Consequently, flooding affects the ongoing traffic. This is due to the increase in impervious land due to urbanization. Even though rainfall has decreased, there is more flooding being observed. During those years, the land was less impervious as compared to the existing land use. History dates back to the situation when precipitation was 205 mm annually, which has decreased by 14 mm since then. By thorough analysis of observed data, these issues can be addressed effectively. These issues can be in designing, planning, and management of the drainage system. In addition, it is needed to improve the existing drainage system to ease the traffic congestion in rainy conditions. To overcome the above-mentioned public-related issues, it is of great value if a research study based on some observed data could be conducted to give recommendations for improvement of the current situation of traffic. This issue needs to be addressed accordingly, especially in the urban environment, since urbanized areas have to be the pivotal focus of planning development and management as mentioned in various studies. This often occurs when there is a poor planning of the region. Due to poor management of drainage and traffic, a rainfall event becomes a tragedy. Substantially, when these two issues are studied together, the scenario becomes more catastrophic, based on complications of each field. Karachi is also facing severe difficulty in dealing with management of drainage and traffic. This inundation sometimes remains for days, if ponded water is not drained by some external means like pump.ĭrainage and traffic management are always two important issues of an urban area. This causes an increase in travel time and a decrease in road capacity. Generally, this inundated water completely blocks the road, resulting in almost zero capacity of that section of the road. Furthermore, due to the bad drainage system of the city, water tends to accumulate at the depression areas and inundation occurs. So, due to rain, when the capacity of road decreases, it results in the long queue. It is because acceleration and speed are directly involved in the capacity of the road section.
#Pcswmm versions drivers
After rain, it is very prominent to see congestion on the arterial and sub-arterials of Karachi city.ĭuring rain, drivers tend not to accelerate high, keep low speed, and drive more cautiously.
![pcswmm versions pcswmm versions](https://www.pcswmm.com/Images/video-5a.png)
Ponding on the roads creates a lot of problems because it disturbs the flow of vehicles.
![pcswmm versions pcswmm versions](http://hopdegoto.weebly.com/uploads/1/3/2/9/132951323/948095258_orig.jpg)
Whenever there is a rainfall event, more specifically during monsoon in Karachi, ponding on the roads is usual. This impervious land is responsible for flooding within the city.
![pcswmm versions pcswmm versions](https://www.chiwater.com/Company/Staff/WJamesWebpage/original/homepage/Teaching/661/Image111.gif)
However, for urbanized cities, there is another factor responsible for the poor performance of the impervious land which is intensified by poor drainage system in the case of Karachi. There exist various reasons such as increasing population, perennial movement of vehicles, poor road structure. Pakistan, especially Karachi, has recently been facing difficulties in the road performance. The performance of the road network determines the capability and capacity development of the city. Road network is the skeleton for any city. Karachi is considered to be the economic hub of Pakistan and contributes a large share in the gross domestic product (GDP) due to her favorable location at the Arabian coast. Analysis of VISSIM shows that for a 100-year return period, there is a maximum delay of 35 min on NIPA to Hasan Square section of University Road. Analysis of PCSWMM shows that for 100-year return period, there is maximum 0.318 ha-m (3180 cubic meters) water stored in the depressions of the road after 10 h of rainfall. These lengths are then marked in VISSIM as low-speed areas, and delays are measured.
![pcswmm versions pcswmm versions](https://www.advanceduninstaller.com/images/aup/9db7e99eae7b0a38c8864933660d90c9.jpg)
Locations and lengths of road sections, where ponding happens for the future scenario, are identified using PCSWMM. Sensitivity analysis of VISSIM is performed. Both models are calibrated for an existing situation on rainfall event of August 3, 2013, and then used for prediction of future scenario based on 50-year and 100-year return periods of rainfall. For urban drainage, PCSWMM, and for traffic, VISSIM is used. In this study, loose coupling of two models is done. This study is carried out on a 3-km section of arterial road. The specific objectives are: (1) to calibrate and validate urban hydraulic and traffic micro-simulation models and (2) to model storm water and traffic for future conditions. The main objective of the study is to model the interdisciplinary issues of storm water and its effect on the traffic of Karachi. Like other big cities, Karachi is also facing problems due to lack of traffic management and poor drainage system. Traffic management and drainage system are two vital issues for any metropolitan city.