There is relatively little study of how natural disasters impact marriage and family relationships, but here are a few of the studies:

Cohan, C. L., & Cole, S. W. (2002). Life course transitions and natural disaster: Marriage, birth, and divorce following hurricane Hugo. Journal of Family Psychology, 16(1), 14-25. doi:10.1037/0893-3200.16.1.14

Lowe, S. R., Rhodes, J. E., & Scoglio, A. A. J. (2012). Changes in marital and partner relationships in the aftermath of hurricane Katrina: An analysis with low-income women. Psychology of Women Quarterly, 36(3), 286-300. doi:10.1177/0361684311434307