FREEWAT Platform Research Articles

A Spatially Distributed, Physically-Based Modeling Approach for Estimating Agricultural Nitrate Leaching to Groundwater

Nitrogen-nitrate, while being fundamental for crop production, is of particular concern in the agricultural sector, as it can easily leach to the water table, worsening groundwater quality. Numerical models and Geographic Information System may support the estimation of nitrate leaching rates in space and time, to support sustainable agricultural management practices. In this paper, we present a module for the simulation of the processes involved in the nitrogen cycle in the unsaturated zone, including nitrate leaching. This module was developed taking steps from the ANIMO and EPIC model frameworks and coupled to the hydrological models integrated within the FREEWAT platform. As such, the nitrogen cycle module was then included in the FREEWAT platform. The developed module and the coupling approach were tested using a simple synthetic application, where we simulated nitrate leaching through the unsaturated zone for a sunflower crop irrigated district during a dry year. The results of the simulation allow the estimation of daily nitrate concentration values at the water table. These spatially distributed values may then be further used as input concentration in models for simulating solute transport in aquifers.

Free and open-source GIS-integrated hydrogeological analysis tool: an application for coastal aquifer systems

This paper demonstrates the application of a recently developed free and open-source GIS-integrated hydrochemical–hydrogeological analysis tool (named AkvaGIS) for the management and interpretation of hydrogeological data with respect to a coastal aquifer system. The aforementioned tool is composed of a geospatial database implemented in Spatialite, complemented with a set of developed tools for the analysis, interpretation, and visualization of groundwater quality parameters and hydrogeological data. This ICT tool is part of the FREEWAT platform, an open-source and public domain GIS-integrated modelling environment based on groundwater flow and solute transport numerical models, including a water management and planning module. The case study that was used to perform a demonstration of the aforementioned tool, is a coastal aquifer system in Greece, suffering from both seawater intrusion and nitrate contamination as a result of extensive agricultural activities. It involves a complex hydrogeological environment incorporating karst and granular aquifer layers, subjected to different exploitation conditions. AkvaGIS was proved a useful ICT tool for the analysis and interpretation of the collected hydrogeological/hydrochemical data and results, which may be considered as a valuable tool for analyzing different aspects of aquifer systems.

Spatial Data Management and Numerical Modelling: Demonstrating the Application of the QGIS-Integrated FREEWAT Platform at 13 Case Studies for Tackling Groundwater Resource Management

Because of the spatial nature of groundwater-related data and their time component, effective groundwater management requires the application of methods pertaining to the Information and Communication Technologies sector, such as spatial data management and distributed numerical modelling. The objective of this paper is to demonstrate the effectiveness of the QGIS-integrated FREEWAT platform and an approach combining spatial data management and numerical models to target groundwater management issues. FREEWAT is a free and open source platform integrated in a Geographic Information System environment and embedding tools for pre- and post-processing of spatial data and integrating numerical codes for the simulation of the hydrological cycle, with a main focus on groundwater. To this aim, this paper briefly presents the FREEWAT platform, introduces the FREEWAT approach, and showcases 13 case studies in European and non-European countries where the FREEWAT platform was applied. Application of the FREEWAT platform to real-world case studies is presented for targeting management of coastal aquifers, ground- and surface-water interaction, climate change impacts, management of transboundary aquifers, rural water management and protection of groundwater-dependent ecosystems. In this sense, compared to other existing software suites, FREEWAT allows data analysis and visualization to accomplish each step of the modelling workflow, i.e., from data analytics, to conceptual model definition, to numerical modelling and reporting of results. The presented experiences demonstrate that improved access to data and the portability of models and models’ results can help to promote water sustainability from the local- to the basin-scale. Furthermore, FREEWAT may represent a valuable tool to target the objective of increasing the capabilities of public authorities and private companies to manage groundwater resources by means of up-to-date, robust, well-documented and reliable software, without entailing the need of costly licensing, nowadays seldom affordable by public water authorities. Based on the strengths highlighted, the FREEWAT platform is a powerful tool for groundwater resources management, and for data collection, sharing, implementation and comparison of scenarios, for supporting planning and decision-making.

Software tools for management of conjunctive use of surface- and ground-water in the rural environment: integration of the Farm Process and the Crop Growth Module in the FREEWAT platform

The coordinated use of surface- and ground-water over time and space as two components of a single irrigation system is of outmost importance in many rural areas of the world, in order to assure crop production sustainability, to restore ongoing and to prevent future issues related to freshwater quality and quantity mismanagement/deterioration. New technological solutions, such as GIS-integrated simulation models, may provide reliable tools in order to evaluate impacts in space and time and to properly manage conjunctive use of surface water and groundwater and water-constrained agricultural production. After presenting the common open source simulation programs for dealing with conjunctive use, we discuss and present the integration of the Farm Process (FMP; embedded in the USGS’s MODFLOW One-Water Hydrologic Model) coupled to a Crop Growth Module (CGM) within the open source and public domain QGIS-integrated FREEWAT platform. Using FMP in FREEWAT gains the benefit of the spatial environment and data management tools of a GIS solution, and to perform proper analysis of dynamically integrated terms of the hydrological cycle, to effectively balance crop water demand and supply from different sources of water. A simple hypothetic, yet realistic, application of the proposed approach with FMP and CGM is presented, simulating the yield of irrigated sunflower at harvest in a Mediterranean area. Results provide an insight on the potential exploitation of the developed solution, including, but not limited, to: quantitative temporal analysis of irrigation water sources, detailed analysis of evaporation and transpiration terms (from irrigation, groundwater or rainfall). The coupling of FMP with CGM to estimate crop yield at harvest provides further management tools when dealing with crop productivity. In the simulated case study, the analysis of the water balance terms allowed identifying the relevance of the groundwater contribution to ETc-act, highlighting the role of natural root uptake. The proposed solution is thought to be deployed by water authorities, large farms and public/private companies managing irrigation areas. The use of these tools calls for dedicated capacity building to boost digitalization in the agricultural water sector in order to achieve data-based agricultural water management.

Groundwater flow simulation through the application of the FREEWAT modeling platform

Abstract FREEWAT is a free and open source QGIS-integrated platform, developed to simulate several hydrological processes by combining the capabilities of geographic information system (GIS) for geo-processing and post-processing tools with several codes of the well-known USGS MODFLOW ‘family’. FREEWAT platform was applied for the groundwater flow simulation of a coastal aquifer system, located in northern Greece. The simulation was conducted using the MODFLOW_2005 code, the Observation Analysis Tool (a FREEWAT module facilitating the integration of time series observations into modeling), while the UCODE_2014 code was used as the main module for the sensitivity analysis and parameter estimation. The statistics used include composite scaled sensitivities, parameter correlation coefficients, and leverage. The simulation of the investigated aquifer system was found to be satisfactory, indicating that the simulated level values were slightly greater than the observed values after the optimization.

Open source GIS platform for water resource modelling: FREEWAT approach in the Lugano Lake

The FREEWAT platform is an innovative Free and Open Source water resource modelling platform integrated in the QGIS geospatial software, using the SpatiaLite database, and including globally-established simulation codes from the USGS MODFLOW models family. This paper demonstrates its application to the Lugano Lake basin case study, Switzerland and Italy. Two specific modules of the platform were used to execute data integration and analyses: the Observation Analysis Tool and the Lake Package. The first one is a newly developed module facilitating the integration of time-series observations into modelling by enabling pre- and post-processing in the model environment; the latter is an existing MODFLOW package allowing dynamic evaluation of groundwater/lakes interaction. In the case study implementation, a participatory approach was adopted to enhance trust and acceptance of results. These show that integration of simulation codes within GIS is highly appreciated. Furthermore, its openness and freeness allow easily sharing of developed analysis and models. Stakeholders also positively evaluated the participatory process as it empowers decision making with a better understanding of model results and uncertainties. The combination of the FREEWAT platform and the participatory approach may constitute a valuable methodology to include scientifically based analysis to be used for policy design and implementation.

Slovenian test case Vrbanski Plato aquifer in the EU HORIZON 2020 FREEWAT project

The Slovenian case study in the EU HORIZON 2020 FREEWAT project was Vrbanski Plato aquifer. Slovenia is divided into two river basin districts: the Danube and the North Adriatic. The Vrbanski Plato aquifer, which he presents both natural and artificial bank filtration from the river Drava, is a part of the Danube river basin district and is the most important water source for 14 municipalities in the northeastern part of Slovenia. We investigated the groundwatersurface water interaction between river Drava and the porous aquifer in the geological old riverbed and possible reduction of city impact. This site is the oldest managed artificial groundwater recharge with riverbank filtration and has more than thirty years of successful operation. It is something special, very abundant in a small space, independent of drought and climate changes, but vulnerable due to the impact of the city. Under the city there is watershed dividing, which is shifting with different water management condition and we would like to have the least possible impact of the city. For optimal water management we decided to use FREEWAT plug-in within QGIS platform. With new developed FREEWAT plug-in in project FREEWAT, we made steady-state and transient groundwater model for presenting this shift of the watershed dividing under the city and optimal water management for this area. The model was designed in a way that it identifies and describes all major aspects of the physical hydrogeological system and water management. During the running of a project, there was an accident with heating oil spillage in city area, right on the watershed dividing. So we oriented with the transient groundwater model as well on heating oil spillage and pumping with additional wells at the place of the accident to present successful rehabilitation and the importance of the managed groundwater recharge. Our experience with FREEWAT platform during the Vrbanski Plato aquifer case study was very positive. The connection data of the GIS tool, open license and the database monitoring and model approaches functioned as the right tool for a professional approach and communicating with stakeholders. With groundwater models in FREEWAT platform, we defined optimal condition, with as less as possible the impact of groundwater below the city, for pumping water on the Vrbanski Plato, managed by Water Supply Maribor company and needed optimal level in river Drava managed by Drava Power Plants Company. Quantities of pumping for water supply and level of Drava River are the dominant components of water management in this area. Due to the time and financial constraints, we took into account the period from July 2014 to June 2017.

Modelling surface water-groundwater interactions at the Palas Basin (Turkey) using FREEWAT

Palas Basin is a semi-arid closed basin located in the Central Anatolia region of Turkey. The major economic activity in the basin is agriculture; therefore, both surface water and groundwater are used for irrigation. However, intensive use of water resources threatens the hydrologic sustainability of a lake ecosystem (Tuzla Lake) located in the basin. In this study, we analyzed the relationships between agricultural water uses in the Palas Basin and water flows to the Tuzla Lake using groundwater flow model developed with the FREEWAT platform. The model grid with 250 m x 250 m resolution was created based on the entire watershed. Two hydrostratigraphic units were identified. The source terms defined in the model were rainfall recharge and the sink terms were evapotranspiration and wells. The model was run for one year at steady state conditions. Three scenarios were simulated to understand the effect of groundwater use on the lake hydrology. The first scenario assumed that there was no groundwater abstraction. As the second and third water management scenario, the model was run with 50% less and %50 more groundwater abstraction than that of the reference conditions. The model successfully simulated the direction of groundwater flow and groundwater levels in the basin. Annual groundwater recharge was simulated as 5.27 million m3. Groundwater losses were due to pumping (1.49 million m3/yr), leakance to Değirmen River (2.25 million m3/yr) and seepage to Tuzla Lake (1.53 million m3/yr). Water flows to Tuzla Lake were significantly related to pumping rates. Increasing groundwater pumping rates reduces groundwater flows to Tuzla Lake and lowers lake water levels. No groundwater abstraction and reduction in groundwater pumping rates increase water flows to Tuzla Lake and cause higher water levels. This analysis showed that protection of hydrologic characteristics of Tuzla Lake is only possible with more control on groundwater abstraction.

The H2O20 FREEWAT participated approach for the Follonica-Scarlino aquifer case study. A common space to generate shared knowledge on the value of water

The “Follonica-Scarlino Aquifer” case study is run within the H2020 FREEWAT project by Regione Toscana as partner of an international consortium. FREEWAT aims at promoting water resource management by simplifying the application of the Water Framework Directive and other EU water related Directives. The tool used to reach this target is an open source and public domain GIS integrated modeling environment for the simulation of water quantity and quality in surface water and groundwater. The case study area is located in a coastal plain in the Southern part of Tuscany (Italy) and the aquifer system is affected by various issues: in particular, the numerical model created through FREEWAT platform was used to study the problem of aquifer over-exploitation . The deficit in quantity of the water resource is mainly caused by the huge industrial and agricultural abstractions, but drinking water supply during the summer season is also notable. The participatory approach, included in the FREEWAT project, became of crucial importance to gather the huge amount of data about the aquifer system and to create a shared knowledge about water resource. It was carried out through seven focus groups and led the stakeholders to reach an agreement about the scenarios to be explored with FREEWAT software platform. Focus Group 1 to 3 were used to identify the case study objectives. Focus Groups 4 to 6 allowed to assess the water management issues and select the scenarios. The community chose two of the four scenarios that came out from the focus group meetings. Simulations corresponding to these two scenarios have shown, the effectiveness of the proposed technical solutions for achieving the objectives set out in the River Basin Management Plan of the Northern Apennines District. At the end of the focus group cycle, useful suggestions and feedbacks came from stakeholders, to set up a new kind of water management. Some experts working for local industries expressed their interest in using the FREEWAT open source platform as professional modeling tool.

Spatial analysis and simulation tools for groundwater management: the FREEWAT platform

FREEWAT is an HORIZON 2020 project financed by the EU Commission under the call WATER INNOVATION: BOOSTING ITS VALUE FOR EUROPE. FREEWAT main result is an open source and public domain GIS-integrated modeling environment for the simulation of groundwater quantity and quality, with an integrated water management and planning module. FREEWAT aims at promoting water resource management by simplifying the application of the Water Framework Directive and other EU water-related Directives. To this scope, the FREEWAT platform results from the integration in the QGIS Desktop of spatially distributed and physically-based codes (mostly belonging to the USGS MODFLOW family), which allow to get a deep insight in groundwater dynamics, taking into account the space and time variability of stresses which control the hydrological cycle. This is attempted in a unique GIS environment, where large spatial datasets can be managed and visualized. In this paper, a review of the tools/modules integrated in FREEWAT for data pre-processing and model implementation is provided. FREEWAT applicability was demonstrated through running 14 case studies, in the general framework of an innovative participatory approach, which consists in involving technical staff and relevant stakeholders (in primis policy and decision makers) during modeling activities, thus creating a common environment to enhance science and evidence-based decision making in water resource management.

The FREEWAT platform for the assessment of water availability and quality

Not available.

Software tools for sustainable water resources management: the GIS-integrated FREEWAT platform

This paper aims at presenting the open source and public domain FREEWAT platform capabilities for water resource management, including: (i) pre-processing modules to facilitate the preparation of input data, (ii) modelling tools for the analysis of several processes aimed at supporting water resource management, and (iii) post-processing tools to present results.The FREEWAT platform is based on open source solutions to perform an integrated coupling between the QGIS desktop software, surface and subsurface model engines, mostly based on fully distributed and numerically-based codes developed by the USGS, and other software applications, and the SpatiaLite spatial database. The development of the FREEWAT platform was supported by the main needs and priorities expressed by relevant stakeholders from the water sector involved in the early stage of the project.Extensive testing on the platform is still going on and training material and six User Manuals were prepared to disseminate its use as a standard software for managing surface/sub-surface water quantity and quality dynamics under demand-driven and supply-constrained conditions. The testing phase also includes demonstration of the platform capabilities on 14 case studies at European scale and beyond, to address specific water management issues. Nine of them are devoted to the application of EU water-related Directives, while the others address water management issues in the rural environment under the requirements of EU and/or national/local regulations. Beyond software testing, this demonstration is thought as an experiment on involving stakeholders in the formation of water plans yet during the technical phase of the analysis.

Dal modello concettuale al modello numerico: il caso di studio del sistema acquifero di Follonica (GR, Toscana meridionale)

The groundwater body hosted in the Follonica coastal plain (Grosseto, Italy) is the Italian aquifer system that was chosen for the experimentation of the FREEWAT Platform, a collection of free andopen source software tools for water resource management and quantitative and qualitative modeling developed within the EU project Horizon 2020. In consideration of the studies carried out by the Institute of Geosciences and Earth Resources of the Italian National Research Council from 2006 to 2015 for the geological, hydrogeological and geochemical characterization of the 66 regional groundwater bodies (CIS), the Tuscany Region, partner of the project, has entrusted CNRIGG for the implementation of the numerical model.A conceptual model of the aquifer system was developed by processing and combining all the geological, hydrogeological and geochemical-isotopic data. The supposed hydrostructure was tested and validated through its 3D solid construction, defining the geometry and the physical limits of the multi-layered aquifer system and ensuring its coherence and consistency with respect to the other geographical databases. Hydrogeological and geochemical data processing ledto identify the aquifer system feeding components, the relationships between surface hydrography and groundwater and the main physical and chemical processes taking place (ion exchange, seawater ingress, etc). On this basis, the development and implementation of the flow model has started, based on the Modflow code.A focus group was organized as part of the project and stakeholders were involved with their active participation to the elaboration of the conceptual model by sharing data and other useful information.This paper describes the methodology used and the results obtained so far.