为了研究可可西里地区的湖泊变化及其与气候变化的响应关系,利用TM/ETM~+图像提取乌兰乌拉湖水体面积,利用高度计数据获得湖泊水位,分析湖泊面积和水位的变化; 并计算得到2003-2009年湖泊水量变化; 然后利用SWAT模型(soil and water assessment tool),对乌兰乌拉湖1970-2012年的径流情况进行模拟,其中土壤分类、土地利用分类和气象数据作为输入数据,利用遥感数据计算湖泊径流量,进行模型率定和验证。结果表明: 1970-1990年,乌兰乌拉湖湖泊面积持续缩小,1990年以后湖泊面积持续增大,1990-2010年湖泊面积共增长了129 km~2,水位也持续上升; SWAT模型模拟值和真实值的决策系数R~2=0.82,模型适用性强,长期模拟结果与遥感监测结果的趋势一致; 乌兰乌拉湖流域多年平均年径流量为103.8 mm,高峰出现在7-9月。
英文摘要:
In order to study the response relationship of the change of the Hoh Xil Lake to the climate change, the authors extracted surface area of the Ulan Ul Lake based on the remote sensing images (Landsat TM/ETM~+) from 1970 to 2010, and examined the lake level elevation variations by GLAS/ICESat lase altimeter during the period of 2003-2009. On the basis of the lake area and level elevation extracted from remote sensing data, the variations of water quantity were calculated. SWAT model(soil and water assessment tool)was used to simulate the runoff in the basin of the Ulan Ul Lake from 1970 to 2012. During the simulation, DEM, land-use classification, soil classification and meteorological data served as input data, and the model was calibrated and verified by the variations of water quantity. The results showed that the lake area decreased by 70 km~2 from 1970 to 1990, and increased by 129 km~2 from 1990 to the present; the correlation coefficient of the simulated and measured data is R~2=0.82. These data suggest that the model is feasible, and the simulation results are in agreement with measured results from remote sensing. The average annual runoff of the Ulan Ul Lake was 103.8 mm, and the peak of runoff occurred from July to September.