As of 2011, 21 districts in Uttar Pradesh had water quality monitoring stations. Some districts have multiple stations: upstream, downstream and at some other strategic points. In that case, the average of all stations was computed to ascertain the pollutant value for this study. Out of these 21, we have included fifteen districts in our dataset. Reasons for the omission of the remaining cities are:
- Some monitoring stations like Unnao and Jhansi gauge the river quality of small tributaries like Sai and Betwa respectively. The data is sporadic for these tributaries, with some years only mentioning “dry river” for Sai. For the same reason, we had to omit Shahpur, Bateshwar, Etawah and Ayodhya – discontinuous and sporadic data of the river pollutants.
- As the monitoring network expands, new monitoring stations are added every few years. Bijnor, for example, was added in 2018 ( station code 10152). For the data to be meaningful, we need at least fifteen years of observations. So we could not incorporate districts which have been recently added in the monitoring network.
- Therefore our final dataset includes – Bulandshahr, Kannauj, Kanpur, Rae Bareily, Allahabad, Varanasi, Ghazipur, Lucknow, Jaunpur, Saharanpur, Gautam Buddh Nagar, Mathura, Agra and Meerut and Gorakhpur. The rivers analysed are Ganga and its tributaries -Yamuna, Gomti, Hindon- Kali and Rapti. We could find continuous data ( with a few years missing ) for the aforementioned districts.