Evaluating the challenges and impacts of mixed-use neighborhoods on urban planning: an empirical study of a megacity, Karachi, Pakistan
Authors: Kausar Anila , Zubair Salman , Sohail Hadeeqa , Anwar Muhammad Mushahid , Aziz Asad , Vambol Sergij , Vambol Viola , Khan Nadeem A. , Poteriaiko Serhii , Tyshchenko Vasyl , Murasov Rustam , Ejaz Fizza , Khan Owais Iqbal 
Published: March 2024

Abstract
Introduction
Modern development is patented by rapid urbanization, which largely negatively affects the quality of life. Over the past few decades in the World; in the field of urban planning and the real estate market, Mixed-use development has become a Centre of attention. Karachi is the mega city with the highest population in Pakistan. Gulshan-e Iqbal is considered an upper to upper-middle-class income group residential place where mostly vertical development is observed. Soon the area gets popular for living, and road-facing flats started to engage in Residential cum commercial activities i.e., mixed-used development problems (traffic jams, people's regular mobility, etc.) for residents arose and as the area got crowded day by day these problems became more critical. The present research aimed to examine the land-use type, and its distribution in the area of Gulshan-e-Iqbal I, and investigate the causes of the failure of Mixed-Use Neighborhood development and to prove the problem environmental impact assessment of the area have also been done.

Materials and methods
Object-based analyses have been conducted on a very high-resolution image of the SAS planet, Digitization has been done on the image later classified into 14 major classes. After attempting the strategic objective identification of issues causing Mobility, an inductive approach (Resident Survey) to analyze the resident perception and to validate issues raised due to mixed-use development, Environmental Impact Analysis has been done. Air Quality of study area has been done, in this regard PM 10 ppm, PM 1 ppm, PM 2.5, CO, CO2, and TVOC have been conducted for different timings. Wind Velocity has also been recorded for the same locations.

Results and discussion
It has been investigated that mixed-use development is spread over the entire area by different ratios i.e., 7.3% by functional land-use, 24% of mixed-use development occupied 24% of total land-use in the area. From public perception, it is concluded that most people have their cars even more than two, and 66.7% park their cars on the streets rather than inside their premises. PM10 ppm values are higher along major roads and expressways and mixed-use development zones. PM2.5 reading is higher (249–267 ppm) at the mixed-use development. The overall Gulshan e Iqbal 1 is under the influence of PM1 pollution i.e., ranged from 153 to 248 ppm. The maximum emission (67–73 ppm) of Carbon monoxide is found at ATMs. The vast spread of CO2 in the atmosphere but along the main roads and interjections i.e., 342 ppm while the highest reading reached up to 800. TVOC is commonly found in congested places where there is more transport in limited areas. Wind velocity is found where the built-up structure is compact wind velocity is ultimately low but the concentration of pollution is higher.

Conclusions and recommendations
This study will be helpful to plan a suitable planning strategy to reduce the daily havoc generated by the constant flux of traffic, for urban development and sustainability.