Polygon intersection - spatial intersection of multiple polygon layers
InfoWater Pro Allocator also offers a highly efficient polygon processing engine for the intersection and allocation of demands between two polygon layers. Demands at junction nodes are allocated according to polygon classes/classifications (e.g., residential, commercial, industrial, recreational, governmental, schools) tributary to a specific junction node. Each of these classes has its own unique water duty factor characteristics. Each class also consumes water within similar diurnal demand patterns. Therefore, categorization on consumer classes and the subsequent spatial allocation of demands is instrumental in estimating an accurate hydraulic model.
Typically, each demand area polygon is assigned to a single junction node and represents one to many classes/classifications. Independent of this demand area assignment, each class/classification categorization is also represented by a polygonal boundary definition. Typically, land use (zoning) categorization is the most common polygon layer for allocating demand. Superimposing the areas of influence from the classes/classifications categorization over the demand area polygon coverage, the InfoWater Pro Allocator engine allocates the demands of individual demand classes to the designated demand node. Involved in this process is a lookup table where classes/classifications are assigned water duty factors. The multiplication of these water duty factors with the composite demand area polygon generates the summation of demands for a single-analysis node that is applied to the hydraulic model.
InfoWater Pro Allocator considers the demand area polygons as the Primary polygon coverage while the classes/classifications layer is represented as a Secondary polygon definition. During the allocation process, the program intersects polygons of the Primary layer with those of the Secondary layer. Additional secondary layers can be further appended to the system evaluation, thus expanding the consideration into a multi-dimensional problem. One typical application of an additional secondary layer is the phase of development, such as existing zoning, the 5-year general plan, the 10-year general plan, etc. The combination of these multiple Secondary layers with the Primary layer enables sophisticated demand evaluation over a range of planning horizons, making InfoWater Pro Allocator an incredibly powerful analysis tool.