TY - JOUR
T1 - Regional Impacts of Urban Irrigation on Surface Heat Fluxes and Rainfall in Central Arizona
AU - Yang, Yan
AU - Smith, James A.
AU - Yang, Long
AU - Baeck, Mary Lynn
AU - Ni, Guangheng
N1 - Funding Information:
This research was financially supported by the National Key Research and Development Program of China (2018YFA0606002) and, the National Science Foundation grants (EAR-576 1632048, AGS-1522492, and CBET-1444758). L.Y. also acknowledges support from Strategic Priority Research Program of the Chinese Academy of Sciences (XDA 230402). The authors would also like to acknowledge high-performance computing support from Cheyenne provided by NCAR Computational and Information Systems Laboratory, sponsored by the National Science Foundation through projects UPRI0004 and UPRI0015. Observational data set are obtained through the Flood Control District of Maricopa (http://alert.fcd.maricopa.gov/alert/Google/v3/wx.html and http://www.suominet.ucar.edu/data/staYrDay) and the University of Wyoming radiosonde archive (http://weather.uwyo.edu/upperair/sounding.html).
Publisher Copyright:
©2019. American Geophysical Union. All Rights Reserved.
PY - 2019/6/27
Y1 - 2019/6/27
N2 - Rapid urbanization over Phoenix has resulted in increased water consumption for maintenance of green spaces and heat stress mitigation. The hydrometeorological impact of urban irrigation is not well understood and is the principal objective of this study. Our results are based on high-resolution numerical experiments using the Weather Research and Forecasting model. A simple irrigation scheme is implemented into the Weather Research and Forecasting model to represent changes in soil moisture due to irrigation. A monthlong simulation using the Weather Research and Forecasting model with irrigation shows improved model performance in representing the regional water and energy cycle. Comparisons of model simulations with and without irrigation highlight the regional impacts of urban irrigation on surface heat fluxes and rainfall variability over Phoenix. There is a strong modulation of irrigation on surface energy partitioning over both irrigated and nonirrigated areas. Irrigation increases (decreases) surface latent (sensible) heat fluxes by enhanced evapotranspiration over irrigated areas, with opposing changes presented over nonirrigated areas. Irrigation contributes little to the domain-average rainfall accumulation, but can noticeably modify its spatial distribution, with increased rainfall over the downwind mountainous regions and decreased rainfall over the irrigated areas. Irrigation-induced rainfall anomalies can be tied to strengthened thermal gradients and induced changes in surface pressure fields, which lead to perturbations on large-scale flow and its interactions with complex terrain. Our results shed light on the hydrometeorological impacts of increasing anthropogenic water use driven by urbanization and highlight the importance of accurate representations of land surface processes in better characterizing land-atmosphere interactions in arid/semiarid regions.
AB - Rapid urbanization over Phoenix has resulted in increased water consumption for maintenance of green spaces and heat stress mitigation. The hydrometeorological impact of urban irrigation is not well understood and is the principal objective of this study. Our results are based on high-resolution numerical experiments using the Weather Research and Forecasting model. A simple irrigation scheme is implemented into the Weather Research and Forecasting model to represent changes in soil moisture due to irrigation. A monthlong simulation using the Weather Research and Forecasting model with irrigation shows improved model performance in representing the regional water and energy cycle. Comparisons of model simulations with and without irrigation highlight the regional impacts of urban irrigation on surface heat fluxes and rainfall variability over Phoenix. There is a strong modulation of irrigation on surface energy partitioning over both irrigated and nonirrigated areas. Irrigation increases (decreases) surface latent (sensible) heat fluxes by enhanced evapotranspiration over irrigated areas, with opposing changes presented over nonirrigated areas. Irrigation contributes little to the domain-average rainfall accumulation, but can noticeably modify its spatial distribution, with increased rainfall over the downwind mountainous regions and decreased rainfall over the irrigated areas. Irrigation-induced rainfall anomalies can be tied to strengthened thermal gradients and induced changes in surface pressure fields, which lead to perturbations on large-scale flow and its interactions with complex terrain. Our results shed light on the hydrometeorological impacts of increasing anthropogenic water use driven by urbanization and highlight the importance of accurate representations of land surface processes in better characterizing land-atmosphere interactions in arid/semiarid regions.
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U2 - 10.1029/2018JD030213
DO - 10.1029/2018JD030213
M3 - Article
AN - SCOPUS:85068073125
SN - 2169-897X
VL - 124
SP - 6393
EP - 6410
JO - Journal of Geophysical Research: Atmospheres
JF - Journal of Geophysical Research: Atmospheres
IS - 12
ER -