The mathematical model of land use is formulated as an extremely problem on graphs.  The edges of this graphs are weighted by fuzzy sets. Authors spare  peculiar attention to a basis of that fact, that the will-known definitions of operations of summation and comparison cannot be used in under consideration  model by virtue of their inadequacy of substantial essence of the problem of land use. The basic result of article are definition and a substantiation of such methods of summation and comparison of fuzzy weights, which are adequate to the additive criterion function used in the problem of land use.