Rocky-Desertification Research And Investigate At Hongshui River Basin In Guangxi Autonomous Region

Rocky-desertification is called as the land degenerating procession occurring in the in karsts area under the frail ecological condition, as a result of the natural evolution and the human unreasonable activity, the land occurred the vegetation destruction,soil erosion and the bedrock exposed. In the Southeast of China, the karsts grows well and the situation of rocky-desertification is serious. This paper maked Hongshui River Basin as the investigative area, the area is the subtropics monsoon climate area, rains richly and it has nice karsts growth and the superior geological condition for karsts water preservation which has formed the model karsts landform.The investigative area develops the stratum of Devonian, Carboniferousl, Permian and Triassic,the tectogenesis in this area is opposite in brief. After extracting information from sensing image of the investigative area by computer and artificial revision, we can get the information of rocky-desertification at last, this method can enhance the investigation efficiency. Unified the researching area's geological data, we know that:1,The rocky-desertificaton in the investigative area is about 385 km~2 and the occurrence rate of rocky-desertification is about 34%.2,The rocky-desertification is controlled by tectogenesis. The tectogenesis has controlled the region stratum environment of deposition and the stratum appears, finally also has controlled the rocky-desertificaton trend; in the fold especially anticline, the rocky-desertification is serious because the center of anticline is Carboniferous. The new tectogenesis formed rift valley and horst has weakened or strengthens function to the rocky-desertification. The rift valley reduced the probability of rocky-desertification because of the Quaternary Period deposition; the horst region aggravated rocky-desertification because the denudation strengthened and the drop in level enlarged.3,The occurrence rate of rocky-desertification has direct relation with stratum and it's different in difference stratum. The rate is high in the stratum of Carboniferous and Permian and low in the stratum of Devonian and Triassic. The occurrence rate of rocky-desertification in stratum has relation with carbonate rock. The occurrence rate in the dolostone is nearly 40%, and subter-20% in clastic stone.4,The rocky-desertification is caused by element and human unreasonable activity, element is the background and the human unreasonable activity make it aggravative.