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sur le développement des zones arides et semi-arides

Titre : Multivariate Analysis of the 2021 Boise Drought in the Context of Natural Human Systems

Auteur : Martinez-Osario, Jesus

Université de soutenance : Boise State University

Grade : Master of Science in Civil Engineering 2022

Résumé partiel
Droughts generally refer to lack of sufficient water to supply specific needs, and has several categories including meteorological, hydrologic, agricultural and socioeconomic droughts [22]. Drought is triggered by the lack of or reduced precipitation, but other factors including low soil moisture, groundwater depletion, insufficient snowpack, reduced surface storage, increased evaporation, and contaminated surface water also contribute to various drought categories [12, 27].

Droughts impact many functional aspects of a community including agricultural production, recreation, access to clean drinking water, and the health of local ecosystems. Arid and semi-arid regions such as Idaho are specifically vulnerable to drought [12]. According to the Idaho State Department of Agriculture, agriculture makes up approximately 18% of the state’s total economic output, and hence drought is a major concern in Idaho. As of October 12th, 2021, > 90% of Idaho was in a severe, extreme, or exceptional drought according to the U.S. Drought Monitor [32]. This drought was specifically impactful for Idahoans, since a reasonable amount of snowpack and dam storage in the spring convinced local farmers to fully cultivate their farms and they struggled to irrigate their crops later in the season.

I focused this research on a multivariate analysis of the 2021 Boise drought in the context of natural-built systems. I considered two natural storages : (1) snowpack and (2) atmospheric storage, i.e., spring precipitation, as well as the built storage facilities like reservoirs, specifically the three dams on tributaries flowing into the Boise River watershed. I obtained historical (1982-2021) data for the Boise River watershed in terms of snow water equivalent and total dam storage on April 1st for each of the years studied, as well as spring precipitation, which collectively supports irrigation of agriculture in the Treasure Valley [4, 6]. Both univariate and multivariate frequency analyses were conducted to obtain a nuanced understanding of the drivers of the 2021 Boise drought. This provides important insights for the future conditions of drought initiation and evolution in the region in a warming climate.

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