Investigation of the Spatial and Temporal Variation of Sediment Yield and Surface Runoff in Offa Watershed Kwara State

ABSTRACT

In this research, an hydrological modelling tool, soil and water assessment tool (SWAT) used to investigate the spatial and temporal variation of sediment yield in a watershed. The model was run for 31years using spatial data such as Digital Elevation Model, soil map, land use and precipitation, wind and solar radiation. The results showed that the maximum value of surface Runoff was estimated as 19100.034mm in the year 2005 while the minimum surface Runoff was 1000.671mm in the year 20017. The maximum value of sediment yield was estimated as 2340.532mm in the 2005 and the minimum value was estimated as 34.769mm in the year 2003  

 

 

 

 

 

 

 

 

 

TABLE OF CONTENTS

Title page                                                                                              

Certification                                                                                             ii

Dedication                                                                                              iii

Acknowledgement                                                                                   iv

Abstract                                                                                                  v

Table of content                                                                                      vi

List of Figures                                                                                         ix

CHAPTER ONE: INTRODUCTION

1.1     Introduction                                                                                  1

1.2     Problem Statement                                                                        2

1.3     Aims & Objectives                                                                         2

1.4     Justification                                                                                   3

1.5     Scope of Study                                                                              3

1.6     Description of Study Area                                                               3

CHAPTER TWO: LITERATURE REVIEW

2.0     Literature Review                                                                          5

2.1     Sediment Source Analytical Techniques                                          5

2.2     Sediment Yield Measurements                                                        6

2.3     Field Measurements of Sediment Yield                                            7

2.4     Sediment Yield Modeling                                                                7

2.5     Brief Description of Selected Hydrology Models                               8

2.5.1   RIBASIM                                                                                       8

2.5.2   WEAP                                                                                           9

2.5.3   Realm Resource Allocation Model                                                   9

2.5.4   HSPF Model                                                                                   10

2.5.5   AGNPS Model                                                                                10

2.5.6   SWAT Models                                                                                11

2.6     SWAT Model Description                                                                11

2.7     Water Shed Hydrological Modeling.                                                11

CHAPTER THREE: METHODOLOGY

3.0     Methodology                                                                                 13

3.1     Model Selection and Description                                                     13

3.2     Model Input Data                                                                          14

3.3     Digital Elevation Model (DEM)                                                        14

3.4     Soil Map                                                                                        15

3.5     Weather Data                                                                               16         

3.6     SWAT Model Set-up and Run                                                          16

3.7     Water Shed Delineation                                                                 16

3.8     Land use map of the watershed                                                     17

CHAPTER FOUR: RESULTS AND DISCUSSION

4.0 RESULTS                                                                                           19

4.1 Temporal Variation of total means for surface runoff                            19

4.2 Temporal variation  of total means for sediment yield                          20

4.3     Temporal variation of annual means for sediment yield                   21

4.4     Temporal variation of annual means for surface runoff                    21

CHAPTER FIVE: CONCLUSION AND RECOMMENDATION

5.0 Conclusion                                                                                         23

5.1 Recommendation                                                                               23

References