Water availability and use pilot: Methods development for a regional assessment of groundwater availability, southwest alluvial basins, Arizona

A simple method for estimating basin-scale groundwater discharge by vegetation in the basin and range province of Arizona using remote sensing information and geographic information systems

“…To put this number in perspective, this average groundwater discharge by vegetation value represents 54% of total groundwater pumpage in the study area in 2005 for all water uses including agricultural, municipal, and industrial (Tillman et al, 2011). Computed daily groundwater discharge by vegetation from 16-day MODIS satellite passes follow a cyclical pattern of low discharge volumes in the cooler, winter months and higher discharge volumes in summer months, with intermediate values occurring between these seasons (Fig.…”

“…Achieving this "safe yield" will depend upon an accounting of recharge and other inputs and withdrawals from groundwater systems in these basins. Discharge of groundwater by phreatophyte vegetation is a major component of groundwater budgets for basins in the study area (Anderson, 1995;Tillman et al, 2011). This manuscript presents the development of a simple method of determining a bounding estimate of basin-scale groundwater discharge by vegetation in southern and central Arizona.…”

“…Groundwater conditions and budgets for basins in the study area were a major focus of the project Tillman et al, 2011). Estimates of groundwater budgets at the basin scale are important for the development of groundwater flow models that may be used to predict the effects of future management actions (for example, expanded or increased pumping, development of aquifer storage facilities, etc.)…”

Foyer de risques agricoles liés à l'eau

“…Pendant les années de sécheresse, lorsque l'eau de surface se raréfie, les nappes souterraines sont de plus en plus fréquemment une source palliative importante pour les agriculteurs (OCDE, 2015a). Cependant, dans certaines zones, notamment certaines parties de la Californie et l'ensemble du bassin du Colorado, l'utilisation actuelle des eaux souterraines n'est pas durable et met en danger cette précieuse réserve pour l'avenir (Tillman et al, 2011 ;Castle et al, 2014 ;Famiglietti, 2014 ;UCCHM, 2014).…”

Estimating geoid height change in North America: past, present and future

“…The aquifers are made mostly of unconsolidated basin-filled deposits. It is estimated that 113 km 3 has been lost to storage during since the early 20th century (Tillman et al 2011). Table 2 summarizes aquifer characteristics and ground water depletion.…”