基于Corona和Spot影像的近40年黑土典型区侵蚀沟动态变化

沟状侵蚀是我国东北黑土区一种比较常见的土壤侵蚀类型。当前国内外学者对侵蚀沟动态变化的研究多采用GPS或摄影测量的方法监测某些侵蚀沟的短期变化，由于缺少早期高分辨率的卫星影像，对于较大时空尺度上侵蚀沟分布格局变化的研究很少报道。本文选择克拜东部地区作为典型区，以1965年的美国高分辨率侦察卫星Corona影像和2005年的Spot-5卫星影像为主要数据源，结合野外实地调查，建立了黑土区侵蚀沟的遥感解译标志，阐述了不同类型侵蚀沟的遥感影像特征，通过对遥感影像的人机交互解译，获取了克拜东部地区1965年和2005年两个时期的侵蚀沟分布图，在此基础上，探讨了1965年以来克拜东部黑土区侵蚀沟分布的格局变化和区域差异。研究结果表明：近40年来克拜东部侵蚀沟密度高值区范围不断扩大，且呈集中连片分布趋势；沿通垦河分水岭两侧受地貌发育自然过程的影响，侵蚀沟密度变化存在明显的东西差异；土地利用方式的转变是促成侵蚀沟形成的重要因素，特别是林地向耕地和草地的转化过程中，侵蚀沟密度迅速增加。

Application of Corona and Spot Imagery on Erosion Gully Research in Typical Black Soil Regions of Northeast China

Gully erosion can be widely observed on cultivated slopes in Black Soil Region of Northeast China.Today,vast areas have been permanently ruined by erosion gullies.In many places,the farmland has been deeply incised,leading to loss of arable land as well as fertile black soil.The erosion gullies in Black Soil Region also affect farming activities and threaten the villages.Global Position System(GPS) and photogrammetry are often used to study the process of erosion gully development in a small scale.However,the research of gully distributing pattern and its variation on a larger spatial-temporal scale is rarely reported,owing to lack of high-resolution satellite imagery in the earlier time.Nowadays,the declassified images from spy satellites are an important addition to the record of the Earth's land surface back to the middle stage of the 20th century.In this paper,taking eastern Kebai area as an example,based on field investigation of erosion gullies,the CORONA images of 1965 acquired by spy satellites of USA and SPOT-5 images of 2005 were used to extract erosion gully and land use information.The interpretation signs of erosion gully were presented and the image character for different type of gullies was described in this paper.With the support of GIS software,the image interpretation was conducted to obtain two stages of gully distribution maps,then the line coverage of erosion gullies were interpolated to gully density map using Arc/info9.0.Based on those work,the spatial distribution of erosion gully development from 1965 to 2005 and its regional variation were analyzed.This study revealed that from 1965 to 2005,the extent of high gully density area enlarged and tends to be connected with each other in eastern Kebai area.But the spatial distribution of erosion gully development is not uniform in the study area.There is a great difference on the gully density change along the ridge of Tongken River,which is related to the natural process of landform evolvement.The study also showed that the gully density increased sharply when forest land changed into arable land or grassland.The unreasonable land reclamation and land use change in Black Soil Region of Northeast China during the past decades may be an important factor in the process of gully formation and development.This study can provide data for research of land degradation process,soil and water conservation and agricultural sustainable development in Black Soil Region of Northeast China.