1. A method, comprising: dividing, by executing an instruction with a processor, an image of a geographic area of interest into geographical zones, the geographical zones being representative of different physical geographical areas; storing, by executing an instruction with the processor, descriptions for the geographical zones in a computer memory based on modified boundaries of a first one of the geographical zones; sorting, by executing an instruction with the processor, the geographical zones into bins based on a comparison of values representative of the geographical zones to ranges of values, the ranges of values corresponding to the bins; determining, by executing an instruction with the processor, a number of zones to be sampled in one of the bins based on the range of values corresponding to the one of the bins; storing, by executing an instruction with the processor, a value representative of a geographical feature represented in the image for the first one of the geographical zones; generating, by executing an instruction with the processor, a sampling plan having a sampling area based on the value; and manually sampling the sampling area based on the sampling plan.