A study of the evolution process of karst rocky desertification in a karst canyon area

Quantitative analysis and located monitoring of the evolution of the karst rocky desertification( KRD) based on GIS and RS are useful to carry out the comprehensive treatment of KRD. In this paper,the evolution process,the change modes and the rate of KRD were examined taking Huajiang demonstration area located in a karst gorge as the study area. The following conclusions are obtained:( 1) the evolution of KRD with a total area is not obvious,but it is very significant that the evolution modes between the internal types and there are 188 tracks.( 2) According to the ecological characteristics under human intervention,there are four modes: no change mode,better transition,repeating transition and serious transition.( 3) The land degradation of the study area is generally recovering.( 4) For different types,the desertification and potential rocky desertification are easy to deteriorate, should be paid attention to preservation. The mild rocky desertification,which repeatedly occurs,should be paid attention to prevention and control. Moderate rocky desertification should be taken as the core of control because it is in a good transition state.( 5) The evolution rate of the mild and moderate rocky desertification is relatively fast. In the period of 2005—2010,theevolution rate of the rocky desertification is the fastest,followed by 2000—2005 and 2010—2013. The significance of quantitative analysis of KRD is to put forward the decision-making and regulation mechanism.