Now showing items 3081-3100 of 3826

    • Broad‐Crested Weir 

      Willi H. Hager; Markus Schwalt (American Society of Civil Engineers, 1994)
      The flow features over the broad‐crested weir with vertical upstream wall and sharp‐crested corner are analyzed experimentally. Only the long‐crested weir is considered, for which the discharge coefficient remains practically ...
    • Supercritical Flow in Circular‐Shaped Side Weir 

      Willi H. Hager (American Society of Civil Engineers, 1994)
      The flow features of a side weir in a prismatic circular‐shaped channel as used in sewage and irrigation systems are considered. The complex cross‐sectional channel geometry is simplified, and a generalized de Marchi ...
    • Minimum‐Impact Modeling of Nonpoint‐Source Ground‐Water Pollution 

      K. Hatfield; N. Samani; R. Noss (American Society of Civil Engineers, 1994)
      A new nonpoint source pollution management model is presented and applied to ascertain scenarios of expanding residential/commercial land uses to minimize impacts on ground‐water quality. The model is a linear program (LP), ...
    • Comparison of Results from Alluvial Fan Design Methodology with Historical Data 

      Syndi J. Flippin; Richard H. French (American Society of Civil Engineers, 1994)
      The Federal Emergency Management Agency (FEMA) method for delineating floodplains on alluvial fans was modified by French in 1992 to estimate design peak flow rates of specified return periods at transportation alignments ...
    • Flow‐Measurement Structures of Compound Cross Section for Rivers 

      Mustafa Göğüş; Doğan Altinbilek (American Society of Civil Engineers, 1994)
      Several types of flow‐measurement structures are used in rivers. One of the more common flow‐measurement structures is the critical‐depth flume. By definition, the velocity increases through the contracted section of the ...
    • Runoff Detention for Flood Volume or Erosion Control 

      A. Osman Akan; Edward N. Antoun (American Society of Civil Engineers, 1994)
      A simple design aid is presented for quick preliminary sizing of flood‐control detention basins and outlet structures. The design objective is to control the postdevelopment flood volume rather than the peak discharge. ...
    • Approximate Form of Green‐Ampt Infiltration Equation 

      Jeffry J. Stone; Richard H. Hawkins; Edward D. Shirley (American Society of Civil Engineers, 1994)
      We develop an approximation of the Green‐Ampt infiltration equation by using the first two terms of a Taylor‐series expansion of the equation. The resulting approximate equation is in the form of the Philip's equation, ...
    • Subcritical Flow over Rectangular Side Weir 

      Prabhata K. Swamee; Santosh K. Pathak; Mukesh Mohan; Sanjai K. Agrawal; Masoud S. Ali (American Society of Civil Engineers, 1994)
      Side weirs are flow‐diversion devices widely used in irrigation, land drainage, urban sewage systems, and so forth. For computation of side‐weir discharge, the de Marchi equation is widely used. Using de Marchi's equation, ...
    • General Stochastic Unit Hydrograph 

      Allen Hjelmfelt; Menghua Wang (American Society of Civil Engineers, 1994)
      Unit hydrographs for a gaged site can be determined from observed events. If several events are used for the derivation, several unit hydrographs result. An averaging procedure must be used to achieve a single representative ...
    • Erosion and Sedimentation Processes on Irrigated Fields 

      Thomas J. Trout; W. H. Neibling (American Society of Civil Engineers, 1993)
      Soil erosion is sometimes excessive during furrow irrigation and under center pivot sprinkler systems. An understanding of erosion processes is required to predict and develop management practices to reduce irrigation ...
    • Erratum: 

      Prabhata K. Swamee (American Society of Civil Engineers, 1993)
    • Furrow Irrigation Erosion Lowers Soil Productivity 

      D. L. Carter (American Society of Civil Engineers, 1993)
      Recent research efforts have shown that soil erosion decreases soil productivity. Erosion‐caused crop production decreases of 15–40% are commonly reported with some values over 50%. Furrow erosion on irrigated land in Idaho ...
    • Editorial 

      David L. Carter (American Society of Civil Engineers, 1993)
    • Development of 24‐Hour Rainfall Frequency Maps for Louisiana 

      Babak Naghavi; Vijay P. Singh; Fang Xin Yu (American Society of Civil Engineers, 1993)
      Maximum annual 24‐hour rainfall maps for return periods of 2, 5, 10, 25, 50, and 100 years were developed by using hourly precipitation data. Data from 92 rain gauges for the period of 1948 to 1987 were compiled and combined ...
    • Optimal Management Strategies for Cutback Furrow Irrigation 

      E. Bautista; W. W. Wallender (American Society of Civil Engineers, 1993)
      The optimal management of a cutback‐furrow‐irrigation system with spatially variable infiltration based on an average intake function was analyzed. The problem was formulated as a cost‐minimization function subject to ...
    • Alfalfa Irrigation during Drought 

      J. C. Guitjens (American Society of Civil Engineers, 1993)
      Alfalfa yields decrease when water supply is inadequate. In drought years, starting and continuing with full irrigation until the water supply has been exhausted will limit full production to earlier harvests. The objective ...
    • Overview of Soil Erosion from Irrigation 

      Paul K. Koluvek; Kenneth K. Tanji; Thomas J. Trout (American Society of Civil Engineers, 1993)
      Of the 15,000,000 ha (37,000,000 acres) of irrigated land in the U.S., 21% is affected by soil erosion to some extent. Irrigation‐induced soil erosion has been studied, primarily in the Northwestern United States, since ...
    • Correction for Settlement of Parshall Flume 

      A. Genovez; S. Abt; B. Florentin; A. Garton (American Society of Civil Engineers, 1993)
      A study was conducted in the Hydraulics Laboratory of Colorado State University to evaluate how settlement affects the accuracy of 30.5‐ and 61.0‐cm (1‐ and 2‐ft) prefabricated metal Parshall flumes. The flumes were installed ...
    • Controlling Erosion and Sediment Loss from Furrow‐Irrigated Cropland 

      D. L. Carter; C. E. Brockway; K. K. Tanji (American Society of Civil Engineers, 1993)
      Irrigation‐induced erosion and subsequent sediment loss is a serious agricultural and environmental problem. Recent recognition of this problem has stimulated the development and evaluation of erosion and sediment‐loss‐control ...
    • Border Advance Using Improved Volume‐Balance Model 

      John D. Valiantzas (American Society of Civil Engineers, 1993)
      A simple cost‐efficient model is developed to predict advance phase in border irrigation. Assuming a power function for the water‐depth profile, a volume‐balance equation is applied using an adjusted surface shape factor. ...