The overuse of fertilizers for high yields in agricultural production increases the leaching problem particularly in areas affected by heavy monsoon precipitations in Republic of Korea.The extent of leaching depends o...The overuse of fertilizers for high yields in agricultural production increases the leaching problem particularly in areas affected by heavy monsoon precipitations in Republic of Korea.The extent of leaching depends on various factors such as rate of monsoon precipitation,agricultural management practices,land use,soil properties,topographic features,and hydrochemistry.We studied spatial variations based on temporal fluctuations of groundwater level below the ground surface,pH,electrical conductivity(EC),and nitrate(NO3)from year 2011 to 2014 in 70 groundwater wells in agricultural region of Korea.We found that groundwater level deepening across the studied period in agricultural area.Low pH(5.50–6.50)gradually vanished in year 2014 and high pH(8.51–9.50)appeared in the same year.Variations in the EC values shifted from high range EC(>500μS/cm)to lower range(<100μS/cm)from 2011 to 2014.Similar to spatial pattern of groundwater EC and contrary to pH,the high values(>50 mg/L)for groundwater NO3 which appeared in the start of the study period,got vanished at the end of the study period.These findings are attributed to improved agricultural practices and change in land use pattern from vegetables to orchards and ginseng fields which do not require excessive fertilizer application.展开更多
Understanding the controlling factor of groundwater quality can enhance promoting sustainable development of groundwater resources. To this end, multivariate statistical analysis（MA） and hydrochemical analysis were ...Understanding the controlling factor of groundwater quality can enhance promoting sustainable development of groundwater resources. To this end, multivariate statistical analysis（MA） and hydrochemical analysis were introduced in this work. The results indicate that the canonical discriminant function with 7 parameters was established using the discriminant analysis（DA） method, which can afford 100% correct assignation according to the 3 different clusters（good water（GW）, poor water（PW）, and very poor water（VPW）） obtained from cluster analysis（CA）. According to factor analysis（FA）, 8 factors were extracted from 25 hydrochemical elements and account for 80.897% of the total data variance, suggesting that groundwater with higher concentrations of sodium, calcium, magnesium, chloride, and sulfate in southeastern study area are mainly affected by the natural process; the higher level of arsenic and chromium in groundwater extracted from northwestern part of study area are derived by industrial activities; domestic and agriculture sewage have important contribution to copper, iron, iodine, and phosphate in the northern study area. Therefore, this work can help identify the main controlling factor of groundwater quality in North China plain so as to make better and more informed decisions about how to achieve groundwater resources sustainable development.展开更多
基金supported by the National Research Foundation of Korea(NRF)grant,funded by the Korean government(MSIT)(NRF-2015R1A4A1041105)Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(NRF-2018R1D1A1B07047200).
文摘The overuse of fertilizers for high yields in agricultural production increases the leaching problem particularly in areas affected by heavy monsoon precipitations in Republic of Korea.The extent of leaching depends on various factors such as rate of monsoon precipitation,agricultural management practices,land use,soil properties,topographic features,and hydrochemistry.We studied spatial variations based on temporal fluctuations of groundwater level below the ground surface,pH,electrical conductivity(EC),and nitrate(NO3)from year 2011 to 2014 in 70 groundwater wells in agricultural region of Korea.We found that groundwater level deepening across the studied period in agricultural area.Low pH(5.50–6.50)gradually vanished in year 2014 and high pH(8.51–9.50)appeared in the same year.Variations in the EC values shifted from high range EC(>500μS/cm)to lower range(<100μS/cm)from 2011 to 2014.Similar to spatial pattern of groundwater EC and contrary to pH,the high values(>50 mg/L)for groundwater NO3 which appeared in the start of the study period,got vanished at the end of the study period.These findings are attributed to improved agricultural practices and change in land use pattern from vegetables to orchards and ginseng fields which do not require excessive fertilizer application.
基金supported by the Major State Basic Research Development Program (No. 2010CB428800)the Geological Survey Projects Foundation of Institute of Hydrogeology and Environmental Geology (No. SK201308)
文摘Understanding the controlling factor of groundwater quality can enhance promoting sustainable development of groundwater resources. To this end, multivariate statistical analysis（MA） and hydrochemical analysis were introduced in this work. The results indicate that the canonical discriminant function with 7 parameters was established using the discriminant analysis（DA） method, which can afford 100% correct assignation according to the 3 different clusters（good water（GW）, poor water（PW）, and very poor water（VPW）） obtained from cluster analysis（CA）. According to factor analysis（FA）, 8 factors were extracted from 25 hydrochemical elements and account for 80.897% of the total data variance, suggesting that groundwater with higher concentrations of sodium, calcium, magnesium, chloride, and sulfate in southeastern study area are mainly affected by the natural process; the higher level of arsenic and chromium in groundwater extracted from northwestern part of study area are derived by industrial activities; domestic and agriculture sewage have important contribution to copper, iron, iodine, and phosphate in the northern study area. Therefore, this work can help identify the main controlling factor of groundwater quality in North China plain so as to make better and more informed decisions about how to achieve groundwater resources sustainable development.
