Numerical Modeling on Migration and Transformation of Ammonia-nitrite-nitrates in Groundwater in Sloped Red Soil
|School||Liaoning Technical University|
|Keywords||Groundwater Non-point source pollution Migration and trans- formation of ammonia-nitrite-nitrates Numerical simulation|
The research targets to Qianyanzhou agro-ecosystems which is located in Ji’an city. Taking the ammonia-nitrite-nitrates in groundwater as index, the migration and transformation regulation of ammonia-nitrite-nitrates in groundwater were studied by analyzing the hydrogeological conditions in the region and observating and monitoring groundwater regularly. Then the research applied Visual MODFLOW to simulate groundwater flow and nitrate and ammonia migration, descripted quantificationally and predicted the pollution condition of ammonia-nitrite-nitrates in groundwater. The scientific basis will be provided for drawing up agricultural management program reasonably and developing the best program of agricultural production. The results showed that the nitrite content in groundwater is lowest and nitrate is highest. pH and Mn and Fe are the main factors which worked on the migration and transformation of ammonia-nitrite-nitrates in groundwater. The nitrite content in groundwater were not exceed the standard for drinking water. In groundwater flow field, there has been non-point ammonia source pollution in the middle reaches and non-point nitrate source pollution in the lower reaches. The research applied solute migration model to predict the pollution condition of ammonia-nitrite-nitrates in groundwater in the next five years. The results showed that ammonia-nitrite-nitrates content in groundwater would be increasing with exceeding fertilizer, then the recharge of nitrogen to Jiazhu River increasing gradually. It would lead to more serious nitrogen pollution for local water environment.