The report attempts to identify sampling sites for water quality monitoring in Narmada basin. The assessment of water quality conditions over a wide area with respect to time and space requires the monitoring of activities to be carried out in a network. The location of a permanent sampling station is probably the most critical factor in a monitoring network which collects water quality data. If the samples collected are not representative of the water mass, the frequency of sampling as well as the mode of data interpretation and presentation becomes inconsequential.
Besides the economic considerations, there are three levels of design criteria of sampling station location. The macro location deals with river reaches in the river basin, the micro location deals with the location of outfalls or other specific features within a river reach and the third level deals with the representative location points within a river’s cross-section. Sharp’s procedure, is used for locating sampling points in the Narmada river basin.
The sequential water sampling sites were identified in the search for pollution source using four different criteria e.g., tributaries, BOD, NPK and pesticides. Only four levels of hierarchy have been used in the study. However, it was found that for detection of single pollution source, sampling stations of the seventh level of hierarchies should be used.
The report emphasizes that the location of sampling stations determined is to be applied using an engineering judgement whereby the monitoring site satisfies most of the technical requirements while minimizing the financial requirements. It is suggested that the proposed monitoring network be used as a guideline in pinpointing the appropriate sampling sites.
Further, it is observed that the present monitoring sites being monitored under GEMS/ MINARS are self-sufficient as far as the Middle and Upper basin is concerned but needs improvement in the downstream portion of the basin particularly for controlling the pesticides and nutrient related problems.
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