Diurnal and seasonal dynamics of the electrical conductivity of water of the northeastern part of the Great Vasyugan Mire (Western Siberia)

In this study, we determined the diurnal and seasonal dynamics of the electrical conductivity of waters of the northeastern part of the Great Vasyugan Mire in Western Siberia. Our studies showed that the electrical conductivity of the waters for the period of April to September 2016 was characterised by a value of 35 μS/cm, and the seasonal amplitude was 25 μS/cm. In seasonal dynamics, there are three maximums of electrical conductivity in waters. The first maximum was formed in April (48 μS/cm) and is associated with snowmelt water supply. The second one was observed in May after the complete thawing of the peat deposit (39 μS/cm), and the third was observed at the end of July as a result of biochemical processes in the peat deposit (43 μS/cm). Our studies have shown the electrical conductivity hysteresis during time intervals from 3–5 to 6–10 days electrical conductivity remains constant despite the change in hydrometeorological conditions (water table level, temperature).

Recording of the ship’s motion in operation on irregular waves and its processing

The safety of the ship state during the voyage is ensured, among other things, by monitoring the state of the ship’s stability. A device for measuring the parameters of the ship’s motion and software for discrete motion recording into a computer have been developed in Siberian State University of Water Transport. With the use of the device, a full-scale experiment to record the motion of the motor ship “Grumant” during an operational voyage has been carried out. For this, the half-periods of rolling and their amplitudes are obtained. Amplitude-half-period distribution of rolling has been built. According to the maximum probability, the half-period of its own roll has been found from it, which makes it possible to assess the stability state of the vessel during the voyage. The spectrum of motion and rolling dispersion has been obtained. If it is possible to obtain objective information about the actual wave spectrum, this opens the way to obtaining the amplitude-frequency characteristic of the motion based on the Wiener- Khinchin theorem. This task is set as a priority for the development of research in this area with the prospect of optimizing vessel navigation in difficult hydrometeorological conditions.

DEVELOPMENT OF A METHODOLOGY FOR STABILITY MONITORING OF A DEFENSE EMBANKMENT LOADED WITH FREQUENT TRAFFIC: THE EXAMPLE OF THE KOVIN MINE

In the present paper, the authors develop a methodology for stability monitoring of the hydrotechnicaldefensive embankment that is exposed to heavy frequent traffic. The proposed methodology envisages several phases of observation, work and monitoring: (1) macroscopic observations, (2) geophysicalgeoelectric tests, (3) group of exploration works, (4) model formation, (5) establishment of a monitoring system, (6) acquisition data processing and modeling. Four of the six proposed phases are illustrated by the example of the left-bank Danube embankment used by the Kovin coal mine for the needs of coal truck haulage. The results of the performed research indicate that there are no deformations that endanger the defensive function of the embankment. In order to ensure safe coal truck haulage and preserve the function of the embankment, it is proposed to establish a system for geophysical, hydrogeological and geotechnical monitoring, to form a model for simulating the behavior of the embankment for different hydrometeorological conditions (consequently, for different consistency states and material compaction), and for different load conditions.

Complex automated monitoring of the hydrological and hydrobiological state of basinal freshwater lake Krasilovskoye (Altai Region)

The results of a comprehensive automated monitoring for the hydrological and hydrobiological state of a freshwater Lake Krasilovskoe, conducted since 2013 are given. The experimental dashboard is considered, including the atmospheric-soil measuring complex (ASMC), developed and created in the IMCES SB RAS, Tomsk. An analysis of the dynamics of the lake level during years with contrasting hydrometeorological conditions was performed, which made it possible to identify the main factors that determine the level mode in the spring. In the hydrobiological terms, the dynamics of phytoplankton concentration at different depths in different seasons of the year were investigated. The results of processing Sentinel-1, 2 satellite data and data of natural observations on the distribution of chlorophyll “A” in the surface layer of water sections of the lake water area are discussed.

Analysis of ice conditions of year-round navigation of Arc7 vessels in the southwestern part of the Kara Sea

Since 2006, a new generation of reinforced ice class Arc7 vessels has been operating on the Northern Sea Route. Safe and efficient sailing of this type of vessels in sea ice demands a detailed study of ice conditions. Accumulation and analysis of data on ice and hydrometeorological conditions for the entire Arctic in comparison with ice conditions along the route of vessels is an essential part of the development of optimal variants and optimal routes for ice navigation.The main aim of the study was to generalize the conditions of ice navigation of Norilskiy Nickel vessels along the optimal navigational routes in the south-western part of the Kara Sea. Based on the reports on sailing obtained from vessels of the “Norilskiy Nickel” type for the 2006–2014 period, we calculated the probability of choosing the optimal route along the Murmansk – Dudinka passage: through the Kara Gate Strait (seaward, central or coastal route) or the north of Cape Zhelaniya. During the year, vessels move predominantly through the Kara Gate. However, for three month per year, from April to June, the most appropriate route lies to the north of the Zhelaniya Cape. In April – May it is, on average, every second navigation, and in June – more than 80 % of all navigation. The features of the ice regime determining the choice of the specific navigation route, are described. The speeds of vessels of the “Norilskiy Nickel” type along various navigation routes in drifting sea ice of the Kara Sea are calculated. The fastest speed in drifting ice was recorded in the winter navigations of 2007–2008 and 2011–2012, in the January-May of these years the average speed was 10.2 and 11.2, correspondingly. The minimum speed in these years, even during the months of maximum ice cover growth, was not less than 4.8 knots. In other years, the average speeds were in the range of 9.2–9.8 knots. During the whole period of study, ice conditions that were extremely difficult for navigation formed three times: at the end of May 2009, at the end of March 2010 and in the middle of March 2011, these are considered in more detail in the present article.

Indication of a ship location by the Earth’s geomagnetic field

The present study focuses on the need to increase the number of methods for indicating a ship location in traffic conditions on routes with heavy shipping, as well as during navigation in hard hydrometeorological conditions. The research purpose is to increase the level of safety and accuracy of ship navigation and effectively meet the requirements in the field of navigation safety and environmental protection. The issue of navigating through physical fields has a wide range of unresolved tasks despite the previously conducted studies. These tasks include investigation of geomagnetic sensors and their relationship to geomagnetic maps, as well as magnetic compasses and ways to improve them by using magnetometers and eliminating errors caused by rotation of the magnetic needle.

Hydrometeorological Triggering of Periglacial Debris Flows Using a Bayesian Approach: A Case Study of the Hailuogou Gully Region, China

Mount Gonggais located in the east of the Qinghai–Tibet Plateau; many debris flows have occurred in small basins with a small glacier cover or snow cover in this area. The hydrometeorological conditions that caused debris flows in this region are complex, making forecasting and early warning difficult. Previous studies for these small-glacial-covered basins have primarily considered rainfall as the only inducing factor of debris flows, and often the effects of temperature are neglected. Thus, we carried out a probabilistic analysis of variables derived from hydrometeorological factors for the Mount Gongga region, Sichuan, China, where debris flows were recorded on 14 days between 1988 and 2019. By analyzing hydrological characteristics when debris flows occurred, three distinct dominant trigger types could be identified. The results show that 7 (50%) of the observed debris flow events during the study period, high-intensity rainfall was the dominant trigger, snowmelt by high temperature was identified as the dominant trigger for 2 (14%). Furthermore, 5 (36%) debris flow events could be attributed to the combined effects of long-lasting (or short-medium) rainfall and sustained higher temperatures. We find that the differences between the trigger types are statistically significant, and a susceptibility prediction differentiating between trigger types can outperform simple rainfall-only situations. This study contributes to an improved understanding of the hydrometeorological impact on debris flow initiation in high elevation watersheds.

Evaluating the impact of hydrometeorological conditions on E. coli concentration in farmed mussels and clams: experience in Central Italy

Highly populated coastal environments receive large quantities of treated and untreated wastewater from human and industrial sources. Bivalve molluscs accumulate and retain contaminants, and their analysis provides evidence of past contamination. Rivers and precipitation are major routes of bacteriological pollution from surface or sub-surface runoff flowing into coastal areas. However, relationships between runoff, precipitation, and bacterial contamination are site-specific and dependent on the physiographical characteristics of each catchment. In this work, we evaluated the influence of precipitation and river discharge on molluscs' Escherichia coli concentrations at three sites in Central Italy, aiming at quantifying how hydrometeorological conditions affect bacteriological contamination of selected bivalve production areas. Rank-order correlation analysis indicated a stronger association between E. coli concentrations and the modelled Pescara River discharge maxima (r = 0.69) than between E. coli concentration and rainfall maxima (r = 0.35). Discharge peaks from the Pescara River caused an increase in E. coli concentration in bivalves in 87% of cases, provided that the runoff peak occurred 1–6 days prior to the sampling date. Precipitation in coastal area was linked to almost 60% of cases of E. coli high concentrations and may enhance bacterial transportation offshore, when associated with a larger-scale weather system, which causes overflow occurrence.

Influence of autumn soil moisture on erosion-accumulation processes in the Krasnoyarsk forest-steppe

The results of field observations of erosion-accumulation processes caused by meltwater in the northern zone of the Krasnoyarsk forest-steppe in 2009-2017 are discussed. Hydrometeorological conditions of melt runoff formation during the study period and their influence on the values of washout and accumulation are analyzed. Data on snow cover, soil moisture in the pre-winter period, meltwater flow to the soil surface, and spring and autumn runoff are compared. Attention is focused on the autumn soil moisture. The correlation between the values of washout and preceding autumn moisture is revealed. Other things being equal, among all hydrometeorological factors on the territory of the Krasnoyarsk forest-steppe, pre-winter soil moisture has a significant impact on the intensity of erosion-accumulation processes. Keywords: soil washout, erosion, autumn moisture, hydrometeorological factors, runoff, snow cover, humidity, freezing, water permeability