[Objective] The water environment quality and its controls in drainage ditches from Ningxia Irrigation area were observed in order to provide theoretial reference for the comprehensive control of water pollution of drainage ditches.[Methods] We collected water environmental data of drainage ditch during 2009-2015 and prefectural socio-economic data. The permanganate index

chemical oxygen demand

ammonia nitrogen

total phosphorus

biochemical oxygen demand

volatile phenols

fluoride

cyanide

and sulfides were selected to evaluate the comprehensive water pollution. Correlation analysis and grey correlation analysis were used to analyze the impact of socio-economic indexes on the water quality.[Results] The water quality of Nangan ditch was gradually improved

while Yinxingan and Qingshui ditchs deteriorated rapidly

and others remained stable and sound. The water quality was highly related to socio-economic indexes. The correlation coefficient(r) was 0.998 for chemical fertilizers utilization with water quality in Zhonggan ditch

and 0.983 for total industrial effluent discharge in Nangan ditch; the correlation between Yongergan ditch and agricultural water consumption was as high as 0.793 41

the correlation degree between Nangan ditch and discharges of total industrial wastewater discharge was as high as 0.75 569

respectively.[Conclusion] The water quality of drainage ditches was greatly affected by agricultural non-point source pollution and industrial waste water. On the prefectural level

the order of correlations between the comprehensive pollution and socio-economic indexes was Wuzhong City

Yinchuan City

Zhongwei City and Shizuishan City. There is a good consistency between the results of correlation analysis and grey correlation analysis. The combination of the two analyses was performed to exploring the main controls for water quality. Generally

agricultural production was the dominant driver for water pollution in Yinchuan City and Shizuishan City

while industrial production was dominant in Wuzhong City and Zhongwei City. Moreover

agricultural non-point source pollution caused by agricultural production has a greater adverse effect on water quality than industrial wastewater produced by industrial production.