Application of SWAT model to assess the impact of land use changes on daily and monthly streamflow of Subarnarekha River Basin Mousumi Ghosh Department of Civil Engineering National Institute of Technology Rourkela Application of SWAT model to assess the impact of land use changes on daily and monthly streamflow of Subarnarekha River Basin Dissertation submitted to the National Institute of Technology Rourkela in partial fulfilment of the requirements of the degree of Master in Technology in Water Resources Engineering by Mousumi Ghosh (Roll Number: 214CE4080) based on research carried out under the supervision of Prof. Kanhu Charan Patra May, 2016 Department of Civil Engineering National Institute of Technology Rourkela Department of Civil Engineering National Institute of Technology Rourkela May 28, 2016 Certificate of Examination Roll Number: 214CE4080 Name: Mousumi Ghosh Title of Dissertation: Application of SWAT model to assess the impact of land use changes on daily and monthly streamflow of Subarnarekha River Basin. We the below signed, after checking the dissertation mentioned above and the official record book (s) of the student, hereby state our approval of the dissertation submitted in partial fulfilment of the requirements of the degree of Master of Technology in Water Resources Engineering at National Institute of Technology Rourkela. We are satisfied with the volume, quality, correctness, and originality of the work. Prof. Kanhu Charan Patra Supervisor Prof. Sisir Kumar Sahoo Head of the Department Department of Civil Engineering National Institute of Technology Rourkela Prof. Kanhu Charan Patra Professor National Institute of Technology Rourkela May 28, 2016 Supervisors’ Certificate This is to certify that the work presented in the dissertation entitled Application of SWAT model to assess the impact of land use changes on daily and monthly streamflow of Subarnarekha River Basin submitted by Mousumi Ghosh, Roll Number 214CE4080, is a record of original research carried out by her under my supervision and guidance in partial fulfilment of the requirements of the degree of Master of Technology in Water Resources Engineering. Neither this dissertation nor any part of it has been submitted earlier for any degree or diploma to any institute or university in India or abroad. Kanhu Charan Patra Professor Dedication This work is dedicated is to my parents who have been with me through thick and thin during the period of my study. Mousumi Ghosh Declaration of Originality I, Mousumi Ghosh, Roll Number 214CE4080, hereby declare that this dissertation entitled “Application of SWAT model to assess the impact of land use changes on daily and monthly streamflow of Subarnarekha river basin” represents my original work carried out as a postgraduate student of NIT Rourkela and, to the best of my knowledge, it contains no material previously published or written by another person, nor any material presented for the award of any other degree or diploma of NIT Rourkela or any other institution. Any contribution made to this research by others, with whom I have worked at NIT Rourkela or elsewhere, is explicitly acknowledged in the dissertation. Works of other authors cited in this dissertation have been duly acknowledged under the section ''Bibliography''. I have also submitted my original research records to the scrutiny committee for evaluation of my dissertation. I am fully aware that in case of any noncompliance detected in future, the Senate of NIT Rourkela may withdraw the degree awarded to me on the basis of the present dissertation. Date: NIT Rourkela Mousumi Ghosh Acknowledgement It is a privilege for me to express my profound gratitude and indebtedness to my supervisor Prof. Kanhu Charan Patra, Civil Engineering Department, National Institute of Technology Rourkela. It would have been impossible for me to proceed in my research work without his guidance. I shall be highly obliged for his full term support. I would like to convey my sincere gratitude to Prof. S.K. Sahoo, Head of the Department, Water Resources Engineering Department, National Institute of Technology Rourkela, for his constant guidance and encouragement. I would also take the pleasure of thanking all faculty members, Prof. Kishanjit Kumar Khatua, Prof. Awadhesh Kumar and Prof. Sanat Nalini Sahoo who had shared their knowledge during our course work. I would also like to thank my seniors Janaki Ballav Swain and Mrunmayee Manjari Sahoo for their immense help in my project. I am grateful to parents for their love, affection and understanding. They have provided constant support throughout the period of my study. I am also thankful to my friends Aatish Anshuman, Pallabi Bhuyan and many others for their help and support during my research work. Special thanks to all my friends for motivating me and assisting me. Without their help and encouragement it would not have been possible for me to undertake this work. I would like to thank all my friends for making my stay at NIT Rourkela lively and without their help this work would not have been possible. May 2016 Mousumi Ghosh NIT Rourkela Abstract Quantifying the impacts of land use change and land cover practices on the hydrological response of a watershed has been an area of interest for the hydrologists in recent years as this information could serve as a basis for developing sound watershed management interventions. The degree and type of land cover influences the rate of infiltration, runoff, and consequently the volumes of surface runoff and total sediment loads transported from a watershed. It often results in significant degradation of land resources such as loss of soil by erosion, nutrient leaching and organic matter depletion. However very few studies in India, have used the physically based hydrological models along with the land use / land cover change conditions. Hence in this current work SWAT model has been used to assess the impact of LU/LC changes on daily and monthly streamflow of Subarnarekha River Basin. The SWAT model has been calibrated and validated against the daily and monthly streamflow for the gauging station of Govindpur in NH5 road situated along the Budhabalanga river. The results depict that SWAT model usually performs well in simulating runoff according to Nash-Sutcliffe efficiency (NSE), Coefficient of determination (R2) and Percentage bias (PBIAS) values. For daily stream flow the NSE, R2 and PBIAS values were 0.61, 0.64 and -12 during calibration period and 0.57, 0.60 and 14.2 during validation period respectively. For monthly stream flows the efficiency increased due to smoothening of curves and the NSE, R2 and PBIAS values were 0.76, 0.81 and 9.2 during calibration period and 0.79, 0.83 and 10.4 during validation period respectively. The results of the study indicated that the though land use patterns have changed resulting in increase in agricultural, barren and buildup land and decrease in forest cover leading to increase in runoff but changes have not occurred as significantly as the changes in annual streamflow. However the number of days of high intensity rainfall has increased over decade which along with the land use changes explains for the increase in streamflow. Keywords: SWAT model, LU/LC changes, daily and monthly runoff, SUFI-2. iii CONTENTS List of figures ......................................................................................................................... i List tables………………………………………………………………………………….. ii Abstract…………………………………………………………………………………….iii 1. INTRODUCTION .......................................................................................................... 1 1.1. General .................................................................................................................... 1 1.2. Surface Runoff ........................................................................................................ 2 1.3. Hydrological Modeling ........................................................................................... 2 1.4. Remote Sensing and GIS in Hydrological Modeling ............................................. 3 1.5. Impact of Land Use/ Land Cover Changes ............................................................. 3 1.6. Environmental Flow Assessment ........................................................................ 4 1.7. Significance and Objectives for the Research ........................................................ 5 1.8. Thesis Outline ......................................................................................................... 6 2. LITERATURE REVIEW ............................................................................................... 7 2.1. Hydrological modelling .......................................................................................... 7 2.2. Regarding various Hydrological models used ........................................................ 7 2.3. Regarding Studies on Indian Catchment............................................................... 10 2.4. Regarding Environmental Impact Assessment ................................................. 11 3. THE STUDY AREA AND DATA .............................................................................. 13 3.1. The study area ....................................................................................................... 13 3.1.2. Climate .............................................................................................................. 14 3.1.3. Land Use/ Land Cover .....................................................................................