Uniform TitleEvaluating the effect of land-use and land-cover change on climate in the Greater Phoenix, AZ, region
NameGeorgescu, Matei (author), Weaver, Christopher (chair), Brocolli, Tony (internal member), Miller, Jim (internal member), Stenchikov, Gera (internal member), Miguez-Macho, Gonzalo (outside member), Rutgers University, Graduate School - New Brunswick,
Land use--Arizona--Phoenix Metropolitan Area--Environmental aspects,
Phoenix (Ariz.)--Environmental conditions,
Climatic changes--Environmental aspects
DescriptionThe effect of land-use/land-cover change (LULCC) on the summer climate of one of the nation's most rapidly expanding metropolitan complexes, the Greater Phoenix, AZ, region, is investigated.
The initial part of this study evaluates the first-order effect of LULCC over Greater Phoenix using high-resolution (2-km grid spacing) Regional Atmospheric Modeling System (RAMS) simulations of three "wet" and three "dry" summer seasons. Experiments were carried out with two different landscape reconstructions for the region: a circa-1992 representation based on satellite observations and a hypothetical "pre-settlement" scenario where the anthropogenic landscape of irrigated agriculture and urban pixels was replaced with current semi-natural vegetation. The main findings are:
--The presence of extensive irrigated agriculture adjacent to the urban area dampens the regional-mean warming due to urbanization.
--The imposed LULCC produces a systematic increase in precipitation to the north and east of the city during dry summers.
Guided by these findings, the impact of the actual landscape evolution, using LULC reconstructions based on circa-1973, circa-1992, and circa-2001 satellite data, on the Greater Phoenix regional climate was examined, and the relevant atmospheric dynamical processes investigated. The main findings are:
--From 1973 to 2001, areal coverage of irrigated agriculture declined and that of urban areas increased, resulting in significantly greater simulated regional-mean temperatures for the 2001 than for the 1973 LULC.
--As with the 1992 to pre-settlement comparison, precipitation is enhanced for the 2001 compared to the 1973 landscape during dry summers. In addition, rainfall enhancement relative to the 1973 LULC is increased for 2001 relative to the 1992 LULC.
--Heterogeneity in the surface fluxes produces preferentially located mesoscale circulations on most days that are stronger for the 2001 compared to the 1973 LULC, due to the increased planetary boundary layer (PBL) heating via enhanced turbulent heat flux.
--The effect of these stronger circulations is to warm and dry the lower part of the PBL and moisten the upper part of the PBL for 2001 relative to 1973.
--The precise physical pathway(s) whereby precipitation enhancement occurs with evolving landscape reveals a complicated interplay among scales that warrants future research.
NoteIncludes bibliographical references (p. 93-101).
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.