����ȶ�ͬλ��( D��18O��13C) ��Ӧ�þ�����������ӷ������ֶ�Ԫͳ�Ʒ����������Զ�����˹ɳĮ��ԭ����ϵ��ˮ�����ˮˮ��ѧ�ݻ����������о����������: �о������������������ˮ���ɷ�Ϊ3 ���࣬�Ҵ����ڵ���ˮ������������������й���ֱ���࣬ÿһ���ˮ��ѧ������ͬλ������������һ���IJ���; �о�������ˮ����Դ�ڴ�����ˮ���������������ˡ�̼���ο����ܽ⡢�����ο����ܽ⡢�����ο����ܽ�������ӽ�����ˮ�ĵ���ѧ���á������������ˮ�����������ˮˮ��ѧ�ݻ��������ܵ��˴�����ˮϡ�����ú�����ݻ���Ӱ�졣

Combined with stable isotopes ( D��18O��13C) ��two kinds of multivariate statistical analysis methods ( cluster analysis and factor analysis) were used to study the hydrogeochemical evolution characteristics of the groundwater Cretaceous aquifer in Ordos desert plateau�� The results indicated that the groundwater of Huan river and Luo river in studied area can be divided into three categories��and generally clustered in recharge��runoff and discharge areas of groundwater�� The hydrogeochemical and isotopic characteristics of each type were different�� The origin of groundwater in studied area was the precipitation��which experienced salt leaching��carbonate mineral dissolution�� sulfate mineral dissolution��silicate mineral dissolution��cation exchange and other hydrogeochemical processes�� Compared with Luo river groundwater��the hydrogeochemical evolution of Huan river groundwater was also influenced by precipitation dilution and pH evolution��