Location: Watershed Physical Processes Research
Project Number: 6060-13000-026-14-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Feb 1, 2014
End Date: Jul 31, 2018
The long-term research objective of this project is to develop a model to estimate the sediment loadings from the Goat Canyon watershed, Tijuana, Mexico, under existing conditions and evaluate the effects of planned and unplanned urban development on hydrology and sediment loadings. Specific objectives are: 1) Characterize channel form; 2) Characterize upland soils and channel boundary materials for their resistance to erosion properties; 3) Develop simulations of the USDA watershed and channel models AnnAGNPS and CONCEPT and; 4) Evaluate the impact of instream, road and upland BMPs on runoff and sediment load and yield.
The overall approach combines fieldwork with modeling to construct a water and sediment budget of the Goat Canyon watershed in cooperation with the U.S. Environmental Protection Agency (USEPA), USDA Agricultural Research Service (ARS), San Diego State University (SDSU), and the Center of Scientific Investigation and Higher Education in Ensenada (CICESE), Mexico. Specific tasks are: 1) Collect and analyze existing data and relevant information regarding hydrological, erosion and sediment transport processes from the watershed and from the literature (USEPA and SDSU); 2) Perform channel cross section survey and analyze soil properties (Identification of erosive substrates) (ARS, CICESE and SDSU); 3) Compile a database of watershed characteristics describing hydrologic, vegetative, soil, topographic and other features including erosion control structures and conservation measure locations (USEPA and SDSU); 4) Monitor rainfall, and runoff and sediment load at the watershed outlet (CICESE and SDSU); 5) Establish permanent monitoring locations where channel changes would be monitored over time, measured once per year from repeat cross sections and/or using aerial photos from different periods (SDSU and ARS); 6) Quantify gully dimensions using topographic surveys and high resolution Digital Elevation Models (DEMs). The DEMs will be created using either aerial or ground-level stereo pairs taken before and after major rainfall events (SDSU and CICESE); 7) Set up hydrological and erosion models AnnGNPS and CONCEPTS to estimate the flow duration curve, frequency of over-bank flows, and annual total sediment loading by erosion process (sheetwash, rill, gully, channel) from the existing condition of the watershed and after implementation of conservation measures and BMPs (ARS, SDSU, CICESE and USEPA) and; 8) Compile and analyze information regarding sediment yield reduction from various implementation measures and BMPs (SDSU, CICESE).