The Water Budget of Los Angeles: Where Does All the Water Go?
Location
ECC 216
Event Website
http://water.usu.edu/
Start Date
4-4-2012 11:40 AM
End Date
4-3-2012 12:15 PM
Description
Semi-arid urban ecosystems present a unique challenge in understanding ecohydrology. Urban landscapes are highly modified, not only by built structures and impervious surfaces, but also by a unique mix of vegetation and soils. These landscapes are often irrigated using imported water from remote sources. The result is a human-dominated hydrologic cycle influenced by many aspects of individual, household, and institutional rules and decision-making as well as biophysical factors. In most urban and urbanizing regions, the hydrologic budgets, ecohydrologic feedbacks, and their key controls are highly uncertain due to the complex interactions between social, biotic, and abiotic factors. Here, we review ecohydrologic research in Los Angeles, the second largest city in the United States and one of the world’s “mega-cities.” This region is experiencing a prolonged drought and reductions in allotments of imported water. However, most of the water imported into the city is unaccounted for in measured runoff and wastewater discharge. The remainder is evaporated and transpired from outdoor landscapes, or drained to deep soil and groundwater recharge. These fluxes are unmonitored in most cities, so the actual water use and water requirements of urban vegetation, as well as the amount and dynamics of groundwater recharge, are unknown. Our measurements show the importance of understanding the drivers, amount, and fate of outdoor irrigation in this semi-arid city, in which most landscapes are heavily irrigated. Both the actual and perceived role of outdoor landscaping in the urban environment play an important role in the local hydrologic budget, with implications for the development and implementation of best management practices for urban water resources.
The Water Budget of Los Angeles: Where Does All the Water Go?
ECC 216
Semi-arid urban ecosystems present a unique challenge in understanding ecohydrology. Urban landscapes are highly modified, not only by built structures and impervious surfaces, but also by a unique mix of vegetation and soils. These landscapes are often irrigated using imported water from remote sources. The result is a human-dominated hydrologic cycle influenced by many aspects of individual, household, and institutional rules and decision-making as well as biophysical factors. In most urban and urbanizing regions, the hydrologic budgets, ecohydrologic feedbacks, and their key controls are highly uncertain due to the complex interactions between social, biotic, and abiotic factors. Here, we review ecohydrologic research in Los Angeles, the second largest city in the United States and one of the world’s “mega-cities.” This region is experiencing a prolonged drought and reductions in allotments of imported water. However, most of the water imported into the city is unaccounted for in measured runoff and wastewater discharge. The remainder is evaporated and transpired from outdoor landscapes, or drained to deep soil and groundwater recharge. These fluxes are unmonitored in most cities, so the actual water use and water requirements of urban vegetation, as well as the amount and dynamics of groundwater recharge, are unknown. Our measurements show the importance of understanding the drivers, amount, and fate of outdoor irrigation in this semi-arid city, in which most landscapes are heavily irrigated. Both the actual and perceived role of outdoor landscaping in the urban environment play an important role in the local hydrologic budget, with implications for the development and implementation of best management practices for urban water resources.
https://digitalcommons.usu.edu/runoff/2012/AllAbstracts/59