【摘要】 本文利用遥感技术通过典型区的分析,对黄土高原土地退化现状及其成因过程进行了深入研究。结果表明,黄土高原地区由于特殊的自然条件,加以长期人类活动影响,土地退化十分严重,并处于不断发展之中,主要表现为水土流失和土地沙化等。更多还原

【Abstract】 Land degradations such as water and soil erosion, desertification, salinization, alkaliza-tion, swamping, loss of the fertility of soil, degradation of soil structure and soil pollution are caused by wind, water and human influence. The Loess Plateau is situated in the central part of China, with the area of 623.7 million ha. and has a arid and semi-arid continental monsoon climate, with strong winds in Spring and torrential rains in autumn. The landfonn gradually becomes higher from southeast to northwest, and the height difference is about 4 500 m. The original parent material is mainly loess. The vegetation coverage is tenuous and the soil is very poor. The results of the study by using remote sensing technology show that, in the Loess Pla-teau, the special natural conditions and the influence of human activity have caused severe land degradation such as water and soil erosion, land desertification. The area of land with water and soil erosion problems makes up more than 30% of the total area. There is 11.8 million ha desertified land, accounting for 18.91% of the total area. The land degradation in-dex(LDI) is more than 5. Thus, in the region, a very fragile environment was formed and land degradation was rapidly increased, which lead to the astonishing loss of soil fertility.更多还原