Preliminary results of investigations related to the ecology of Urdari open-pit lake

Abstract

Flooding the remaining gaps of lignite open-pits and the formation of so-called open-pit lakes tends to become an increasingly common practice in Romania (in the Oltenia Mining Basin, where the lignite deposit contained in Dacian and Romanian formations was and is extracted through open-pits). This type of ecological reconstruction of former exploitation areas has been applied worldwide for quite a time, and there are many references in this regard in the scientific literature. In this context, the present paper aims to present some preliminary results regarding the ecology of these lakes, being taken as case study the lake formed in the remaining gap of Urdari open-pit, within the Rovinari Mining Basin. However, given the multitude of similar conditions (bioclimate, geological framework, the formation of the remaining gaps, etc.) in which they form, we appreciate that the conclusions of this study can be extrapolated for other lakes in the area (eg. South Peșteana). We point out from the outset that this study presents data on the existing biotope and biocenoses (restricted to species identification), without going into details about populations, ecosystem production, energy and matter flows within it, these investigations being foreseen for a future development stage of the present study.

Analysis of the Stability State of Jilț North Internal Dump in the Perspective of its Ecological Reconstruction

“…The stability analysis was performed using limit equilibrium methods (Fellenius, Bishop and Simplified Janbu), as they offer credible and satisfactory results [31].…”

“…Jilț; -For most situations, the lowest values of the stability factor were determined by Janbu's method. The exceptions to this rule are represented by steps TH4 -TH7, for which the lowest value of the stability factor was obtained by Fellenius' method; -There is only one situation for which, although the value of the stability factor is above unit (1), there are values below 1.3, recommended by the specialized literature [10,11,13,[30][31][32] for definitive slopes or with a long duration of staying in place. This situation is recorded for the TH2 step (Fs = 1.133).…”