中国北方典型区沙漠化数据集（2000年）

我国北方暖温带与温带地区由于远距海洋及受青藏高原地势隆起的影响，形成了大面积干旱、半干旱气候区，干燥少雨，日照强烈，冷热巨变，植被稀少，风化作用强烈，风沙活动十分活跃，风力成为地貌塑造的最重要营力，形成了大面积的沙漠、戈壁、风蚀地和沙漠化土地，其面积约有164万km^2，占国土总面积的17%。 在这些地区，干旱多风和人类不合理的土地利用方式与强度等因素作用于疏松沙质地表，破坏了脆弱的生态平衡，使原非沙漠的地区出现了以风沙活动为主要标志的土地沙漠化。沙漠化是干旱、半干旱及部分半湿润地区由于人地关系不相协调所造成的以风沙活动为主要标志的土地退化。沙漠化已经成为一个严重的环境-经济-社会问题，沙漠化给生态环境和社会经济带来极大危害。 为了准确了解我国北方现代沙漠化时空分布情况，在国家重点基础研究发展计划（973计划）“中国北方沙漠化过程及其防治”（G2000048700）项目的支持下，利用2000年左右1-2年内的Landsat TM数据为底图，经过重投影、几何纠正、人工解译等工作生产了本数据集。 数据集按典型区域对研究区进行分区，分为新疆（北疆地区、中疆地区、南疆地区、其他地区），库姆塔格沙漠，柴达木盆地，黑河流域，祁连山区，黄河源区，石羊河流域，内蒙古中部典型区(包括乌拉特后旗、乌拉特中旗、达茂旗及四子王旗)（c152825），库布齐沙漠，毛乌素沙漠（榆林），浑善达克沙地，锡林郭勒草地（n152221），呼伦贝尔草地，科尔沁沙地，松嫩沙地。将沙漠化土地按程度分为轻度、中度、重度和严重四级，按沙漠化发生成因类型分为沙丘活化或流沙入侵、灌丛沙漠化、砾质沙漠化、风蚀劣地化和旱地农田耕作沙漠化五种类型。In the warm temperate and temperate zones of northern China, due to their distance from the ocean and the uplift of the Qinghai-Tibet Plateau, large-scale arid and semi-arid climate zones have developed. These regions are characterized by dryness, low rainfall, intense sunlight, sharp temperature fluctuations, sparse vegetation, intense weathering, and highly prevalent wind-sand activities. Wind has become the most dominant geomorphic agent in landform shaping, forming large areas of deserts, Gobi deserts, wind-eroded lands and desertified lands, with a total area of approximately 1.64 million km², accounting for 17% of China's total land area. In these regions, factors such as aridity, frequent winds, and unreasonable human land use patterns and intensities act on loose sandy surface soils, disrupting the fragile ecological balance, leading to land desertification characterized by wind-sand activities in areas that were originally non-desert. Desertification is a form of land degradation marked by wind-sand activities, occurring in arid, semi-arid and some semi-humid regions due to disharmonious human-land relationships. Desertification has become a serious environmental, economic and social problem, causing severe harm to the ecological environment and socio-economic development. To accurately understand the spatial and temporal distribution of modern desertification in northern China, this dataset was developed with support from the National Key Basic Research and Development Program (973 Program) project titled "Processes and Control of Desertification in Northern China" (Grant No. G2000048700), using Landsat TM imagery acquired within 1 to 2 years around 2000 as the base map, through processes including reprojection, geometric correction, and manual interpretation. The dataset divides the study area into typical regional units, including: Xinjiang (Northern Xinjiang, Central Xinjiang, Southern Xinjiang, other regions), Kumtag Desert, Qaidam Basin, Heihe River Basin, Qilian Mountains Area, Yellow River Source Area, Shiyang River Basin, typical central Inner Mongolia area (including Urat Back Banner, Urat Middle Banner, Darhan Muminggan United Banner and Siziwang Banner) (c152825), Kubuqi Desert, Mu Us Sandy Land (Yulin), Otindag Sandy Land, Xilingol Grassland (n152221), Hulunbuir Grassland, Horqin Sandy Land, and Songnen Sandy Land. Desertified lands are classified into four severity levels: slight, moderate, severe and extreme, and five types based on desertification causes: dune activation or sand invasion, shrub encroachment desertification, gravelly desertification, wind-eroded badland formation, and dryland farmland tillage-induced desertification.