IMPACT OF HYDRO-CLIMATIC FACTORS AND RESOURCE EXTRACTION ACTIVITIES ON SURFACE WATER AND GROUNDWATER INFLOWS TO SALT PLAINS NATIONAL WILDLIFE REFUGE IN OKLAHOMA, USA

The Salt Plains National Wildlife Refuge (SPNWR) ecosystem in northwestern Oklahoma, U.S.A., consists of roughly 65 km² of hypersaline salt flats, wetlands, and the Great Salt Plains (GSP) Lake, which serve as critical habitat for an array of migratory bird populations. The SPNWR flats and GSP Lake are fed by tributaries of the Arkansas River and increasing pressure on surface and groundwater inflows have resulted in declining surface flow and lake levels with negative implications for habitat management. Limited work has been conducted to determine whether climatic fluctuations or anthropogenic activities, such as the expansion of nonconventional gas and oil extraction activities, have driven these declines. The objective of this work is to investigate potential influence of climatic characteristics and the oil and gas extraction activities on the surface and groundwater inflows in the SPNWR contributing watershed. We collect historical streamflow and well level records from USGS monitoring stations, GSP Lake level data from the US Army Corps of Engineers Water Control Data System records, monthly temperature and precipitation data from the Western Regional Climate Center for the GSP Dam, oil and gas well records from the Oklahoma Corporation Commission and Kansas Corporation databases, and ground and surface water permit records from the Kansas Geological Survey Water Information Management and Analysis System and the Oklahoma Water Resources Board. Preliminary results indicate that precipitation at the site has experienced a weak positive increase since 1943 (p < 0.01; 𝜏 = 0.07). Notably, the number of recorded oil and gas well constructed exhibits a linear increase of roughly 5 wells per year until the early 2010s, when the rate appears to increase to more than 200 wells per year until around 2015. This increase in construction rate coincides with observed water level anomalies observed in streamflow and lake level data. Further statistical analyses will determine whether significant streamflow change points exist coinciding with nonconventional oil and gas well development. Understanding how climatic and anthropogenic influences impact water inflows that support critical habitat in the SPNWR flats is imperative for both management of the flats and mitigating the impacts of anthropogenic activity.