Evaluation Of Ecological Environment Quality In Rocky Desertification Area Based On Remote Sensing Ecological Index

Karst Rocky desertification is the main ecological environment problem of ecological protection,construction and sustainable development in mountainous areas of Guizhou Plateau.The state began to carry out comprehensive prevention and control projects for this in the planning period of 1995.However,due to the vulnerability of rocky desertification area,and the unreasonable use of human beings,the ecological environment is still more sensitive.Therefore,how to grasp the changes of ecological environment in karst rocky desertification area in time and quickly is of great theoretical and practical significance to the two bottom lines of coordinated protection and development in karst area.The Huajiang Demonstration area is a typical representative of Karst Plateau Canyon area,the ecological environment is very fragile,and the intensity of rocky desertification is high.Aiming at the special environmental conditions and ecological problems in karst rocky desertification area,based on GIS and remote sensing technology,the paper selects remote sensing images from 1990,2001,2009 and 2017 as the research data,and uses remote sensing Ecological Index(RSEI)as the evaluation index,which includes 4 elements such as wet,green,thermal and dryness.The RSEI was calculated by Principal component analysis method,and the change of ecological environment in the demonstration area of Flower River in 27 was evaluated quantitatively.Based on the field survey data,social survey data,land use in the 1990-2017 and spatial distribution data of rocky desertification in 1990-2017,the response of land use and different levels of rocky desertification to the ecological environment quality of the demonstration area was analyzed.The main findings are as follows:(1)In 1990,2001,2009 and 2017,the mean RSEI of the study area were 0.524,0.563,0.658 and 0.816 respectively.The gradual rise of RSEI shows that the quality of ecological environment is gradually getting better.Between 1990 and 2017,the ecological environment quality of the Huajiang demonstration area changed greatly,the overall trend became better,the overall change was also significant,significantly changed area accounted for 91.39% of the area of the demonstration area,the significant variation area was 1.763km2,distributed in the TIANBA group and the GE Dam Group Junction,the Shapotou group,the large Slate group Quarry area,And along the Beipanjiang Canyon,which has become worse due to water erosion.(2)There is a close relationship between ecological environment quality and land use mode in rocky desertification area.Characteristics of different land use types and ecological environment quality: the ecological environment quality is higher in the areas with less human activities,such as woodland,shrub woodland and sparse woodland,and two kinds of land use types in drylands and orchards are areas with more frequent human activities,although the quality of ecological environment is rising,but the change is slower than that in other regions.(3)The change of different levels of rocky desertification affects the quality of ecological environment to a certain extent.From 1990 to 2017,the quality of ecological environment is on the rise as a whole,and the non-karst geomorphological areas are less artificially interfered with by human intervention,and the quality of ecological environment is relatively stable.With the comprehensive management of Rocky desertification,the construction of cisterns,the implementation of returning farmland to forest and grassland,and the improvement of soil and water loss in the demonstration area,the ecological environment quality gradually became better with the decrease of rocky desertification intensity grade.