Calculation of Ecological Base Flow of the Yellow River Based on a Markov Chain Method

基於瑪律科夫鏈法的黃河生態基流計算

柯浩成(HAOCHENG KE) ； 李正勤(ZHHENGQIN LI) ； 李占斌(ZHANBIN LI) ； 李鵬(PENG LI) ； 時鵬(PENG SHI)

《台灣水利》 69卷2期 (2021/06) Pp. 44-57

https://doi.org/10.6937/TWC.202106/PP_69(2).0006

摘要

A novel, simple and effective method, the base-flow ratio, for calculating ecological base flows based on a Markov chain that incorporates inter- and intra-annual dynamic changes of ecological water requirements was proposed in this article. A long series of runoff data of hydrological years was firstly divided into five types: wet, partially wet, normal, partially dry, and dry years. The rationality of this classification was then determined. Finally, the base-flow relationships among the year types was estimated by calculating the ratio of the mean runoff for one type to the other types. The ecological base flows could therefore be calculated for the various year types. The Lanzhou section of the Yellow River was used as an example to test the effectiveness of the recommended method by comparing it to traditional methods. The inter- and intra-annual dynamic changes in ecological base flow reflected by the suggested method in this paper agreed with the regional characteristics, and the guaranteed rate of ecological base flow was ＞90%. Despite the simplicity of the proposed method, the regional characteristics has been taken into account, this simplifies the calculation of ecological base flow for watershed-management institutions and water administrative authority utilizations.

關鍵字

Markov chain method ； base-flow ratio ； ecological base flow ； hydrological-year type ； Yellow River

並列摘要

結合河流生態需水年內和年際的動態變化，本文基於瑪律可夫鏈法提出了一種簡便有效的計算生態基流的方法，即，基流比率法。首先，將長期水文徑流系列資料劃分為豐水年、偏豐年、平水年、偏枯年及枯水年等不同年型。其次，對不同年型的劃分合理性進行判斷。最後，通過確定某一年型的基流比率後，通過該年型與其他各年型平均徑流量之間的比值，推求出不同年型之間基流比率的關係，由此計算出不同年型的生態基流值。本文以黃河幹流蘭州段為例，通過基流比率法與傳統方法計算結果相比較，進而驗證基流比率法的有效性。基流比率法的計算結果也反映出生態基流年際和年內動態變化與區域特徵相吻合，且生態基流的保證率大於90%。由於基流比率法考慮了區域特徵，為流域管理機構和水行政主管部門計算生態基流提供了簡便的計算方法。

並列關鍵字

瑪律可夫鏈法 ； 基流比率 ； 生態基流 ； 水文年型 ； 黃河

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