| The karst rocky desertification is the main ecological environment problem for ecological protection,construction and sustainable development in the Guizhou plateau mountainous areas.The state began to carry out comprehensive prevention and control projects for this in the planning period of 1995.The research on rocky desertification has maked considerable progress.However,there are still problems such as the classification system needs to be improved,the depth of data mining is not enough and the mechanism of evolution is not clear.This paper attempts to explore the evolutive characteristic of the rock desertification coupled with the tupu information and the spectrum feature in the rocky desertification management project.The spatial-attribute-process-map integrated data information coupled with the spatial feature map and the spectrum is established to explore the fractal dynamics of the spatial structure of rock desertification over a long time scale and the change mechanism of the process map information.It is an important theoretical and practical significance for the optimization and regulation of rock desertification management.This paper use the spectrum and texture features of collaborative high-resolution remote sensing images to propose rock desertification classification methods based on multi-knowledge RS-tupu information.On one hand,this use long-time landsat satellite data to obtain spatial features of rocky desertification landforms in the Huajiang demonstration area during the period from 1990 to 2016.Based on the fractal theory,the fractal dynamics of the rocky desertification spatial structure in the gorge region of the Karst plateau were revealed.On the other hand,based on the method of tupu process analysis,this paper analyze the tupu of the rocky desertification levels in five temporal units(1990-1995,1995-2000,2000-2005,2005-2010 and 2010-2016)to illustrate the pattern of rocky desertification change in the gorge region of the Karst Plateau in 26 years.The evolutionary mechanism of the rocky desertification tupu was explored from the three aspects of the influence of topographic gradient(topography index),surface temperature on rocky desertification and response of soil physical properties to rocky desertification.The main conclusions are as follows.(1)This paper use the spectrum and texture features of collaborative high-resolution remote sensing images to propose rock desertification classification methods based on multi-knowledge remote sensing map information.The principal component transformation method is used to compress and enhance the spectral information of landsat8 OLI data and the texture information of GF1 data respectively.Finally,the spectral information of landsat8 OLI data and the texture information of GF data are coordinated,and the vegetation coverage and rock exposure ratio are assisted.Such as index,improve classification accuracy,reached90.17%.(2)During the 26 years,the total area of the rock desertification land(KRD)in the Huajiang demonstration area decreased from 2840.02 hm~2 to 2704.77 hm~2and the area was reduced to 135.25 hm~2.From the perspective of spatial pattern,the changes of rocky desertification are mainly concentrated on three regions.Falang-Bangui in the north of the demonstration area,Chaeryan-Yindongwan in the middle of the demonstration area,and Yanshang-Banwei-Xinfazhai in the south of the demonstration area.(3)In the Huajiang demonstration area from 1990 year to 2016 year,the fractal dimension D rose steadily from 2.766 to 2.872,illustrating that the spatial mosaic pattern of the spot becomes increasingly complex.The spatial structure stability index SK roses steadily from 1.266 to 1.372.This result shows that the heterogeneity and complexity of the rocky desertification landscape in the demonstration area are continuously increasing and the structure is becoming more and more complex and more and more stable.(4)During the 26 years from 1990 to 2016,the tupu of rocky desertification in the Huajiang demonstration area produced 557 tupu unit.Among them,the 551unit has changed.The unit changes are divided into six categories,including stable,continuous recovery,continuous aggravation,intermittent recovery,intermittent aggravation,and instability.The degree of rocky desertification in the demonstration area is mainly stable and sustained recovery type.The two accounted for 79.94%of the total karst area,followed by continued heavy lifting,accounting for 9.78%of the total karst area.(5)The Moran's I index of the rocky desertification during the six periods from 1990 to 2016 in the study area was positive,illustrating that the clustering trend was indicated.The Moran's I index value has been increasing continuously from 1990 to 2010 and it has slightly declined in 2016.As a whole,in the past 26years,the rocky desertification land in the Huajiang demonstration area has a spatial auto-correlation relationship.There is a clustering pattern between blocks.(6)There are significant differences in the topographic distribution index of different rocky desertification maps,and the topographic index 1.225-1.3556 is a key turning point in the evolution of rocky desertification.(7)From 2009 and 2016,the overall temperature of Huajiang Demonstration Zone has increased significantly.The high-temperature zone is distributed along the banks along the Huajiang River Canyon.the maximum surface temperature in the study area was 40.31°C,and 36.41°C.The rocky desertification evolution patterns have significant differences in surface temperature distribution indices,especially the intermittent recovery type,which is U-shaped evolution law.Continuous aggravation,intermittent aggravation and unstable type all increase with the increase of surface temperature.The continuous recovery type and the stable type fluctuate with the rise of temperature. |
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