Open Hydrosystem Information Network: Greece’s new research infrastructure for water

Author(s):  
Andreas Efstratiadis ◽  
Nikos Mamassis ◽  
Antonis Koukouvinos ◽  
Demetris Koutsoyiannis ◽  
Katerina Mazi ◽  
...  

<p>The Open Hydrosystem Information Network (OpenHi.net) is a state-of-the-art information infrastructure for the collection, management and free dissemination of hydrological and environmental information related to Greece’s surface water resources. It was launched two years ago as part of a the national research infrastructure “Hellenic Integrated Marine Inland water Observing, Forecasting and offshore Technology System” (HIMIOFoTS), which also comprises a marine-related component (https://www.himiofots.gr/). The OpenHi.net system receives and processes real-time data from automatic telemetric stations that are connected to a common web environment (https://openhi.net/). In particular, for each monitoring site it accommodates stage measurements, raw and automatically post-processed. Furthermore, in some specially selected sites time series related to water quality characteristics (pH, water temperature, salinity, DO, electrical conductivity) are provided. The web platform also offers automatically-processed information in terms of discharge data, statistics, and graphs, alerts for extreme events, as well as geographical data associated with surface water bodies. At the present time, the network comprises about 20 stations. However, their number is continuously increasing, due to the open access policy of the system (the platform is fully accessible to third-parties uploading their data). In the long run, it is envisioned that a national-scale hydrometric infrastructure will be established, covering all important rivers, lakes and reservoirs of the country.</p>

2020 ◽  
Author(s):  
Flavio Alexander Asurza Véliz ◽  
Kevin Arnold Traverso-Yucra ◽  
Waldo Sven Lavado-Casimiro ◽  
Oscar Felipe-Obando ◽  
Cristian Albert Montesinos-Cáceres ◽  
...  

<p>Surface water resources in Peru show high spatio-temporal variability, being the prediction of streamflow at ungauged sites, one of the fundamental challenges today.  This research presents a methodology for regional parameter estimation at national scale using SWAT (Soil and Water Assessment Tools) model, with the goal of estimating the streamflow for three hydrographic regions in Peru: the Pacific, Titicaca and Amazonas. Hydrological models were calibrated using observed discharge data which is sparse and poorly distributed over Peru. In this context, we design a regional parameter estimation following the next steps: i) First, a regionalization of 3394 hydrological response units (HRU) in the whole country were built through Ward’s hierarchical cluster criterion, in which 14 calibration regions were defined. ii) A calibration procedure to obtain the best calibration parameters was made with Non-dominated Sorting Genetic Algorithm (NSGA-II) optimization using the Kling-Gupta (KGE) and Nash Sutcliffe Logarithmic (LogNSE) statistics. A total of 31 hydrological stations were selected to calibration and validation procedure with the condition of leaving at least one in each region defined at point i) iii) Using the physical similarity approach, each set of calibrated parameters was averaged in each region to get the regional parameter sets.</p><p>The Pacific drainage was grouped into 6 regions, in which the results of daily flows estimations showed a good performance (KGE varies between -0.89 and 0.79) with some exceptions in the central zone; and acceptable results in the low- flow estimation (logNSE varies between -1.66 and 0.82), whose performance declines in some stations in northern and southern areas. On the other hand, the Amazon and Titicaca drainages regions were grouped into 7 and 1 region respectively. The calibration in the Amazon resulted in a very good performance in the Andean part (KGE> 0.5 and LogNse> 0.3), however in the north (region shared with Ecuador), the results are moderately satisfactory (KGE varies 0.0 and 0.4). In the Titicaca region, very acceptable KGE calibration values ​​were obtained (KGE> 0.75, LogNSE> 0.6). This first stage of the research will allow evaluating the climate change impacts on the water resources availability in Peru.</p>


2021 ◽  
Author(s):  
Goedele Verreydt ◽  
Niels Van Putte ◽  
Timothy De Kleyn ◽  
Joris Cool ◽  
Bino Maiheu

<p>Groundwater dynamics play a crucial role in the spreading of a soil and groundwater contamination. However, there is still a big gap in the understanding of the groundwater flow dynamics. Heterogeneities and dynamics are often underestimated and therefore not taken into account. They are of crucial input for successful management and remediation measures. The bulk of the mass of mass often is transported through only a small layer or section within the aquifer and is in cases of seepage into surface water very dependent to rainfall and occurring tidal effects.</p><p> </p><p>This study contains the use of novel real-time iFLUX sensors to map the groundwater flow dynamics over time. The sensors provide real-time data on groundwater flow rate and flow direction. The sensor probes consist of multiple bidirectional flow sensors that are superimposed. The probes can be installed directly in the subsoil, riverbed or monitoring well. The measurement setup is unique as it can perform measurements every second, ideal to map rapid changing flow conditions. The measurement range is between 0,5 and 500 cm per day.</p><p> </p><p>We will present the measurement principles and technical aspects of the sensor, together with two case studies.</p><p> </p><p>The first case study comprises the installation of iFLUX sensors in 4 different monitoring wells in a chlorinated solvent plume to map on the one hand the flow patterns in the plume, and on the other hand the flow dynamics that are influenced by the nearby popular trees. The foreseen remediation concept here is phytoremediation. The sensors were installed for a period of in total 4 weeks. Measurement frequency was 5 minutes. The flow profiles and time series will be presented together with the determined mass fluxes.</p><p> </p><p>A second case study was performed on behalf of the remediation of a canal riverbed. Due to industrial production of tar and carbon black in the past, the soil and groundwater next to the small canal ‘De Lieve’ in Ghent, Belgium, got contaminated with aliphatic and (poly)aromatic hydrocarbons. The groundwater contaminants migrate to the canal, impact the surface water quality and cause an ecological risk. The seepage flow and mass fluxes of contaminants into the surface water were measured with the novel iFLUX streambed sensors, installed directly in the river sediment. A site conceptual model was drawn and dimensioned based on the sensor data. The remediation concept to tackle the inflowing pollution: a hydraulic conductive reactive mat on the riverbed that makes use of the natural draining function of the waterbody, the adsorption capacity of a natural or secondary adsorbent and a future habitat for micro-organisms that biodegrade contaminants. The reactive mats were successfully installed and based on the mass flux calculations a lifespan of at least 10 years is expected for the adsorption material.  </p>


2010 ◽  
Vol 44-45 (2010-2011) ◽  
pp. 11-17
Author(s):  
Michael Aide ◽  
Indi Braden ◽  
Neil Hermann ◽  
David Mauk ◽  
Wesley Mueller ◽  
...  

Abstract Controlled subsurface drainage irrigation systems promote crop productivity; however, these land management systems also allow an efficient pathway for the transport of elements from soils to surface water resources. The nitrate and macro-element effluent concentrations from tile-drainage involving a 40 ha controlled subsurface drainage irrigation system are described and compared to soil nitrate availability. Soil nitrate concentrations generally show an increase immediately after soil nitrogen fertilization practices and are sufficiently abundant to promote their transport from the soil resource to the tile-drain effluent waters. The data indicates that: (1) the transport of nitrate-N in tile-drain effluent waters is appreciable; (2) denitrification pathways effectively reduce a portion of the soil nitrate-N when the controlled drainage system establishes winter-early spring anoxic soil conditions, and (3) the best strategy for reducing nitrate-N concentrations in tile-drain effluent waters is adjusting N fertilization rates and the timing of their application. The development of bioreactors for simulating wetland conditions may further limit nitrate concentrations in surface waters because of soil drainage.


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