Developing a Derivative Model for the Environmental Flow Index and Exploring its Applications in Modern Urban Contexts

This study develops a derivative model for the Environmental Flow Index (EFI) to evaluate the relationship between urban porosity and environmental flow in high-density urban areas. The model was applied to Sadr City in Baghdad, focusing on the city's unique challenges, such as overcrowding, poor ventilation, and environmental degradation. Using computational simulation tools such as ENVI-MET 5.7 and AutoLISP, the study analyzed environmental variables, including wind speed, temperature, relative humidity, and radiant heat, under two scenarios: the current state with 30% urban porosity and a modified state with 40% porosity.The results demonstrate that increasing urban porosity significantly enhances environmental flow, reflected in improved wind circulation, reduced thermal stress, and better outdoor thermal comfort. For instance, wind speed increased from 2.798 m/s to 6.2361 m/s, while relative humidity decreased by 0.394%, showing a positive correlation with higher porosity levels. The EFI model effectively integrates these variables, offering a standardized and scalable metric for measuring environmental flow. The research contributes valuable insights for urban planners and policymakers, supporting the development of sustainable and livable cities in Baghdad and similar urban contexts.