A novel high-frequency groundwater quality monitoring system
A novel high-frequency groundwater quality monitoring system
复制标题
一种新型高频地下水质量监测系统
DOI：
10.1007/s10661-018-6853-6
复制
发表时间：
2018
影响因子：
3
通讯作者：
Timothy M. Mathany
中科院分区：
文献类型：
--
作者：
J. Saraceno;J. Kulongoski;Timothy M. Mathany
近年来，对水质的高频率、长期监测彻底改变了对地表沃茨的研究。然而，这些技术在地下水中的应用受到远程抽取和分析地下水的能力的限制。本文介绍了一种新的自主地下水水质监测系统，采样多个威尔斯，以评估时间的变化，并确定地下水化学的趋势。该系统部署在美国加州弗雷斯诺附近，实时收集和传输供水和监测威尔斯井的高频数据，包括水温、电导率、pH值、溶解氧和硝酸盐。该系统由水质探头和光学硝酸盐传感器、歧管、潜水三相泵、变频驱动器、数据收集平台、太阳能电池板和可充电电池组组成。该歧管将水从三口威尔斯井引导到一组传感器，从而降低了与多传感器网络相关的设置和操作成本。在几年内以高频率对多口威尔斯井进行取样，提供了一种监测含水层中溶质垂直分布和迁移的手段。初步结果表明，短期内的硝酸盐，比电导率，溶解氧在浅层含水层的变化，而含水层的较深的部分保持不变的意见，可能会错过与传统的离散采样方法。在该含水层系统中，浅层含水层中的硝酸盐和电导率正在增加，而深层地下水化学的不变变化可能反映了相对缓慢的地下水流。相反，具有高地下水流速的系统，如岩溶含水层，已被证明表现出更高频率的地下水化学变化。利用监测期间较深含水层的稳定性来估计测量系统的不确定性，这些不确定性通常低于制造商规定的规格，从而能够识别水化学的细微变化，否则可能会被遗漏。
High-frequency, long-term monitoring of water quality has revolutionized the study of surface waters in recent years. However, application of these techniques to groundwater has been limited by the ability to remotely pump and analyze groundwater. This paper describes a novel autonomous groundwater quality monitoring system which samples multiple wells to evaluate temporal changes and identify trends in groundwater chemistry. The system, deployed near Fresno, California, USA, collects and transmits high-frequency data, including water temperature, specific conductance, pH, dissolved oxygen, and nitrate, from supply and monitoring wells, in real-time. The system consists of a water quality sonde and optical nitrate sensor, manifold, submersible three-phase pump, variable frequency drive, data collection platform, solar panels, and rechargeable battery bank. The manifold directs water from three wells to a single set of sensors, thereby reducing setup and operation costs associated with multi-sensor networks. Sampling multiple wells at high frequency for several years provided a means of monitoring the vertical distribution and transport of solutes in the aquifer. Initial results show short period variability of nitrate, specific conductivity, and dissolved oxygen in the shallow aquifer, while the deeper portion of the aquifer remains unchanged—observations that may be missed with traditional discrete sampling approaches. In this aquifer system, nitrate and specific conductance are increasing in the shallow aquifer, while invariant changes in deep groundwater chemistry likely reflect relatively slow groundwater flow. In contrast, systems with high groundwater velocity, such as karst aquifers, have been shown to exhibit higher-frequency groundwater chemistry changes. The stability of the deeper aquifer over the monitoring period was leveraged to develop estimates of measurement system uncertainty, which were typically lower than the manufacturer’s stated specifications, enabling the identification of subtle variability in water chemistry that may have otherwise been missed.
影响因子：
11.4
作者：
Rode, Michael;Wade, Andrew J.;Jomaa, Seifeddine
通讯作者：
Jomaa, Seifeddine