林木材積調查在不同取樣設計暨不同地面樣區測計方法之優劣點比較

Comparison Study on Forest Survey among Four Different Sampling Designs and Five Field Enumeration Methods

吳英陵(Yin-Lin Wu)

《航測及遙測學刊》 1卷1期 (1996/12) Pp. 25-36

https://doi.org/10.6574/JPRS.1996.1(1).2

摘要

依林型分層的二種取樣設計及簡單逢機取樣設計，在95%機率水準10%取樣誤差設定前題下，均以水平樣點係數值為2之水平樣點最為節省調查時間及費用，係數值為4者次之，再依次分別為0.0125公頃、0.0250公頃之圓形樣區，並以0.05公頃圓形樣區者最差。調查地區模擬比例擴大為一萬公頃及十萬公頃，甚至調查地區十萬公頃取樣誤差降為20%，亦得同樣研究結果。純就最佳地面測計方法，即係數值為2之水平樣點而言，二種不同設計之分層逢機取樣設計均較簡單逢機取樣設計節省調查時間（費用），其中並以依針葉林、針闊葉混淆林及闊葉林之二層逢機取樣法所需調查時間（費用）最為節省，此項結果不隨調查地區增大為一萬公頃或十萬公頃有所不同。

關鍵字

航空測量 ； 航照判釋 ； 分層逢機取樣 ； 地面測計方法

並列摘要

Both the simple random sampling and three forms of forest-type oriented stratified random sampling are the four designs in this comparison study. Samewise, three forms of circular plot sampling, i.e. 0.0125ha, 0.0250ha and 0.0500ha, and two forms of horizontal point sampling i.e. BAF4 and BAF2, are enumerated with the common center or point in every observations. The 140 observations are allocated to the strata according to the degree of precision desired for the particular strata, i.e. 32 for coniter-hardwood plantation, 48 for coniferplantation, 20 for natural hardwood forest, 40 for natural conifer forest.For time and cost concerned, the two forms of horizontal point sampling are superior to three kinds of circular plot sampling whatever the simple random sampling design or stratified random sampling design might be; Among the sampling designs, the horizontal point sampling of BAF 2 is the best, horizontal sampling of BAF 4 comes next and the circular plot sampling of 0.050ha be the worst; Compared with the simple random sampling, three forms of stratified random sampling gain in time/cost in corresponding form of horizontal point sampling respectively. The ”R1” (BAF2) on 3-stratum stratification is with the least survey time/cost among four different sampling designs and five field enumeration methods.

並列關鍵字

Aerial survey ； Photo interpretation ； Stratified random sampling ； Field enumeration methods