Potential effects of projected climate variability on base flow and groundwater storage in the North Fork Red River aquifer, Oklahoma (USA), were estimated using downscaled climate model data coupled with a numerical groundwater-flow model. The North Fork Red River aquifer discharges groundwater to the North Fork Red River, which provides inflow to Lake Altus. To approximate future conditions, Coupled Model Intercomparison Project Phase 5 climate data were downscaled to the watershed and a time-series of scaling factors were developed and interpolated for three climate scenarios (central tendency, warmer and drier, and less warm and wetter) representing future climate conditions for the period 2045–2074. These scaling factors were then applied to a soil-water-balance model to produce groundwater recharge and evapotranspiration estimates. A MODFLOW groundwater-flow model of the North Fork Red River aquifer used the scaled recharge and evapotranspiration data to estimate changes in base flow and water-surface elevation of Lake Altus. Compared to a baseline scenario, the mean percent change in annual base flow during 2045–2074 was −10.8 and −15.9% for the central tendency and warmer/drier scenarios, respectively; the mean percent change in annual base flow for the less-warm/wetter scenario was +15.7%. The mean annual percent change in groundwater storage for the central tendency, warmer/drier, and less-warm/wetter climate scenarios and the baseline are −2.7, −3.2, and +3.0%, respectively. The range of outcomes from the climate scenarios may be influenced by variability in the downscaled climate data for precipitation more than for temperature.

使用缩减的气候模型数据和数值地下水流模型，估算了预计的气候变化对俄克拉荷马州北福克红河含水层基本流量和地下水存储的潜在影响。北叉红河含水层向北叉红河排放地下水，该水向阿尔特斯湖流入。为了近似未来的条件，将耦合模型比较项目的第5阶段气候数据缩小到分水岭，并针对代表未来的三种气候情景（集中趋势，温暖和干燥以及较少温暖和潮湿）开发了比例因子的时间序列并进行了内插。 2045–2074年期间的气候条件。然后将这些比例因子应用于土壤-水平衡模型，以产生地下水补给量和蒸散量估计值。北叉红河含水层的MODFLOW地下水流模型使用规模化的补给量和蒸散量数据估算了阿尔特斯湖的基本流量和水面高程的变化。与基准情景相比，在2045–2074年期间，集中趋势情景和暖/干情景的年平均基准流量变化百分比分别为-10.8和-15.9％。较不温暖/较冷的情况下，年度基本流量的平均变化百分比为+ 15.7％。对于中心趋势，较暖和较干燥，较不暖和较暖的气候情景以及基线，地下水存储的年均变化百分比分别为-2.7％，-3.2％和+ 3.0％。气候情景的结果范围可能受到降尺度气候数据变化的影响，降水量多于温度。