青海省贵南县土地荒漠化动态变化遥感分析

Land Desertification Dynamic Analysis Based on Remote Sensing in Guinan County of Qinhai Province

利用1976年、1996年、2006年3期遥感影像,在RS与GIS支持下,解译提取贵南县土地荒漠化信息,分析其时空变化。结果表明:①1976年、1996年与2006年贵南县3期荒漠化土地面积分别占贵南县总土地面积的42.6%、58.6%和56.8%。30 a来贵南县荒漠化土地面积增加了14.19%,平均每年增加0.47%,土地荒漠化呈总体加剧趋势。②贵南县土地荒漠化成因主要有风蚀荒漠化、水蚀荒漠化,荒漠化程度以中度和重度为主。③由动态度分析得知,1976年到1996年期间荒漠化严重,尤其是轻度荒漠化发展快,1996年到2006年期间荒漠化形势有所好转。贵南县荒漠化的发生和变化,既有自然因素的作用,又有人类活动的影响。

By using three-period （1976,1996,2006） remote sensing images and under the support of RS and GIS techniques,spatial information of land desertification in Guinan county was interpreted and extracted, and the spatio-temporal pattern of desertification information change was analyzed in this paper. The analyzed results indicated that：①The degradation land account for 42.6%,58.6% ,56.8% of the total land area in 1976,1996,2006 respectively in Guinan County, Qinhai Province. In the past 30 years, the desertification land area in Guinan county was increased by 14.19 %,with the average annual increase percentage of 0. 47 % , indicating that the land desertification in Guinan county was aggravated as a whole. ②In Guinan county,the main reasons causing land desertification were the erosion derived from wind force and water force,and the main grade of desertification land was moderated grade and severe grade desertification. ③ During 1976 to 1996 ,the analysis for dynamic degree showed that the land desertification was severe, especially unimportant grade desertification land area increased fast, and in the period of 1996-2006, the severe land desertification situation began to transfer to good situation. The main reasons causing the generation and development of land desertification of Guinan county included natural factor and human actions.