抄録
Qibainong is one of the groups of hamlets which are located in the north of Guanxi Province, China, where karst topography spread out. Qibainong consists of about 700 hamlets. One hamlet forms a closed society where tens to hundreds of people live by themselves, at the bottom of a doling formed by a karts phenomenon. Environment of karts area is deteriorated in 1958 by the economical advance period when many forests were cut down. The authors started researching water quality since 1999, aiming at getting water safe for living in quality and quantity under the condition of unstable water cycle of Nongshitun, one of Qibainong in krast area. We found out that the clean water spring contains much alkaline earth metals and carbonates. And while it flows through field, it is contaminated by fertilizer and agricultural waste that makes concentration of nutrients increase. And we found out that in rainy season, those valuable nutrients flow out from the outlet of the doline. From the results, we proposed to use the lucid spring water for drinking, and to build a pond near the outlet of the doline to make nutrients to circulate.
