坡地檳榔園試區水土流失量第一年成果初步探討

Preliminary Results of Runoff and Soil Erosion from Slope Plots of Betel Nut

吳輝龍(Huei-Long Wu) ； 張文詔(Wen-Jaur Chang) ； 黃俊德(C. T. Huang)

《中華水土保持學報》 26卷3期 (1995/09) Pp. 197-209

https://doi.org/10.29417/JCSWC.199509_26(3).0005

摘要

目前臺灣地區檳榔業市場廣大、利潤優厚，坡地種植檳榔的面積正快速增加中。然新植幼齡檳榔園多數位於新墾陡坡，且鮮有實施水土保持處理者，因而加速地表冲蝕易發生土石災害。本試驗以快速建立田間試區，獲取陡坡地檳榔園水土流失量數據，冀以從試驗過程與結果中得到解決坡地檳榔園水土保持問題之可行方法爲主要目的。本試區第一年初步水土流失量觀測值顯示，在降雨總量爲2,170.6 mm情況下，檳榔淨耕區之年土壤冲蝕量爲每公頃114公噸，比本區之土壤年容許流失量每公頃20公噸大5.7倍。逕流量方面，檳榔淨耕區所產之逕流量顯著大於有地表植生覆蓋試區，而且檳榔淨耕區每公噸土壤冲蝕量所對應之地表逕流量（逕流量/冲蝕量）爲38.49 m^3，較之裸露區的8.70 m^3，芒果淨耕區的10.85 m^3皆高，顯示檳榔淨耕區地表逕流問題比冲蝕問題嚴重。臺灣地區坡地新植檳榔，大多採機械化大規模刨除地表覆蓋物的方式，其地表情況勢必比小試區惡劣，故可能產生之水土流失量應比上述數據爲高。初步數據同時顯示植生覆蓋之水土保持方法可以有效降低檳榔園區之水土流失量。

關鍵字

檳榔 ； 土壤沖蝕 ； 逕流

並列摘要

Betel nut has wide market and good profits in Taiwan. The planting area of betel nut on steep slope has been increasing rapidly. Most of these newly reclaimed betel nut orchards were absent of proper protections against runoff and soil erosion. Hence the damage due to top soil erosion and runoff concentration was happened frequently in downstream section of these betel nut orchards. In order to solve soil and water conservation problems in betel nut orchards, the purpose of this study was to establish experiment plots and to collect related data of soil erosion and runoff. Preliminary results of soil erosion and runoff data showed that soil erosion from clear cultivated betel nut plot under a yearly accumulative precipitation of 2,170.6 mm high was 114 tons per hectare which was 5.7 times more than local acceptable erosion limits. Runoff form clear cultivated betel nut plot was significantly different form that of vegetation cover plots. Besides, the runoff ratio (runoff/erosion) of clear cultivated betel nut plot was 38.49 m^3/ton which was higher than 8.70 m^3/ton of bare plot and 10.5 m^3/ton of clear cultivated mango plot. This result showed that runoff was more serious than erosion in clear cultivated betel nut plot. In actual newly reclaimed betel nut orchards, the situation could be worse than that of experiment plots, since surface cover was moved and destroyed massively by reclaimed machinery in slope orchards. Preliminary results also showed that plant cover was an effective soil and water conservation method to reduce soil erosion and surface runoff.

並列關鍵字

Betel Nut ； Soil Erosion ； Runoff