Sampling survey to the total area of the forest of Heshun county in Shanxi province in year 2000

Implementation steps:

1. Calculate the optimal sample size n according to the known precision requirement.
2. Population (2,697,460 pixels) is equally divided into n groups, namely, the whole zone is divided into n grids with the same size, and number the samples for each group; In the first group, the number L of the starting individual is confirmed by simple random sampling, then extract the Lth sample of the other groups.
3. Estimate the total forest area (unit m²）, and estimate the sampling precision.

Calculation:

1. 
   The total sample size is 100 in fact
   The sampling size after extending 10% is 117 （ Due to the specialties of systematic sampling—equidistant sampling, ultimately, the whole area is filled with the sample sites, so the sampling results are more than the sample size in the computation ）

2. Estimate the total forest area according to the mean of 117 pixels:

Sampling accuracy: