Chester Watson | Colorado State University (original) (raw)
Papers by Chester Watson
Journal of Hydraulic Engineering, Sep 1, 2015
Journal of Hydraulic Engineering, 2015
: The objectives of this study are: (1) to review the international literature and to determine t... more : The objectives of this study are: (1) to review the international literature and to determine the effect of neotectonics on alluvial rivers, (2) to deduce the effects of neotectonics of various types on alluvial rivers, (3) to determine if neotectonic activity is influencing the Mississippi River between Cairo, Illinois and the Gulf of Mexico. In order to provide the background necessary for a study of the possible effects of neotectonics on the lower Mississippi River, a review of the neotectonic literature is presented in Chapter 2. In Chapter 3, the existing relationships between river morphology and effect of valley-floor gradient on channel patterns is used to deduce the types of changes that can be expected as alluvial rivers adjust to deformation. In the final portion of this report, evidence is presented for deformation of the alluvial valley of the Mississippi River and on the effect of this deformation on the Mississippi River and some of its tributaries.
World Environmental and Water Resources Congress 2007, 2007
Stream modification or channelization activities are listed among the top 10 sources for non-poin... more Stream modification or channelization activities are listed among the top 10 sources for non-point source pollution impacts to rivers (U.S. Environmental Protection Agency 1993). Activities such as straightening, widening, deepening, and clearing streams of debris generally fall into this category. Modification of water and sediment supplied from the watershed by altered land-use change can be equally as disturbing to the fluvial system. These activities can severely impact major river projects such as navigation and flood control, as well as alter or reduce the diversity of instream and riparian habitats. Without proper understanding of the fluvial system, even projects intended to rehabilitate streams can cause severe instability. The primary purpose of the manual is to develop a general approach for stream-rehabilitation design based on sound engineering principles and understanding of the fluvial system.
AGRIS record. Record number, US875051588. Titles, Incised channels: morphology, dynamics, and con... more AGRIS record. Record number, US875051588. Titles, Incised channels: morphology, dynamics, and control. Personal Authors, Schumm, Stanley A.,Harvey, Michael D.,Watson, Chester C. Publisher, Water Resources Publications. Publisher Place, Littleton, Colo. (USA). ...
As water resource projects become more and more complex, there is a growing emphasis on the abili... more As water resource projects become more and more complex, there is a growing emphasis on the ability to implement effective regional sediment management. A common goal of many regional sediment management (RSM) projects is the reduction of sediment loading from the watershed. This is usually accomplished by rehabilitation features such as grade control, bank stabilization, drop pipes, and land treatments. While these features are often implemented with the stated purpose of reducing sediment yields to downstream reservoirs, flood-control channels, or wetlands, the spatial and temporal impacts of these features with respect to downstream sediment loads are far from straightforward, and often result in unanticipated morphologic adjustments and degradation of riverine habitats and ecosystems. Effective regional sediment management lies in identifying the sediment sources and sediment sinks in the watershed sediment system and understanding the processes responsible for transferring sediment along the pathways that link sediment sources and sinks at the reach and catchment scales. This technical note describes how the concepts of wash load and bed-material load can be used to document the transfer of sediment from its source, through its pathways, to its ultimate sinks, thereby, serving as the foundation for effective regional sediment management.
Incised channels are caused by an imbalance between sediment transport capacity and sediment supp... more Incised channels are caused by an imbalance between sediment transport capacity and sediment supply that alters channel morphology through bed and bank erosion. Consistent sequential changes in incised channel morphology may be quantified and used to develop relationships describing quasi-equilibrium conditions in these channels. We analyzed the hydraulic characteristics of streams in the Yazoo River Basin, Mississippi in various stages of incised channel evolution. The hydraulic characteristics of incising channels were observed to follow the sequence predicted by previous conceptual models of incised channel response. Multiple regression models of stable slopes in quasi-equilibrium channels that have completed a full evolutionary sequence were developed. These models compare favorably with analytical solutions based on the extremal hypothesis of minimum stream power and empirical relationships from other regions. Appropriate application of these empirical relationships may be useful in preliminary design of stream rehabilitation strategies.
Geomorphology, 2000
This study documents slope and stream power changes in the Lower Mississippi River during the pre... more This study documents slope and stream power changes in the Lower Mississippi River during the pre-cutoff 1880s-. Ž. 1930s , and post-cutoff 1943-1992 periods. The study reach extends from New Madrid, MO, to Natchez, MS, a distance of about 900 km. Analyses for six major reaches and 13 sub-reaches for the pre-and post-cutoff periods indicate that the river presently has a much larger slope and stream power than prior to the cutoffs. The largest increases have occurred between Fulton, TN, and Lake Providence, LA, where slope and stream power increases range from about 27% to 36% and 20% to 38%, respectively. Increases in slope and stream power in reaches upstream and downstream have also occurred, but to a lesser degree. Previous investigations have shown that no coarsening of the bed material has occurred since 1932, and that the bed material may actually be somewhat finer overall. As the Lower Mississippi River is not a sediment-starved system, an increase in stream power with no change in D would be expected to be offset by an increase in the bed material 50 load as the river adjusts towards equilibrium. Previous investigators have inferred a reduction in the sediment loads on the Mississippi River this century based on analyses of total measured suspended loads. However, these results should be viewed as primarily representing the changes in wash load and should not be taken to imply that bed material loads have also decreased. Therefore, the bed material loads in the study reach should be greater than in the pre-cutoff period. Excess stream power in the sub-reaches directly affected by cutoffs resulted in scour that increased downstream bed material load. These elevated sediment loads play a key role in driving morphological adjustments towards equilibrium in the post-cutoff channel. The stability status of the channel in the study reach currently ranges from dynamic equilibrium in the farthest upstream reaches through severe degradation to dynamic equilibrium in the middle reaches, and aggradation in the lowest reaches. These evolutionary trends cannot be explained by consideration of changes in slope and stream power alone. Changes in the incoming bed material load to each reach generated by upstream channel evolution must also be considered.
Wetlands Engineering & River Restoration 2001, 2001
Aquatic habitat quality is dependent on water quality, bed slope, water temperature, dissolved ox... more Aquatic habitat quality is dependent on water quality, bed slope, water temperature, dissolved oxygen, substrate, vegetation, and hydraulic parameters in the stream system. The Riverine Community Habitat Assessment and Restoration Concept (RCHARC) is a methodology developed by the U.S. Army Engineer Waterways Experiment Station, Environmental Laboratory, to compare hydraulic parameters (depth and velocity) between natural, degraded, and restored channel reaches. The methodology is generally applied to alternate reaches in the same stream; therefore, the habitat quality variables must also be closely matched. RCHARC assumes that if the diversity of hydraulic and habitat quality parameters for a `comparison standard` reach can be replicated in the stream restoration reach, then the aquatic habitat quality can be enhanced. The RCHARC Methodology has been successfully applied to large, warm-water rivers. The objective of this study was to Beta test the RCHARC methodology for its applica...
Channel modification or channelization activities are listed among the top 10 sources for non-poi... more Channel modification or channelization activities are listed among the top 10 sources for non-point pollution impacts to rivers (U.S. Environmental Protection Agency (EPA), 1993). Activities such as straightening, widening, deepening, and clearing channels of debris generally fall into this category. These activities can severely impact major river projects such as navigation and flood control, as well as alter or reduce the diversity of in-stream and riparian habitats. River systems maintain stability by providing just the necessary flow to transport the available water and sediment.
Building Partnerships, 2000
The PI, co-PI and a team from WES spent a five-day period reconnoitering the four study reaches i... more The PI, co-PI and a team from WES spent a five-day period reconnoitering the four study reaches in order to become familiar with the banks and the in-channel morphology of the river. As a result of this, a short report recommending an approach to the study was written by the PI and sent to staff at WES. It was recommended that geomorphologically distinct subreaches be identified within each of the four main reaches, based on their geology, planform sinuosity and degree of stability or instability, be this natural or artificial. The Brice channel classification system for categorising the degree of channel sinuosity was advocated for this purpose. Identification of these subreaches was recommended in order to supply the basis for determination of channel response to any future stabilisation works. Another product of this reconnaissance trip was a series of thoroughly annotated aerial photographs showing the heights and extent of eroding areas of bank line, the types of terrace deposi...
Journal of Hydraulic Engineering, Sep 1, 2015
Journal of Hydraulic Engineering, 2015
: The objectives of this study are: (1) to review the international literature and to determine t... more : The objectives of this study are: (1) to review the international literature and to determine the effect of neotectonics on alluvial rivers, (2) to deduce the effects of neotectonics of various types on alluvial rivers, (3) to determine if neotectonic activity is influencing the Mississippi River between Cairo, Illinois and the Gulf of Mexico. In order to provide the background necessary for a study of the possible effects of neotectonics on the lower Mississippi River, a review of the neotectonic literature is presented in Chapter 2. In Chapter 3, the existing relationships between river morphology and effect of valley-floor gradient on channel patterns is used to deduce the types of changes that can be expected as alluvial rivers adjust to deformation. In the final portion of this report, evidence is presented for deformation of the alluvial valley of the Mississippi River and on the effect of this deformation on the Mississippi River and some of its tributaries.
World Environmental and Water Resources Congress 2007, 2007
Stream modification or channelization activities are listed among the top 10 sources for non-poin... more Stream modification or channelization activities are listed among the top 10 sources for non-point source pollution impacts to rivers (U.S. Environmental Protection Agency 1993). Activities such as straightening, widening, deepening, and clearing streams of debris generally fall into this category. Modification of water and sediment supplied from the watershed by altered land-use change can be equally as disturbing to the fluvial system. These activities can severely impact major river projects such as navigation and flood control, as well as alter or reduce the diversity of instream and riparian habitats. Without proper understanding of the fluvial system, even projects intended to rehabilitate streams can cause severe instability. The primary purpose of the manual is to develop a general approach for stream-rehabilitation design based on sound engineering principles and understanding of the fluvial system.
AGRIS record. Record number, US875051588. Titles, Incised channels: morphology, dynamics, and con... more AGRIS record. Record number, US875051588. Titles, Incised channels: morphology, dynamics, and control. Personal Authors, Schumm, Stanley A.,Harvey, Michael D.,Watson, Chester C. Publisher, Water Resources Publications. Publisher Place, Littleton, Colo. (USA). ...
As water resource projects become more and more complex, there is a growing emphasis on the abili... more As water resource projects become more and more complex, there is a growing emphasis on the ability to implement effective regional sediment management. A common goal of many regional sediment management (RSM) projects is the reduction of sediment loading from the watershed. This is usually accomplished by rehabilitation features such as grade control, bank stabilization, drop pipes, and land treatments. While these features are often implemented with the stated purpose of reducing sediment yields to downstream reservoirs, flood-control channels, or wetlands, the spatial and temporal impacts of these features with respect to downstream sediment loads are far from straightforward, and often result in unanticipated morphologic adjustments and degradation of riverine habitats and ecosystems. Effective regional sediment management lies in identifying the sediment sources and sediment sinks in the watershed sediment system and understanding the processes responsible for transferring sediment along the pathways that link sediment sources and sinks at the reach and catchment scales. This technical note describes how the concepts of wash load and bed-material load can be used to document the transfer of sediment from its source, through its pathways, to its ultimate sinks, thereby, serving as the foundation for effective regional sediment management.
Incised channels are caused by an imbalance between sediment transport capacity and sediment supp... more Incised channels are caused by an imbalance between sediment transport capacity and sediment supply that alters channel morphology through bed and bank erosion. Consistent sequential changes in incised channel morphology may be quantified and used to develop relationships describing quasi-equilibrium conditions in these channels. We analyzed the hydraulic characteristics of streams in the Yazoo River Basin, Mississippi in various stages of incised channel evolution. The hydraulic characteristics of incising channels were observed to follow the sequence predicted by previous conceptual models of incised channel response. Multiple regression models of stable slopes in quasi-equilibrium channels that have completed a full evolutionary sequence were developed. These models compare favorably with analytical solutions based on the extremal hypothesis of minimum stream power and empirical relationships from other regions. Appropriate application of these empirical relationships may be useful in preliminary design of stream rehabilitation strategies.
Geomorphology, 2000
This study documents slope and stream power changes in the Lower Mississippi River during the pre... more This study documents slope and stream power changes in the Lower Mississippi River during the pre-cutoff 1880s-. Ž. 1930s , and post-cutoff 1943-1992 periods. The study reach extends from New Madrid, MO, to Natchez, MS, a distance of about 900 km. Analyses for six major reaches and 13 sub-reaches for the pre-and post-cutoff periods indicate that the river presently has a much larger slope and stream power than prior to the cutoffs. The largest increases have occurred between Fulton, TN, and Lake Providence, LA, where slope and stream power increases range from about 27% to 36% and 20% to 38%, respectively. Increases in slope and stream power in reaches upstream and downstream have also occurred, but to a lesser degree. Previous investigations have shown that no coarsening of the bed material has occurred since 1932, and that the bed material may actually be somewhat finer overall. As the Lower Mississippi River is not a sediment-starved system, an increase in stream power with no change in D would be expected to be offset by an increase in the bed material 50 load as the river adjusts towards equilibrium. Previous investigators have inferred a reduction in the sediment loads on the Mississippi River this century based on analyses of total measured suspended loads. However, these results should be viewed as primarily representing the changes in wash load and should not be taken to imply that bed material loads have also decreased. Therefore, the bed material loads in the study reach should be greater than in the pre-cutoff period. Excess stream power in the sub-reaches directly affected by cutoffs resulted in scour that increased downstream bed material load. These elevated sediment loads play a key role in driving morphological adjustments towards equilibrium in the post-cutoff channel. The stability status of the channel in the study reach currently ranges from dynamic equilibrium in the farthest upstream reaches through severe degradation to dynamic equilibrium in the middle reaches, and aggradation in the lowest reaches. These evolutionary trends cannot be explained by consideration of changes in slope and stream power alone. Changes in the incoming bed material load to each reach generated by upstream channel evolution must also be considered.
Wetlands Engineering & River Restoration 2001, 2001
Aquatic habitat quality is dependent on water quality, bed slope, water temperature, dissolved ox... more Aquatic habitat quality is dependent on water quality, bed slope, water temperature, dissolved oxygen, substrate, vegetation, and hydraulic parameters in the stream system. The Riverine Community Habitat Assessment and Restoration Concept (RCHARC) is a methodology developed by the U.S. Army Engineer Waterways Experiment Station, Environmental Laboratory, to compare hydraulic parameters (depth and velocity) between natural, degraded, and restored channel reaches. The methodology is generally applied to alternate reaches in the same stream; therefore, the habitat quality variables must also be closely matched. RCHARC assumes that if the diversity of hydraulic and habitat quality parameters for a `comparison standard` reach can be replicated in the stream restoration reach, then the aquatic habitat quality can be enhanced. The RCHARC Methodology has been successfully applied to large, warm-water rivers. The objective of this study was to Beta test the RCHARC methodology for its applica...
Channel modification or channelization activities are listed among the top 10 sources for non-poi... more Channel modification or channelization activities are listed among the top 10 sources for non-point pollution impacts to rivers (U.S. Environmental Protection Agency (EPA), 1993). Activities such as straightening, widening, deepening, and clearing channels of debris generally fall into this category. These activities can severely impact major river projects such as navigation and flood control, as well as alter or reduce the diversity of in-stream and riparian habitats. River systems maintain stability by providing just the necessary flow to transport the available water and sediment.
Building Partnerships, 2000
The PI, co-PI and a team from WES spent a five-day period reconnoitering the four study reaches i... more The PI, co-PI and a team from WES spent a five-day period reconnoitering the four study reaches in order to become familiar with the banks and the in-channel morphology of the river. As a result of this, a short report recommending an approach to the study was written by the PI and sent to staff at WES. It was recommended that geomorphologically distinct subreaches be identified within each of the four main reaches, based on their geology, planform sinuosity and degree of stability or instability, be this natural or artificial. The Brice channel classification system for categorising the degree of channel sinuosity was advocated for this purpose. Identification of these subreaches was recommended in order to supply the basis for determination of channel response to any future stabilisation works. Another product of this reconnaissance trip was a series of thoroughly annotated aerial photographs showing the heights and extent of eroding areas of bank line, the types of terrace deposi...