Climate Sensitivity of Agricultural Water Demand Depends on Control Over Growing Season: Implications for Producers in the Upper Colorado River Basin
Journal Article
Overview
abstract
Abstract; Climate change impacts on agricultural water demand are deeply uncertain due to complex interactions between precipitation, temperature, growing season dynamics, and water allocation systems. Accordingly, it remains unclear whether a producer who lengthens their growing season in response to warming increases production or compounds temperature‐driven stress, and whether the answer depends on crop choice, location, and water allocation. To address this, we pair a multivariate, multisite stochastic weather generator with a regional consumptive use model in a bottom‐up exploratory analysis of drought‐driven agricultural impacts across diverse water users. We apply this framework in Colorado's Upper Colorado River Basin, where users hold water rights of varying seniority, grow a variety of crops, and frequently experience drought. Through this exploration of plausible hydroclimatic conditions, we find that a user's sensitivity to the hydroclimate depends more on their choice to lengthen the growing season than on their choice of crops, elevation, or location in the basin. Producers with enough legally allocated water to extend their growing seasons are more sensitive to annual temperature mean and variance, while those without sufficient water or who restrict their seasons are more sensitive to the variance of annual precipitation. Notably, while this temperature sensitivity exposes producers extending their seasons to greater magnitudes of water demand, the frequency of exceeding historical demand across explored conditions is approximately equal whether or not they extend. These differential vulnerability drivers underscore the need for stakeholder‐specific assessments that account for spatial heterogeneity and decision‐relevant uncertainties in agricultural water demand.
