【作者】 郭晓宁；

【导师】 李林； 杨德保；

【作者基本信息】 兰州大学 ， 气象学， 2010， 硕士

【摘要】 雪灾是青海高原常见的气象灾害之一,是影响青海畜牧业发展、制约青海经济增长的主要因素。本文以青海高原作为研究对象,利用1951-2008年青海高原雪灾实际灾情资料、青海高原45个气象站1961-2008年48a冬季(10-2月)和春季(3-5月)积雪深度资料、以及2000年之后部分时间MODIS卫星积雪观测数据资料,采用相关气候统计方法和积雪特征的遥感监测分析方法等,对过去50年来青海高原雪灾的时空变化特征、参照SPI(标准化降水指数)指数确定雪灾等级新方法以及遥感在雪灾监测的应用进行了系统研究。结果表明：(1)近50a来青海高原特大雪灾发生变化趋势不明显,而重灾、中灾、轻灾发生均呈现逐年上升趋势。而各等级雪灾在上世纪90年代均有一个小高峰出现。(2)在空间上,青海高原南部(玉树、果洛、黄南南部、海南南部)及海西东部是雪灾发生的高频区,柴达木盆地和青海高原东部地区是低频区。(3)从上世纪60年代到2008年,雪灾发生频次呈现上升趋势。雪灾发生站次变化倾向率为1.366次/(10a),从这种趋势可以看出,青海高原近50a来雪灾出现站次增加的趋势很显著。上世纪60年代和21世纪头5年雪灾发生站次处于相对低值,70年代到90年代中期呈现稳定高峰。(4)对于经济方式以畜牧业为主的青海高原,利用雪灾造成的牲畜死亡率和遥感观测资料相结合来划分雪灾等级是一种符合高原实际的新方法。(5)在地形复杂、海拔高差大的青海高原,应用EOS/MODIS卫星遥感数据监测积雪,并按照相关气象灾害标准来判断雪灾程度,与地面站观测资料相比具有准确性高、客观性强等优点。而且遥感图像能真实反映这种高原降雪场的不连续、离散性。应用遥感监测弥补了地面台站网空间间隔大,边远高寒山区无测站等带来的观测空白。应用EOS/MODIS卫星监测资料对几次雪灾个例分析发现积雪覆盖面积计算并生成研究区域图像可为政府相关部门提供积雪及雪灾决策参考依据。(6)在雪灾防灾减灾上,要加强科学研究,依靠科技应对雪灾。合理利用草原资源,提高牧业商品率,加快草原建设步伐,缓解畜草矛盾。采取预防与救助相结合,最大程度减少灾害损失,严格执法,实现依法减灾。更多还原

【Abstract】 Snow disaster is a meteorological disaster that often takes place in Qinghai plateau.It not only has negative effect on animal husbandry,but also restricts the economic growth of Qinghai.In this study, Based on the real disastrous conditions of snow from 1951 to 2008 in Qinghai plateau and the snow depth data in winter and spring at 45 stations in the Qinghai Plateau from 1961 to 2008, in addition,snow cover data of MODIS of some years after 2000,by using the climate statistical and RS monitoring of snow cover method, the spatio-temporally distributive characteristics,a new snow disaster standard and RS application in the snow disaster monitoring were analyzed comprehensively. The main conclusions of the research are as follows:(1)The snow disasters of all levels in Qinghai plateau displayed a rising trend over the past 50 years except the exceptionally heavy snow disaster,and there is a peak level in 1990s of all levels of snow disaster.(2) The spatial distribution showed that The south of Qinghai Plateau (including Yushu, Guoluo, southern Huangnan, southern Hainan and eastern Haixi) is the high frequency region of snow disasters but the snow disaster occurred rarely in the Qaidam basin and eastern Qinghai.(3) From 1960s to 2008,the frequency of snow disasters has shown a generally rising trend,and the climatic tendencies of snow disaster is 1.366 times/10a,this figure also explains that in recent 50 years the rising trends of the snow disaster is prominent,it is a low frequency in 1960s and first five years in 21st century,and high frequency in1970s to the mid’1990s.(4)In Qinghai plateau,By using the death rate of the livestock that caused by the snow disaster,It is a practical standard to set the snow disaster levels.(5)To monitor the snow cover by using the EOS/MODIS data,and combine the related standard of snow disaster,it is superior to the observational data.because the RS image can reflect the real snow cover and it’s characteristics of discontinuity and discreteness.it also has the high accuracy and strong objectivity.Using the RS to monitor the snow cover can make up the weakness of large margin of surface stations and lack of stations in highland.Moreover,to calculate the areas of snow cover and disaster by RS method then make the image can give the government a superior advise which conduces seasonable decision.(6) In the snow disaster prevention and reduction,we should strengthen the scientific research,and depend on the science and technology, understand the snow disaster scientifically,and make use of the grasslands reasonably.Meanwhile,we must increase the commodity rate of livestocks,combine the prevention and salvation measures to reduce the loss caused by snow disaster.At last, related departments must be strict enforcement of law,then the disaster reduction according to law can come true.更多还原