Integrated evaluation of water quality and quantity of the Yellow River

This study presents an integrated water quantity and quality management method for the entire Yellow River system where the eco-environment has been deteriorating and water quantity is very scarce. The supply and demand of water resources has been investigated. The integration of the concepts of water resources functional capacity and water resources functional deficit have been put forward, and their characteristics have been analyzed. The results, based on 1997 to 1999 data, indicate that approximately 39 percent of the total river length was of excellent to good quality, 26 percent was moderate, and 35 percent was poor to very poor. The total natural runoffs of the river were 31.8, 43.9, and 43.4 billion m3, and about 94, 65, and 71 percent of them were withdrawn for agricultural, industrial, and domestic uses in 1997, 1998, and 1999, respectively. The total water resources availabilities were 21.1, 28.8, and 29.2 billion m3 occupying about 66, 66, and 67 percent of the total runoffs in 1,997, 1998, and 1999, respectively. From 199 7 to 1999, the river could provide only 53 percent (on average) of the total water resources demand for the uses and discharge to the Bohai Sea; about 5 7 percent of the water deficiency resulted from pollution and 43 percent from quantity deficit. For the main pollution parameter (CODMn), the averages of water resources functional capacity and deficit were 29,571.54 and 199.70 kg, respectively; for NH4-N, the averages of water resources functional capacity and deficit were 3774.26 and 113.08 kg, respectively. These demonstrated that the influence of NH4-N on water resources availability was more than that of CODMn and that the functional capacity was much higher than functional deficit, suggesting that the actual water quality was mostly better than the required one for water supply functions.