# Towards Urban Sustainability: Developing Noise Prediction Model in an Informal Setting
## 2 Materials and Methods  
The study area, Kano Metropolis, is the second largest urban center in Nigeria and the administrative capital of Kano State. Kano is located within latitudes 11\({}^{\circ}\)50\({}^{\prime}\) to 12\({}^{\circ}\)07\({}^{\prime}\) North and longitudes 8\({}^{\circ}\)22\({}^{\prime}\) to 8\({}^{\circ}\)47\({}^{\prime}\) East [24]. Currently, the city has a population of nearly 5 million inhabitants, has a population density of over 15,000 persons per square kilometer, and a growth rate of 3.9% [24]. Kano Metropolis has assumed the status of city as far back as the 12 th century [29] and since then it continues to grow in terms of population and commerce [26]. Kano is arguably the second most important commercial city in Nigeria. Fortunately, the city's administrators have left the informal development to constitute a larger portion of its landscape [26]. Indeed, the informal development has not only constituted nearly half of its landmass, but even within what is considered formal a lot of informal development exists. A crucial attribute of Kano City is the use of informal commercial transport system which constitutes 60% for public use [20]. A sound level meter (model Graiger TL 200, manufacture by Shenzhen Handsome Technology Co., Ltd, Shenzhen, China) was used to measure the sound level at locations. Noise logger communication application was used to record sound level data into computer at a height of 1.5 as requested by standards. Multi-layer stratification was employed to create the sampling clusters for the study. Land use and housing density formed the basis for the creation of sampling clusters. The study area was classified based on land use into residential, industrial, and commercial areas. The residential areas were further classified based on housing density into low, medium, and high-density areas. In addition, samples were collected from the major metropolitan roads. Thus, the strata for data collection were industrial, commercial, low density residential, medium density residential, high density residential, and traffic corridors. Thirty-eight sampling areas were used and in each area three points (sampled locations) were selected using convenience sampling techniques--selecting major areas, making a total 114 sampled locations. Global Positioning System (GPS) Garmin 76\(\times\) (made by Nuvi Accessories, Hong Kong, China) model was used to record the coordinates of the sampled location for GIS analysis. Sound level was measured for seven days. Within each location, data were collected for morning (8-10 a.m.), afternoon (12-2 p.m.), and evening (4-6 p.m.). All nine major commercial areas of the metropolis, which include Abubakar Rimi (Sabon Gari), Kantin Kwari, Kurmi, Kofar Ruwa, 'Yankaba, Naibawa (Yanlemo), Rimi, Wapa, and Kofar Wambai markets, were included. This made a total of twenty-seven sampled points. Five industrial areas included are Sharada, Bampai, Tokarawa, Challawa, and Dakata. In each of them, three points were also selected for the data collection. These made a total of fifteen locations with forty-five sampling sites. Twenty-one locations were selected from the four residential clusters within the metropolis. The residential areas in the metropolis were categorized into low, medium, and high density [30]. Another category described as peri-urban metropolitan area was also sampled [31]. The high-density areas include the Birni (old walled city), Gwangwarwa-Tudun Murtala, Kurna Rijiyar Lemo, Unguwa Uku, Giginyu, Naibawa and Sheka. Medium density areas are predominantly new layouts that include: Hausawa, Tarauni, parts of Hotoro, Rijiyar Zaki, Gadon Kaya, Kundila, Shagari Quarters, Gwammaja, Tukuntawa, and Danladi Nasidi. The Low-density areas are mainly the GRAs and Institutional lands. Two of the major GRAs, Nasarawa and NNDC were selected as representatives for this cluster. There are also peri-urban residential areas of Ungogo and Kumbotso to the north and south of the Metropolis. The areas sampled constitute the major spatial clusters in the metropolis [32].