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A generalized least squares (GLS) technique was used with at-site n-day low-flow time series and frequencies, from SWToolbox (Kiang and others, 2018), and 14 basin characteristics (basin perimeter, drainage area, maximum basin elevation, mean total annual reference evapotranspiration, groundwater head, length of longest flow path, minimum basin elevation, runoff-curve number, relief, ruggedness, slope ratio, percentage of hydrologic soil type B, available water capacity, and total length of streams in a basin) for 28 selected streamflow gaging stations in Puerto Rico to calculate regional n-day low-flow frequency regression equations for ungaged stream locations. The GLS approach assigns weights based on uncertainty...
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The intense demand for river water in arid regions is resulting in widespread changes in riparian vegetation. We present a direct gradient method to predict the vegetation change resulting from a proposed upstream dam or diversion. Our method begins with the definition of vegetative cover types, based on a census of the existing vegetation in a set of 1 x 2 m plots. A hydraulic model determines the discharge necessary to inundate each plot. We use the hydrologic record, as defined by a flow duration curve, to determine the inundation duration for each plot. This allows us to position cover types along a gradient of inundation duration. A change in river management results in a new flow duration curve, which is used...
An ordinary least squares (OLS) technique was used with at-site flow-duration exceedance probabilities, from SWToolbox (Kiang and others, 2018), and 14 basin characteristics (basin perimeter, drainage area, maximum basin elevation, mean total annual reference evapotranspiration, groundwater head, length of longest flow path, minimum basin elevation, runoff-curve number, relief, ruggedness, slope ratio, percentage of hydrologic soil type B, available water capacity, and total length of streams in a basin) for 28 selected streamflow gaging stations in Puerto Rico to calculate regional flow-duration regression equations for ungaged stream locations. The final flow-duration regression equations were developed in R (R...
Flow-duration statistics at the 99th, 98th, 95th, 90th, 80th, 70th, 60th, and 50th percent exceedance probabilities and annual n-day low-flow statistics for the 1-, 7-, 14-, and 30-day mean low flows with 2-year (0.5 nonexceedance probability), 5-year (0.2 nonexceedance probability), and 10-year (0.1 nonexceedance probability) recurrence intervals were computed for 28 selected streamflow gaging stations in Puerto Rico. The 28 selected streamflow gaging stations were required to have 10 or more years of daily mean streamflow data through water year 2018. The flow-duration statistics and n-day low-flow frequencies were computed using the U.S. Geological Survey program, SWToolbox. Regional regression equations were...


    map background search result map search result map Relating Riparian Vegetation to Present and Future Streamflows Data Files for the Development of Regional Regression Equations for Flow-Duration Statistics and N-day Low-Flow Frequencies for Ungaged Stream Locations in Puerto Rico Using Data Through Water Year 2018 Puerto Rico N-day Low-Flow Regression Files Puerto Rico Flow-Duration Regression Files Relating Riparian Vegetation to Present and Future Streamflows Data Files for the Development of Regional Regression Equations for Flow-Duration Statistics and N-day Low-Flow Frequencies for Ungaged Stream Locations in Puerto Rico Using Data Through Water Year 2018 Puerto Rico N-day Low-Flow Regression Files Puerto Rico Flow-Duration Regression Files