Figure 1.
Seasonal changes in different types of nitrogen in the groundwater of agricultural areas of Xinchang village.
Water quality grades are defined in Table 1. (a) total N; (b) nitrate nitrogen; (c) ammonia nitrogen; (d) nitrite nitrogen.
Table 1.
Classification standard for groundwater quality in China based on nitrogen levels. [18]
Figure 2.
Seasonal changes in different types of nitrogen in the groundwater of residential areas of Xinchang village.
Water quality grades are defined in Table 1. (a) total N; (b) nitrate nitrogen; (c) ammonia nitrogen; (d) nitrite nitrogen.
Figure 3.
Relationships between the four types of nitrogen and rainfall.
(a, b) agricultural areas; (c, d) residential areas.
Figure 4.
Noncarcinogenic dermal risk values for different types of nitrogen in the groundwater.
(a, b, c) agricultural areas; (d, e, f) residential areas.
Figure 5.
Noncarcinogenic oral risk values for different types of nitrogen in the groundwater.
(a, b, c) agricultural areas; (d, e, f) residential areas.
Figure 6.
Location of the study area and sample points.
17 wells with red dot are in agricultural areas and 12 wells with blue dot are in residential areas.