Acoustic, Spatial, and Sediment Size Data Collected on the Upper Colorado River to Estimate the Flushing Flows, Colorado, 2019

In 2019, the U.S. Geological Survey, in cooperation with the Upper Colorado River Wild and Scenic Stakeholder Group, studied the magnitude and frequency of streamflow needed to initiate bedload transport of gravel-sized and finer sediment on the Colorado River to maintain spawning habitat for fish and maintain substrate and interstitial spaces for benthic macroinvertebrates. Bedload transport occurs more frequently and at lower streamflows downstream from State Bridge compared to the study area upstream from State Bridge. Two independent, yet complementary, lines of evidence were collected to determine the presence of bedload transport. Two stationary hydrophone systems were installed on April 23, 2019 at the above Catamount Bridge site and two others on April 24, 2019 at the Radium site. These four systems monitored bedload transport until all the stationary hydrophone systems were removed on August 26, 2019. These provided continuous temporal data on the presence of bedload transport at four stationary locations. Two longitudinal profiles were carried out at different streamflows which collected hydrophone data throughout the study area on June 6-8, 2019 (June 6-8 longitudinal profile) and June 18-19, 2019 (June 18-19 longitudinal profile). The June 6-8 longitudinal profile began at the Pumphouse Recreation Area and ended at the Dotsero boat launch located at Dotsero, CO. The June 18-19 longitudinal profile began at the Pumphouse Recreation Area and ended at the Catamount Bridge boat launch which is at the Catamount streamgage.

2019年，美国地质调查局（U.S. Geological Survey）与科罗拉多河上游野生与风景河段利益相关者小组合作开展研究，旨在明确科罗拉多河各河段启动砾石级及更细沉积物推移质输运（bedload transport）所需的径流量规模与频率，以维持鱼类产卵栖息地，并为底栖大型无脊椎动物（benthic macroinvertebrates）保留底质与空隙空间。相较于州桥（State Bridge）上游的研究区域，该桥下游的推移质输运发生频率更高，且所需径流量更低。研究采用两组独立且互为补充的证据路径判定推移质输运的存在。2019年4月23日，研究人员在卡吞特桥（Catamount Bridge）上游点位部署了两套固定式水听器系统（stationary hydrophone systems）；同年4月24日，又在镭点位（Radium site）布设了另外两套。上述四套系统持续监测推移质输运，直至2019年8月26日所有固定式水听器被拆除，由此获取了四个固定点位上推移质输运存在情况的连续时序数据。研究团队在不同径流量条件下开展了两次纵向剖面（longitudinal profiles）测量，分别于2019年6月6日至8日（6月6-8日纵向剖面）及6月18日至19日（6月18-19日纵向剖面）采集了整个研究区域的水听器数据。其中，6月6-8日纵向剖面的测量起点为泵房游乐区（Pumphouse Recreation Area），终点为位于科罗拉多州多瑟罗的多瑟罗船只停靠点；6月18-19日纵向剖面的起点同样为泵房游乐区，终点为卡吞特河流水位监测站处的卡吞特桥船只停靠点。