在全球气候变暖的背景下,研究中国西北内陆地区湖泊的面积变化不仅对水资源管理和可持续发展战略有着重要意义,也为评价气候变化与人类活动对湖泊的影响提供参考。以中国西北内陆区5个典型湖泊为研究对象,利用1970-2015年的Landsat MSS /TM/ETM + /OLI影像数据,利用归一化差异水体指数(Normalized Difference Water Index, NDWI)和改进型归一化差异水体指数(Modified Normalized Difference Water Index,MNDWI)分别提取5个典型湖泊边界并获取湖泊面积,同时利用5个典型湖泊周边的气象站降雨量、蒸发量等气象数据,尝试分析湖泊面积发生变化的原因。结果表明:红碱淖近30年来面积呈减小趋势,入湖河流拦蓄和煤炭地下开采等是导致面积减少的原因;博斯腾湖近40年来的面积呈先增加后减少的趋势,其面积变化主要受地表径流和积雪融水的影响;呼伦湖近40年来面积呈减少的趋势,其面积变化主要受入湖径流量的影响;贝尔湖近30年来呈相对稳定的趋势,其面积变化主要入湖径流量的影响;青海湖近40年来面积呈现先减小后增大的趋势,其面积变化主要受区域降水和入湖径流量的影响。
英文摘要:
In the context of global warming,study on the change of inland lakes in Northwest China not only has great significance in inland water resources management and sustainable development strategy,but also provides reference for assessing the impact of climate change and human activities on lakes. This paper selects five inland lakes in Northwest China,using Landsat MSS /TM/ETM + /OLI data from 1970 to 2015, normalized difference water index (Normalized Difference Water Index and NDWI) and modified normalized difference water index (Modified Normalized Difference Water Index,MNDWI) to extract five typical lake boundaries and obtain the annual precipitation,evaporation and temperature from meteorological station data of 5 lakes were used to analyze reasons for the area change. The results showed that area of Hongjiannao in the past 30 years overall was reduced,and the groundwater impoundment and underground coal mining were the main causes for area reduction. Bosten Lake in recent 40 years area showed a decreasing trend after the first increase,whose area was mainly affected by the surface runoff and snowmelt. The area of Hulun Lake tended to decrease in the past 40 years,and its area change was mainly affected by the runoff into the lake. Baer lake is relatively stable in recent 30 years,and its area was mainly affected by the runoff; the area of Qinghai Lake in the past 40 years showed a trend of decreasing and then increasing,and the change of its area was mainly affected by the regional precipitation and the inflow of lake.