Application of geomorphometric analysis for small river basins in the Selenga middle mountains (on the example of Tarbagatayka river basin)

2019 ◽  
Vol 948 (6) ◽  
pp. 30-38
Author(s):  
M.Y. Opekunova ◽  
A.V. Bardash

The authors present the data of a geomorphometric Tarbagatayka river basin analysis (Selenga middle mountains) for the purpose of subsequent geomorphological zoning within the framework of allocating the erosion-and-accumulative potential of the basins. The basis for the surface curvature maps were the creation of a DEM basing upon ALOS data, the construction of water flow orders’ scheme in the Straler-Filosofov coding system. Maps of horizontal, vertical and total curvature were obtained, statistical coefficients of these indicators were determined for each of the basins of the 3–4th order and in general for the Tarbagatayka. In the Tarbagatayka basin both in terms of plan and profile convex shapes of the surface pre-dominate, variations in curvature indices correlate well with the morphostructural plan of the territory, which is illustrated by the map of the total curvature. Applying the vector ruggedness measure (VRM) together with surface curvature maps can be used later to determine the erosion-accumulative potential of basins using the methods of structural basins’ coefficients. This approach can be successfully implemented in geomorphological studies and within the framework of the basin concept as well.

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2480
Author(s):  
Meiyan Feng ◽  
Kwansue Jung ◽  
Joo-Cheol Kim

This paper presents the modified framework of geomorphologic analysis based on the concept of fractal tree. Especially, it is intended to provide hydrologic practitioners with the information on the fractal property of small river basins. To this end, the complete drainage path network is applied to a growth process of a fractal tree for the basin of interest by connecting a channel network to overland drainage pathways. The growth process of a fractal tree would occur only within the limited region possessing channel flow properties in a natural river basin. The exponent of the intra basin type of Hack’s law could show a variable trend in small river basins mainly due to anisotropic property of the catchment planform. The bifurcation process of a drainage path network might be more sensitive to the growth step of the fractal tree than the meandering process of drainage path segment. The fractal dimension from the sinuosity of a channel segment is relatively stable compared to the one from the bifurcation process of the network, so that the geomorphologic features of a small river basin can be characterized by the anisotropic property of catchment planform as well as the bifurcation property of drainage path network with the growth of the fractal tree.


Author(s):  
І. V. Gopchak ◽  
T. O. Basiuk

Relevance of research. As a result of economic activities and irrational use of water and land resources in small river basins there are problems connected with pollution, destruction of natural landscape complexes of river valleys and adjoining territories, engineering reorganization of canals and floodplains as a result of melioration works. All these changes in river basins require operational control and response, which is possible only if real estimation of the level of anthropogenic load on river basins is carried out and the limits of permissible economic interference in their ecosystem are determined. The purpose of research – assessment of the ecological condition of the basin of the Veselukha River by the criteria of anthropogenic load. Research methods. The analysis of anthropogenic load and evaluation of the ecological condition of the Veselukha River basin was carried out in accordance with "Methodology for calculation of anthropogenic load and classification of the ecological state of small river basins of Ukraine". The calculation was made using the logic-mathematical model "Small River Basin", for four independent models of the main subsystems of the river basin: radioactive contamination of the territory, land use, use of river runoff, water quality. The quantitative and qualitative anthropogenic conditions by various indicators of four subsystems for classification of the ecological state of the river basin were estimated. Research results. According to the state of radioactive contamination, the area of the river catchment was estimated as "satisfactory". Based on the results of the analysis, the integrated value of land use was 3.7 and the state of the subsystem "Use of land" in the basin of the Veselukha river was determined as "good". The general state of river runoff use in the basin based on the joint effect of all these indicators of anthropogenic load on the state of the subsystem "Use of river runoff" was evaluated as "good" with a quantitative value of 3.0. The general condition of the subsystem "Water Quality" in the basin of the Veselukha River is characterized by the IV class of water quality, it corresponds to "polluted", with a quantitative level of -1. According to the results of the integrated assessment of all subsystems of the river basin, an induction coefficient of anthropogenic load (ICAN) was specified as is -1.0 and classifies the ecological state of the Veselukha River basin as "minor changes".


Author(s):  
V. G. Andrieiev ◽  
H. V. Hapich

Formulation of the problem. For the last 30 years, water management in the basins of small rivers in the steppe zone of Ukraine has led to a deterioration of the environmental safety in water use. The current ecological state of small rivers is close to critical, and for today some river basins are subject to catastrophic environmental changes. Almost all small rivers from 70 to 100% in the south and central water-short regions of Ukraine are under regulation due to the construction of a large number of ponds and reservoirs. In most cases, this causes a lack of transportation and low self-cleaning ability. Thus, the conservation, restoration and rational use of water, based on the principles of basin management, should get started along with the improvement of the ecosystems of small rivers.Research results. The paper describes the dynamics of changes in water management, which shows a rapid increase in the number of new ponds in the period of 1990 - 2018 almost threefold. At the same time, the overall dynamics of water consumption in the region in the same period decreased fourfold. Unjustified imbalance between the construction of new facilities and water demand was determined, as well as non-compliance with the current statutory provisions. Due to the transformation of natural watercourses into cascades of "evaporator ponds" an ecologically dangerous transformation of small river basins with the change of hydrological, hydrochemical, hydrobiological and sanitary regimes takes place. To evaluate the level of environmental hazards associated with water management, it is proposed to determine the river fragmentation coefficient, which is the ratio of the number of ponds and reservoirs to the length of the river. When evaluating the environmental hazard for rivers in a specific territory (administrative area, district or catchment area), the fragmentation coefficient is determined by the ratio of the number of ponds and reservoirs to the size of the territory. Comparative analysis indicates that Dnipropetrovsk region is one of the most environmentally dangerous in terms of the negative impact of river basins fragmentation by artificial reservoirs. The case of a small river basin (the Nyzhnia Tersa River) presents the application of the approach to evaluate the level of environmental safety associated with water management. It is proposed a mechanism for increasing the level of environmental safety in water use by observing and implementing heterogeneous groups of indicators that determine the overall efficiency of the river ecosystem functioning.Conclusions. In order to stabilize and restore the hydrological and ecological state of small rivers in the steppe zone of Ukraine, it is important to: 1) make a detailed evaluation of the compliance of the available number of ponds and small reservoirs in river basins with the requirements of the Water Code of Ukraine; 2) prove ecologically and economically the feasibility of further operation for each individual reservoir and structure; 3) develop regional programs for the elimination of ponds and reservoirs that do not fulfil their water management functions and cause environmental hazards to the functioning of the river basin ecosystem; 4) improve methodological approaches to evaluation of the environmental safety of water facilities in small river basins.


2014 ◽  
Vol 25 (1-2) ◽  
pp. 61-68 ◽  
Author(s):  
V. I. Monchenko ◽  
L. P. Gaponova ◽  
V. R. Alekseev

Crossbreeding experiments were used to estimate cryptic species in water bodies of Ukraine and Russia because the most useful criterion in species independence is reproductive isolation. The problem of cryptic species in the genus Eucyclops was examined using interpopulation crosses of populations collected from Baltic Sea basin (pond of Strelka river basin) and Black Sea basin (water-reservoires of Dnieper, Dniester and Danube rivers basins). The results of reciprocal crosses in Eucyclops serrulatus-group are shown that E. serrulatus from different populations but from water bodies belonging to the same river basin crossed each others successfully. The interpopulation crosses of E. serrulatus populations collected from different river basins (Dnipro, Danube and Dniester river basins) were sterile. In this group of experiments we assigned evidence of sterility to four categories: 1) incomplete copulation or absence of copulation; 2) nonviable eggs; 3) absence of egg membranes or egg sacs 4) empty egg membranes. These crossbreeding studies suggest the presence of cryptic species in the E. serrulatus inhabiting ecologically different populations in many parts of its range. The same crossbreeding experiments were carries out between Eucyclops serrulatus and morphological similar species – Eucyclops macruroides from Baltic and Black Sea basins. The reciprocal crossings between these two species were sterile. Thus taxonomic heterogeneity among species of genus Eucyclops lower in E. macruroides than in E. serrulatus. The interpopulation crosses of E. macruroides populations collected from distant part of range were fertile. These crossbreeding studies suggest that E. macruroides species complex was evaluated as more stable than E. serrulatus species complex.


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