不同網格解析度與流向演算法對蓮華池集水區地形指標之影響

The Effects of DTM Resolution and Flow Direction Algorithms on the Topographic Index in the Lien-Hwa-Chi Watersheds

莊永忠(Yung-Chung Chuang) ； 廖學誠(Shyue-Cherng Liaw) ； 詹進發(Jihn-Fa Jan) ； 黃正良(Jeen-Liang Hwong)

《地理學報》 50期 (2007/12) Pp. 73-100

https://doi.org/10.6161/jgs.2007.50.04

摘要

本文探討不同數值地形模型的網格解析度與流向演算法，對蓮華池四號及五號集水區地形指標之影響，結果顯示，地形指標相對高值多位於集水區內地形低緩之谷地與河川匯集區域，此乃由於該處累積上游水量能力較強，且坡度又較緩所致。此外，網格解析度降低時坡度減緩，因此平均地形指標值相對提升。3種流向演算法中，由於多流向演算法求得之平均坡度，較八流向演算法與無限流向演算法而言相對低緩，因此相同網格解析度下，多流向演算法所計算出之平均地形指標值，均比八流向演算法與無限流向演算法所計算出之結果爲高。本文並以KS檢定比較蓮華池四號及五號集水區水文相似性，就地形指標觀點而言，蓮華池四、五號集水區具相同之水文特性。

關鍵字

地形指標 ； 流向演算法 ； 水文相似性

並列摘要

The purpose of this paper is to study the effects of different grid resolutions and flow direction algorithms on the topographic index in the Lien-Hwa-Chi watersheds No.4 and No.5. The results show that topographic indices with higher values are located near valleys or streams where there are greater cumulative upslope areas and flatter gradient. In addition, when the grid resolution decreases, the mean value of topographic indices will increase due to the decrease of slope. Because the multiple flow direction algorithm results in lower gradient than those of the deterministic-8 and deterministic-infinity flow direction algorithms, the mean value of topographic indices calculated by the multiple flow direction algorithm is the highest on the basis of the same gird resolution. Furthermore, the hydrological similarity is compared between the Lien-Hwa-Chi watersheds using the Kolmogorov-Smirnov test. Based on the topographic index, Lien-Hwa-Chi watersheds No.4 and No.5 have the same hydrological similarity.

並列關鍵字

topographic index ； flow direction algorithm ； hydrological similarity

參考文獻

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