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題名 | 福山試驗林的水文特性=Hydrological Characteristics of Fushan Experimental Forest |
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作者 | 夏禹九; 黃正良; Hsia, Yue-joe; Hwong, Jeen-lian; |
期刊 | 中華林學季刊 |
出版日期 | 19990300 |
卷期 | 32:1=124 1999.03[民88.03] |
頁次 | 頁39-51 |
分類號 | 436.19 |
語文 | chi |
關鍵詞 | 森林生態系; 水文收支; 暴雨水文特性; Ecosystem studies; Hydrological cycles; Storm hydrological characteristics; |
中文摘要 | 瞭解森林生態系的水文及能量收支是瞭解生態系功能的重要關鍵。以集水區為單 位長期監測福山試驗集水區1號(38ha)及2號(94ha)的溪流量與雨量,是福山森林生態 系研究中重要的一環。本區年位蒸發散依Penman, Hamon,及Thornthwaite方法估算均低於 900mm;年雨量近3700mm。全年均為溼潤無乾、溼季之分。福山地區雨量超過l0mm的事 件,70%是屬於雨量少於50mm的暴雨事件。這些發生較頻的小事件,其暴雨流出量佔淨雨 量的比率在5%左右;其暴雨流出的來源是鄰近溪流的地區。當降雨超過100mm,福山l號 與2號集水區均已有超過15-20%的地區成為逕流的來源地區。這種情況下,地表逕流與溪 流水面的直接降雨對暴雨流出的重要性降低,沿著山坡面的地下逕流逐漸成為暴雨流出的主 要來源。福山2號集水區1997年逕流係數超過80%較福山l號集水區高出30%,不過二集 水區的暴雨流出量佔全年(1997)溪流量的比率相若(FS1,39%;FS2,36%)。可能的原因是福 山l號集水區有相當比率的伏流水並未能量測的到,這些伏流水是構成基流的主要成分,而 在暴雨流出量中伏流水的比率較低影響不大。颱風是福山地區最具影響力的水文因子,每年 的極端洪峰流量與最大降雨量均是出現在颱風侵襲的場合。颱風期間的暴雨流出量約佔全年 暴雨流出量的70%。在颱風豪雨情況下,所有的降雨均立即反應於溪流水流出,超過50% 的集水區都成為溪流水的來源地區。森林覆蓋良好,人為干擾很低的森林集水區,固然在降 低泥砂輸出上有很重要的功能,不過在水源涵養上對溪流洪峰與暴雨流出量的減低功效其實 是不能過分強調的。不過颱風對營養鹽收支及生態系的結構與功能的影響相當重要,需要進 一步的研究。 |
英文摘要 | Hydrological and energy budgets are key functions of forest ecosystems. Two mall hardwood evergreen forest watersheds at the Fushan experimental forest were gauged and their streamflow and rainfall were measured. Annual potential evapotranspiration estimated by the Penman, Hamon, and Thornthwaite methods were all lower than 900 mm. With a total annual rainfall closed to 3,700 mm and low evapotranspiration, there were no wet and dry seasons at Fushan. The hydrological characteristics at the Fushan Forest were marked by the torrential rainfall brought by typhoons. Analysis of stormflow indicated that stream flow responsed quickly to the storm rainfall. For the more frequent small storm, the ratio of stormflow to net rainfall was small but for storm events with rainfall greater than 100 mm, the ratio reached more than 50%. The contribution area of stormflow for small storm, therefore, generally was confined to the narrow channel valley and the area extended up to hillslope for those large storms. The deep incised channel steep slope, short hillslope length, and high infiltration rate contributed to that subsurface runoff was the main mechanism of stream flow generation during storm periods. Annual runoff ratio at Fushan Watershed No. 1 (FS1) averaged around 50% whereas the ratio reached 80% at Fushan Watershed No. 2 (FS2). The lower runoff ratio at FS1 was mainly caused by the deep seepage in the fractured bed rocks at the FS1 gauging site. However, ratios of stormflow to the precipitation at the two watersheds were similar (in 1997, 39% and 36% for FS1 and FS2, respectively). The high stormflow response of rainfall indicated that the hydrological function of these two forested watersheds could not be over emphasized in terms of the aster conservation. However, the role of typhoons in the nutrient budget and other ecosystem structure and functions is significant and needs to be carefully investigated. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。