Eddy covariance-measured greenhouse gas exchange in the Dutch peat meadows and fens: first results on effects of peat type and management

Drivers of nitrogen and phosphorus dynamics in a groundwater-fed urban catchment revealed by high-frequency monitoring

Time lags of nitrate, chloride, and tritium in streams assessed by dynamic groundwater flow tracking in a lowland landscape

Urban hydrogeology: Transport routes and mixing of water and solutes in a groundwater influenced urban lowland catchment

Urban areas in coastal lowlands host a significant part of the world's population. In these areas, cities have often expanded to unfavorable locations that have to be drained or where excess rain water and groundwater need to be pumped away in order to maintain dry feet for its citizens. As a result, groundwater seepage influences surface water...

Transient groundwater travel time distributions and age-ranked storage-discharge relationships of three lowland catchments

The contribution of groundwater to streams is controlled by temporally and spatially variable groundwater flow paths with distinctive travel times. The aggregated average travel time distribution (TTD) of all these flow paths functions as a catchment characteristic. Currently, research on TTDs is expanding towards dynamic TTDs and building on...

High-frequency monitoring of water fluxes and nutrient loads to assess the effects of controlled drainage on water storage and nutrient transport

High nitrogen (N) and phosphorus (P) fluxes from upstream agriculture threaten aquatic ecosystems in surface waters and estuaries, especially in areas characterized by high agricultural N and P inputs and densely drained catchments like the Netherlands. Controlled drainage has been recognized as an effective option to optimize soil moisture...

Strategic monitoring to account for rapid variations in the nitrate concentration of groundwater and surface water

As part of two PhD projects, we installed ion-selective electrodes and passive samplers for monitoring nitrate concentrations in a 7 km 2 catchment and compared the results to grab samples. We also monitored nitrate concentrations at the catchment outlet. We tested the effectiveness of these monitoring approaches to estimate the long-term...

Improving catchment discharge predictions by inferring flow route contributions from a nested-scale monitoring and model setup

Identifying effective measures to reduce nutrient loads of headwaters in lowland catchments requires a thorough understanding of flow routes of water and nutrients. In this paper we assess the value of nested-scale discharge and groundwater level measurements for the estimation of flow route volumes and for predictions of catchment discharge. In...

Direct measurements of the tile drain and groundwater flow route contributions to surface water contamination: From field-scale concentration patterns in groundwater to catchment-scale surface water quality

Enhanced knowledge of water and solute pathways in catchments would improve the understanding of dynamics in water quality and would support the selection of appropriate water pollution mitigation options. For this study, we physically separated tile drain effluent and groundwater discharge from an agricultural field before it entered a 43.5-m...

Nitrate response of a lowland catchment: On the relation between stream concentration and travel time distribution dynamics

Nitrate pollution of surface waters is widespread in lowland catchments with intensive agriculture. For identification of effective nitrate concentration reducing measures the nitrate fluxes within catchments need to be quantified. In this paper we applied a mass transfer function approach to simulate catchment‐scale nitrate transport. This...

Improving load estimates for NO₃ and P in surface waters by characterizing the concentration response to rainfall events

For the evaluation of action programs to reduce surface water pollution, water authorities invest heavily in water quality monitoring. However, sampling frequencies are generally insufficient to capture the dynamical behavior of solute concentrations. For this study, we used on-site equipment that performed semicontinuous (15 min interval) NO...

Application and evaluation of a new passive sampler for measuring average solute concentrations in a catchment scale water quality monitoring study

We present a field based testing, optimization, and evaluation study of the SorbiCell sampler (SC-sampler); a new passive sampling technique that measures average concentrations over longer periods of time (days to months) for various substances. We tested the SC-sampler within a catchment-scale monitoring study of NO₃ and P...

Integrated modeling of groundwater-surface water interactions in a tile-drained agricultural field: The importance of directly measured flow route contributions

Understanding the dynamics of groundwater-surface water interaction is needed to evaluate and simulate water and solute transport in catchments. However, direct measurements of the contributions of different flow routes from specific surfaces within a catchment toward the surface water are rarely available. For this study, we physically...

Field-scale measurements for separation of catchment discharge into flow route contributions

Agricultural pollutants in catchments are transported toward the discharging stream through various flow routes such as tube drain flow, groundwater flow, interflow, and overland flow. Direct measurements of flow route contributions are difficult and often impossible. We developed a field-scale setup that can measure the contribution of the tube...

Nested-scale discharge and groundwater level monitoring to improve predictions of flow route discharges and nitrate loads

Identifying effective measures to reduce nutrient loads of headwaters in lowland catchments requires a thorough understanding of flow routes of water and nutrients. In this paper we assess the value of nested-scale discharge and groundwater level measurements for predictions of catchment-scale discharge and nitrate loads. In order to relate...