Articles | Volume 20, issue 9
Hydrol. Earth Syst. Sci., 20, 3619–3629, 2016

Special issue: High resolution monitoring strategies for nutrients in groundwater...

Hydrol. Earth Syst. Sci., 20, 3619–3629, 2016

Review article 07 Sep 2016

Review article | 07 Sep 2016

High-resolution monitoring of nutrients in groundwater and surface waters: process understanding, quantification of loads and concentrations, and management applications

Frans C. van Geer1,2, Brian Kronvang3, and Hans Peter Broers1 Frans C. van Geer et al.
  • 1TNO – Geological Survey of the Netherlands, P.O. Box 80015, 3508 TA Utrecht, the Netherlands
  • 2Department of Physical Geography, Faculty of Geosciences, Utrecht University, P.O. Box 80115, 3508 TC Utrecht, the Netherlands
  • 3Department of Bioscience, Aarhus University, Vejlsøvej 25, 8600 Silkeborg, Denmark

Abstract. Four sessions on "Monitoring Strategies: temporal trends in groundwater and surface water quality and quantity" at the EGU conferences in 2012, 2013, 2014, and 2015 and a special issue of HESS form the background for this overview of the current state of high-resolution monitoring of nutrients. The overview includes a summary of technologies applied in high-frequency monitoring of nutrients in the special issue. Moreover, we present a new assessment of the objectives behind high-frequency monitoring as classified into three main groups: (i) improved understanding of the underlying hydrological, chemical, and biological processes (PU); (ii) quantification of true nutrient concentrations and loads (Q); and (iii) operational management, including evaluation of the effects of mitigation measures (M). The contributions in the special issue focus on the implementation of high-frequency monitoring within the broader context of policy making and management of water in Europe for support of EU directives such as the Water Framework Directive, the Groundwater Directive, and the Nitrates Directive. The overview presented enabled us to highlight the typical objectives encountered in the application of high-frequency monitoring and to reflect on future developments and research needs in this growing field of expertise.

Short summary
The paper includes a review of the current state of high-frequency monitoring in groundwater and surface waters as an outcome of a special issue of HESS and four sessions at EGU on this topic. The focus of the paper is to look at how high-frequency monitoring can be used as a valuable support to assess the management efforts under various EU directives. We conclude that we in future will see a transition from research to implementation in operational monitoring use of high-frequency sensors.