CONG Xin1, ZHANG Shanshan2, XU Zhenghe1, XU Lirong1, PAN Weiyan1, WANG Rongzhen1
(1. College of Water Conservancy and Environment, University of Jinan, Jinan 250022, China；
2. China Gezhouba Group Survey and Design Co., Ltd, Wuhan 430022, China)
Abstract: Shallow groundwater is an important part of local water resources for the Linqing City, Shandong Province. The local groundwater overdraft is serious, and groundwater quality is easy to be polluted by life, agricultural production and other activities. In this study, the inverse distance weighted (IDW) method was used to analyze the spatial interpolation of "three nitrogen" (nitrate nitrogen, nitrite nitrogen and ammonia nitrogen) concentrations in groundwater in the study area. The cluster analysis method was used to analyze the spatial and temporal variability of "three nitrogen" concentrations. Based on the analysis of the status of "three nitrogen" pollution in the study area, the driving factors were further explored. The results showed that NH4+-N was the main nitrogen pollution of groundwater, and its concentration ranged from 0.239 mg/L to 2.304 mg/L, with the exceeding standard rate of 100%. Under the influence of rainfall, the concentration of "three nitrogen" in the wet season was higher than that in the normal season. Affected by land use and topography, the concentration of "three nitrogen" in dry land and rural residential land in the middle of the study area all presented different spatial distribution characteristic. The domestic pollutants and human and animal wastes were the main sources of NH4+-N pollution, which would be the first step to control the nitrogen pollution of study area. Land use types, groundwater depth, pH, DO, Mn2+, and Fe2+ were the impact factors that influence the distribution and transformation of "three nitrogen" in groundwater, which could be the considerable factors in the control of nitrogen pollution in groundwater of study area. The research results are of great significance for understanding the pollution status of nitrogen in groundwater and the control and prevention of nitrogen pollutant.
Key words: shallow groundwater; nitrate-N; nitrite-N; ammonia-N; temporal and spatial characteristics; driving factors
EARTH AND ENVIRONMENT Vol.49, No.1, Tot No.344, 2021, Page 603-614