МІНІМАЛЬНИЙ ВОДНИЙ СТІК РАЙОНУ БАСЕЙНУ РІЧОК ПРИАЗОВ’Я В ПЕРІОДИ ЛІТНЬО-ОСІННЬОЇ ТА ЗИМОВОЇ МЕЖЕНІ

Abstract

For the purpose of value and analysis of the statistical characteristics of low-water runoff during summer-autumn and winter low flow periods on the rivers of the Priazov’s, used the time series of the minimum runoff of the rivers by 16 WGS during the period of from beginning observation till 2015 inclusive. In order to protect the water resources in the region, it is necessary to use its rationale, especially during low water periods than are minimal water discharges. For these aims, It is necessary to estimate the values of the characteristics of the minimum runoff in the Priazov region on the modern initial data, which is relevant, both in scientific and practical terms. Before generalizing the mean runoff modules in the summer-autumn and winter periods, the influence of local factors (latitudinal position, aforestation, and swampy watersheds) on their value was investigated. No significant influence of local factors was revealed, except for a good relationship with the latitude of the catchment centers. To determine the minimum runoff in winter for unexplored rivers of the territory, a map of isolines of 30-day minimum runoff modules is proposed. The distribution over the territory is uneven and varies from 0.30 l / (s • km2) in the southwestern part of the territory to 3.25 l / (s • km2) in the northeastern parts. The isolines are drawn with a step of 0.20 l / (s • km2). The map error is ± 4.3%, which corresponds to the accuracy of the initial information and the requirements of the current regulatory document SNiP 2.10.14-83. In the summer-autumn period, the distribution over the territory of the average minimum runoff modules is similar – in the south (in the Molochnaya river basin) low values are observed from 0.080 l / (s • km2), significantly increases in the northeast direction to 2.50 l / (s • km2) in the Kripenʹka river basin. Isolines are also drawn with a step of 0.20 l / (s • km2). The error in determining the minimum runoff in the summer-autumn period according to the proposed map is slightly higher and amounts to ± 7.7%, but it also meets the requirements for the accuracy of calculating the low-water runoff. To determine the coefficients of variability of low-water runoff, the obtained regional calculation equations, the accuracy of the calculation for which is provided by significant correlation coefficients; the skewness coefficient is normalized in relation to the coefficient of variation at the 2.0 level. The proposed regional method for determining the value of the minimum runoff for the summer-autumn and winter periods makes it possible to use it without modifications in order to reliably substantiate the runoff characteristics during the dry season on the Priazov rivers.