Monitoring spatio-temporal compliance of urban development plans using GIS and remote sensing in Nairobi City County, Kenya
Development control aims to provide an urban environment with quality service delivery, optimal use of available resources, conservation, and reduction of haphazard urban growth. At the core of development control is the compliance assessment process, which ensures adherence to regulatory policies. The City of Nairobi compliance assessment process lacks considerable enforcement capacity and this has led to uncontrolled development. This study uses GIS and remote sensing to assess the spatio-temporal compliance of development plan(s) in Nairobi City County. Land use/cover of Nairobi City County from 1976 to 2019 were obtained from classified Landsat images at a nearly 10-year interval of six epochs (1976, 1984, 1993, 2002, 2010 and 2019). The zoning plan maps were digitised and superimposed on the classified images to determine compliance, taking subsequent reviews of spatial development plans into account. The non-compliance rates for residential, commercial, and industrial activities varied at 57~84%, 63~81% and 65~92%, respectively, during the study period (1976–2019). A comparison between the planned and non-compliant areas showed that residential, commercial, and industrial activities occurred mostly outside planned areas from 1976 to 2019. The analysis showed a considerably less increase in noncompliance on commercial land use. This is so because of the review done on the zoning plan for Nairobi City in 2005. The industrial land use non-compliance was constantly increasing over the study period, an indicator of the ever-rising rate of urbanisation in the Nairobi metropolitan area. This study illustrates the power of rapid spatial mapping in monitoring compliance of urban development plans for informed decision making.