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为了提高森林调查的精度和效率我们于1978年设计了“定角样地调查法”,並进行了一些试验,从试验结果看,用该法所测定的森林蓄积量、株数、平均直径等项因子的精度稳定可靠。该法的特点是:外业操作方便,内业计算简便,工效较常规样地提高四倍,便于使用和推广。现将试验结果简介于后,谨供参考,业望指正。一、定角扇形样地的原理 (一)扇形样地定角的导算扇形的形状和大小是由扇形的中心角Q和扇形半径R两个因子确定,其面积公式为:M ha=i=1 R乞式中Mha为每公顷蓄积
In order to improve the accuracy and efficiency of forest surveys, we designed the “Cornerstone Survey Method” in 1978 and conducted some experiments. From the test results, we can see the amount of forest stock, the number of trees and the average diameter measured by this method The accuracy of the factor is stable and reliable. The law is characterized by: easy operation of the field, the calculation of the industry is simple, work efficiency than the conventional sample quadruple, easy to use and promote. Brief introduction of the test results now, for reference, industry correction. First, the fixed angle fan-shaped ground principle (A) fan-shaped fixed angle guide fan shape and size is determined by the fan center angle Q and fan radius R two factors, the area formula is: M ha = i = 1 R begging Mha for each hectare accumulation