Analysis of Changes in Surface Energy Fluxes Due to Urbanization in Las Vegas

Document Type

Conference Proceeding

Publication Date

5-16-2019

Publication Title

World Environmental and Water Resources Congress 2019: Groundwater, Sustainability, Hydro-Climate/Climate Change, and Environmental Engineering

Publisher

American Society of Civil Engineers

Publisher Location

Pittsburgh, PA

Volume

2019

First page number:

175

Last page number:

186

Abstract

Las Vegas have undergone significant development in the past two decades in the form of pavements and buildings. Surface energy of the city has changed due to urbanization that plays crucial role in urban heat island effect and in altering the energy for evaporation and transpiration. It indirectly contributes to the urban hydrological cycle. Role of urbanization on the surface energy balance is an active area of research. The objective of this study is to relate surface energy fluxes (net radiation and soil heat flux) to urban land cover. The changes of buildup and vegetation land cover between pre-urbanized and urbanized conditions are analyzed for their impact on surface energy budget in the Las Vegas city. Changes from rural surface to four land use classes including residential, commercial, vegetative turf, and parking areas are considered. The surface energy balance algorithm (SEBAL) is used with Landsat data to estimate surface fluxes including net radiation and soil heat flux density. The land surface characteristics including normalized difference vegetation index (NDVI), land surface temperature (LST), and albedo are analyzed. The time frame of the study is 2002 to 2017 which coincides with implementation of water smart landscape (WSL) program in Las Vegas. WSL is a rebate program that has promoted xeriscaping thus reducing the vegetation turf and urban water demand. The results reveal increase in net radiation and reduction in soil heat flux due to land cover change from rural to urban. These are related to the surface albedo and potentially the cause of decrease in temperature.

Keywords

Land cover change; Las vegas; Surface energy balance algorithm (SEBAL); Surface fluxes

Disciplines

Environmental Engineering | Environmental Sciences

Language

English

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