THE EFFECT OF LAND SCOPE ON SOIL LOSS FROM EROSION SITES (A CASE STUDY OF NEKEDE AND AKAOKWWA

THE EFFECT OF LAND SCOPE ON SOIL LOSS FROM EROSION SITES (A CASE STUDY OF NEKEDE AND AKAOKWWA ALL IN IMO STATE

LIST OF TABLES

Table 3.3.1 A Plastic Limit test - - - - 32

Table 3.3.1B: Plastic Limit Test - - - - 33

Table 3.3.2A Liquid Limit test - - - - 35

Table 3.3.2B Liquid Limit Test - - - - 36

Table 3.3.3A Grain Size Analysis - - - - 39

Table 3.3.3B Grain Size Analysis - - - - 40

Table 3.3.4 Moisture content of sample A and B 41

Table 3.3.5A Shear strength reading - - - 45

Table 3.3.5B Shear strength reading - - - 45

Table 3.4A A Rainfall stimulator calibration - 49

Table 3.4B Erosivity computation - - - 51

ABSTRACT

Soil loss is as a result of detachment and transportation of soil particles from one place to another due to rainfall. The rate of soil erosion has been of great concern to the government and people of Imo state as regards to farm land and environmental degradation. This work analyzed the soil samples collected from two erosion sites namely, nNkede and Akaokwa all in Imo State and the soil loss for the samples which is the mainstay of this project was determined using a rainfall simulator. It was observed that Nekede recorded the highest soil loss of 190.3g and Akaokwa with a soil loss of 178.0g both at 9% slope. In terms of steepness of slope, Nekede has the steepest slope of 1/253.3 which led to a greater volume of run off and resulted to the highest soil loss. Recommendations were made on how best to reduce soil loss in Imo state.

TABLE OF CONTENTS

Cover page - - - - - - - i

Title page - - - - - - - - ii

Approval page - - - - - - - - iii

Dedication - - - - - - - - iv

Acknowledgement - - - - - - - v

List of tables - - - - - - - - vi

Abstract - - - - - - - - - vii

Table of contents - - - - - - - viii

CHAPTER ONE

1.0 INTRODUCTION - - - - - - 1

1.1 Background of the Study - - - - 1

1.2 Specifically the Objectives of the study are - 5

1.3 Justification of the Study - - - - 5

CHAPTER TWO

2.0 LITERATURE REVIEW - - - - 7

2.1 Definition of Erosion - - - - - 7

2.2 Water Erosion - - - - - - - 11

2.3 Raindrop Erosion or Splash Process - - 12

2.4 Surface Flow Erosion Process - - - - 24

2.4.1Sheet Erosion - - - - - - 16

2.4.2Interill Erosion - - - - - 16

2.5 Gully Erosion - - - - - - - 17

2.6 Factors Affecting Soil Erosion - - - 18

2.6.1 Erodibility - - - - - - 19

2.6.2 Erosivity- - -- - - - - 21

2.6.3Topography - - - - - - 22

2.7 Soil conservation - - - - - - 22

2.8 Approaches to soil conservation - - - 24

2.9 Soil Stability - - - - - - - 25

CHAPTER THREE

3.0 MATERIALS AND METHODLOGY - - - 27

3.1 Area of study - - - - - - - 27

3.2 Materials Used - - - - - - 28

3.3 Soil Test - - - - - - - - 29

3.3.1 Plastic Limit - - - - - - 30

3.3.2 Liquid Limit - - - - - - 33

3.3.3 Grain Size Analysis - - - - - 36

3.3.4 Moisture Content - - - - - 40

3.3.5 Shear Strength- - - - - - 42

3.4 Soil Loss Determination - - - - - 47

CHAPTER FOUR

4.0 RESULTS AND DISCUSSION - - - - 56

4.1 Results - - - - - - - - 56

4.2 Discussion - - - - - - - 56

4.2.1Erodibility Determination - - - 58

4.2.2Precipitation - - - - - - 61

4.2.3Relating Slope To Erosion - - - - 62

CHAPTER FIVE

5.0 CONCLUSION AND RECOMMENDATION - 63

5.1 Conclusion