Non-Contact River Discharge and Precipitation Measurements

美国地质调查局经常通过监测河流的高度或水位来测量美国7000多个地点的河流流量。这就要求准确地知道水位和流量之间的关系。目前获取此类校准数据的方法是将仪器和人员放入水中。在高流速下，这种测量既困难又危险；在极高流速下，根本无法进行测量。然而，在非常高的流速下，为了监测和预测洪水情况，对这些测量的需求尤其迫切。在这项提案中，我们概述了开发一种能够在几乎所有水流条件下遥测河流流量的微波系统的研究。此外，该系统还将提供降雨信息。我们的方法是构建一组简单的连续波微波系统和算法来分析它们的输出，以便远程和连续地获得河流表面速度和雨量。该项目的主要重点将是获得准确的电流和降雨率所需的算法，因为微波和数据采集系统将相对简单。水流信息包含在从河流向后散射的微波的多普勒频移中，而降雨率与雨滴返回的强度有关。原型系统的初步应用将是在华盛顿州卡斯尔罗克附近的考利茨河上的一座桥上进行长期测量。这项工作将与美国地质调查局合作进行，美国地质调查局将在大桥附近的索道上安装探地雷达的天线。这项研究将为河流流量和降雨量的测量提供廉价、便携的系统。利用这些系统进行持续的远程测量将改进关于水资源分配的国际和国家间协定的发展和监测；提供径流数据以管理和改善水质；评估影响河流和河岸生境质量的河流环境变化；并改进对洪水频率和洪水淹没面积的估计。

0106391PlantThe US Geological Survey routinely measures river discharge at more than 7000 sites in the United States by monitoring the height, or stage, of the rivers. This requires that the relation between stage and discharge be accurately known. Present methods of acquiring such calibration data place instruments and, often personnel, in the water. At high flow rates such measurements are both difficult and hazardous; at extremely high rates, they cannot be made at all. Yet the need for these measurements is especially acute at very high flow rates in order to monitor and predict flooding conditions. In this proposal we outline research to develop a microwave system capable of remotely measuring river discharge under nearly all flow conditions. Additionally, the system will provide infon-nation on rainfall.Our approach is to construct an array of simple continuous-wave microwave systems and algorithms for analyzing their output in order to obtain river surface velocities and rain rates remotely and continuously. The primary focus of the project will be on the algorithms needed to obtain accurate currents and rain rates since the microwave and data acquisition systems will be relatively simple. Current information is contained in the Doppler shift of the microwaves backscattered from the river while rain rates are related to the intensity of the return from raindrops. The initial application of the prototype system will be long-term measurements from a bridge on the Cowlitz River near Castle Rock, WA. The work will be carried out in collaboration with the USGS, who will mount the antenna of a ground-penetrating radar on a cableway near the bridge. The combined measurements have the potential to yield discharge.This research will provide inexpensive, portable systems for making river discharge and precipitation measurements. Continuous, remote measurements with these systems will improve development and monitoring of international and interstate agreements on allocation of water resources; provide streamflow data to manage and improve water quality; assess changes in the riverine environment that affect the quality of river and riparian habitat; and improve the estimation of flood frequency and flood inundation areas.