台灣中部坡地不同土地利用及降雨強度土壤入滲

Soil Infiltration of Different Rainfall Intensities and Land Uses on Slopeland of Central Taiwan

盧惠生(Hui-Sheng Lu) ； 林壯沛(Jaung-Pey Lin) ； 林介龍(Chieh-Lung Lin) ； 黃良鑫(Liang-Shin Hwang) ； 王秋嫻(Chiu-Hsien Wang)

《坡地防災學報》 10卷1期 (2011/06) Pp. 10-26

https://doi.org/10.29995/JSHR.201106.0002

摘要

土壤入滲為影響坡地水土流失的重要因子，如坡地土壤入滲大，超滲雨量減少，地表逕流與土壤流失自然隨之減少。本文以野外模擬降雨裝置於台灣中部蓮華池與畢祿溪坡地不同土地利用，進行不同人工降雨強度入滲測定。獲悉Philip入滲推估式不適用於少部份土地利用與降雨強度，大體而言，Philip入滲推估式較Horton入滲推估式為佳。不同土地利用的土壤最終入滲率以畢祿溪針葉林最大，其次依次為畢祿溪針闊混交林、蓮華池闊葉林、蓮華池草生地、蓮華池竹林地、蓮華池砍伐跡地、畢祿溪果園地、蓮華池杉木林、蓮華池裸露地。不同土地利用的土壤最終入滲率隨降雨強度增加而增加，呈凸形指數型曲線上升，但降雨強度愈大時，土壤最終入滲率增加速度趨緩，最後將以漸近線方式，逼近土壤最終入滲率的最大極端值。不同降雨強度時以土壤粗孔度推估土壤最終入滲率，土壤最終入滲率隨著土壤粗孔度增加而增加。

關鍵字

土壤入滲 ； 降雨強度 ； 土地利用

並列摘要

Soil infiltration was one of important factors in affecting soil and water losses. If soil infiltration on hillslope was large, the rainfall excess would be small. Then surface runoff and soil loss of slopeland would be also small. This study used rainfall simulator under different rainfall intensities to carry out infiltration tests at different land uses of Lienhuachi and Piluchi slopeland in central Taiwan. Based on infiltration data analysis, Philip's estimated equations were better than Horton's estimated equation for most different rainfall intensities and land uses, except for a few inadaptable cases. The final infiltration rates of respective test plots in decreasing order were as follows: natural coniferous forest of Piluchi, natural coniferous-hardwoods mixture forest of Piluchi, natural hardwoods forest of Lienhuachi, grass land of Lienhuachi, bamboo plantation of Lienhuachi, deforested land of Lienhuachi, orchard of Piluchi, China-fir pltantation of Lienhuachi, and bare land of Lienhuachi. The final infiltration rates will increase as rainfall intensities increase. But rainfall reach to larger intensity rates, the final infiltration rates will increase gradually slow, until to maximum final infiltration rate. Based on final infiltration estimated equation by macro-porosity volumes, the final infiltration rates will increase as macro-porosity volumes increase.

並列關鍵字

Soil infiltration ； Rainfall intensity ； Land uses