摘要
变化环境下,干旱指数可能表现出非一致性特征。本文假设径流序列为二阶非平稳序列,建立以时间为协变量的时变矩GAMLSS模型,该模型采用非一致性Gamma分布拟合实测径流序列,并基于该模型计算出的时变标准化径流指数SRIt,与传统指数SRI进行对比分析,以验证其合理性与必要性。结果表明:基于时变矩模型的时变标准化径流指数SRIt更适应于潘家口水库流域变化环境下水文干旱的评价。时变标准化径流指数SRIt的值整体上比基于一致性模型的指数SRI偏小,即所表示的干旱程度更加严重,主要是因为时变矩GAMLSS模型能够反映出变化环境下径流序列的变化趋势,该趋势是影响径流的一系列因素共同导致的,如气候变化,人类活动等。而在受这些因素的影响下,潘家口水库流域的水文干旱事件频率增加,严重程度增强。
In a changing environment,the drought index may appear the non-stationary characteristic.In this study,we assuming that the runoff series are second-order non-stationary sequences,a non-stationary model was established and optimized to fit the runoff observations and was used to calculate the Time-dependent Standardized Runoff Index (SRIt)that could reflect the drought characteristics in a river basin. The results show that SRIt based on the non-stationary model is more suitable for the evaluation of hydrological drought in the changing environment of Panjiakou Reservoir watershed.The SRIt value calculated by the non-stationary model is generally smaller than SRI value that calculated by the stationary model,which represents the more seriously drought degree.The main reason is that time-varying moment model can reflect the trend of runoff series under changing environment,which is caused by a series of factors affecting runoff,such as climate change,human activities and so on.Under the influence of these factors,the frequency and severity of hydrological drought events in Panjiakou reservoir basin increased.
作者
李敏
李建柱
冯平
陈亮
LI Min;LI Jianzhu;FENG Ping;CHEN Liang(State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University,Tianjin 300350,China)
出处
《水利学报》
EI
CSCD
北大核心
2018年第11期1386-1395,共10页
Journal of Hydraulic Engineering
基金
国家自然科学基金项目(51779165)
关键词
变化环境
水文干旱
标准化径流指数
时变标准化径流指数
非一致性
changing environment
hydrological drought
Standardized Runoff Index
Time-dependent Stan- dardized Runoff Index
non-stationary
