河北省中南部农区地下水硝态氮含量特征分析

Spacial Variation of Nitrate Contents of Groundwater in Middle-South Agricultural Area of Hebei Province

于2005和2006年沿横贯河北省中南部的北纬38°带,分别在低山丘陵、山前平原、低平原和近滨海平原冬小麦夏玉米轮作农区,采集灌溉机井水样分别为24,120,71和44个,并分析水样中的硝态氮含量.结果显示,河北省中南部农区浅层地下水硝态氮总体上达到了饮用水标准,没有发生大面积污染,但硝态氮含量空间变异很大;地下水埋深及施肥量对地下水硝态氮含量都有明显的影响;低山丘陵区硝态氮含量最高,平均含量为13.39 mg/L;山前平原区含量其次,平均含量为4.03 mg/L;低平原及近滨海平原区含量最低,平均为0.41 mg/L;低山丘陵和山前平原部分样点硝态氮含量超过饮用水标准,地下水污染明显,需要采取防治措施.

Irrigation groundwater were sampled along latitude 38° North in middle-south area of Hebei province to check nitrate contents of shallow groundwater in a zone of growing winter wheat and summer maize with high application rate of fertilizer. Sampling area covered four landforms of low hills,piedmont, low plain and coast plain, and 24, 120, 71 and 44 groundwater samples were analyzed in these landforms, respectively. Nitrate contents in most groundwater samples were lower than drink water standard and no nitrate pollution occurred in a large scale. However, the spatial variations of the nitrate contents were significant with effects of groundwater buried depth and application rate of fertilizer. The average nitrate contents in low hills, piedmont, and low plain and coast plain were 13.39 mg/L, 4.03 mg/L and 0. 41 mg/L, respectively. The nitrate contents of several samples in low hills and piedmont were higher than drink water standard, which showed groundwater was contaminated and it is necessary to act to prevent pollution of groundwatere.