Nitrate-nitrogen contamination in groundwater: Spatiotemporal variation and driving factors under cropland in Shandong Province, China

3rd International Conference on Water Resource and Environment

地球科学;生态环境科学

Liu, J.^1 ; Jiang, L.H.^2 ; Zhang, C.J.^1 ; Li, P.^1 ; Zhao, T.K.^1

Institute of Plant Nutrition and Resources, Beijing Academy of Agriculture and Forestry Sciences, Beijing

100091, China^1

Institute of Plant Nutrition and Resources, Shandong Academy of Agriculture Sciences, Jinan

250100, China^2

关键词: Agricultural productions;    Annual mean temperatures;    Geostatistical techniques;    Groundwater nitrates;    Significant variables;    Spatial-temporal distribution;    Spatio-temporal variation;    Stepwise regression analysis;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/82/1/012059/pdf
DOI  :  10.1088/1755-1315/82/1/012059

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

High groundwater nitrate-N is a serious problem especially in highly active agricultural areas. In study, the concentration and spatialtemporal distribution of groundwater nitrate-N under cropland in Shandong province were assessed by statistical and geostatistical techniques. Nitrate-N concentration reached a maximum of 184.60 mg L-1and 29.5% of samples had levels in excess of safety threshold concentration (20 mg L-1). The median nitrate-N contents after rainy season were significantly higher than those before rainy season, and decreased with increasing groundwater depth. Nitrate-N under vegetable and orchard area are significantly higher than ones under grain. The kriging map shows that groundwater nitrate-N has a strong spatial variability. Many districts, such as Weifang, Linyi in Shandong province are heavily contaminated with nitrate-N. However, there are no significant trends of NO3--N for most cities. Stepwise regression analysis showed influencing factors are different for the groundwater in different depth. But overall, vegetable yield per unit area, percentages of orchard area, per capita agricultural production, unit-area nitrogen fertilizer, livestock per unit area, percentages of irrigation areas, population per unit area and annual mean temperature are significant variables for groundwater nitrate-N variation.