Page 8, lines 13-17: How valid is this assumption of constant pollutant levels throughout the basin? I understand that the assumption may need to be made due to lack of data, but it would be helpful for the authors to explain if there are regions that are generally known to have higher/lower pollution levels.
Page 8, lines 13-17: How valid is this assumption of constant pollutant levels throughout the basin? I understand that the assumption may need to be made due to lack of data, but it would be helpful for the authors to explain if there are regions that are generally known to have higher/lower pollution levels.