CN103162676B - A kind of angle gauge measures the accurate estimation method of the accumulation of forest bottom class and biomass - Google Patents

Abstract

The invention discloses a method for accurately estimating the accumulation and biomass of a forest subcompartment with a corner gauge. According to the size of the subcompartment area, the count values of other corner gauge points are estimated by using the measured values of 2-5 corner gauge points. , and then estimate the forest volume and biomass of sub-compartments based on the measured and estimated point count values. The field workload of forest survey is greatly reduced, and at the same time, the measurement error caused by the difference in the selection of the position of the angle gauge point.

Description

An Accurate Estimation Method of Angle Gauges to Measure Forest Small Class Stock and Biomass

1. Technical field

The present invention relates to an accurate estimation method for measuring the accumulation and biomass of forest subcompartments with angle gauges, in particular, using the actual measured 2-5 angle gauge points count value, and using the least squares estimation method, using unknown angle gauge points to the known Knowing the method of estimating the distance of the angle gauge points to obtain the count value of 5-36 angle points.

2. Technical background

So far, the angle gauge is still widely used in forestry as a rapid forest stand measurement tool, but in the actual operation of the field survey, there are still the following problems.

1. The number of observation points of the diagonal gauge is required to be large. In my country's forestry survey regulations, it is clearly stipulated that the number of corner gauge points is determined according to the stand area, as shown in Table 1. If the sampling accuracy is required to reach more than 90%, at most 36 angle gauge points are required. If too many points are required for the angle gauge, the workload in the field must be increased, and the work efficiency will be greatly reduced.

Table 1 Determination of corner gauge points in forest stand investigation

2. It is required that the position of each angle gauge point be selected to be a representative position for the forest stand, and avoid setting angle gauge points in places that are too sparse or too dense. This requires high work experience for field investigators. Investigators with different work experience have great differences in the selection of angle gauge points, and differences in operator experience will lead to measurement errors.

Therefore, the present invention estimates the count value of 5-36 square gauge points by measuring the count value of 2-5 square gauge points according to the size of stand area, and then utilizes the measured square gauge point count value and estimated square gauge point The counting value of the point can realize the accurate calculation of forest stock and biomass, which can greatly reduce the workload in the field, and at the same time avoid the measurement error caused by the difference in the selection of the position of the angle gauge point.

3. Contents of the invention

In order to overcome the traditional method that requires a large number of corner gauge points and a large workload in the field; the selection of corner gauge points is demanding, and the measurement error caused by the difference in the position of the corner gauge points. Invented an accurate estimation method of angle gauge to measure forest subcompartment accumulation and biomass. Its characteristics are: according to the size of the small class, use the measured value of 2-5 angle gauge points to estimate the value of other angle gauge points, and then estimate the value of angle gauge points based on the measured angle gauge value and the estimated angle gauge point count Measure the stock volume and biomass of Xiaoban forest. The determination of the number of corner gauge points, when the area of the small class is less than 1 hectare, the number of corner gauge points is 2, when the area of the small class is less than 5 hectares, the number of corner gauge points is 3, when the area of the small class is less than 10 hectares, the number of corner gauge points is 4, and the area of the small class is greater than 10 For hectares, the number of square gauge points is 5. Randomly select n corner gauge points in the forest class, count the corner gauges, and record as Using digital and analog (1)

According to the measured value of the square gauge of n square gauge points Estimate the count value of r square gauge points, denoted as In digital model (1), According to the digital model (2) obtain; By digital model (3) $m_{p_i{p}_j}=c_o{e}^{{-k}^2{d}_{p_i{p}_j}^2}$ obtain; By digital model (4) $m_{p_i{q}_j}=c_o{e}^{{-k}^2{d}_{p_i{q}_j}^2}$ Get it. In digital model (3), is the distance from the i-th measured goniometer point to the j-th measured goniometer point. In digital model (4), is the distance between the i-th measured square gauge point and the j-th estimated square gauge point. According to the count value of the measured n square gauge points Estimate the count value of r square gauge points Using digital and analog (5) Obtain the stand angle gauge value, and then further calculate the forest subcompartment stock volume and biomass according to the traditional method.

Compared with existing methods, the present invention has the following advantages:

(1) The number of measured angle gauge points is reduced from 5-36 to 2-5, greatly reducing the field workload of forest surveys and improving work efficiency.

(2) The measurement error caused by the selection difference of the position of the angle gauge point is avoided.

4. Description of drawings

The present invention will be further described below in conjunction with accompanying drawings and examples.

Fig. 1 is a schematic diagram of the present invention.

5. Specific implementation methods:

Randomly select n corner gauge points in the forest class, count the corner gauges, and record as Using digital and analog (1)

According to the measured value of the square gauge of n square gauge points Estimate the count value of r square gauge points, denoted as In digital model (1), According to the digital model (2) obtain; By digital model (3) $m_{p_i{p}_j}=c_o{e}^{{-k}^2{d}_{p_i{p}_j}^2}$ obtain; By digital model (4) $m_{p_i{q}_j}=c_o{e}^{{-k}^2{d}_{p_i{q}_j}^2}$ Get it. In digital model (3), is the distance from the i-th measured goniometer point to the j-th measured goniometer point. In digital model (4), is the distance between the i-th measured square gauge point and the j-th estimated square gauge point. According to the count value of the measured n square gauge points Estimate the count value of r square gauge points Using digital and analog (5) Obtain the stand angle gauge value, and then further calculate forest subcompartment stock volume and biomass according to the traditional method.

The above data processing is completed by PDA (PersonalDigitalAssistant, personal electronic assistant), which realizes fast storage and automatic processing of data.

Claims (3)

1. angle gauge measures an accurate estimation method for the accumulation of forest bottom class and biomass, it is characterized in that: according to the size of subcompartment area, utilizes actual measurement 2-5 angle gauge point angle gauge count value, selects n angle gauge point immediately, carry out angle gauge counting, be denoted as in block utilize digital-to-analogue (1)

According to the angle gauge count value of n angle gauge point of actual measurement estimate out the count value of r angle gauge point, be denoted as in digital-to-analogue (1), according to digital-to-analogue (2) try to achieve; by digital-to-analogue (3) try to achieve; by digital-to-analogue (4) try to achieve; In digital-to-analogue (3), be i-th bevel protractor point to the distance of jth between bevel protractor point; In digital-to-analogue (4), be i-th bevel protractor point to estimate distance between angle gauge point to jth.

2. the accurate estimation method of the accumulation of forest bottom class and biomass is measured according to claim 1 angle gauge, it is characterized in that: the determination that angle gauge is counted: when subcompartment area is less than 1 hectare, angle gauge point numerical digit is 2, when subcompartment area is less than 5 hectares, it is 3 that angle gauge is counted, and when subcompartment area is less than 10 hectares, it is 4 that angle gauge is counted, when subcompartment area is greater than 10 hectares, it is 5 that angle gauge is counted.

3. measure the accurate estimation method of the accumulation of forest bottom class and biomass according to claim 1 angle gauge, it is characterized in that: according to the count value of n the angle gauge point surveyed estimate the count value of r angle gauge point utilize digital-to-analogue (5) obtain standing forest angle gauge count value, then calculate forest subcompartment's stock volume and biomass according to classic method further.