森林资源连续清查是我国获取宏观森林面积的主要手段,采用的是系统抽样方法。用理论分析的方法对样地森林面积计量3种不同确定方法的偏性与有效性进行论证。结果表明:1)连续变量法是无偏的,且效率最高;2)点定法也是无偏的,但效率较连续变量法低;3)优势地类法在某些情况下是有偏的,当总体单元的森林面积比例均接近于0或1时,结果接近无偏;4)本文结论表明,在遥感大样地调查中选择连续变量法是最合理的。

Continuous Forest Inventory (CFI) is the main method to get the China's forest area,which is conducted in a systematic sampling manner.In this paper,bias and efficiency of these three plot forest measurement methods will be proved by theoretical analysis.The result shows that:1.CV is unbiased,and it has the highest efficiency;2.PLB is also unbiased,but the efficiency is lower than CV;3.DLB is biased,however the population proportion of forest is almost 0 or 1,the result is nearly unbiased;4.CV method,which is unbiased and has high efficiency,should be chosen for remote sensing large-plot inventory.