Impact des eaux usées sur la répartition des espèces dans les zones humides du Sud de l’Algérie : Cas de Kef Doukhane (Ghardaïa)

Abstract

The treated wastewater at the Kef Doukhane wastewater treatment plant (Ghardaïa) is discharged in the area surface. These discharged waters have a dark color which means that are poorly treated. For that, this site is conducted by a study to assess its waters in order to know their impact on the plant distributions in the wetland for two seasons. To achieve our aim, we performed in situ tests (pH, EC, T°, dissolved O2) of 8 points at Kef Doukhane, random sampling, laboratory analyses (nitrates, nitrites, ammonium, phosphorus) and bacteriological analyses (enumeration of : reverivible anaerobic germs, total and faecal coliforms, faecal and sulphitoreductive anaerobic streptococci) and on the other hand, a floristic inventory was made in parallel. The results obtained, for the wetland of Kef Doukhane, showed an acidic water (pH = 5) in the first season and basic in de second season with a high salinization (high EC). The bacteriology analyses gave positive results which are different from one station to another and from one season to another. The floristic inventory gave, in both seasons, 36 species and 23 families (61 % of plant are perennials and 39 % of plant are ephemerals) and per season there are 20 species and 16 families, in season 1, and 33 species and 21 families in season 2. These results confirm that there is an influence of pollution on the phytodiversity distribution in this wetland.