�������������������ö�ӹdz���� Nx, Na, Nb, ��� Nc ��ҡѺ �ٹ��
����ҳ����ʶҹ� a = 0 ૹ������
����ҳ����ʶҹ� b = 0 ૹ������
����ҳ����ʶҹ� c = 0 ૹ������
����ҳ��ӽ���Шӻջ��� (normal annual rainfall) �ͧʶҹ� x : Nx = 0 ૹ������
����ҳ��ӽ���Шӻջ��� (normal annual rainfall) �ͧʶҹ� a : Na = 0 ૹ������
����ҳ��ӽ���Шӻջ��� (normal annual rainfall) �ͧʶҹ� b : Nb = 0 ૹ������
����ҳ��ӽ���Шӻջ��� (normal annual rainfall) �ͧʶҹ� c : Nc = 0 ૹ������
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����ᵡ��ҧ�ͧ��һ���ҳ��ӽ���Шӻջ��Ԣͧʶҹ� x ��� a = 0 %
����ᵡ��ҧ�ͧ��һ���ҳ��ӽ���Шӻջ��Ԣͧʶҹ� x ��� b = 0 %
����ᵡ��ҧ�ͧ��һ���ҳ��ӽ���Шӻջ��Ԣͧʶҹ� x ��� c = 0 %
����ҳ��һ���ҳ��ӽ�������仢ͧʶҹ� x �� �����Ը��ѵ����ǹ���� (Px) = 0 ૹ������