Analysis of the condition of karst springs included in the National Groundwater Monitoring Network

Approximately 20% of the monitored points in the National Groundwater Monitoring Network (NGMN) of Bulgaria are karst springs. The number of monitored karst springs is changing over time for various reasons and currently there are 33 springs monitored continuously and 53 on monthly basis. The monitoring points are distributed over 39 karst basins around the whole country. There are between 1 and 5 monitored springs per karst basin and no monitoring points in 23 karst basins. The present analysis includes the determination of some of the main statistical characteristics of karst springs and it is based on the monitoring data series. The obtained data allow us to make some conclusions of the nature of their water regime. Based on the analysis, some suggestions and recommendations are made with regard to improvements in the monitoring of karst springs in Bulgaria.

Pilot-Scale Groundwater Monitoring Network for Earthquake Surveillance and Forecasting Research in Korea

Although there is skepticism about the likelihood of predictive success, research on the prediction of an earthquake through precursory changes in natural parameters, including groundwater, has continued for decades. One of the promising precursors is the changes in groundwater, i.e., the level and composition of groundwater, and the monitoring networks are currently operated to observe earthquake-related changes in several countries situated at the seismically active zone. In Korea, the seismic hazards had not been significantly considered for decades since the seismic activity was relatively low; however, the public demands on the management and prediction of earthquakes were raised by two moderate-size earthquakes which occurred in 2016 and 2017. Since then, a number of studies that were initiated in Korea, including this study to establish a pilot-scale groundwater-monitoring network, consisted of seven stations. The network is aimed at studying earthquake-related groundwater changes in the areas with relatively high potentials for earthquakes. Our study identified a potential precursory change in water levels at one particular station between 2018 and 2019. The observed data showed that most monitoring stations are sufficiently isolated from the diurnal natural/artificial activities and a potential precursory change of water level was observed at one station in 2018. However, to relate these abnormal changes to the earthquake, continuous monitoring and analysis are required as well as the aid of other precursors including seismicity and geodetic data.

Application of MCLP and LINGO methods to optimal design of groundwater monitoring network in an oil refinery site

Groundwater-monitoring network is a set of boreholes (wells) that is used to monitor the water table fluctuation and to detect groundwater contamination. In this research, the maximal covering location problem (MCLP) method is employed to discretize the area, and the LINGO modeling program is used to optimize the number of boreholes. Tabriz oil refinery at the northwest of Iran with high pollution potential that imposes a serious threat to the beneath multilayered aquifer was chosen to evaluate the feasibility of these techniques in field scale. The location and content of storage tanks, leakage history, groundwater flow direction, contaminated well location and the facilities leakage potential are considered as the weighting factors to calculate the number and location of the optimal wells. As a result of optimization, the initial estimated number of boreholes by the MCLP model for the study area is reduced from 349 to 184. A high density of optimal boreholes is allocated to refining zone and oil storing yard, especially near tanks containing dangerous substances due to their toxicity and potential for contaminating water. A vulnerability zoning map prepared using the analytical hierarchy process method indicates a suitable conformation between locations of the boreholes and the vulnerable areas.

Fresh Groundwater Monitoring in Georgia, EUWI+ project support to Georgia in implementing the EU Water Framework Directive and improvment the monitoring network

<p>Georgia is among the countries which have fresh groundwater distinguished for significant resources and drinking qualities of naturally high quality. Hydrogeological exploration and monitoring works for the purpose of identification, study and protection of fresh groundwater were not conducted in the period of 1990–2013. Considering the long-term termination of centralized researches and the intensively increasing anthropogenic pressures on the environment and on water in particular, the assessment and protection of groundwater resources becomes a very pressing issue. For this purpose, in 2013, on initiative of the Geology Department of LEPL National Environmental Agency of Georgia and the Czech Development Agency, restoration of the hydrogeological monitoring network and research of fresh groundwater using modern methodology began. The modern equipment was gradually installed on the water objects to obtain information about quantitative and qualitative characteristics in "online" mode and taking water samples for chemical and bacterial analysis twice a year. Currently, 56 water points (mainly wells) are being monitored. The database on quantitative and qualitative characteristics of fresh groundwater of Georgia is being expanding based on information received online from water points, fieldwork results, laboratory analyzes (chemical and bacteriological), and on the processing, analyzing and generalizing of the collected actual materials. As the issue concerns fresh groundwater (which is used by at least 90% of the population), it’s necessary to expand the state monitoring network. According to the EU Water Framework Directive, based on the basin management principles of water resources, conduct of researches is granted particular significance in the trans-boundary zone.</p><p>The „European Union Water Initiative Plus for Eastern Partnership (EaP) Countries (EUWI+)″, which is the biggest commitment of the EU to the water sector in the EaP countries, helps Armenia, Azerbaijan, Belarus, Georgia, Moldova and Ukraine to bring their legislation closer to EU policy in the field of water management, as identified by the EU Water Framework Directive. The EUWI+ project addresses existing challenges in both development and implementation of efficient management of water resources.. Monitoring data are an important basis for water management, for risk, status and trend assessment and for the design and implementation of an effective and cost-efficient program of measures .</p><p>Within the EUWI+ project, the following key activities were undertaken in Georgia: „Delineation and characterization of groundwater bodies and the design of a groundwater monitoring network in the Alazani-Iori and Khrami-Debed River Basin Districts in Georgia“, „Performed hydrogeological preliminary field works in the Alazani-Iori and Khrami-Debed River Basin“. Currently „Geophysical, isotope, hydrochemical, bacteriological and hydrodynamic assessment of twelve selected wells to be included in the national groundwater monitoring network in the Alazani-Iori River Basin District in Georgia“ is in progress. The results of this study are a basis for the improvement of the groundwater monitoring network and the development of River Basin Management Plans. As a part of the EUWI+ project, several new monitoring stations are planned.</p><p>The results are important in the process of implementation of integrated management of water resources, which should finally ensure sustainable management of water resources and reliable health protection of the population.</p>

Optimal Design and Prediction-Independent Verification of Groundwater Monitoring Network

In this study, we developed a workflow that applies a complex groundwater model for purpose-driven groundwater monitoring network design and uses linear uncertainty analysis to explore the predictive dependencies and provide insights into the veracity of the monitoring design. A numerical groundwater flow model was used in a probabilistic modelling framework for obtaining the spatial distribution of predicted drawdown for a wide range of plausible combination of uncertain parameters pertaining to the deep sedimentary basin and groundwater flow processes. Reduced rank spatial prediction was used to characterize dominant trends in these spatial drawdown patterns using empirical orthogonal functions (EOF). A differential evolution algorithm was used to identify optimal locations for multi-level piezometers for collecting groundwater pressure data to minimize predictive uncertainty in groundwater drawdown. Data-worth analysis helps to explore the veracity of the design by using only the sensitivities of the observations to predictions independent of the absolute values of predictions. A 10-bore monitoring network that collects drawdown data from multiple depths at each location was designed. The data-worth analysis revealed that the design honours sensitivities of the predictions of interest to parameters. The designed network provided relatively high data-worth for minimizing uncertainty in the drawdown prediction at locations of interest.