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ARS Home » Plains Area » Fort Collins, Colorado » Center for Agricultural Resources Research » Water Management and Systems Research » Research » Publications at this Location » Publication #387739

Research Project: Improving the Sustainability of Irrigated Farming Systems in Semi-Arid Regions

Location: Water Management and Systems Research

Title: Explaining water security indicators using hydrologic and agricultural systems models

Author
item VEETTIL, ANOOP - Prairie View A & M University
item MISHRA, ASHOK - Clemson University
item Green, Timothy

Submitted to: Journal of Hydrology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/11/2022
Publication Date: 1/22/2022
Citation: Veettil, A.V., Mishra, A.K., Green, T.R. 2022. Explaining water security indicators using hydrologic and agricultural systems models. Journal of Hydrology. 607. https://doi.org/10.1016/j.jhydrol.2022.127463.
DOI: https://doi.org/10.1016/j.jhydrol.2022.127463

Interpretive Summary: Water security assessment has attracted much political and economic attention in recent years. Water demand has increased sharply in many regions and sectors as a result of drastic population growth and economic expansion. Likewise, changing patterns of land use and climate variables affect water supply. Here, we discuss the need for improved water security assessment, the various water security indicators used to address the water shortage, application of the water footprint concept in different sectors, and the importance of physically based hydrological models, which can be used to perform water security assessment at the necessary details. In particular, the study focused on the application of a fully distributed Agricultural Ecosystems Service (AgES) model to determine water footprints across an intensively managed and irrigated semiarid watershed located in the western United States.

Technical Abstract: Over the last several decades, water security assessment has attracted much political and economic attention. An improved understanding of the relationships between water demand and supply is needed to mitigate the impacts of diminishing water security. This study provides an overview of water security assessment by focusing on the various water security indicators and the concept of water footprint (blue, green, and grey water). Our review identifies many water security indicators capable of addressing and characterizing water security at different scales. Currently, the set of water security indicators based on the water footprint concept is receiving more attention because it accounts for the return flow from the total water withdrawn from a watershed. We also investigate the application of different physically-based hydrological models, such as Soil and Water Assessment Tool (SWAT) and Variable Infiltration Capacity (VIC) on water security assessment at a regional to continental scale. However, quantifying blue and green water footprint separately from a mixed rain-fed (i.e., green water) and irrigated (i.e., blue water) land scape is challenging because none of the hydrological/crop models can quantify consumptive use from irrigated and rainwater separately. For illustration purposes, we apply the fully distributed Agricultural Ecosystems Services (AgES) model in the Big Dry Creek Watershed (BDCW), an intensively managed and irrigated watershed located in semiarid Colorado. The results indicate that the blue water footprint is higher than the green water footprint in the watershed. In addition, the spatial distribution of grey water footprint is highly correlated with the amount of fertilizer application. The variation of grey water footprint in the irrigated fields is higher than blue and green water footprints. We conclude that applying a physically distributed model can provide useful insight into the impact of climate and anthropogenic activity on water security at different scales.