Case introduction

Next page

 

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

 

Description:

We need to take some samples to investigate (the minimum investigated unit is a TM image ) from 2,697,460 image units for understanding the area of forest coverage of Heshun county in Shanxi province in year 2000, require that the absolute error isn't greater than 8×107m2, when s ignificance l evel is 0.05, According to the previous investigated results, the standard deviation of the forest area of a TM image is approximately 150m2, the spatial correlation coefficient is 0.15
 

Sampling method:

Spatial random sampling

 

Objective:

To estimate the forest area of Heshun county in year 2000 by sampling

 

Condition: 
  1. Significance l evel is 0.05;
  2. The absolute error of the estimated total forest isn't greater than 8×107m2；
  3. The expectation estimation of standard deviation of the forest area in each pixel is 150m2。
 
Request:
  1. Optimal sample size, namely, the least pixel size to meet the requirement of sampling accuracy ;
  2. Distribute the samples, namely, extract the pixel number that need to be investigated from the sampling box by spatial random way.
  3. Calculate, namely, estimate the total forest area and sampling accuracy according to the sampling pixel and investigated data.
 
 
 
 
 
 
 
 
 
 
 
 

Next page