Weather Station Siting and Consumptive Use Estimates

Abstract

ABSTRACT:The environment of a weather station site is important in estimating consumptive use by irrigated crops. Consumptive use may be overestimated when air temperature and vapor pressure data from a weather station with an arid local environment are used without modification. To document the effect of weather station aridity on consumptive use estimates, three sites in irrigated areas and two sites in nonirrigated, arid rangeland in southern Idaho were instrumented with weather stations during 1981. Air temperatures were higher and vapor pressures were lower at the arid sites. Use of air temperatures and dewpoint estimates from arid sites caused an overestimation of ET, by 17% (210 mm) over the irrigation season. Results indicate the importance of weather site evaluation and adjustment of siting effects and weather before consumptive use estimates are made. A procedure is outlined for adjusting historical temperature data to reflect an irrigated condition.

Untangling global change impacts on hydrological processes: Resisting climatization

“…As the saying "garbage in, garbage out" attests, the results of research will be no better than the input data selected. A great deal of literature has demonstrated compellingly the wide variance of data source quality (Allen, 1996;Allen, Brockway, & Wright, 1983;Allen, Pereira, Howell, & Jensen, 2011) and the sensitivity of modelling outcomes to input data quality (Oyler, Dobrowski, Ballantyne, Klene, & Running, 2015). Data quality issues may include both inhomogeneity of measurements over time-thus preventing time series analysis-and biases in which measurement protocols remain homogeneous, but a shortcoming of the methodology results in consistent overestimation or underestimation of the quantity of interest.…”

Identifying Seasonal Opportunities to Save Water: Using Weekly Rainfall and Evapotranspiration Patterns to Evaluate Outdoor Water Restriction Policy in South Florida

“…It is worth noting that urban settings are fundamentally different from the open field conditions where estimates of RET are based on measurements of solar radiation, temperatures, and wind speeds that are optimized by large, undeveloped, unshaded expanses of vegetation [33]. Just as the built and landscaped suburban environment provides wind breaks to reduce rainfall measurements, so does it also introduce wind breaks and shade factors that reduce rates of evapotranspiration [34,35].…”

Evaporation and Transpiration

“…When air temperature and humidity data are required for use in an ET 0 calculation, they may need to be adjusted to account for dryness of the weather station environment. Allen et al (1983) and Allen and Pruitt (1986) developed empirical procedures for adjusting air temperature measurements from weather stations located in environments where ET was less than maximum rates due to limited soil moisture or green vegetation. The objective of the adjustments was to create air temperature data sets reflective of well-watered environments over clipped grass for use in an ET 0 equation.…”

“…In the application to weather stations in Idaho, daily maximum and minimum air temperatures were adjusted downward by as much as 4.5°C for stations having nonirrigated, nontranspiring surfaces surrounded by similar conditions. The magnitude of adjustments by Allen and Pruitt were based on paired observations of air temperatures by Allen et al (1983). Ley and Allen (1994) applied more complex methods for adjusting air temperature and humidity data from nonreference stations using energy balance and water balance relationships.…”