Tracing the Origin of Groundwater Nitrate in an Area Affected by Acid Rain Using Dual Isotopic Composition of Nitrate

Table 1

Chemical composition of rainfall for Jinyunshan (JYS) from 2002 to 2017 [9], Zunyi (ZY) from 2002 to 2006 [34, 35], Guilin (GL) in 2010 [38], and Guiyang (GY) from 2003 to 2009 [36, 37, 40]. The unit for precipitation (Preci) is mm/yr and the unit for concentration is mg/L.

Year	Location	Preci	pH	SO4^2-	NO3^-	Cl^-	NH4^+	Na^+	K^+	Ca^2+	Mg^2+	H^+
2002	JYS	1607	4.18	7.521	1.825	0.459	1.502	0.136	0.402	1.189	0.081	0.044
	ZY	1226	4.37	10.42	0.700		1.920			1.980
2003	JYS	1233	4.36	7.986	2.136	0.364	1.541	0.115	0.336	1.228	0.069	0.050
	ZY	949	4.25	11.730	2.790		3.040			1.970
	GY				2.259		1.041
2004	JYS	1518	4.30	10.490	2.283	0.455	1.892	0.283	0.457	2.819	0.085	0.026
	ZY	1111	4.28	13.750	1.600		2.070			0.670
2005	JYS	1461	4.59	9.784	2.131	0.549	1.895	0.352	0.443	2.308	0.076	0.024
	ZY		4.79
	GY		4.74
2006	JYS	1196	4.63	13.530	2.860	0.482	2.183	0.153	0.444	3.932	0.096	0.020
	ZY		4.30
	GY		4.35
2007	JYS	1645	4.69	8.676	1.951	0.309	1.353	0.143	0.264	2.205	0.067	0.030
	GY		4.44
2008	JYS	1213	4.52	11.540	2.880	0.545	1.778	0.237	0.372	2.733	0.111	0.044
2009	JYS	1098	4.33	10.910	3.370	0.573	1.976	0.177	0.340	2.667	0.133	0.047
	GY	1107	4.23	25.500	0.453	0.736	2.030	0.320	0.375	7.316	0.252	0.059
2010	JYS	979	3.94	14.540	4.648	0.570	2.230	0.188	0.404	2.749	0.138	0.115
	GL	1950	4.83	16.760	3.728	0.815	1.653	0.359	0.364	4.374	0.287	0.015
2011	JYS	848	4.04	13.510	4.807	0.423	2.097	0.141	0.405	2.603	0.147	0.091
2012	JYS	1006	4.09	11.930	4.366	0.413	2.234	0.144	0.298	2.367	0.140	0.082
2013	JYS	1127	4.20	7.814	3.293	0.256	1.621	0.090	0.214	1.246	0.106	0.063
2014	JYS	1490	4.39	5.796	2.827	0.202	1.271	0.103	0.172	1.041	0.105	0.041
2015	JYS	1288	4.70	4.214	2.258	0.181	1.126	0.051	0.133	0.869	0.078	0.020
2016	JYS	1217	4.97	3.836	2.323	0.168	1.184	0.059	0.131	1.522	0.093	0.011
2017	JYS	1268	5.15	3.508	2.284	0.190	1.080	0.068	0.140	2.077	0.114	0.007