【摘要】 水文水资源序列是一个具有周期变化、随机变化和递增或递减趋势变化的复杂时间序列。作为一种近似,可以把水文序列{Qt}分为趋势序列{Nt}、周期序列{Pt}和随机性的平稳时间序列{St},即式:Qt=Nt+Pt+St。采用时间序列分析的方法,建立了甘肃省水资源的时间序列模型,分析了其变化规律,结果表明,甘肃省水资源呈明显下降趋势,并存在一定的周期变化规律。更多还原

【Abstract】 Hydrologic sequence is a complicated time sequence, which has characteristics such as periodic changes, random changes and increasing or decreasing trend changes. Hydrologic sequence{Q_t} could be approximately divided into three components, that is: trend sequence{N_t}, periodic sequence {P_t} and random sequence{S_t}, and calculated by, viz. Q_t =N_t +P_t +S. The time sequence model of water resources in Gansu Province is established in this essay, and the change pattern is analyzed. The result shows that water resources in Gansu Province has a downtrend and periodic change trend.更多还原