Difference between revisions of "Sample design"
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''NB: There should be at least three sample stands in each stratum. Moreover, aviod extreme differences in the representative area of different strata.'' | ''NB: There should be at least three sample stands in each stratum. Moreover, aviod extreme differences in the representative area of different strata.'' | ||
| − | *''' | + | *'''The presupposed number of plots in a sample stand is set, depending on stand characteristics (chosen by the user)''' |
This is called the sample plot intensity-definition part. The matrix can be re-arranged as in previous parts, by selecting preferred variables and number of classes and class width. | This is called the sample plot intensity-definition part. The matrix can be re-arranged as in previous parts, by selecting preferred variables and number of classes and class width. | ||
| + | *'''The sample plot size is set in a similar manner''' | ||
| + | Definitions corresponds to the radius, in meters, of the circular plots. Finally, some additional settings are made, necessary in the inventory (e.g. in the sample tree sampling). Read more about the sample tree parameters 1-3 here. | ||
| − | ''NB: The number of plots per stand is set considering costs and assumed losses (caused by bad decisions made from erratic forest descriptions), less than three is only considered stupid. A corresponding line of reasoning is held for the number of sample trees per plot, where less than 0.5 is stupid. The plots are circular, however when, e.g., acting as reference ("ground truth") to remotely sensed data with certain (quadratic) pixel size, you should adjust the plot radius hereof and define radii in meters with two decimals.'' | + | ''NB: The number of plots per stand is set considering costs and assumed losses (caused by bad decisions made from erratic forest descriptions), less than three is only considered stupid. Unless they are very large, with radius >>10 m (and in small stands, with area <0.5 ha). A corresponding line of reasoning is held for the number of sample trees per plot, where less than 0.5 is stupid. The plots are circular, however when, e.g., acting as reference ("ground truth") to remotely sensed data with certain (quadratic) pixel size, you should adjust the plot radius hereof and define radii in meters with two decimals.'' |
| − | |||
*'''This part is finished by actually sampling the sample stands in each stratum (done PPS where size is the stand area)''' | *'''This part is finished by actually sampling the sample stands in each stratum (done PPS where size is the stand area)''' | ||
Inspect the sampled sample stands regarding, e.g., the total number and each stands corresponding stratum. When values in corresponding columns (e.g. P1-P3, Stratum, Plots, and Radius) looks ok, you can finish and lock the sample. | Inspect the sampled sample stands regarding, e.g., the total number and each stands corresponding stratum. When values in corresponding columns (e.g. P1-P3, Stratum, Plots, and Radius) looks ok, you can finish and lock the sample. | ||