The Distribution Pattern Of Ardeidae Birds Based On 3s Technology In Hebei Province

We collected avian distribution data and numeric the RS image into the vegetation type map and physiognomy by the plotting function of GIS(Geographic Information Systems). We made avian point distribution map in Hebei province according to the data of literature, sample record and field investigation. According the relations between the avian and its habitats, we get the suitable habitat of Ardeidae birds. We select the suitable habitat type of each Ardeidae bird by the use of analyzing, pick-up and fold of GIS to forecast the whole distribution structure of Ardeidae birds in Hebei province.Ⅰ. Heber Province Ardeidae birds altogether 8 genues 13 species, including Ardea cinerea,Ardea purpurea,Egretta alba,Egretta garzetta,Egretta eulophotes,Bubulcus ibis,Ardeola bacchus,Butorides striatus,Nycticorax nycticorax,Botaurus stellaris,Ixobrychus sinensis,Ixobrychus eurhythmus and Ixobrychus cinnamomeus。Ⅱ. Through the field investigation and the literature record, we got each kind of Ardeidae birds'optimum habitat model in Hebei Province, its main factors includes: The vegetation degree of cover, the vegetation type, the hight of the vegetation, the distance away from water, the distance away from human. used unifies the GIS database from the Ardeidae birds'habitat model and uses its cartography function we drew up a Hebei Province Ardeidae birds'distribution map.Ⅲ.Relative factors with Ardeidae birds'habitats1)Vegetation typeAccording to 2000 Hebei Province satellite TM (Thematic Mapper), Hebei Province vegetation was divided to 9 types: The fallen leaf foliage forest, the often green coniferous forest, the fallen leaf coniferous forest, the bosk, the brushwood, the meadow, the prairie, the prairie meadow and the agricultural vegetation. The Ardeidae birds of Hebei Province often nested in the fallen leaf foliage forest, the often green coniferous forest and the meadow, in the different vegetation type, the Ardeidae birds'habitat type is mainly the Chinese scholartree tree, the willow tree, the Poplar, the pine tree and the clump of reeds, in several kinds of common vegetation types, poplar tree's use factor is primarily highest, reaches 34%, next is the clump of reeds is 26%, most lowers for the Chinese pine accounts for 6%, but the willow tree and the Chinese scholartree account for 23% separately, 11%.2)vegetation cover degreeVegetation cover degree plays important role for the safety and coverupping of The Ardeidae birds, the vegetation cover degree of Ardeidae birds'habitat is relatively high, especially reed nesting Ardeidae birds, the vegetation cover degree of whose habitat is 90%, which can make sure the safty and coverupping of adult birds and young birds. In the 38 nests surveyed, the vegetation cover degree is among 40%-90%, reed nesting Ardeidae birds like Ardea purpurea, Botaurus, Ixobrychus, whose nests vegetation cover degree is 90%, vegetation cover degree of Ardea cinerea nest in the oil pine is relatively low, which is 40%, and other Ardeidae birds nests vegetation cover degree is 80% on an average, which has high enshrouding nature.3)Vegetation heightThe average height of vegetation in Ardeidae birds habitats in Hebei province is 12.6m, 0～5m and 16～20m occupy large portion. Ardeidae birds in reed nests such as Ardea purpurea, Botaurus stellaris, Ixobrychus sinensis, Ixobrychus eurhythmus and Ixobrychus cinnamomeus is in the 0～5m vegetation, Ardeidae birds in tree nests like Ardea cinerea, Egretta alba, Egretta garzetta, Egretta eulophotes, Bubulcus ibis, Ardeola bacchus, Butorides striatus and Nycticorax nycticorax is in the height of 16～20m.4)ElevationThe Hebei Province Ardeidae birds from the elevation distribution range in 0~1300m, the majority of Ardeidae birds mainly distribute in elevation 200m, Ardea purpurea, Botaurus, Ixobrychus generally in the wetland, the lake or in the reservoir clump of reeds, its elevation is lower, the birds which nested in the tree elevated higher, the Ardea cinerea nested higer, from 850m to 1230m.5)Distance From water sourceThe water source can provide abundant food origin for the Ardeidae birds, therefore the Ardeidae birds' nest is far away from the water, the distance is relatively near, the reed nest birds' nest often nidifies in the water's edge, the distance is about 11m, certain individual bird's habitat is far from water because of the factors of hiding degree and human disturbing etc.the farest distance is about 3000m.6)The distance from human disturbbingArdeidae birds has humanity, the higher the nest is and the better the cover-upping is, the closer they live to people, the closest nest to people is only 600m. Result from analyzing the 38 sample squares showed the average distance to the human is 1200m.Ⅳ.Ardeidae birds'distributing structure forecasting in Hebei province According to the field investigation and relative literature, we get the most suitable habitat index of each Ardeidae birds, which include vegetation covery degree, vegetation height, vegetation type, altitude, the distance from water and distance from human and so on. And we gain the most suitable habitat model. By the use of 3S technology, Erdas and Arcgis, we translated the RS TM image of Hebei province in the year of 2000, and gain the maps of vegetation type, vegetation cover degree, contour line, topographty and physiognomy. With the habitat model of each heron, we picked up the Ardeidae birds point distributing map. By use of GIS technology, we picked up the suitable habitat type map and forecast the ditributing structure of Ardeidae birds in Hebei province.