Measuring Spatio-temporal Trends in Residential Landscape Irrigation Extent and Rate in Los Angeles, California Using SPOT-5 Satellite Imagery

Irrigation is a large component of urban water budgets in semi-arid regions and is critical for the management of landscape vegetation and water resources. This is particularly true for Mediterranean climate cities such as Los Angeles, where water availability is limited during dry summers. These interactions were examined by using 10-m resolution satellite imagery and a database of monthly water use records for all residential water customers in Los Angeles in order to map vegetation greenness, the extent and distribution of irrigated areas, and irrigation rates. A water conservation ratio between rates of irrigation and vegetation water demand was calculated to assess over-irrigation. The analyses were conducted for the water years (WY) 2005–2007, which included wet, average, and dry extremes of annual rainfall. Although outdoor water usage was highest in the dry year, vegetation greenness could not be maintained as well as in wetter years, suggesting that lower greenness was due to water stress. However, annual rainfall from WY 2005 to 2007 did not significantly influence the variability in the magnitude and spatial pattern of irrigation, with mean irrigated rates ranging only from 81 to 86 mm. The water conservation ratio showed that 7 % of the postal carrier routes across the city were over-irrigated in the dry year, but 43 % were over-irrigated in the wet year. This was largely because the climatic demand for water by vegetation decreased in wet years, but irrigation rates changed little from year-to-year. This overwatering can be addressed by water conservation, planning and public education, especially in the current California drought. The approach demonstrated here should be transferable to other cities in semi-arid climates

Glaciation During the Late Paleozoic Ice Age

The Late Paleozoic Ice Age (LPIA) was one of Earth’s most extreme climatic events where sea level and biotic restructuring were driven by linked oscillations in the climate system. Despite an evolving understanding of the ice age, the size, distribution, paleogeography, timing, depositional settings, and possible bipolarity of the glaciation remains unresolved. However, new and refined radioisotopic age dates are revising the timing and extent of individual stages of the ice age. Recent studies suggest numerous, ice centers fluctuated diachronously as glaciation shifted across Gondwana. The LPIA began in the Famennian in northern South America and Africa and ended in eastern Australia during the Wuchiapingian. Although glaciation was widespread, numerous ice-free areas occurred adjacent to major glacial centers. Deglaciation was also diachronous beginning in the Bashkirian in western Argentina, shifting to the Paraná Basin by the end of the Pennsylvanian, with deglaciation of the South Polar Region occurring during the late Early Permian. Deglaciation culminated in eastern Australia with the disappearance of high, mid-latitude, alpine glaciers during the Wuchiapingian at a time when Polar Gondwana was ice-free. Recent work on diamictites in northeastern Russia indicates that these strata were not glacigenic but instead were deposited as volcanic debris flows and slides/slumps associated with concurrent activity in the Okhotsk-Taigonos volcanic arc. Therefore, bipolar glaciation cannot be confirmed. Although fluctuations in greenhouse gases were a major driver of climate, paleogeography, tectonism, and other minor drivers also played a role in the nucleation and disappearance of LPIA glaciers.Fil: Isbell, John L.. University of Wisconsin; Estados UnidosFil: Fedorchuk, N. D.. University of Wisconsin; Estados UnidosFil: Pauls, Kathryn N.. University of Wisconsin; Estados UnidosFil: Griffis, N. P.. University of California at Davis; Estados UnidosFil: Ives, L. R. W.. University of Wisconsin; Estados UnidosFil: Moxness, Levi D.. University of Wisconsin; Estados UnidosFil: Survis, S. R.. University of Wisconsin; Estados UnidosFil: Vesely, F. F.. Universidade Federal do Paraná; BrasilFil: Montañez, I. P.. University of California at Davis; Estados UnidosFil: Limarino, Carlos Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaFil: Iannuzzi, R.. Universidade Federal do Rio Grande do Sul; BrasilFil: Biakov, A. S.. Academia de Ciencias de Rusia; RusiaFil: da Rosa, E. L. M.. Universidade Federal do Paraná; BrasilFil: Mundil, R.. Berkeley Geochronology Center; Estados UnidosFil: Taboada, Arturo Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Centro de Investigación Esquel de Montaña y Estepa Patagónica. Universidad Nacional de la Patagonia "San Juan Bosco". Centro de Investigación Esquel de Montaña y Estepa Patagónica; ArgentinaFil: Pagani, María Alejandra. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Ciccioli, Patricia Lucia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaFil: Schencman, Laura Jazmín. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaFil: Alonso Muruaga, Pablo Joaquin. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaFil: Davydov, V. I.. Boise State University; Estados UnidosFil: Vedernikov, I. L.. Academia de Ciencias de Rusia; RusiaFil: McNall, N. B.. University of Wisconsin; Estados UnidosVII Simposio Argentino del Paleozoico SuperiorEsquelArgentinaCentro de investigación Esquel de montaña y estepa patagónic