The research was set up in the Neretva River valley in the Southern part of Croatian Karst area, where implementation of modern hydrotechnical practices within the river catchment’s area led to intrusion of seawater to groundwater resulting in soil salinization in the delta. The region has great agro-ecological potential for intensive production of vegetables and Mediterranean fruits. Since the combination of the effects of saline groundwater and the use of this water for irrigation may have disastrous effects on the productivity of agricultural soils water, a project was started in order to set up a permanent monitoring network. The aim of this study was to determine the salt dynamics in the surface water on five locations which are considered as potential sources of the irrigation water (Modric canal, Neretva River near Opuzen, Crepina, Jasenska and Vidrice pumping station) during a 4-year period (1999–2002). The surface water samples had been collected on monthly basis and analyzed for all parameters required in the irrigation water quality classification. The results show considerable spatial and temporal variability of determined parameters. Thus, in the Neretva River near Opuzen, total salt concentrations in water ranged from 0.4 to 7.7 dS·m–1, and in Modric from 1.65 up to17.2 dS·m–1. Dominant cations and anions on all observed locations were Na+ and Cl–. Constantly high concentration of Na+ in sampled surface waters is of a special concern. Utilization of the water of such quality may cause problems related to the use of alkaline waters for irrigation, which can further cause permanent loss of fertile soil.
Nine samples of basic (dolerite, gabbro) intrusions collected at Bellsund, South Spitsbergen, have been K−Ar dated. Three dates, between 87.8 and 102.9 Ma, obtained from dolerite sills which intrude Carboniferous and Permian deposits in Van Keulenfjorden point to a Cretaceous age of intrusive activity (Diabasodden Suite). The K−Ar dates obtained from dolerite and gabbro which intrude Upper Proterozoic metasedimentary terrane of Chamber− lindalen form two groups: the dates between 97.1 and 178.6 Ma point to a Mesozoic age of the intrusions (Diabasodden Suite); the dates from a tectonized gabbroid (280.9–402.0 Ma) might point to a Late Palaeozoic age of the intrusion. No K−Ar dates which would indicate a Proterozoic age of the basic intrusions were obtained
A high performance distributed sensor system with multi-intrusions simultaneous detection capability based on phase sensitive OTDR (Φ−OTDR) has been proposed and demonstrated. To improve system performance, three aspects have been investigated. Firstly, a model of one−dimensional impulse response of backscattered light and a Monte Carlo method have been used to study how the laser line width affects the system performance. Theoretical and experimental results show that the performances of the system, especially the signal−noise−ratio (SNR), decrease with the broadening of laser linewidth. Secondly, a temperature−compensated fibre Bragg grating with a 3 dB linewidth of 0.05 nm and a wavelength stability of 0.1 pm has been applied as an optical filter for effective denoising. Thirdly, a novel interrogation method for multi−intrusions simultaneous detection is proposed and applied in data denoising and processing. Consequently, benefiting from the three−in−one improvement, a high performance Φ−OTDR has been realized and four simultaneous applied intrusions have been detected and located at the same time along a 14 km sensing fibre with a spatial resolution of 6 m and a high SNR of 16 dB. To the best of our knowledge, this is the most multifunctional Φ−OTDR up to now and it can be used for perimeter and/or pipeline intrusion real−time monitoring.
The Neogene basaltoid intrusions found in the S-7 borehole in the Sumina area (USCB) caused transformations of the adjacent Carboniferous rocks. The mineral and chemical compositions of the basaltoides are similar to those of the Lower Silesian basaltoides. The transformations that took place in the vicinity of the intrusion were manifested in the formation of natural coke, the secondary mineralization of these rocks (calcite, chlorite, zeolites and barite) and in the specific distribution of rare earths (REY). Among REY, the light elements (LREY) had the highest share, while the heavy elements (HREY) had the lowest share. Regardless of the lithological type of the analyzed rock, with increasing distance from the intrusion, the percentage of MREY and HREY elements increases at the expense of the light elements LREY. All analyzed distribution patterns of the REYs are characterized by the occurrence of anomalies, which often show a significant correlation with the distance of sampling points from the basaltoid intrusion. The specific distribution of REYs in the vicinity of the intrusion of igneous rocks is an indication of the impact of hydrothermal solutions associated with the presence of basaltoides on the rocks closest to them located at a temperature of over 200°C.