1 / 13

Nathan Lowe, Shawn Stanley and Jeffery Crump

Runoff Analysis of the Watersheds “El Arroyo El Chilito” and “La Presa Bernardez” Guadalupe, Zacatecas, Mexico. Nathan Lowe, Shawn Stanley and Jeffery Crump. The Problem.

silas
Download Presentation

Nathan Lowe, Shawn Stanley and Jeffery Crump

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Runoff Analysis of the Watersheds“El Arroyo El Chilito” and “La Presa Bernardez” Guadalupe, Zacatecas, Mexico Nathan Lowe, Shawn Stanley and Jeffery Crump

  2. The Problem • Between the city of Zacatecas and a nearby town called Guadalupe, a significant amount of urbanization is taking place, which is altering the runoff of two small watersheds, “Arroyo El Chilito” and “la Presa Bernardez”. • Due to the recent development, flooding has increased in frequency and magnitude. The pavement has caused the ground surface to become less permeable, so that precipitation accumulates on the surface rather than absorbing into the soil. • As urbanization continues, this hazard is expected to escalate, a concern to those who are aware of the problem.

  3. Data Needed • Digital Elevation Model (DEM) • Land use distribution • Soil type distribution • Precipitation • Aerial photos and maps

  4. Delineation of the Sub-basins • Import the DEM • Run TOPAZ (flow accumulation software) • Choose the outlet point for the basin • Run “Delineate Basins Wizard”

  5. DEM Data • 30-meter resolution • UTM NAD 27 coordinate system • Digital basin delineation by flow accumulation La Presa Bernardez El Arroyo El Chilito

  6. Land Use and Soil Type Data Land Use • Digital images from INEGI (National Institute of Statistics, Geography and Informatics) • Superposition of land use and soil type polygons • Association of permeability with polygons for infiltration calculations Soil Type

  7. Precipitation Data • Intensity-Duration-Frequency (IDF) curves from historical data • Design storm: • SCS Type II 2- or 24-hour distribution

  8. Projected Flows • By modeling a hypothetical expansion of urbanized areas, the average permeability of the watersheds further decreases. • An additional analysis in HEC-1 and HMS was performed to reflect this change. • Comparing the two scenarios, further development will increase peak flows by approximately 1.5 to 2 times the current flows.

  9. HEC-HMS vs HEC-1 • Problems with computations • Differences in calculations

  10. Hy-8 Culvert Analysis

  11. Recommendations • La Presa Bernardez • Reinstate the existing detention basin by controlling the outflow with an adjustable gate. • Determine the basin volume necessary to effectively delay and attenuate the peak flow through the outlet. • This will reduce the risk of flooding downstream for design storm events. • El Arroyo El Chilito • Clear the debris from the channel downstream of the highway. • Determine if the channel is capable of conveying design storm flows. • Use the abandoned area upstream of the highway as a retention basin.

  12. Further Analysis Needed • HEC-RAS models of channels below outlets • Topographical surveys of detention basins above outlets • Basin outlet analyses to size detention basins based on headwater requirements

  13. Questions? Special thanks to Dr. Jim aka “Mascarita Divina”

More Related