青海省贵南县土地荒漠化动态变化遥感分析

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:① 1976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。

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

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.③During 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.