Date of this Version
XX Congresso Brasileiro de Águas Subterrâneas pg. 1-4
Groundwater is vital worldwide for water supply, agriculture and industry. Nearly 60% of all water use in Nebraska is from groundwater. Over 90% of groundwater is used for irrigation in Nebraska, which has the largest area of irrigated land in the United States. Many Nebraskans depend on groundwater for drinking water, both from private wells and municipal wells. The sustainability of groundwater resources is dependent on groundwater recharge. The recharge processes, as well as climatic patterns, influence the stable isotope signatures.
Based on weekly samples collected at two monitoring stations managed by the National Atmospheric Deposition Program (NADP), Harvey (2001) and Harvey and Welker (2000) presented an overview of isotopic composition of precipitation in Nebraska. Two stations, located in Mead and North Platte (Figure 1), were monitored from 1992-1994 and 1989-1994, respectively. This data illustrated patterns in the isotopic composition of precipitation, both spatially and seasonally.
To better understand the recharge processes, over 789 groundwater samples were collected across Nebraska in 2011 and their isotopic signatures analyzed. While other studies have evaluated isotope ratios (seasonal ratios) (Jasechko et al., 2017; Sanchéz-Murillo and Birkel., 2016), in this study we compared the precipitation signals. The objective of this study was to investigate recharge characteristics based on stable isotope signatures of groundwater and comparisons of the isotopic composition of groundwater and precipitation across Nebraska.