Spatial Changes of Landscape Patterns in Baiyangdian River Basin
白洋淀流域景观空间格局变化研究

Based on land use and land cover data, the landscape has been classified into six types; and then the changes of landscape patterns in Baiyangdian Basin have been studied from 1986 to 2000 using GIS and FRAGSTATS. According to the results, the driving mechanism has been analyzed and the countermeasures have been proposed. The results show: 1) At the landscape level, the fragmentation of landscape decreases with a decrease in patch number from (9 571) to (10 378). The density of patch edge is 20.54 and 89.09 respectively, which leads to the shape of patches more regular; and the index of landscape shape changed from 20.54 to 21.84, which results in the patch types more aggregative; and the assembled index are 82.98 and 89.09 respectively; spatial connectedness is decreasing, the patch area change variability is (4 029.78) and (4 881.93) respectively, both the diversity and evenness are increasing and more relying on water resources; the density index are 1.35 and 1.25 respectively, and the equality index are 0.75 and 0.64 respectively; 2) At patch level, cultivated land becomes more fragmented, along with the area decreasing from (9 689.53)km~2 to (8 827.84)km~2 and patch shape become more irregular. Reversely, residential area is increasing from (1 206.18)km~2 to (1619.49)km~2, which has increased by 34.7 percent, and the shape tends to be more regular. Though the increased forests have come from the conversion of grassland, the fragmentation, patch shape and the connectedness of the forests and grasslands have similar change trends. The water body is decreasing from 656.78km~2 to 523.35km~2, and its patch shape becomes more regular and patches more aggregative; 3) Changes of landscape in ecotone between agriculture and animal husbandry or between forest and animal husbandry are obvious, which represents ecotone is more vulnerable than others; 4) The disturbance coming from human activities are focused on dry land in the East. Moreover, the ecological construction policy of"closing hill for afforestation" and "returning farmland to forest land and grassland" in the West mountain area has taken effect.