| As an important role in the Earth’s climate system and the biogeochemical cycles, land cover reflects the close relationship between human and land and is closely related and mutually complement to landscape pattern. With the improvement of the satellite data and the development of the models and the methods, the types of the global land cover (GLC) products have been greatly enriched. However, the researches of these GLC products are rarely involved in the analysis of monitoring the changes of land cover and the evolutions of landscape pattern at present. Because of the regional land cover characteristics of Wanbei, Wanzhong and Wannna region, Anhui Province was treated as the study area. And the consistency analysis of the global land cover product (MCD12Q1) based on Moderate Resolution Imaging Spectroradiometer (MODIS) was firstly actualized to acquire the most suitable scheme for the study area among the five classification systems of this product,i. e., International Geosphere Biosphere Programme (IGBP) global vegetation classification, University of Maryland (UMD), MODIS-derived Leaf Area Index and Fractional Photosynthetically Active Radiation (LAI/FPAR), MODIS-derived Net Primary Production (NPP), and Plant Functional Type (PFT) based on the Chinese 30 m GLC product (GlobeLand30). And the result illustrated that the IGBP scheme showed to be the most suitable for the study on land cover in Anhui Province. Then, the analyses of the general changes on the area and structure, the transform between the different land cover types and the dynamic change degree of the single and comprehensive land cover types were implemented. From these three aspects, the research on the temporal and spatial variation of land cover in Anhui Province was made based on the most suitable IGBP scheme of MCD12Q1 and the GlobCover data, which was chosen among other GLC data in view of the same time and space. Finally, the suitable landscape indexes were selected to analyze the spatial variation of landscape pattern in Anhui Province on the basis of the above researches. This thesis can provide the scientific basis for making the reasonable and effective land planning policy and maintaining the good ecological environment. The main research contents and results were as follows:(1) The consistency of five classification schemes of the MCD12Q1 product at a provincial scale was evaluated. A harmonization method was firstly used to reclassify the land cover types between the five classification schemes of MCD12Q1 and ten classes of GlobeLand30 by the knowledge rule (KR) and C4.5 decision tree (DT) classification algorithm. A total of five harmonized land cover types were derived including "woodlands", "grasslands", "croplands", "wetlands" and "artificial surfaces", and four evaluation indicators were selected including the area consistency, spatial consistency, classification accuracy and landscape diversity in the three sub-regions of Wanbei, Wanzhong and Wannan. The results indicated that the consistency of IGBP was the best among the five schemes of MCD12Q1 according to the correlation coefficient (R). The "woodland" LAI/FPAR was the worst, with a spatial similarity (O) of 58.17% due to the misclassification between "woodland" and "others". The consistency of NPP was limitd to the regions as the overall accuracy OA varied from 1.61% to 56.23% in the three sub-regions. Furthermore, with the biggest difference of diversity indices MSIDI and MSIEI between LAI/FPAR and GlobeLand30, the consistency of LAI/FPAR was the weakest.(2) The temporal and spatial variations of land cover in Anhui Province were studied. By using GlobCover2005 and GlobCover2009 and the MCD12Q1 data of IGBP classification scheme, the research on the temporal and spatial variation of the land cover in Anhui Province was carried out in three aspects of the overall analysis of the temporal and spatial variation of land cover, the transform between the land cover types and the dynamic change degree of the single and comprehensive land cover types. The result illustrated the increase of the area of the "woodlands" type and the decrease of the "wetlands" type. Moreover, the value of A/2009-2005, is., the degree of land use change, was more than zero, which indicated the development stage of the land use structure of Anhui Province from 2005 to 2009. With |K|= 0.12, the annual rate of change on the "grasslands" of the MCD12Q1 data occupied the biggest. The value of LC, i.e., the integrated land-use dynamic degree, was respectively 3.06% of MCD12Q1 and 0.90% of GlobCover, which indicated a small annual rate of land cover change in the study area.(3) The spatial variations of landscape pattern in Anhui Province were analyzed. Based on GlobCover2005, GlobCover2009 and the MCD12Q1 data in 2005 and 2009, the spatial variation of landscape pattern in Anhui Province was analyzed from two levels of the landscape types and the landscape. Conclusion were obtained:the number of patch NP and the patch density PD of the "farmlands" landscape type in Anhui Province were reduced and the values of NP and PD of the "wetlands" were increased during 2005-2009, while the values of NP and PD of the "artificial surfaces" remained the same and the landscape fragmentation of the "woodlands" and "grassland" showed to be larger. Moreover, the type edge of the "farmlands" was weakened while the type edge of the "wetlands" was enhanced and its aggregation became larger. The aggregation and shape complexity of the "artificial surfaces" remained the same. And the values of CLUMPY of the "farmlands" varied from 0.8995 to 0.9050, which illustrated the high aggregation and the more concentrated distribution. The values of HT varied respectively from 0.9642 to 0.9053 of the MCD12Q1 data and from 0.8867 to 0.8751 of the GlobCover data, indicating that the landscape heterogeneity of Anhui Province became smaller during 2005-2009. |
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