tailieunhanh - The effect of tropical monsoon climate on the karst activity in Cam Lo District–Quang Tri Province

In this paper, first, we would like to mention and analyse main factors which effect the karst activity in limestone constituting Co Bai Formation (D2-3 cd), and then quantitatively estimate the alteration in the karstification intensity to this limestone as they are under the influence of the tropical monsoon climate in Cam Lo region, Quang Tri province. | JOURNAL OF SCIENCE, Hue University, Vol. 69, No. 6, 2011 THE EFFECT OF TROPICAL MONSOON CLIMATE ON THE KARST ACTIVITY IN CAM LO DISTRICT–QUANG TRI PROVINCE Nguyen Van Canh, Nguyen Thanh, Tran Thanh Nhan College of Sciences, Hue University Abstract. In this paper, first, we would like to mention and analyse main factors which effect the karst activity in limestone constituting Co Bai Formation (D2-3 cd), and then quantitatively estimate the alteration in the karstification intensity to this limestone as they are under the influence of the tropical monsoon climate in Cam Lo region, Quang Tri province. Keywords: Karstification, karst activity, Calcium carbonate dissolving product, calcium carbonate activity product, calcium carbonate saturation deficiency, average coefficient of calcium carbonate activity. 1 Introduction Karstification is one of the exogenic natural geodynamic processes that have developed most widespread in several nations all around the world as well as in Vietnam and Cam Lo district. Therefore, what is karstification? In our opinion “karstification is the aggregation of geological processes occurring both in the crust and on the earth surface, being generated by dissolution (chemical erosion), corrasion (mechanical erosion) of the surface water and the underground water accompanied by the formation of various shape- and size-differed spaces in the crust, creation of special movement and behaviour of ground water as well as specific morphological topography and regional hydrological system”. Karst territory may create both positive and negative effects on the environment, the local life, economy and national security. These are the most sensitive places in terms of causing many nature and human-induced geohazards. In Cam Lo plain-Quang Tri, karst has induced vertical land subsidences and indeed occurred frequently in recent days and has induced the loss of useland, damaged constructions and threatened the local life. In order to minimize such .