Kaspars Krauklis

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.

Hydrogeological Modelling for the Development of Raised Bog Conservation and Restoration Projects

Hydrogeological modelling was carried out within the framework of the LIFE project “LIFE Restore – Management and sustainable use of degraded bogs in Latvia” (project No. LIFE14 CCM / LV / 001103). A stabilizing hydrological regime is one of the important preconditions for successful restoration of degraded bogs. Many practices of regeneration of degraded bogs are known in the world, and most of them relate to the exchange, stabilization or recovery of hydrological regime. It is very common to rebuild, block or eliminate land drainage systems, land elevation planning and building of terraces, as well as many other methods. Most of these techniques are aimed at mitigating the impact of drainage of the bog in order to provide a favourable hydrological environment for the restoration of raised bogs vegetation. Hydrogeological modelling is an important tool that greatly facilitates the development of hydrological regime restoration and stabilization projects for degraded high bogs. Hydrogeological modelling was carried out applying the data provided by hydrogeological model of Latvia LAMO4. Development of the model was supported by the Latvian State Research Program EVIDEnT.

Evaluation of Hydrogeological Quality of Various Implementations of Riga City Water Supply System

Drinking water for Riga city is provided by the groundwater well field “Baltezers, Zakumuiza, Rembergi” and by the Daugava river as a surface water source. Presently (2016), it amounts to 122 thous.m3/day and both sources do not exploit even half of their power. Therefore, in future it seems reasonable to use only groundwater, because the river water is of low quality and its treatment is expensive. Scientists of Riga Technical University by using hydrogeological model of the well field “Baltezers, Zakumuiza, Rembergi” proved that its capacity covers the demand for 120–122 thous.m3/day of drinking water in Riga until 2030. Therefore, it is possible not to exploit the Daugava river as the water source. The research was done as to the request of the company “Aqua-Brambis”. The company asked to evaluate hydrogeological properties of several versions of water supply of Riga city. It was necessary to check the stability of syphon type systems that extract the groundwater for the city under the conditions of their increased productivity. It was also proved that the syphons may be replaced by a pumping station. Then the number of exploitation wells considerably decreases. The impact of expenses related to reconstruction of the wellfield and the water distribution network was not considered. The publication may be of interest for the specialists dealing with problems of water supply for large cities.

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.