Landform Information Obtains And Landscape Spatial Pattern Analyses Of Hainan Island Based On Aster G-Dem

With the rapid development of GIS spatial analysis and DEM technology, the technology which can get fast and accurate access to the data of terrain and land use is maturing, and on this basis, the continuous development and improvement of landscape ecology happens, and utilizing the landscape pattern analysis method to analyze the land use spatial structure and evolution has become an effective technique currently. Therefore, the utilization of the digital elevation model to establish the full regional covered digital land use spatial pattern, and on the basis of terrain analysis and topographic features understanding, the utilization of the landscape pattern analysis method to study the spatial structure of land use, understand and grasp the characteristics of land use and landscape pattern, establish the interrelation between land use/landscape pattern and land ecosystem function are of great significance to the maintenance of regional ecological balance, the improvement of regional ecological environment, the reinforcement of land resources protection, the prohibition of irrational development activities and the sustainable development of land resource utilization.The former researchers mainly published their results about the spatial distribution of topography in text description, but less in quantitative analysis, especially the research work on the quantitative statistical analysis of topography in Hainan Island is rare. At the same time, as economic development, population growth and the extensive and deep boost of industrialization and urbanization processes, the land use and cover pattern of Hainan Island has undergone great changes. The regional spatial pattern of natural ecosystems is being changed by various ways of human land use, which forms specific spatial pattern of landscape of regional land use.Hence, this research is based on the data of 30m resolution Aster G-Dem and the ArcGIS spatial analysis technique. It extracted and quantitatively analyzed several terrain factors of Hainan Island's topographic terrain features, which obtained the area ratios and number distribution characteristics of them respectively. Their spatial distribution rule and reflected regional characteristics were also analyzed. On this basis, the landscape distribution maps and terrain factors of land use were analyzed together to study the relationship between the landscape spatial structure features of land use in Hainan Island and the changes of terrain and landscape pattern. The conclusions were as follows: 1. Through the window analysis method, the best analysis window of the amplitude of landforms and the surface cutting depth in Hainan Island is 115.21km2. What's more, the factors of the topography and terrain in Hainan Island were extracted, mapped and analyzed. All the extracted results of terrain features and terrain factors could better reflect the distribution patterns of topography in Hainan Island. The basic landform shapes were divided into six types by the basic landform shape analysis. Most terrains were relatively low which were approximately the north mesa plain and the south mountainous area.2. Resulted from the analysis of macro-topography factors, Hainan Island belonged to low altitude areas and most of them were below 800m above sea level which mainly dominated by micro, small projections. The surface roughness of most areas was small with the largest roughness in middle southern mountainous areas and smallest roughness in flats, platforms and hilly areas. The surface cutting depth was dominated by shallow cutting and the difference between south and north was significant. The variance coefficients in elevation of most areas were small and the relative variances in elevation were all not big. Resulted from the analysis factors of micro-topography, the Hainan Island was mainly consisted with gentle slope. The differences of distributions of all slope aspects except the flats without any areas of slope aspect were insignificant and showed characteristics of smooth distribution. Negative terrains were more than positive terrains and the regional characteristics were mostly flat slopes without many ups and downs.3. The terrain factors of Hainan Island possessed obvious characteristics of spatial distribution. The distribution rule of elevation and slope was related to the regional difference of combinations of the surface forms in Hainan Island, but the slope aspect distributed relatively equally without any obvious difference among regions. By dividing areas, the description of elevation and slope aspect proved that the division of five economic circles in Hainan Island was related to terrains. The terrains in east, north and west which were the integrated industrial and mining development aggregations of the city were flat. The southern terrains which were the integrated development regions of tourist city were a bit of rough. The water and soil conditions were good in the island regions which were the major agricultural production areas. The central ecological conservation areas had high lands and steep slopes which limited their economic development to a certain extent.4. The combined analysis of elevation, slope and aspect on the spatial patterns features of landscape in Hainan Island indicated that the extend of land use in regions which had some strong human impacted factors such as low altitude and small slope was relatively higher and various types of landscape distributed extensively. In case of the high altitude and steep slope areas, the impact of human activities weakened and the distribution of landscape types were also affected, especially for the landscape types which regarded the forest and grassland as the main land use way in high altitude and steep slope areas. The slope aspect distributions of different landscape types had insignificant difference.5. Selecting seven landscape indices (number of plaques, the percentage of landscape area, fractal dimension, dominance index, landscape diversity index, evenness index and fragmentation index) to analyze the relationships between the landscape patterns and landforms in different topographic areas of Hainan Island. Generally, it showed that from the low altitude and gently slope areas which were severely disturbed by human activities to the high altitude and steep slope areas, the landscape patch number, area ratioand, diversity and uniformity index decreased, while dominance index increased.Eccept for flat areas,the diversification and apatial heterogereity of several other aspect landscape is not high.6. The case of topographic differentiation frequency of landscape types in Hainan Island were analyzed on the basis of the combination of the terrain index and distribution index of free volume. The actual differentiation of different landscape elements in different terrain sections was described accurately. The distribution structures of different landscape types in terrain sections showed as high, middle and low patterns. In the low pattern, the landscape components competed intensely and distributed relatively intensively. In the high pattern, the survival and development of some landscapes were limited and the landscape elements were relatively homogeneous which indicated that due to the topographic conditions limited different social production activities, the different landscapes were also bound significantly.