Author: Johannes J. DeVries
Publisher:
ISBN:
Category : Floodplains
Languages : en
Pages : 70
Book Description
Effects of Flood Plain Encroachments on Peak Flow
Author: Johannes J. DeVries
Publisher:
ISBN:
Category : Floodplains
Languages : en
Pages : 70
Book Description
Publisher:
ISBN:
Category : Floodplains
Languages : en
Pages : 70
Book Description
Effects of Flood Plain Encroachments on Peak Flow
Author: J. J. DeVries
Publisher:
ISBN:
Category : Floods
Languages : en
Pages : 0
Book Description
When land development encroachments into river flood plains are permitted, the magnitude of the flood peak discharge will be increased due to removal of flood plain storage. When the flood plain encroachment is limited (for example, when no more than one foot of water surface rise is permitted), the study results indicate that the increase in the flood peak is usually relatively small; it is generally less than 10 percent. The arrival time of the flood peak can be affected to a much greater extent, and in stream systems with significant tributary flows, consideration must be given to the effects of encroachments on the coinciding of the flood peaks. Various hydrograph shapes and mean river slopes were used in the investigation of encroachment effects. Both unsteady flow simulations and steady flow profile calculations with hydrologic routing were used in the analyses. (Author).
Publisher:
ISBN:
Category : Floods
Languages : en
Pages : 0
Book Description
When land development encroachments into river flood plains are permitted, the magnitude of the flood peak discharge will be increased due to removal of flood plain storage. When the flood plain encroachment is limited (for example, when no more than one foot of water surface rise is permitted), the study results indicate that the increase in the flood peak is usually relatively small; it is generally less than 10 percent. The arrival time of the flood peak can be affected to a much greater extent, and in stream systems with significant tributary flows, consideration must be given to the effects of encroachments on the coinciding of the flood peaks. Various hydrograph shapes and mean river slopes were used in the investigation of encroachment effects. Both unsteady flow simulations and steady flow profile calculations with hydrologic routing were used in the analyses. (Author).
Flow Modifications by Storage Loss Through Flood Plain Encroachment
Author: L. A. Traille
Publisher:
ISBN:
Category : Floodplains
Languages : en
Pages : 157
Book Description
When highways and other developments encroach on natural stream valleys, they act to obstruct the flow and consequently modify natural flooding characteristics. The impact of a particular channel or flood plain encroachment on flooding is governed by the degree it alters natural valley properties, as well as orientation or alignment with respect to flow. Most encroachments can be classified as either lateral or transverse to the flow, although an embankment aligned with an acute skew angle could be considered both lateral and transverse. Alteration of the natural floodway through the loss of overbank storage and the resulting constriction of the flow will ultimately result in increased flood stages and peak discharges, as well as scouring of the main channel bed. Assessing impacts on flow of a design alternative is important in preliminary design stages. At present this can only be achieved through the use of complex models requiring considerable data collection and preparation. To avoid such lengthy procedures, there is urgent need for simpler techniques that would use minimum amounts of input data without seriously sacrificing accuracy. The objective of NCHRP Project 15-7 is to develop simple short-cut procedures for assessing changes in water surface profiles, peak discharges, and scour. As they are intended for use in preliminary estimates, the results of this study in no way substitute for the detailed procedures required in final design studies. These procedures emphasize predicting changes rather than developing absolute values.
Publisher:
ISBN:
Category : Floodplains
Languages : en
Pages : 157
Book Description
When highways and other developments encroach on natural stream valleys, they act to obstruct the flow and consequently modify natural flooding characteristics. The impact of a particular channel or flood plain encroachment on flooding is governed by the degree it alters natural valley properties, as well as orientation or alignment with respect to flow. Most encroachments can be classified as either lateral or transverse to the flow, although an embankment aligned with an acute skew angle could be considered both lateral and transverse. Alteration of the natural floodway through the loss of overbank storage and the resulting constriction of the flow will ultimately result in increased flood stages and peak discharges, as well as scouring of the main channel bed. Assessing impacts on flow of a design alternative is important in preliminary design stages. At present this can only be achieved through the use of complex models requiring considerable data collection and preparation. To avoid such lengthy procedures, there is urgent need for simpler techniques that would use minimum amounts of input data without seriously sacrificing accuracy. The objective of NCHRP Project 15-7 is to develop simple short-cut procedures for assessing changes in water surface profiles, peak discharges, and scour. As they are intended for use in preliminary estimates, the results of this study in no way substitute for the detailed procedures required in final design studies. These procedures emphasize predicting changes rather than developing absolute values.
Use of Paleoflood Investigations to Improve Flood-frequency Analyses of Plains Streams in Wyoming
Author: Maurice E. Cooley
Publisher:
ISBN:
Category : Drainage
Languages : en
Pages : 88
Book Description
Publisher:
ISBN:
Category : Drainage
Languages : en
Pages : 88
Book Description
North-south Coors Connection Alignment of Coors Blvd, Albuquerque
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 280
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 280
Book Description
Proposed Master Plan Update Development Actions, Seattle-Tacoma (Sea-Tac) International Airport, King County
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 810
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 810
Book Description
Wolf Creek Pass East, Mineral County
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 178
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 178
Book Description
Geological Survey Professional Paper
Author:
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 846
Book Description
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 846
Book Description
State College Bypass System, LR-1050-US-322
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 358
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 358
Book Description
Oil and Gas Leasing Environmental Impact Statement
Author: United States. Forest Service
Publisher:
ISBN:
Category : Cimarron National Grassland (Kan.)
Languages : en
Pages : 586
Book Description
Publisher:
ISBN:
Category : Cimarron National Grassland (Kan.)
Languages : en
Pages : 586
Book Description