Identifying mixed use indicators for including informal settlements as a distinct land use: Case study of Delhi

Abstract

This paper explores the possibility of including ‘informal settlements’ as a distinct category of land use in context of travel behaviour studies. Characteristics of these settlements are first outlined to differentiate them from formal residential settlements. Further, the process adopted for compiling informal settlements data from different sources is described. This underscores how readily available satellite imagery, census dataset and other secondary dataset can be used to quantify ‘Informal’ land use. This dataset is compiled using satellite imagery and other relevant sources of information for the year 2014. Seven primary land use categories are included in the study including Residential, Commercial, Educational, Industrial, Public/semi-public, Recreational and Informal. We then examines the utility of existing land use mix indicators in capturing the presence of informal land use in context of Delhi. Land use entropy, Herfindahl-Hirschman Index and Land use dissimilarity are calculated for both cases of including and excluding informal land use. Paired t-test indicates that though these indicators are able to capture the presence of ‘Informal’ land use, the effect size remains small. All of these indicators use proportions of geographical footprint of different categories of land use for mix estimation. Although in case of ‘Informal’ land use the geographical footprint usually remains small and scattered irrespective of the fact that these are high density mixed use settlements. The paper brings out specific limitations of these indicators. Limitations of the indices include aggregation at zonal level, insensitivity to nomenclature assigned, and their symmetric nature.