Factors and characteristics of the spatial correlation of the annual runoff of the Upper Ob basin rivers

The main features of the spatial and temporal oscillations of the annual runoff of the rivers in the Upper Ob basin, which is characterized by various landscape and hydrologic conditions, are discussed. It is found that the coefficients of pair correlation of the annual runoff have been decreasing since the late 1990s-early 2000s. Correlation functions for mountain areas should be constructed separately for river basins ranked according to the prevailing type of river feed. The coefficients of pair correlation can be described by multiple regression equations, which, apart from the distance between the centers of gravity of the basins, may include landscape characteristics such as the difference in their average elevation and forest cover.     

Contents to Volume 47

Volume Contents

Contents to Volume 47     

Glaciation and Permafrost Dynamics on the Antarctic Peninsula in the 21st Century

The results of mass balance observations of the ice dome and measurements of the active layer thickness on the Fildes Peninsula, King George (Waterloo) Island, Western Antarctica are presented for the period of 2007 to 2019. The dynamics of the main meteorological parameters affecting the active layer thickness is determined. The numerical experiments based on the mathematical model are performed to determine the effects of various parameters on the active layer thickness. The calculated and measured values of the active layer thickness are compared. The thermal instability of permafrost in the study area in some years with high (above the means) summer air temperature is demonstrated. The climate cooling which started in the region in the recent years has increased the number of years with the positive ice mass balance. However, the positive ice mass balance has not yet become a dominant factor against a background of the negative balance in the previous years.     

Basin organization of nature management for solving hydroecological problems

Presented are the development of the concept and projects of the basin nature management and the organization of their implementation in the whole region using the basin-administrative approach. Based on the multidimensional analysis and forecast of river runoff variations using the artificial neural networks, the typification of catchments is carried out mainly defined by such factors as its area, order of the river, and degree of anthropogenic load. Depending on the hydrological functioning type, the adapted complexes of Hydroecological activities are determined. The need in the integration of the geodata for each river basin with the inherent morphological and process characteristics as well as of the results of Hydroecological monitoring enables to recommend the structure of the database of the basin organization of nature management in the regions of Russia based on the European experience in the river network monitoring in the context of the EU Water Framework Directive and of the creation of the single infrastructure of the spatial data.     

Possibilities to detect trends in spectral UV irradiance

Summary It is investigated how long-term UV trends can be assessed by analysing the longest time series of measured spectral UV irradiance in Europe, which have been started in the early 1990s in Thessaloniki, Greece and Sodankylä, Finland. It can be concluded that both time series do not yet show an unambiguous yearly trend in UV irradiance. The regression lines show no uniform behaviour and vary irregularly in strength and from one solar zenith angle to the next if all sky conditions are analysed. It is emphasised that these findings do not disagree with previous studies, that significant changes in UV irradiance have been observed over Europe especially in spring.Our study introduces a new method to estimate the required time series length for trend detection using the measured time series in combination with model calculations. At Sodankylä, a reduction of the total ozone column of –5.7% per decade has been observed from 1979 to 1998. A positive UV trend due to such conditions may be detected after 12 years at the earliest. For Thessalonki, a decrease in total ozone of –4.5% per decade has been observed. A corresponding increase of UV irradiance should be detectable after 15 years. It should be noted that a constant ozone trend over the whole period had to be assumed for this analysis.Since 1990 there has been a considerable variability of total ozone, but no steady decrease could be observed. Consequently, no general UV increase could be expected due to ozone changes. Even if there was a constant ozone trend over that period it is shown that even the longest European time series of UV irradiance are still too short to show distinct trends. However, this does not imply that no changes have occurred, it only shows that the large natural variability of UV irradiance has so far hindered the identification of unambiguous trends. The only way to find significant and consistent UV trends is the continuation of high-quality long-term measurements of spectral UV irradiance.     

Temperature fluctuation beats as a reason for the anomalously hot summer of 2010 in the European part of Russia

Presented are the explanations of reasons for the anomalous heat in summer of 2010 in the central area of the European part of Russia. It is demonstrated that this event occurred due to the beating of the solar annual (365 days) and lunar annual (355 days) fluctuations of air temperature. To substantiate this conclusion, the data are given on the synchronization of changes in atmospheric processes with the tidal variations of the Earth??s rotation velocity and on the nature of lunar cycles. Illustrated are the evidences of their existence in air temperature fluctuations. Revealed is the sequence of anomalously hot summer seasons in 1901, 1936 (1938), 1972, and 2010 corroborating the existence of the 35-year period of air temperature beats. Proposed is a mechanism of the impact of luni-solar tides on the air temperature based on the interaction between the gravitational luni-solar tides and the radiation conditions in the atmosphere (caused by the cloudiness amount variations).     

Estimation of water balance components in the Black Sea

Presented are the estimates of precipitation amount and evaporation for the Black Sea basin based on the data of numerical regional reanalysis. The spatial distribution of considered variables is compared with the results obtained before using the method of extrapolation of measurements at the coastal meteorological stations. The computed water balance components of the Black Sea compared with the available literature data are used for obtaining the estimate of the mean water discharge in the Bosphorus.     

Method of determination of heat,moisture, and momentum fluxes in the stratified surface layer

The method is proposed to determine the main fluxes characterizing the surface stratified layer of plants’ habitat using the Monin-Obukhov length scale. The gradient measurements of the profiles of wind flow speed, relative humidity, and air temperature are carried out. The experimental data are obtained using the mobile automated system. The wavelet analysis of time series is carried out. The nonlinear equation system is numerically solved to determine the heat, moisture, and momentum fluxes which can be used for the optimum control of the plant moisture supply in the agricultural field.     

Land-surface segmentation as a method to create strata for spatial sampling and its potential for digital soil mapping

Sampling efforts are constrained by limited availability of resources. Therefore, methods to reduce the number of samples, while still achieving reasonable accuracy are needed. Land-surface segmentation (LSS) has proven a powerful technique to partition digital elevation models (DEMs) and their derivatives into relatively homogeneous areas, which can be further employed as support in soil sampling. Though topography is one of the main soil forming factors, a robust assessment of the potential of this technique to digital soil mapping (DSM) is still missing. In this study, we aimed at evaluating the potential of LSS in stratifying a landscape into relatively homogeneous areas, which can be used as strata for guiding the selection of sampling points in DSM. The experiments were carried out in two study areas where soil samples were available. Land-surface derivatives were derived from DEMs and segmented with a tool based on the multiresolution segmentation algorithm, into objects considered as homogeneous soil-landscape divisions. Thus, one sample was randomly selected within each segment from the existing sample data, based on which predictions of soil classes/sub-orders and properties, i.e. soil texture and A-horizon thickness, were made. Results were compared with predictions based on simple random sampling (SRS) and conditioned Latin hypercube (cLHS). The segmentation-based sampling (SBS) scheme performed better than SRS and cLHS schemes in predicting the A-horizon thickness, soil texture fractions and soil classes, showing a high potential of LSS in stratifying a landscape for the purposes of DSM. The novelty of this study is in the way strata are constructed, rather than in the sampling design itself. Further research is needed to demonstrate the value of a SBS design for practical use. The analyses presented here further highlight the importance of considering locally adaptive techniques in optimization of sampling schemes and predictions of soil properties.