Избыточное увлажнение как фактор активации оползней на склонах Киевского водохранилища

Abstract

С использованием методик Н. Биндемана, В. Ампилова и авторских разработок установлено, что территория исследований урочища “Межигорье” получает тройную норму поверхностных вод по отношению к природным осадкам. Количественно оценены все техногенные составляющие и доказано более чем тройное увеличение инфильтрации в водоносные горизонты с последующей разгрузкой на склоне водохранилища. Последнее обстоятельство послужило причиной активизации оползневых процессов в значительных масштабах.

З використанням методик М. Біндемана, В. Ампілова і авторських розробок установлено, що територія досліджень отримує потрійну норму поверхневих вод порівняно з кількістю природних опадів. Кількісно оцінено всі техногенні складові та доведено більш як потрійне збільшення інфільтрації у водоносні горизонти з подальшим розвантаженням на схилі водосховища. Остання обставина спричинила активізацію зсувних процесів у значних масштабах.

Purpose. The aim of the research is to study the moistening of subsurface soils under intensive technogenic load of the territory with further distribution of priority tasks such as comparative assessment of the amount of natural and technogenic surface water, balance assessment of transit and infiltration water; selection of natural and technogenic components in the infiltration. The object of the study is the territory of the tract Mezhigorie on the right bank of the Kiev hydroelectric station water reservoir. The authors used detailed geological characteristics of the territory, regime measurements of groundwater levels, graphics of irrigation area and leakage from water bodies, information about the number of natural rainfall as initial data. Design/methodology/approach. Calculation of infiltration and its division into natural and technogenic components are made taking into account methods created by N. Bindeman, V. Anpilov and elaborations made by authors based on observations of groundwater level regime on monitoring wells and comparative characteristics of their regime in the high water (spring and summer) and low water (summer-autumn) periods. Findings. During investigations, the authors reduced the technogenic component of subsurface water to units that are comparable with the amount of rainfall. As a result, we have the opportunity to use quantitative assessment of the balance of the natural and technogenic components of rainfall and surface waters as a basis for calculating the infiltration. The authors estimated the ratio of natural and technogenic water that is equal to one to two. All components of infiltration were quantified and authors proved more than a threefold increase of infiltration into the aquifer at the expense of amount of technogenic waters, followed by unloading the aquifer on the slope of the water reservoir. Practical value/implications. Slope stability calculations for predominant area of the territory of landslide studies on the observation platform allowed us to estimate the risk of landslides in quantitative calculation. With these estimates of excess moistening and full water flooding of separate engineering and geological elements the value of stability coefficient decreases in comparison with the natural regime for determined slipping plane from 1.7 to 0.9.Consequently, infiltration technogenic load is the main cause of landslides and thus activation of landslide in recent years.