3.Die Rolle der Fluß- und Grundwasserdynamik als entscheidender Faktor der Aue
[Ecological analysis of the river Yamuna - a functional approach in a diversified ecosystem in India]
Agrawal, Sanjeev; Trivedi, R. C.
This paper addresses to the general account of the ecological observation of the river Yamuna. The problem of pollution in any aquatic ecosystem can not be obtained/defined without the knowledge of its ecology. The ecological observation will provide extensive information on a given water body. The River Yamuna, which is extensively used for abstractive and instream purposes, has a diversified ecosystem in the Indian subcontinent. A stretch of 490 km can be recognized as a saprobic system due to severe pollution, mainly due to sewage drains, and diffuse eutrophication in the stretch. The river Yamuna is a large Himalayan river. With its total length of 1376 km it travels through historic cities of northern India where this river is polluted by point source discharges, mainly domestic sewage and mixed sewage (industrial + domestic) discharges in some places. On the basis of hydro-geo-morphological, ecological and pollution characteristics, the river can be divided into five different zones viz. i) Himalayan segment, from origin to the Tajewala barrage (172 km), ii) Upper segment, from the Tajewala barrage to the Wazirabad barrage (224 km), iii) The Delhi segment, from the Wazirabad barrage to the Okhla barrage (22 km), iv) Eutrophicated segment, from the Okhla barrage to the confluence ofthe river Chambal (490 km), v) Diluted segment, from confluence of the Chambal to the confluence with the river Ganges (468 km). From 1982 to 1988, hydro-geo-morphological, physico-chemical and ecological observations were taken for this study. Seasonal variations of the water quality evaluation and especially the functional and other relevant parameters give a picture of the trophic state of each segment of the river.