基于QuickBird影像的艾比湖及周边土壤风蚀研究

Soil Erosion by Wind in Aibi Lake and Surrounding Areas Based on QuickBird Image

近年来,艾比湖湖面发生严重萎缩,造成湖泊大面积裸露,为沙尘暴提供了大面积沙源。通过对高分辨率QuickBird影像数据的处理,分析了艾比湖湖域的风蚀现状。在湖岸周边强度以上的风蚀面积约占63%,主要分布在无植被覆盖的东部和西部;微度风蚀和中度风蚀面积约占37%,主要分布在有植被覆盖的南北两岸。湖泊裸露的干涸湖底,位于湖泊的西北部,面积达430km2。影像的色调、形状和纹理变化上反映了干涸湖底的地貌形态和风系的方向。结合实地测量数据的分析发现,湖泊西北向东南方向形成宽约4.5km,长约10km,坡度为1/5 000的带状坡面,为沙尘暴的发生创造了有利的条件。要改善艾比湖流域生态环境,主要依靠增加入湖水量以减小干涸湖底的沙源,达到控制艾比湖地区风蚀的目的。

With the heavily shrink of the Aibi Lake level in recent years, a large area of the lake has become bare land which provides sand for sandstorm. The wind erosion status of the Aibi Lake is analyzed through the process of high resolution QuickBird image data. The strong wind erosion area occupies 63% of the total lake area and is mainly dis tributed in the east and west part of the lake without vegetation cover. The micro-degree and moderate wind erosion areas occupy 37% of the total area and are mainly distributed in the south and north part of the lake with vege tation cover. The area of bared lake bottom is 430 km2 and is located in the northwest of the Aibi Lake. From the hue, shape and texture changes of image, the landform and wind direction of bared lake bottom are reflected. From the measured data analysis, the band sloping area with a width of 4.5 kin, length of 10 km and 1/5 000 gradient forms in northwest to southeast direction, creating favorable condition for forming sandstorm. In order to improve the ecological environment of the Aibi Lake basin, the main method adopted is increasing the input water of the lake to reduce bared lake bottom and control wind erosion.