Digital data sets that describe aquifer characteristics of the Tillman terrace and alluvial aquifer in southwestern Oklahoma

This data set consists of digital water-level elevation contours for the Tillman terrace and alluvial aquifer in southwestern Oklahoma. The Tillman terrace and alluvial aquifer is an unconfined aquifer that extends over an area of approximately 285 square miles and is used for irrigation and domestic purposes. The aquifer encompasses the unconsolidated terrace deposits and river alluvium associated with the North Fork of the Red River and the Red River in the western half of Tillman County. These sediments consist of discontinuous layers of clay, sandy clay, sand, and gravel. Water-level elevation contours for ground-water levels measured in 1969 were digitized from a paper map in a thesis in which the ground-water flow was modeled in the Tillman terrace and alluvial aquifer. The map was published at a scale of 1:249,695. Water-level elevations ranged from about 1,360 feet above sea level in the eastern part of the aquifer to 1,120 feet above sea level in the southern part of the aquifer.本数据集收录俄克拉荷马州西南部蒂尔曼阶地（Tillman terrace）与冲积含水层（alluvial aquifer）的数字水位高程等值线。蒂尔曼阶地及冲积含水层为无压含水层（unconfined aquifer），分布面积约285平方英里，主要用于灌溉与生活供水。该含水层涵盖与雷德河北支流（North Fork of the Red River）及雷德河（Red River）相关的未固结阶地沉积物与河流冲积物，分布于蒂尔曼县（Tillman County）西部区域。此类沉积物由不连续分布的黏土、砂质黏土、砂及砾石层构成。 1969年实测地下水位对应的高程等值线，源自一篇针对蒂尔曼阶地及冲积含水层开展地下水流模拟研究的学位论文中的纸质地图，经数字化处理所得。该纸质地图的比例尺为1:249,695。地下水位高程介于1120英尺至1360英尺之间，其中含水层东部区域海拔约1360英尺，南部区域海拔约1120英尺。