【作者】 刘巍巍；

【导师】 安顺清；

【作者基本信息】 中国气象科学研究院 ， 气象学， 2003， 硕士

【摘要】 干旱是我国危害最为严重的主要气象灾害之一。不同领域对干旱的定义不同，所制定的干旱指标也不同，由于干旱的复杂性和影响的广泛性，现有的大多数干旱指标考虑因素少、专业性和地域性较强。气象干旱是各类干旱的基础，本研究的目的是建立一个考虑因素较为全面且、能反映干旱的成因、程度、开始、结束和持续时间、具有时空可比较性的气象干旱严重程度评估模式。 在美国帕默尔旱度模式和我国1985年修正的帕默尔旱度模式的基础上，针对其中存在的问题，从建模选用较多站点、可能蒸散计算采用彭曼—蒙特斯公式和土壤田间有效持水量进一步准确划分等三个方面进一步修正了帕默尔旱度模式。 应用进一步修正的帕默尔旱度模式计算了我国160个站点1961-2000年逐月旱度值，并与各个站点40年实际旱涝灾情及1986年修正的帕默尔旱度模式计算的旱度值相比较验证，结果表明进一步修正的帕默尔旱度模式提高了原有模式的科学性和客观性，能较好地反映旱涝程度，特别对一些严重干旱时段更为吻合，更适合应用于我国大部分地区。 应用进一步修正的帕默尔旱度模式计算的我国北方地区124个站点的40年逐月旱度值，分析了我国北方地区的一些干旱特征，包括北方地区旱情较重的大旱年及其严重程度、主要干旱区；华北、西北和东北地区各等级干旱发生频率、主要干旱时段、干旱周期等，为防旱抗旱提供了科学依据。 在进一步修正的帕默尔旱度模式基础上，应用24站40年逐日资料建立了适用于我国的逐日帕默尔旱度模式，计算结果表明其反映的干旱趋势与逐月模式十分一致，并能从细节上反映干旱的发生、发展和结束的过程，为逐日评价干旱程度提供了依据。更多还原

【Abstract】 Drought is one of the most serious meteorological disaster in China.There are different definition and index of drought in different field.Because of the complexity of drought and the universality of its influence,most of the existent drought indexes have limitation in speciality and regionally application. Meteorological drought is the foundation of other kinds of drought.The objective of this research is to develop a meterological drought severity model considering climate factor comprehensively,which reflecting the beginning,end, the cause of formation and the severity of drought ,and is comparable in space and time.On the base of the Palmer Drought Severity Model of America and the modificated Palmer Drought Severity Model(1986),we further modificate the Palmer Drought Severity Model in the following aspects;?4 stations were chosen to develope the model and adjust the weighting factor; ㏕he potential evapotranspiration for an each month was computed by the Penman-Monteith equation commended by FAO;(3) The getting of available water capacity of the soil(AWC) in each station was based on the data of AWC that we can find and the characteristic of soil in each station.The monthly Palmer Drought Index of 160 stations from 1961 to 2000 were computed based on the further modified Palmer Drought Severity Model Compared the computed Palmer Drought Index with the actual drought and waterlog,it shows that the further modified Palmer Drought Severity Model can reflect the severity of meteorological drought or waterlog better and is more applicable for china than the Palmer Drought Severity Model modified in 1986.The computed Palmer Drought Index of 124 stations in the north of china are used to analyse some charactersin this region,including the main drouthy years and its severity,the drought range,etc..we also analyse the main drouthy periods,the frequency of each drought degree,the main area and the drought cycle in northwest china,north china and northeast china.On the base of the Further Modification of Palmer Drought Severity Model,a daily Palmer Drought Severity Model are developed.lt indicated that the daily drought index is accordant with the monthly drought index,and can reflect the change of severity in detail.更多还原