Climate Scenario Committee has been
established. The Committee consists of Reclamation, OS, and contractor personnel. Most of
Reclamation's work in scenario development to date has been accomplished by an unofficial
scenario team in the Research and Laboratory Services Division at the Denver Office. In
another joint study, the scenario team is working with scientists of the National Center for
Atmospheric Research to obtain and adapt output from existing general circulation models
(OCMs) and regional models for use on the GCCRP.

Printed January 18, 1991

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