Aivars Spalvins

Methods And Tools To Be Applied For Creating Of Regional Hydrogeological Model Of Latvia.

The hydrogeological model of Latvia will be established during 2010-2012. It will be used for management of drinking groundwater resources in order to implement standards of European Union Water Directives. The model will be created in environment of the commercial program Groundwater Vistas. It includes the broadly used software tools. The area to be modeled is represented by 95160125 finite difference grid, which plane approximation step is 500 metres. Novel methods and software tools will be applied to create the highly complicated model: the map of the ground surface elevations will serve as the piezometric boundary condition for obtaining distribution of infiltration; for creating digital maps of the model initial data, original software tools of data interpolation will be used; in the initial phase of the model establishment the actual geometry of a model may not be applied.

Making Of Credible Permeability Maps For Layers Of Hydrogeological Model Of Latvia.

In 2010–2012, the hydrogeological model (HM) of Latvia (LAMO) was developed by the scientists of Riga Technical University (RTU). LAMO comprises geological and hydrogeological data provided by the Latvian Environment, Geology and Meteorology Centre (LEGMC) for the active groundwater zone of Latvia. In 2013–2015, LAMO was notably upgraded. The density of hydrographical network (rivers, lakes) was increased, cuttings of river valleys into primary geological layers were done, plane approximation step was decreased, hydraulic conductivity distributions of layers were refined by creating more reliable permeability maps. In the paper, methods of obtaining these maps are described.

Upgrading Of The Hydrogeological Model Of Latvia.

In 2010–2012, the hydrogeological model (HM) of Latvia (LAMO) was developed by scientists of Riga Technical University (RTU). The model generalizes geological and hydrogeological information accumulated by the Latvian Environment, Geology and Meteorology Center (LEGMC). LAMO simulates the active groundwater zone that provides drinking water. The worldwide used commercial program Groundwater Vistas is applied for running LAMO. In 2013 – 2014, LAMO has been considerably upgraded and, presently, three successive versions (LAMO1, LAMO2, LAMO3) can be marked. The main innovations are considered that have converted the basic LAMO1 into the more advanced LAMO3 version that accounts for larger amount of real hydrographical and geological field data.

Methods Used To Develop Hydrogeological Model Of Latvia.

In 2010-2012, the hydrogeological model (HM) of Latvia LAMO was established by scientists of Riga Technical University. The model will be applied for management of water resources of Latvia. The commercial program Groundwater Vistas (GV) is used for running LAMO. GV includes the MODFLOW program that is worldwide applied for development of HM. Original methods were used to develop LAMO. They took part in performing the following tasks: creating geometry of HM; arrangement of various boundary conditions (digital terrain map, hydrographical network, infiltration flow, conditions on the HM shell surface); calibration process of HM. The methods have been proposed and developed by the RTU team. Because their appliance considerably improves quality of HM they may be of interest for modelers worldwide.

Evaluation Of Contamination By Using Hydrogeological Model For The Incukalns Area, Latvia

In the Incukalns area (Latvia), the Devonian sandstone aquifer is heavily polluted by emissions of sulphur sludge pools. In 1998, a hydrogeological model (HM) for the place has been created and rough prognoses of contaminant migration in groundwater have been obtained. In 2004-2005, this model has been considerably improved in order to find the best methods of stopping pollution plumes and of lessening their impact on the local environment. Improved HM is described and the new results obtained are presented.

Interpolation for creating hydrogeological models

Credibility and sustainability of a hydrogeological model (HM) depends not only on worthy initial data, but also upon interpolation technologies applied to create HM. An interpolation system for HM has been developed.