THE INFLUENCE OF PONDS ON DISSOLVED OXYGEN IN SMALL RIVERS OF BERRY (FRANCE)

The influence of ponds on dissolved oxygen in small rivers of Berry (France). Water temperature and oxygen saturation are two major indicators of water quality in surface hydrology. Geographical and cartographic studies about ponds of Central France did no exist until now. During two years, we measured dissolved oxygen using a hand oximeter upstream and downstream of three ponds in the headwaters of the Loire basin. Our results show that oxygen saturation depends on equipments located before and behind the dam, and upstream and downstream: spillways, outlets with a monk, diversion channel, artificial reoxygenation weirs and so on. In some cases (low water quality upstream, existence of weir), relative and absolute saturation of dissolved oxygen increases downstream of ponds.