Hydrologic and Geochemical Research at Pinios Hydrologic Observatory: Initial Results

Abstract

The Pinios Hydrologic Observatory (PHO) is located in the River Pinios basin, which is one of the most productive basins in Greece. The PHO was established to develop deep knowledge of water balance at the river basin scale and to improve understanding of the major hydrodynamic mechanisms to improve hydrological modeling and ultimately sustainable water resource management. The PHO comprises three meteorological stations, 12 groundwater monitoring sites, and one soil moisture monitoring site, which includes frequency domain reflectometry sensors (SoilNet) and a cosmic-ray neutron sensor (CRNS) probe. Although the PHO was recently established (at the end of 2015), the preliminary findings from data analysis are promising. Calculated reference evapotranspiration (ETo) gradients demonstrate differences regarding their annual cycle, total amount, and altitude level. Moreover, climate analysis indicates nocturnal mountain-valley winds. Groundwater level spatial distribution indicates the dominant recharge mechanisms to the alluvial aquifer system. These findings are also supported by the hydrochemical data analysis (electrical conductivity and, secondarily, NO 3 distribution). Locally elevated NO 3 concentrations are attributed to agricultural activities and call for review of the adopted farming practices. Results from the soil moisture monitoring site indicate a very good match between the CRNS probe and the average SoilNet data. Future perspectives of the PHO include geophysical surveys to accurately delineate the geometry of the groundwater system, the expansion of groundwater and soil moisture observation networks, and the application of the mGROWA hydrologic model to accurately simulate the hydrological processes in the PHO and upscale in the entire River Pinios basin. Finally, in support of the local farmers, we plan to develop and implement a distributed irrigation programming protocol in the entire area of the PHO.

Monitoring of Snowpack Dynamics With Cosmic-Ray Neutron Probes: A Comparison of Four Conversion Methods

“…The experimental test site CS3 investigated in this study is part of the PHO, which covers an area of ∼45 km² and is located at the eastern boundary of the Pinios River Basin in the municipality of Agia, Greece (Figure 1). The Pinios river basin is one of the most productive agricultural areas in the country and irrigation practices are responsible for more than 80% of the total fresh water consumption, leading to overuse of groundwater (Pisinaras et al, 2018). The mountain ranges framing the basin are responsible for the majority of groundwater recharge of the aquifer systems (Panagopoulos et al, 2015).…”

“…In order to support these efforts, the mGROWA model (Herrmann et al, 2015) has recently been applied in the Pinios river basin (Panagopoulos et al, 2018). First analyses of simulation results and associated uncertainties revealed a lack of continuously available climatic data including snowpack data for model calibration purposes, which was the main motivation to establish the Pinios Hydrologic Observatory (Pisinaras et al, 2018).…”

Impact of EU Environmental Policy Implementation on the Quality and Status of Greek Rivers

“…This is also true for the dry period of the year where river parts may desiccate because of excess irrigation water use, thus, threatening river integrity and biodiversity. Moreover, the results of applying river basin water balance models remain questionable, due to a lack of reliable model input data [77]. To assess model-based reliable water balances and develop appropriate water resources management plans, there is an urgent need to re-design and maintain hydrological monitoring networks and collect appropriate environmental model input data, under a single management authority.…”

COSMOS-Europe: A European Network of Cosmic-Ray Neutron Soil Moisture Sensors

“…12 The Zugspitze sensor is located in the Schneefernerhaus (UFS) observatory and surrounded by rocky mountain terrain and not suited for soil moisture analysis. Forschungszentrum Jülich GmbH (Pisinaras et al, 2018;Bogena et al, 2020).…”