1. Bocco, G., Mendoza, M., and Velazquez, A.: 2001, Remote sensing and GIS-based regional geomorphological mapping: a tool for land use planning in developing countries. Geomorphology 39, 211–219.
2. Chen, L. and Qu, Y.: 1992, Rational development and utilization on water and soil resources in Hexi region (in Chinese with English abstract). Science Press, Beijing, pp 143–176.
3. Chen, Q. and Liang, Q.: 1998, Study on degraded rangelands in Darlag county of Qinghai Province. Journal of Pratacult Science 7(4), 44–48
4. Chen, X. and Kang, E.: 2001, A comparative analysis on sustainable utilization of water resources in arid and semi-arid regions of Gansu province (in Chinese with English abstract). J Glaciol Geocryol 23(1), 74–79
5. Cheng, G.: 1998, Some understandings about the eco-environmental protection and building in the source region of Yangtze and Yellow Rivers. Advance in Earth Sciences 13 (Suppl): 1–5