Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/34263
標題: 關刀溪森林集水區流量之推估
Estimation of Stream Flows from Guandaushi Forest Watershed
作者: 蕭明芳
Shiau, Ming-Fang
關鍵字: 水文反應值;hydrological response value;前期降雨;突現性;稽延時間;尖峰到達時間;最大日雨量;直接逕流量;滲漏;antecedent precipitation;flashiness;lag time;time to peak;maximum daily rainfall;runoff;percolated
出版社: 水土保持學系
摘要: 
Abstract
The main purpose of this thesis was going to set up a hydrological model between the main watershed and sub-watershed in Guandaushi watershed where located in the middle of Taiwan, in order to estimate the stream flow of main watershed.
The results were shown as follows:
1. According to the annual discharge and rainfall collected from 1996 to 1998, the average outflow rate in the sub-watershed was 35.2% and was 61.4% in the main watershed. The reason why the sub-watershed outflow rate less than the main watershed was that most of the precipitation percolated into the ground.
2. According to the collected 19 events of storms in the main watershed, the average hydrological response value was 15.3%;the range was 1.4%∼64.3%. The hydrological response value increased with the duration of storm. If the antecedent precipitation moistened the watershed damp, the rainfall of the storm would outflow more by runoff and made the hydrological response value increased with the duration of storm to show the higher flashiness.
3. According to the statistical analysis, the average lag time (TL) and the time to peak (Tp) of the sub-watershed were 1.7hours and 4.8hours but it took 1.6 days and 3.8 days in the main watershed which was 23 times of the TL and 19 times of the Tp in the sub-watershed . This showed that with the similar shape of these two watersheds, TL and Tp in the main watershed was shorter than the square times of watershed length ratio. The main watershed area was 47 times larger than the sub-watershed. TL and Tp in the main watershed were shorter in proportion to ratio of the area and the length of the stream. This might due to the average slope of the geography in the main watershed was steeper than that in the sub-watershed.
4. The regression analysis of rainfall and discharge flow on recession hydrograph in the main watershed, The result showed that rainfall did not have much influence on the recession hydrograph. Even if the extreme value of the discharge parameter was deleted,the regression analysis would showed that there was highly correlation between the maximum daily rainfall and runoff. However, we found that some rainfall events were over the threshold value, but there were no runoff occurred. This might be due to un-uniform rainfall distribution in space.

中 文 摘 要
本研究乃以台灣中部關刀溪森林集水區為試區,將位於試區西北側之一小集水區為對照區,藉由所設置之水文、氣象觀測設施與關刀溪集水區接近出口處之流量測定,來探討兩大小集水區之溪流量變化關係,期能建立一上、下游間集水區之相關模式,茲將分析結果摘要如下:
一、由年流量與年雨量之間的關係,推得1996∼1998年間子集水區之流出率平均為35.2%,主流集水區則為61.4%。子集水區流出率偏小的原因,可能係大部分之降水滲漏至地下所致。
二、由主流集水區19場暴雨事件所求得之水文反應值平均為 15.3%;最小者僅1.4%,最大者為64.3%;水文反應值有隨暴雨延時的增加而呈上昇之趨勢;且若前期降雨使集水區處於一較濕潤狀態,則暴雨雨量將以較多逕流量之形式流出,而使集水區之水文反應值隨著暴雨延時增加而增顯其高度之突現性。
三、由統計結果顯示,子集水區之平均稽延時間(TL) 及尖峰到達時間(Tp) 分別為1.7hr及4.8hr;主流集水區則分別為1.6天及3.8天,分別約為子集水區平均稽延時間之23倍與尖峰到達時間之19倍,顯示在兩集水區形狀相似之情況下,主流集水區之稽延時間與尖峰到達時間為略小於兩集水區最高點至出水口距離之比值之平方倍,而主流集水區面積約為子集水區面積之47倍,依此面積及溪流長度比例顯示主流集水區之尖峰到達時間及稽延時間較之子集水區均呈現較快之趨勢,此可能因主流集水區地形之平均坡度較子集水區為陡所致。
四、將主流集水區退水曲線上再度降雨之流量參數作一迴歸分析,顯示退水曲線之流量並非單純受降雨之影響。若將流量參數中
之極端值刪除,由迴歸分析顯示最大日雨量與直接逕流量雖具有顯著之相關性,但仍有部分降雨之雨量雖多卻未能成為直接逕流流出之情形,這可能係降雨之空間分佈不均所致。
URI: http://hdl.handle.net/11455/34263
Appears in Collections:水土保持學系

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