Impact of off -channel reservoirs on environment in Nakhchivan AR of Azerbaijan

Abstract

The article is dedicated to the issues of investigating the impact of off-channel reservoirs on the environment, as well as setting seepage losses for working out measures for improvement of the ecological situation and land-reclamation condition in the Nakhchivan Autonomous Republic (AR) of Azerbaijan. According to the investigations conducted, after putting into operation 16 off-channel reservoirs, the hydrogeological conditions and land-reclamation state have changed fundamentally. The ground water level has risen from 30–40 m depth to surface, mineralization has increased in 2–10 times at the reservoir affected zone, soils were subjected to re-salinization. Seepage losses from off-channel reservoirs are one of the signifi cant factors leading to negative features indicating a deterioration of the environment. It has been found experimentally that the value of seepage losses under active pressures changes from 9 up to 13 per cent per reservoir general capacity. This is connected with the fact, that the reservoir’s base consists of permeable rocks, the aquifer lies at 30–40 m depth, dam embankment (without impervious barrier) consists of solid loamy soil. That’s why the main part of seepage losses come from the reservoir base. Application of anti-seepage measures, for example, artificial mudding and catchment of seepage water by the intercepting drainage are needed for seepage prevention. Refs 13. Figs 1. Tables 4.