| Ecological environmental security has became more and more risky which is the hot research in the world. Ecological environmental security problem is paied more and more attention in China. Ecological environmental security problem stands out in karst region due to karst background fragility. Karst rocky desertificaiton has became the most severe ecological environmental problem in the southwest of China, which threaten the balance and development of nature, society and economy in karst region. The study of karst ecological environmental system security assessment is the base of scientific analysis for karst ecological environmental security and objective assessment for rocky desertification comprehensive treatrment effect.The concept of karst ecological environmental system security was set up and defined in this study. Based on driving force-Pressure-State-Impact-Response (DPSIR) model, karst ecological environmental system security assessment conceptual framework was founded. Karst ecological environmental system security evaluation index system and karst ecological environmental system security standard were established for the first time, it improved the theory of karst ecological environmental system security assessmentConsider Guangxi Guohua rocky desertification monitoring area as a typical small watershed research unit, the rocky desertification monitoring technic and method were discussed and regulated. Based on PCI, ENVI, MAPGIS software platform, digital elevation mode(DEM) and digital orthophoto map (DOM) were produced through a sereis treatment of QuickBird(QB) and ALOS images. Based on eCognition software, process tree was built to find 5 thematic information and dynamic change inspect of landuse, vegetation cover rate, ecological landuse, water and soil loss, roky desertification. Based on ArcGIS software platform,terrain analysis, spatial overlay analysis were conducted and geographical information database of Guohua rocky desertification monitoring area was designed. In this monitoring area, mild, moderate and intensity 3 grades rocky desertificaiton runoff area were built. Buyang first spring, Buyang second spring and Longhexia spring total 3 monitoring stations were built to monitor epikarst spring changes.20 typical plots were selected to survey and sampling for karst ecological environmental research. Society and economy information were surveyed in 5 villages. Systematic karst ecological environment and rocky desertificaiton monitoring in Guohua rocky desertificaiton monitoring area were observed by remote sensing monitoring combined with field monitoring methods.Karst ecological environmental system security assessment model was established. Karst ecological environmental system security level was adopted to measure the security status. Karst ecological environmental system security of Guohua roky desertification monitoring area was assessed by Delphi method-Analytic Hierarchy Process-information entropy-AHP compound assessment method and Delphi method-AHP-information entropy-fuzzy compound assessment method. Two compound assessment methods were compared. Reserach result as follow:(1)Based on theory of karst ecological environmental system security assessment and combined with karst region fact,4 levels frame model which included taget level, rule level, factor level and index level was established and so did karst ecological environmental system security assessment index hiberarchy system, which included 4 tagets,13 rules and 34 indices(2) Weight value of each index was worked out by Delphi method combined with AHP and then it was corrected by information entropy. Ultimately, karst ecological environmental system security assessment index weight value was determined by this way and reordered based on weight value.(3) based on 3S technology and field monitoring, QuickBird and ALOS digital orthorectif ied maps were produced which updated large scale maps of Guohua rocky desertification monitoring area. Resolution of QuickBird was 0.6m and resolution of ALOS was 2.5m. Information from high-resolution remote sensing image of Guohua roky desertification monitoring area was extracted by eCongnition software. Landuse, vegetation cover rate, water and soil loss,rocky desertification 5 thematic data were analyzed and mapped. The change of 5 indices included Landuse colligate index, ecological landuse colligate index, karst vegetation cover rate, water and soil loss colligate index and rocky desertification colligate index from 2003 to 2009, which showed prominent effect of karst rocky desertificaiton comprehensive treatment in Guohua but the whole karst environment still was unsafe.(4) 20 natural ecological invironmental status of 20 tapical plots in Guohua rocky desertification monitoring area were observed in the field, inclued soil physical and chemical characters, vegetation, landuse, bare rock rate, etc. Longhe epi-karst water system was observed and analyzed. Total natural epi-karst groundwater resource was about 319000m3/a. Combinate field survey with remote sesing analysis, drought and flood hazard distribution maps were drew.22.53% area was easy to suffer flood and 94.22% area was easy to suffer drought. Most of this rocky desertification monitoring area was impacted both by drought and flood. A series of monitoring technic and method were executed in mild, moderate and intensity rocky desertificaiton runoff areas. data of vegetation, soil,water and soil loss, bare rock rate, etc were collected. Field monitoring and remote sensing monitoring are good at consistency.It is scientifical and accurate to monitoring the small scale karst rocky desertification with high resolution remote sensing. Aim at karst peak cluster depression, a systematic karst rocky desertificaiton monitoring technic and methord were established, which supplied reference and example of technic and method for southwest karst region to monitoring rocky desertification.(5) Based on comprehensive assessment model, karst ecological environmental system security was assessed by using the compound method as Delphi method-AHP-information entropy correction-AHP in Guohua roky desertification monitoring area. The standardization value was 0.2905, karst ecological environmental system security belonged to extremely warning. Using another compound method as Delphi method-AHP-information entropy correction-fuzzy, the membership grade of 5 security grades like extremely warning, moderate warning, pre-warning, moderate safe, safe was 0.3924,0.2254,0.2272,0.1073, 0.0477,so the karst ecological environmental system security of this monitoring area belonged to extremely warning. The results of two compound methods were consistent. Compared two compound methods, fuzzy comprehensive assessment method was more fit for karst ecological environmental system security assessment, Because, it was good at detail analysis for karst ecological environmental system security and it could describe the assessment result more concretely. This study enhanced and completed basic theory of karst ecological environmental system security assessment. it was a typical small scale research on karst ecological environmental system security assessment, which provided a reference and example for middle scale and large scale karst ecological environmental system security assessment framework and model. Karst rocky desertificaiton monitoring technic and method were worked out and normalized, which were research referece of ecological envrionment and rocky desertificaiton monitoring for other karst regions. it provided ideas and methods for study of karst ecological environmental system security assessment in southwest of China.
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