Korean Journal of Soil Science and Fertilizer ISSN:0367-6315(Print) 2288-2162(Online) 한국토양비료학회 학회지

This study aimed to identify the changing trends in the agricultural water quality of the major watersheds in Gyeongbuk province over a 5-year period ranging from 2013 to 2017. The results of water quality analysis revealed that the mean chemical oxygen demand was 3.6 mg L^-1, with the median values being 3.3 mg L^-1. The mean and median values of electrical conductivity (EC) were 0.24 dS m^-1 and 0.23 dS m^-1, respectively. The mean and median values of the total nitrogen (T-N) content were 2.6 mg m^-1 and 2.4 mg m^-1, respectively. The mean and median values of the total phosphorous (T-P) content were 0.12 mg m^-1 and 0.11 mg m^-1, respectively. EC and T-P contents had increased as the area ration of agricultural land increased, although there were no statistically significant differences. The trend of T-N content was reversed. Therefore, further researches are needed to evaluated contribution of artificial pollution such as livestock as well as change in flow rate.

Changes in precipitation and Chemical Oxygen Demand (COD_MN) in April, July, and October.