Geostatistical analysis and optimization of the state hydrogheological monitoring network within the Pripyat river basin (Ukraine)

Formulation of the problem. The State Hydrogeological Monitoring Network has to provide the necessary information to manage groundwater resources and prevent negative changes in the geological environment. Currently, there is a negative tendency to decrease the number of observation wells, loss of information about the space-time variability of the hydrogeological regime elements in Ukraine. In conditions of limited funding, an important task is to develop an effective strategy for reforming the hydrogeological monitoring system, taking into account international experience and based on modern geoinformation technologies. Particular attention has to be given to transboundary territories. One of them is the Pripyat River basin, which is characterized by the low level of the State Hydrogeological Monitoring Network representativeness, both in comparison with European Union standards and with the existing groundwater monitoring network of neighbouring Belarus. The purpose of the article is to evaluate the actual state of the hydrogeological observation wells network and optimize it within the territory of the Ukrainian part of the transboundary Pripyat watershed basin. Methodology and materials. The State Scientific and Production Enterprise "Geoinform of Ukraine" database of State Groundwater Monitoring System composition and functioning as well as zoning map under the conditions of water exchange formation in the upper water-bearing level were used for the study. For the studied territory of the water exchange basin of Pripyat, the analysis of density and uniformity of the observation points distribution as well as the variogram analysis of the spatial distribution of groundwater-level altitudes within the study area were carried. For the actual monitoring network, the expected error of the spatial modelling of the groundwater-surface was evaluated. Results. The obtained results of the geostatistical analysis made it possible to substantiate the project wells locations within the water exchange sub-basins to improve the quality of hydrogeological monitoring problem solutions. Scientific novelty. The method of the hydrogeological monitoring network optimization has been improved based on geoinformation and geostatistical approaches and implemented for the Ukrainian part of the Pripyat River basin, taking into account the hydrogeological conditions of the territory and the configuration of the existing network. Practical significance. Optimization and increment of the observation wells network, taking into account the obtained results, will provide the effective functioning of the hydrogeological monitoring system within the Ukrainian part of the Pripyat River basin and will have an economic effect, given that the cost of any measures to improve the groundwater quality and quantity is far more expensive than the monitoring system optimization.