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A. Harrison

Publications and source records attributed to A. Harrison.

2 recordsLinked to original sources

Rivers of the Lower Mississippi Basin

Discussed in this chapter are seven significant tributaries of the Lower Mississippi River and its major distributary. As a group, these eight rivers and their basins encompass substantial variation in physical form, hydrology, biota, ecology, and human impacts. The Current River, Ouachita River, and Saline River, flow to the Mississippi out of the U.S. Interior Highlands. The Cache River basin, centered in Arkansas, contains a vast expanse of bottomland hardwood forest and is famous for wintering waterfowl. The Hatchie River, flowing west out of Tennessee, is the longest free-flowing tributary of the Lower Mississippi River and famous for its rich diversity of mussels and fishes. The Wolf River of Tennessee supports a magnificent bald cypress-tupelo swamp and is notable as a protected urban river that flows through Memphis. The Big Sunflower River begins and ends in the alluvial floodplain of the Mississippi River and flows through a basin of intense agriculture and historical human conflict. The Atchafalaya River, the primary distributary of the Mississippi River, supports the nation's largest expanse of bottomland hardwood forest and swamp wetlands. In this chapter, we review the physiography, geomorphology, hydrology, water chemistry, land use, biological diversity, ecological processes, human impacts, and areas of need for research and management of each of these eight rivers and their basins.

Lower Mississippi River basin↗

Assessing reservoir operations risk under climate change

Risk-based planning offers a robust way to identify strategies that permit adaptive water resources management under climate change. This paper presents a flexible methodology for conducting climate change risk assessments involving reservoir operations. Decision makers can apply this methodology to their systems by selecting future periods and risk metrics relevant to their planning questions and by collectively evaluating system impacts relative to an ensemble of climate projection scenarios (weighted or not). This paper shows multiple applications of this methodology in a case study involving California's Central Valley Project and State Water Project systems. Multiple applications were conducted to show how choices made in conducting the risk assessment, choices known as analytical design decisions, can affect assessed risk. Specifically, risk was reanalyzed for every choice combination of two design decisions: (1) whether to assume climate change will influence flood-control constraints on water supply operations (and how), and (2) whether to weight climate change scenarios (and how). Results show that assessed risk would motivate different planning pathways depending on decision-maker attitudes toward risk (e.g., risk neutral versus risk averse). Results also show that assessed risk at a given risk attitude is sensitive to the analytical design choices listed above, with the choice of whether to adjust flood-control rules under climate change having considerably more influence than the choice on whether to weight climate scenarios. Copyright 2009 by the American Geophysical Union.

Water Resources Research↗