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 ofsurface 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                                                            Â
CHAPTER ONE
- INTRODUCTION
Water is an integral part of life, as human beings derived from the environment several services that are necessary for the survival, Water is one of the basic needs that human beings cannot live without; indeed water is life! Therefore, water-related (hydrological) ecosystem services provided by the environment (e.g provision, regulation and purification of freshwater) are quite valuable and important for human well-being. This underscores the importance of sound watershed management for continued provision of hydrological ecosystem services. From a hydrological point of view, a watershed includes all land contributing water (surface and ground water) to a reference point.
It is therefore obvious that land comprising of any watershed would generally be under other uses such as forests, agriculture and urban centers, which might commonly be considered ‘primary’ land uses. This means that watersheds provide other important ecosystem services, beside provision of hydrological ecosystem services. In some cases, enhanced provision of some ecosystem services may also lead to reduced capacity of watersheds to provide other services e.g. intensive cultivation to maximize food production may also lead to increase in soil erosion and consequently degradation of water quality.
Sediment yield is the amount at a point of interest in a particular period of time which occur due to heavy rainfall, are normally as tones per year or kilogram per year.
A large part of failure to achieve reasonable estimates of average annual sediment lies in particles of extrapolating relationship derived from field data with no consideration of appropriateness for future conditions.
Sediment yield is affected by many factors such as climate, soil, relief, vegetation and human influence. Runoff refers to as the part of water cycle that flow over land as surface water.
Runoff has been used as a variable representing climatic conditions and includes not only the water that travel over the land surface and through channels to reach a stream but also interflow, the water that infiltrates the soil surface and travels by means of gravity toward a stream channel.
     In this study offa water shed is simulated to predict the surface runoff and sediment yield. The spatial and temporal variation obtained can be used as a decision support tool in the management of the water shed.
