Karst rocky desertification is a geo-ecological problem in Southwest China. The rocky desertification risk zone delineation could be used as a guide for the regional and hierarchical rocky desertification management a...Karst rocky desertification is a geo-ecological problem in Southwest China. The rocky desertification risk zone delineation could be used as a guide for the regional and hierarchical rocky desertification management and prevention. We chose the middle and lower reaches of the Houzhai underground basin on the karst plateau in Puding County, Guizhou Province, China as the study area and selected land use type, elevation, slope, aspect, lithology and settlement buffer as the main driving factors of the rocky desertification. The potential risk of rocky desertification was quantifed with the factor-weights union method and statistical analysis method. Five grades of rocky desertification risk were delineated based on Geographic Information System. The extremely low, low, moderate, high and extremely high rocky desertification risk zones accounted for 5.01%, 44.17%, 33.92%, 15.59% and 1.30%, respectively. As a whole, the rocky desertification risk level was moderate because the area of low and moderate rocky desertification risk zones occupied 78.09% of the study area. However, more than half of the area (about 50.81%) was predicted to have moderate rocky desertification risk and above, indicating that the study area was subject to rocky desertification. Rocky desertification risk was higher in the southeast and lower in the northwest of the study area. Distinct differences in the distribution of rocky desertification risk zones corresponding to different factors have been found.展开更多
The principle of three-level delineation is adopted in determination of a potential seismic source for the new National Seismic Ground Motion Parameters Zoning Map of China,to embody the inhomogeneity of the spatial d...The principle of three-level delineation is adopted in determination of a potential seismic source for the new National Seismic Ground Motion Parameters Zoning Map of China,to embody the inhomogeneity of the spatial distribution of background seismic activity and induct a uniform seismotectonic model for each seismotectonic region. Based on achievements of determining potential seismic sources in southwestern China,this paper introduces the basic characteristics, historical earthquakes magnitude and frequency distribution,identification of deformation mechanism of main active tectonic structures for the Longmenshan and Chengdu seismotectonic region in the Longmenshan seismic region,establishes the seismogenic model for each seismotectonic region,and identifies the upper limit of background earthquakes. A simple method is also put forward for calculating the spatial distribution function of a background seismic source.展开更多
基金Under the auspices of Major Basic Reseach Development Program of China (973 Program) (No. 2006CB403201)
文摘Karst rocky desertification is a geo-ecological problem in Southwest China. The rocky desertification risk zone delineation could be used as a guide for the regional and hierarchical rocky desertification management and prevention. We chose the middle and lower reaches of the Houzhai underground basin on the karst plateau in Puding County, Guizhou Province, China as the study area and selected land use type, elevation, slope, aspect, lithology and settlement buffer as the main driving factors of the rocky desertification. The potential risk of rocky desertification was quantifed with the factor-weights union method and statistical analysis method. Five grades of rocky desertification risk were delineated based on Geographic Information System. The extremely low, low, moderate, high and extremely high rocky desertification risk zones accounted for 5.01%, 44.17%, 33.92%, 15.59% and 1.30%, respectively. As a whole, the rocky desertification risk level was moderate because the area of low and moderate rocky desertification risk zones occupied 78.09% of the study area. However, more than half of the area (about 50.81%) was predicted to have moderate rocky desertification risk and above, indicating that the study area was subject to rocky desertification. Rocky desertification risk was higher in the southeast and lower in the northwest of the study area. Distinct differences in the distribution of rocky desertification risk zones corresponding to different factors have been found.
基金sponsored by the Study on the Determination of the Seismicity Parameters of Background Source-A Case Study of the Longmenshan Seismic Statistical Zone,Earthquake Administration of Sichuan Province
文摘The principle of three-level delineation is adopted in determination of a potential seismic source for the new National Seismic Ground Motion Parameters Zoning Map of China,to embody the inhomogeneity of the spatial distribution of background seismic activity and induct a uniform seismotectonic model for each seismotectonic region. Based on achievements of determining potential seismic sources in southwestern China,this paper introduces the basic characteristics, historical earthquakes magnitude and frequency distribution,identification of deformation mechanism of main active tectonic structures for the Longmenshan and Chengdu seismotectonic region in the Longmenshan seismic region,establishes the seismogenic model for each seismotectonic region,and identifies the upper limit of background earthquakes. A simple method is also put forward for calculating the spatial distribution function of a background seismic source.