摘要
以乌鲁木齐柴窝堡湖为例,根据Corona和Landsat遥感数据,提取近50 a湖泊水面变化的时间序列,利用激光测高卫星ICEsat/GLAS数据,提取2003—2009年水位变化信息,进而分析湖泊在气候变化和人类活动条件下的年、月空间变化特征。结果表明:柴窝堡湖水面变化分3个阶段:1964—2004年、2005—2010年和2011—2014年,其面积变化率分别为0.012 km2·a-1、-0.256 km2·a-1和-4.798 km2·a-1。水面变化由缓到急,并在2014年9月25日首现干涸,湖泊水体生态功能正在逐步丧失。湖泊水面的月变化在2005年以后逐渐明显,春季处于水面峰值,秋季处于低谷,多年的月变化曲线直观地反映了水面面积加速减退的趋势。湖面边界的空间变化与湖面水位的变化过程体现了"陡岸平底"的湖泊形态特征。2005年以前,湖水面积变化较小,而湖水水位变化相对明显;2005年以后,湖水面积显示有规律的加速缩减;2012年湖水边界退缩到湖盆底部后,湖水面积与地下水位变化呈现明显的相关性。驱动因素分析结果表明,1993年以后的地下水开采是湖泊水位与面积变化的主要动因,1999—2004年显著增加的降水减缓了湖泊水面的萎缩速度;而2004年以后,由于持续高强度地开采湖区地下水,湖泊的水量平衡被打破,导致了柴窝堡湖干涸的生态灾难。
In order to analyze the annual, monthly and spatial characteristics of arid lake extent change under the impacts of climate change and human activities, Chaiwopu lake of Urumqi is selected as an example to map the lake area change and level change with time-series Corona and Landsat imagery in the last 50 years, and its lake level changes from 2003 to 2009 are also delineated with ICESat/GLAS altimetry data. The results showed that, Chai- wopu lake changes are presented as 3 stages： 1964 -2004,2005 -2010 and 2011 -2014, and the annual area changing rate are -0.012 km^2 · a^-1, -0.256 km^2· a^-1 and -4. 798 km^2 · a^-1 ,respectively. The overall lake area shrinking mode is from gentle to significant, and the lake water was firstly found dry up on September 25th, 2014, and its ecological function is weaker and weaker. The seasonal characteristic of Chaiwopu lake extent changes are showed as, lake water extent reach its peak in spring and touch its valley in autumn, and the seasonal change be- comes more obvious when the drastic water area change happened after 2005. Monthly lake area curves showed that Chaiwopu lake is losing its area rapidly year by year. When it comes to lake water level and spatial boundary, their change matches well with the Chaiwopu lake basin topography, which is represented as ＂rock-ribbed shore and flat bottom＂. Before 2005, water area change was insignificant while lake water level was significant when lake water volume is decreasing. After 2005, lake water boundaries were shrinking. When they are shrinking to the lake bot- tom in 2012 ,the underground water level has high correlations with water area change. In the wet years between 1999 and 2004 ,lake shrinking rate is decreasing and Chaiwopu lake keep its dynamic water balance during that pe- riod. Exceeding groundwater exploitation after 1993 is the main reason of lake extinction ,leading to ecological dis- aster in this region.
出处
《干旱区研究》
CSCD
北大核心
2015年第3期417-427,共11页
Arid Zone Research
基金
国家自然科学基金(U1178302
41101041
41371419)
新疆自然科学基金(2012211A102)
科技部国际科技合作项目(2010DFA92720-04)
