EVALUATING THE IMPACT OF LAND USE AND CLIMATE CHANGE ON REGIONAL HYDROLOGY BY UTILIZING LOW IMPACT DEVELOPMENT TECHNIQUES.

Author

Mandip Banjara, Southern Illinois University CarbondaleFollow

Date of Award

8-1-2024

Degree Name

Master of Science

Department

Civil Engineering

First Advisor

Kalra, Ajay

Second Advisor

Kolay, Prabir

Abstract

Regional hydrology is experiencing significant changes due to a combination of land use and land cover (LULC) transformations and the growing impact of climate change. As cities expand into what were once agricultural or forested areas, the hydrological characteristics of watersheds undergo substantial shifts, influencing stream flow and flood volumes. To better understand these changes, this study integrates two complementary approaches. The first utilizes the Cellular Automata–Markov (CA–Markov) model to project LULC changes, predicting substantial urban growth from 11.6% of total area in 2021 to 34.1% by 2050 and 44.2% by 2080. This urbanization correlates with increased peak discharge and runoff volume for a 100-year return period storm event, with peak discharge rising by 5% and 6.8%, and runoff volume by 8% and 13.3% by 2050 and 2080, respectively. The second approach employs the North American Regional Climate Change Assessment Program (NARCCAP) climate model to project future storm depths, with extreme climate scenarios suggesting an increase of up to 104% in storm depths, leading to a 37.72% rise in peak discharge and an 88.73% rise in flooding volume. To mitigate these impacts, Low Impact Development (LID) techniques such as Permeable Pavement, Green Roofs, and Bio-Retention Cells were evaluated for their effectiveness in reducing climate change-induced flood risks. Using the validated Personal Computer Storm Water Management Model (PCSWMM) to simulate rainfall-runoff scenarios, the results indicated that Permeable Pavement could reduce peak discharge by up to 28.57%, with Green Roofs and Bio-Retention Cells reducing peak discharge by up to 19.93% and 14.25%, respectively. These findings underscore the importance of implementing sustainable water management practices as part of urban planning to address the dual challenges of LULC changes and climate change-induced flooding, providing a path toward more resilient urban environments.