Dongtai Reclamation Area Landscape Change And Scale Effect

Coast with abundant natural resources, is the most beneficial to human survival and development. Only clear the changing trend of coastal landscape pattern, can reasonable plan the coastal landscape pattern, reduce the influence of the change on the coastal ecological environment, realize the sustainable development of the coastal resource utilization. But the research of landscape pattern may be affected by scale. So how to choose the appropriate scale becomes the primary task for the research of coastal landscape pattern.Using 1995,2002 and 2008 TM remote sensing image, as Dongtai reclamation for example, this paper analyzed the district landscape pattern by calculating various kinds'landscape indexes. it found that, in whole study area, the patch shape of artificially landscape became regular, pattern fragmentation enhanced, the whole distribution of landscape pattern trended to be simple under the influence of human activities; the old reclamation area were artificial landscape, the change of landscape pattern was consistent with the whole study area, but the landscape pattern evenly distributed; in Badou and Sancang reclamation area, mainly with the natural landscape, the extent of human activities was different because the reclamation time was different, but eventually the shape of patch was becoming rules, fragmentation aggravating, landscape pattern equalization distribution, the cultivated land had the trend of replacing Suaeda glauca became advantage patches. In addition to the different of landscape pattern in each area caused by objective cause, the choice of research area' size can also affect the analysising results of landscape pattern.On analysising the rule of landscape indexes under different resolution ratio, the classified figure was resampled to 18 kinds of resolution ratios by using GIS, and then respectively calculated those landscape indexes of different scale on patch level and landscape level. It found that the index showed 4 trend on different resolutions:①index kept unchanging;②index kept unchanging on the whole, but had too turning points;③index were regular rising or falling, but had no distinct turning points;④index were regular rising or falling, but had obvious turning points. Almost all of those indexes mutated in 60m and 160m. so, on studying the landscape pattern, the remote satellite image resolution should be controlled within 60m, the maximum did not exceed 160m.On analysising the rule of landscape indexes under different range, cut the classification diagram with 0.5km, 1km,1.5km and 3km four different sizes of square grid under the support of GIS, separately calculated the diversity index, aggregation index and fractal dimension index of each grid, and Then simulated the semivariance model of landscape index on different ranges by using GS+. Results showed that, in 0.5km, three indexes had the maximum nugget, means that the spatial changes of each index more complex within the range; the nugget effect of each index weakened with the increase of scales, means that the spatial heterogeneity which random part caused constantly weakened, which mainly because of ignoring anisotropy effect on spatial variation; along with the increase of scales, the ratio of nugget and sill Co/(Co+C) of each semivariogram constantly decreased, namely the proportion of spatial heterogeneity which random part caused on total spatial heterogeneity gradually decreased. So when the scale was too big, would lose too much spatial information; scale was too small, the general rules would be covered by local rules, can not reflect the main rules of landscape pattern. So comprehensive considered, in study the spacial structure of Dongtai's land-use, thinking 1.5km is the best range of sample.