Anthropogenic drivers such as urbanization and economic dependence have been a major force shaping various landscapes. Zaria town is no exception of such landscapes. This study is aimed at an assessment of the impact of the growth of Zaria town on the vegetation covers of the surrounding region. The objectives were to map out and analyse the land use and land cover of the area, derive the vegetation cover index (NDVI) from the multitemporal data set, correlate the city expansion rate with the vegetation cover index, and assess the current status of woody biodiversity in the study area. The study area is within

20km radius around Zaria. The first part of the study employed remote sensing and Geographic Information System techniques to analyze the general land use/land cover of the area using four data sets: Land sat MSS (1973), Land sat TM (1990), Land sat ETM (1999) and NigeriaSat -1 (2009). The results of the land use/land cover analysis showed that the built-up area expanded from 44km2 in 1973 through 69km2 in 1990 and 81km2

in 1999 to 130km2 in 2009. The cultivated land also showed a general increase trend over time

from 409km2 in 1973 to 433km2 in 2009. While the forested land showed a decrease, from

89km2 in 1973 to 63km2 in 2009. Using the NDVI results, it was found out that ‘Dense

vegetation’ (NDVI classification value of 0.51 to 0.96) decreased from 206 km2

in 1973 to

mere 37 km2

in 1990. It subsequently increased to 88 km2

in 1999 then to 134 km2

in 2009.

On the other hand, the ‘No vegetation’ (NDVI classification value of -0.95 to 0.00) steadily

increased from 1,168 km2

in 1973 to 1,736 km2

in 2009. The second part of the study

involved field survey to determine the physiognomic characteristic of tree species in the

study area. Overall, 161 tree stands belonging to 23 species were enumerated over the 25

(50 by 50 m) sample plots covered in the study. The dominant species found among others

species are Khaya senegalensis (45 trees). This was followed by Mangifera indica (26

trees), Azadirachta indica, (17 trees) and Adansonia digitata, (14 trees). When the

differences in the number of trees amongst the various land uses were subjected to analysis

of variance, the results showed highly significant value at greater than 0.05 level. It was

also noted from the field survey that, the plantation/ forest area recorded the highest

average tree stand of 23.5. This was followed by the fadama/wetlands with an average of 8

tree stand. The built-up area has an average of 7 tree stand and the cultivated lands 5. The

scrubland has the least average of 1.6 tree stand. With respect to the other vegetation

characteristics, the built-up areas, plantation/forest and the fadama/wetland have

comparatively higher mean values for tree height, DBH, biomass and basal area. The result

of ANOVA shows that the differences in most of the measured parameters of the woody

species amongst the land uses are statistically significant at 0.05 level. It was concluded

that the expansion of Zaria town posed a formidable threat to biodiversity in the region and

strategies to improve forest conservation in the region are urgently needed. 

TABLE OF CONTENT

Title

Page- - - - - - - - - - - - - - - - - - - - - - - - - - .- - - - ..- - i

Declaration - - - - - - - - - - - - - - - - - - - - - - - - .- - - ..- - - ii

Certification - - - - - - - - - - - - - - - - - - - - - - - - .- - - - - iii

Dedication - - - - - - - - - - - - - - - - - - - - - - ..- - .- - ..- - - .iv

Acknowledgement - - - - - - - - - - - - - - - - - - - - - - .- - - - - v

Abstract - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ..vii

Table of Contents- - - - - - - - - - - - - .- - - - - - - - - - - - - - - viii

List of Figures- - - - - - - - - - - - - - - - - - - - - - - - - - - - - xii

List of Tables - - - - - - - - - - - - - .- - - - - - - - - - - - - - - - .xiv

List of Plates- - - - - - - - - - - - - - - - - - - - - - - - .- - - - - - xv

List of Appendices- - - - - - - - - - - - - - - - - - - - - .- - - - - - xvi

Abbreviations - - - - - - - - - - - - - - - - - - - - - - .- - - - - - ..xvii

CHAPTER ONE: INTRODUCTION

1.1 Background- - - - - - - - - - - - - - - - - - - - - - - - - - - - .- 1

1.2 Statement of the research problem- - - .- - - - - - - ..- - - - - - - ..- - .3

1.3 Research Questions- - - - - - - - .- - - - - - - - - - - - - - - - - .7

1.4 Aim and Objectives of the study- - - - - - - - - - - - .- - - - - - - - - 7

1.5 Research Hypotheses- - - - - - - - - - - - - - - - - .- - - - - - - - .8

1.6 Delimitation and scope of the study- - - - - - - - - - - - .- - - - - - - ..8

1.7 Justification of the study- - - - - - - - - - - - - - - - - - - - - .- - - 9

CHAPTER TWO: LITERATURE REVIEW

2.1 Urbanization and Environmental Changes- - - - - - - - - - ..- - - - - - .10

2.2 Urbanization Challenges in Nigeria - - - - - - - - - - - - - - - - - - - 16

2.3 Remote Sensing and GIS Application in Urban Studies in Nigeria- .- - - - - - 19

2.4 Urbanization and Biodiversity Loss - - - - - - - - - - - - .- - - - - - - 21

2.5 Summary of Review - - - - - - - - - - - - - - - - - - - - - - - - - 25

CHAPTER THREE: ENVIRONMENT OF THE STUDY AREA

3.1 Location of the Study Area- - - - - - - - - - - - - - - ..- - - - - - - 26

3.2 Climate- - - - - - - - - - - - - - - - - - - - - - - .- - - - - - - 27

3.2.1 Rainfall- - - - - - - - - - - - - - - - - - - - - - .- - - - - - - .27

3.2.2 Temperature- - - - - - - - - - - - - - - - - - - - .- - - - - - - .27

3.3 Geology - - - - - - - - - - - - - - - - - .- - - - - ..- - - - - - - 28

3.4 Landforms- - - - - - - - - - - - - - - - - - - - - - - - - - - - - .30

3.5 Relief and Geomorphology- - - - - - - - - - - - - - - - - - - - - .- .31

3.6 Drainage - - - - - - - - - - - - - - - - - - - - - - - - - - - - ..- 33

3.7 Soils- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ..- 34

3.7.1 Fadama soils- - - - - - - - - - - - - - - - - - - - - - - - - - - ..35

3.7.2 Weakly developed soils - - - - - - - - - - - - - - - - .- - - - - - - 35

3.8 Vegetation- - - - - - - - - - - - - - - - - - - - - - .- - - - - - - 36

3.9 Land use and Economy- - - - - - - - - - - - - - - - - .- - - - ..- - .41

3.10 Population and Settlement- - - - - - - - - - - - - - - - .- - - - - .- 42

CHAPTER FOUR: MATERIALS AND METHODS

4.1 Data Required and Sources- - - - - - - - - - - - - - - - - - - - - - ..44

4.2 Research Design and Methodology- - - - - - - - - - - - - - - - - - - ..45

4.2.1 Reconnaissance survey - - - - - - - - - - - .- - - - - - - - - - - - 47

4.2.2 Land use/ land cover analysis- - - - - - - - - - ..- - - - - - - - - - - .47

4.2.3 Ground truthing and detailed field survey- - - - - - - - - - - - - - .- - 52

4.3 Data Analysis- - - - - - - - - - - - - - - - - - - - - - ..- - - - .- 56

CHAPTER FIVE: RESULTS AND DISCUSSION

5.1 Land use/land cover change- - - - - - - - - - - - - - - - - - - - .- - 58

5.1.1 The spatial temporal variation of area of coverage of different land uses- - - .- 61

5.1.2 Description of net change- - - - - - - - - - - - - - - - - - - - - ..- 67

5.2 Normalized Difference vegetation index- - - - - - - - - - - - - - - - .- 73

5.2.1 Variation of area coverage of the NDVI- - - - - - - - - - - - - - - ..- - 76

5.2.2 Correlation of different land uses, population figures and NDVI- .- - - - - .- 83

5.3 The characteristics of the tree stand over different land uses- - - ..- - - - - - 85

5.3.1 Species diversity- - - - - - - - - - - - - - - - - - - - - - - - - - 87

5.3.2 Tree Density- - - - - - - - - - - - - - - - - - - - - - - - - .- .- 90

5.3.3 Other physiognomic features- - - - - - - - - - - - - - - - - - - - - 91

5.4 Discussion - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 92

5.4.1 Land use/land cover change- - - - - - - - - - - - - - - - .- - - .- - 92

CHAPTER SIX: SUMMARY AND CONCLUSION

6.1 Summary of findings- - - - - - - - - - - - - - - - - - - - - - - - - 98

6.2 Conclusion- - - - - - - - - - - - - - - - - - - - - - - - - - - - - 99

6.3 Recommendations- - - - - - - - - - - - - - - - - - - - - .- - - - .100

REFERENCES - - - - - - - - - - - - - - - - - - - - - - - - - - - ..104

APPENDICES- - - - - - - .- - - - - - - - - - - - - - - - ..- - - .- 116