Measuring land fragmentation considering the shape of transportation network: A method to increase the accuracy of modeling the spatial structure of agriculture with case study in Poland

The studies assessed the impact of various measurement methods on the distances and values of selected land fragmentation indicators. The study covered three villages of varied spatial structure. The proposed model includes the coordinates: the barycenters of the farms, village centers, the actual locations of the farmsteads, centroids of the plots, and local transport network presented in the form of a graph. Four sets of distances were assessed: three rectilinear between a centroid of plot and a farmstead, village center, and barycenter of farm's lands, and one between a farmstead and plots, regarding the shape of road network. Also the variability of average distance of hectares index (avdhai) and grouping index (grpgii) was studied. It has been proven that the change in the method of determining the distance completely changes the structure of the sets of fragmentation indicators. The largest change in the average value of grpgii calculated for the whole village using the real distance was 144.6%, while in the case of the avdhai it was 91.8%, in relation to the rectilinear distance calculated to the barycenters of the farms' lands in both cases.