| In this paper, the Chongqing central ridge line as typical mountainous landscape was studied based on the theory of landscape ecology and GIS geographic information technique. The actual plots and plots were investigated and Auto CAD, Adobe Photoshop, Arc GIS9, Fragstats3.3and other analysis software were applied. First of all, landscape in the study area was classified, the features of overall landscape structure and distribution, including space and composition characteristics of different types of landscape and landscapes with different altitude and slope, and gradient patterns of landscape under different disturbance conditions. Secondly, we analyzed the types, composition characteristics, distribution and the space distribution variation with altitude and slope; Then,5typical interference areas were chose to analyze the composition characteristics and changes of landscape of different space scale under these interference conditions by contiguous grid quadrate investigation, and the reasonable composition of landscape in different scales was discussed. Finally, the relation between surface runoff with the ecological sensitivity and landscape composition distribution was investigated. The main results are as follows.(1) in our studied areas, the land use landscape can be divided into six types including forest land, construction land, traffic land, unused land, cultivated land, water area. Among them the area of forest land was195.53hmz, accounting for42.58%, and the forest land include different size of patch and was high heterogeneity; construction area of131.49hm2, accounting for28.64%of the largest number of plaque, plaque uniform distribution; traffic land area of62.04hm2, accounting for13.51%, plaque area is not the same size, the aggregation index was the lowest; unused land accounted for12.82%, more patch number, distribution of cultivated land and waters are rarely aggregation.(2) The slope has a great influence on the composition of the landscape in the study area. In flat slope, construction land accounting most of as high as39.90%, also is road but the forest land only represents22.22%; Gentle slope had considerable proportion of construction land and forest land and lesser road; In gentler slopes, forest land reached44.24%, next by the construction land, and road account for12.62%; In gentle slope, forest land is far more than the other three landscapes, construction land account for17.54%and road account for7.22%, and other landscapes are relatively more compared with that in other slope; In steep slope, forest land represent49.41%, building represent22.12%, the road only represent6.23%, other landscape represent more than in other slope.; Steep is mainly composed with forest land and construction land, forest land is slightly more than construction land.Altitude landscape composition of the study area is also large, low-altitude construction accounted for27.51%, accounted for18.13%of roads, woodland ratio of33.25%, the high proportion of other landscapes; lower elevations, woodland largest, accounting for49.77%, construction accounted for30.51%, while roads and other relatively small; altitude of270-320m, woodland39.04%, construction up to31.03%; higher elevations, woodland only26.45%, building a little more than woodland, road ratio of16.17%, the high proportion of other landscapes; high altitude, no building and woodland, shrub and grassland and a small amount of road.In addition, with the increasing of altitude, the areas of construction land and roads declined in different speed under different disturbance conditions, and the area proportions of the two among all the landscapes become close; Meanwhile other landscape showed an increasing trend with altitude increased; Area of forest land increased under most interference conditions and account for high proportion.(3) The study area had a total of seven forest types, among them, evergreen broad-leaved forest had an area of38.25hm2, accounting for19.56%, and numerous patches; deciduous broad-leaved forest holds largest area accounting for about42.45%of the total area and had most patches which were of uneven size; mixed evergreen and deciduous broadleaved forests accounted for30.18%of the total area and had the relatively more patches; the average area of patch of clustered forest is the largest forest types; the distribution and the average area of patches were least of coniferous forests, mixed broadleaf-conifer forest had19well agglomerated patches; thin woodland accounted for4.02%, in which patches are small, numerous and broken.(4) With the increasing of area studied-that is the expanded of the studied scale, the area proportion of construction land showed a trend of decreasing under most interference conditions; the area proportion of road generally declined; forest land almost gradually increased in all conditions, although forest slightly decreased under the disturbance of construction, but the area proportion is still higher than that of construction land; while the area proportion of other landscapes tends to be stabilized in a certain a range.(5) The ecological sensitivity of all the study area was relatively high, among them, extra high sensitive area accounted for7.20%, mainly concentrated in the halfway and top of mountain of Eling Park; high sensitive area accounted for14.88%, was mainly located in Pingdingshan-Tuwan, Hongyan village and the western side of Eling park; less high sensitive area accounted for16.50%, and distributed dispersedly, most was located in Pingdingshan periphery and the southern side of Tiandi Lake, there are distribution at Chongqing Industrial school and Hutouyan also; middle sensitive areas accounted for17.12%, was mainly located in the six shop and Heaven Lake, left parts were distributed at Hutouyan and Liziba; less sensitive areas accounted for the highest proportion of26.97%and had a wild range of distribution, mainly concentrated at the Hongyan village, Liudianzi and Hualong bridge which were belong to the central part of the study area; the area proportion was only lower than the that of the less sensitive area, it was mainly located in the region between Xiaolongkan and Majiayan, region between the western side of Tiandi Lake and Hualong bridge also had clumpped distribution. |
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