青藏高原湖泊环境要素的多源遥感监测及其对气候变化响应

发布时间：2018-07-26 16:47

【摘要】：青藏高原以其复杂的形成机制、独特的地理位置、气候特点和地质地貌,成为全球地学研究的焦点,青藏高原湖泊众多,是地球上海拔最高、数量最多和面积最大的高原内陆湖区,利用遥感和GIS技术监测青藏高原湖泊环境要素的动态变化,进一步分析各要素对气候变化的响应,对促进青藏高原的水循环和能量循环研究以及青藏高原生态环境的可持续发展战略实施有重要的意义。本文基于多源遥感数据对青藏高原的湖泊水文和环境要素进行监测,湖泊水文要素包括湖泊面积、湖泊水位、湖冰物候,地表环境要素包括NDVI、雪覆盖和反照率。使用MOD09地表反射率产品,通过单波段双峰谷值法提取高原湖泊面积;使用T/P、Jason_1/2、ENVISAT、ICESat高度计数据,根据测高原理计算青藏高原湖泊水位;使用MOD10冰雪产品,通过阈值法提取青藏高原湖泊湖冰物候期和封冻期;NDVI、雪覆盖和反照率分别使用MOD09地表反射率产品、MOD10冰雪产品、GLASS地表短波反照率产品计算提取,根据不同生态地理分区,分析不同生态地理分区各要素的变化特点和规律。通过分析青藏高原1970-2015年温度、降水、蒸发的时空变化特点,结合各湖泊水文要素和环境要素的监测数据,分析各要素对气候变化的响应,并对不同生态区的响应特点进行对比分析,结论如下:(1)2000-2015年青藏高原湖泊面积整体呈扩大趋势,各湖泊变化率在-3.92km2/a到14.82km2/a之间,北部地区湖泊面积扩张最强烈,面积缩小的湖泊主要集中在南部地区。青藏高原湖泊水位大多在4000m以上,湖泊水位呈上升趋势,水位变化率在-1.480m/a到1.038m/a之间,水位减小的湖泊主要分布在南部藏南山地地区,湖泊面积和水位的变化基本一致。(2)青藏高原湖泊开始结冰一般在十一月初到十二月中旬,完全结冰一般在十一月中旬到次年一月初,开始融化在三月中旬到五月初,完全融化在四月中旬到六月初。封冻期平均175天,完全封冻期平均130天;湖冰物候有明显区域差异,北部湖区开始结冰期早,完全融化期晚,封冻期长,南部湖区开始结冰期晚,完全融化期早,封冻期短;湖冰封冻期变化率在-4.28d/a到7.34d/a之间,北部湖区湖泊封冻期变化较大。(3)青藏高原积雪覆盖由西北向东南逐渐减小,2001-2015年青藏高原积雪覆盖率呈小幅下降趋势;青藏高原NDVI值由西北向东南逐渐增加,2001-2015年青藏高原NDVI呈上升趋势,变化率为0.0005/a;青藏高原黑空反照率呈现东南部低,西北部高的空间分布特点,2001-2010年青藏高原地表反照率呈变小趋势,变化率为-0.0014/a;反照率与积雪覆盖率和NDVI有较好的相关性,相关系数分别是0.737和-0.806。(4)青海湖、羊卓雍错、色林错三个湖泊中色林错面积对温度和降水的敏感性最大,羊卓雍错次之,青海湖最小,并且羊卓雍错和色林错面积对单位温度变化的响应大于对单位降水变化的响应。湖冰物候主要受温度、降水、风速的影响,温度是主要的影响要素,温度或降水的增加,使湖泊封冻期缩短,风速的增加,使封冻期延长。(5)青藏高原积雪覆盖率、NDVI和反照率与区域温度和降水有较好的相关性,积雪覆盖率与温度呈负相关关系,与降水主要呈正相关关系;NDVI与温度呈正相关,与降水相关性根据区域降水量的不同有正相关也有负相关;反照率与温度和降水基本呈负相关关系,并且不同地理分区积雪覆盖率、NDVI和反照率与区域温度和降水存在明显的空间差异。
[Abstract]:The Qinghai Tibet Plateau, with its complex formation mechanism, unique geographical location, climate characteristics and geological and geomorphology, has become the focus of global geoscience. There are numerous lakes in the Qinghai Tibet Plateau, which are the highest, largest and largest inland lake area of the earth and Shanghai, which are used to monitor the dynamic changes of the lake environmental factors in the Qinghai Tibet Plateau by remote sensing and GIS technology. Further analysis of the response of various factors to climate change is of great significance for promoting the study of the water cycle and energy cycle of the Qinghai Tibet Plateau and the implementation of the sustainable development strategy of the Qinghai Tibet Plateau. Mooring area, lake water level, lake ice phenology and surface environmental factors include NDVI, snow cover and albedo. Using MOD09 surface reflectance products to extract Plateau Lake area through single band Shuangfeng valley value method; use T/P, Jason_1/2, ENVISAT, ICESat altimeter data to calculate the lake level in the Qinghai Tibet Plateau Based on the principle of height measurement; use MOD10 ice and snow products, The threshold method was used to extract the ice phenology and the freezing period of lake and lake in the Qinghai Tibet Plateau. NDVI, the snow cover and albedo used MOD09 surface reflectance products, MOD10 ice and snow products, and GLASS surface shortwave albedo products to be extracted. According to different ecological geographical areas, the characteristics and laws of the various elements of different geographical regions were analyzed. The characteristics of the 1970-2015 years' temperature, precipitation and evaporation in the Qinghai Tibet Plateau are analyzed, and the responses of various factors to climate change are analyzed in combination with the monitoring data of the hydrological and environmental factors of various lakes, and the response characteristics of different ecological regions are compared and analyzed. The conclusions are as follows: (1) the overall area of the Qinghai Tibet Plateau Lake area is expanded in the 2000-2015 year. The lake change rate is between -3.92km2/a and 14.82km2/a, the area of Lake area in the northern region is the strongest, the lake area is mainly concentrated in the south area. The lake level of the Qinghai Tibet Plateau is mostly above 4000m, the lake water level is rising, the water level change rate is from -1.480m/a to 1.038m/ a, and the lake is mainly distributed in the south of the lake. The changes in Lake area and water level are basically the same in Zangnan mountain area. (2) the Qinghai Tibet Plateau Lake begins to freeze from the beginning of November to mid December, and the ice is generally melted from mid March to early May and melts from mid March to early May and completely melts from mid April to early May. The freezing period is 175 days on average. The freezing period is 130 days on average; there are obvious regional differences in the lake ice phenology. The Northern Lake area begins with early freezing period, complete melting period late, long freezing period, late freezing period in the southern Lake area, early melting period, short freezing period, the change rate of lake ice sealing period from -4.28d/a to 7.34d/a, and the great change of the lake sealing period in the Northern Lake area. (3) snow cover over the Qinghai Tibet Plateau The cover from northwest to Southeast gradually decreases, and the snow cover rate of the Qinghai Tibet Plateau is decreasing in 2001-2015 years. The NDVI value of the Qinghai Tibet Plateau is gradually increasing from northwest to Southeast, and the NDVI of Qinghai Tibet Plateau is on the rise in 2001-2015 years, the rate of change is 0.0005/a, and the albedo of the Qinghai Tibet Plateau is low in the southeast and high in the northwest of the Qinghai Tibet Plateau, 2001-2010 The albedo of the surface of the Qinghai Tibet Plateau is a small trend in the year, the rate of change is -0.0014/a, the albedo has a good correlation with the snow cover rate and NDVI, the correlation coefficient is 0.737 and -0.806. (4) Qinghai Lake, the Yang Zhuoyong error is wrong, the color forest fault area is the most sensitive to temperature and water reduction in three lakes, Yang Zhuoyong is wrong and Qinghai Lake is the smallest. The response of the Yang Zhuo fault and the area of the color forest to the unit temperature change is greater than the response to the change of unit precipitation. The lake ice phenology is mainly influenced by temperature, precipitation and wind speed. The temperature is the main influencing factor, the increase of temperature or precipitation, the shortening of the freezing period of the lake, the increase of wind speed, and the prolongation of the freezing period. (5) the snow cover of the Qinghai Tibet Plateau Rate, NDVI and albedo have a good correlation with regional temperature and precipitation, the snow cover rate is negatively correlated with temperature, and there is a positive correlation with precipitation, and NDVI is positively correlated with temperature, and the correlation with precipitation is positive and negative according to the difference of precipitation in the region, and the albedo is negatively correlated with temperature and precipitation. There is obvious spatial difference in snow cover, NDVI and albedo with regional temperature and precipitation.
【学位授予单位】：山东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P332;P343.3

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