【摘要】 基于遥感数据的解译分析,从1987年到2007年敦煌市自然植被面积下降543.69 km2,自然生态系统面积缩小17.62%,土地荒漠化趋势明显。根据实际测定的样方生物量与对应的土地利用类型面积拟合曲线,估算这一时期自然植被的生物量从102.42×104t下降到72.33×104t。敦煌市自然植被和人类活动的用水量此消彼长,总用水规模在6.3×108m3左右。自然植被用水量从1987年的3.072 7×108m3减少到2007年的2.17×108m3,净减少达30%。人类活动用水量从1987年的3.315 7×108m3增加到2007年的4.093×108m3。疏勒河干流及其支流党河都因为人类活动用水大量增加,挤占了自然植被的用水。特别是农业灌溉占用了绝大部分水资源,成为敦煌生态环境退化的主要原因。恢复和保护敦煌的生态问题,不仅需要调控党河流域的人类活动,也要调控疏勒河干流地区的人类活动。更多还原

【Abstract】 Based on the interpretation analysis of remote sensing data,it was found that the area of natural vegetation decreased 543.69 km2 and natural ecosystems area reduced 17.62% from 1987 to 2007 in Dunhuang City,which shows the obvious trend of land desertification.According to actual quadrate biomass measured and area of each land use type,we fit curves and estimate total biomass of the natural vegetation.The results demonstrate that the total biomass decreased from 102.42×104 t in 1987 to 72.33×104 t in 2007(nearly 30%).Water consumption of natural vegetation decreases from 3.0727×108 m3 to 2.17×108 m3 in this period.Water consumption of human activity increases from 3.3157×108 m3 to 4.093×108 m3 accordingly.However,the total volume of water consumption is about 6.3×108 m3.In the main stream of Shule River and its tributary Danghe River,the water used for natural vegetation was crowded out because water consumption of human activity increased greatly.Especially,agricultural irrigation occupies most of water resource.This became the main reason for eco-environmental degradation in Dunhuang.To recover and protect the eco-environment from degradation,not only human activity should be regulated in Danghe River Basin,but also in Shule River Basin.更多还原