A COMPARATIVE STUDY OF LANDSLIDES AND GEOHAZARD ...

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9.2.2.7 Engineering Structures to Reduce Damage 198 9.2.2.8 Proper Designing of Roads and Drainage 198 9.2.2.9 Integration of Indigenous Knowledge in the Education Curriculum 198 9.2.2.10 Monitoring of Landslide Occurrences 198 CHAPTER TEN: CONCLUSIONS AND SUGGESTED AREAS FOR FURTHETR STUDY 200 10.1 Conclusions 200 10.2 Suggested Areas for Further Study 205 10.3 Limitations of the Study 206 REFERENCES 208 APPENDICES 230 xx
LIST OF FIGURES Figure 2.1a : The Physiography of the country 9 Figure 2.1b : Map of Malawi showing Ntcheu and Rumphi Districts 10 Figure 2.2 : Erosion Surfaces of Malawi 13 Figure 2.3 : The Geology of Malawi 15 Figure 2.4 : Land use and land cover of Malawi 17 Figure 2.5 : Location of the Ntchenachena and the Chiweta Study Areas of Rumphi District in Northern Malawi 21 Figure 2.6 : Part of the Ntchenachena Area with interlocking Spurs and funnel-like valleys: Note the landslide scars 23 Figure 2.7 : Deep Ferrisols of the Ntchenachena Area in Rumphi District which are prone to liquefaction 24 Figure 2.8 : Ferrisols of the Ntchenachena Area with quartz floats which affect the shear strength of the soil. Note the Formation of gullies 24 Figure 2.9 : Afro-Montane Vegetation of the Ntchenachena. Grass and Shrubs are dominant which do not provide maximum mechanical binding to the deep ferrisols 26 Figure 2.10 : Tobacco Curing Shed in the Ntchenachena Area, contributing to deforestation. Note the location of Shed is on a remodeled slope affecting the balance Of forces 27 Figure 2.11 : Pit Sawing in the Ntchenachena Area, contributing to deforestation and slope instability 28 Figure 2.12 : The geology of the Chiweta Area, showing the stratigraphy of the beds 30 Figure 2.13 : Miombo woodlands typical of the Chiweta, Mvai and Livilivi Areas, contributing to slope stability through mechanical binding of particles 32 Figure 2.14 : The Ntcheu District, showing the Mvai and Livilivi Study Areas 34 Figure 2.15 : Rock outcrop (gneisses) within the Mvai/Livilivi Catchments. Rockfalls have been reported this area. Note the Miombo woodlands in the foreground which arrest some falling boulders 35 Figure 6.1 : Recorded landslides for each study area 93 Figure 6.2 : Landslides occurrences for each district 93 Figure 6.3 : Mapped Landslides in the Ntchenachena Study Area 94 Figure 6.4 : Mapped Landslides in the Chiweta Study Area 95 Figure 6.5 : Mapped Landslides in the Mvai/Livilivi Catchments 96 Figure 6.6 : Curved surface rupturing, common in the Livilivi and Ntchenachena Areas. Photo taken at Livilivi, Ntcheu District 97 Figure 6.7 : Landslide classification based on mass movement 98 Figure 6.8 : The remains of the Phoka Bridge at the confluence of the Mzinga and North Rumphi Rivers after the 2003 Landslides in the Ntchenachena Area 101 xxi
Page 1 and 2: A COMPARATIVE STUDY OF LANDSLIDES A
Page 3 and 4: DECLARATION I declare that this the
Page 5 and 6: It was found that 131 landslides ha
Page 7 and 8: OPSOMMING In 2003 het ‘n aantal g
Page 9 and 10: verminder, gemeenskapsdeelname in n
Page 11 and 12: ACKNOWLEDGEMENTS I would like to ex
Page 13 and 14: us all that determination and commi
Page 15 and 16: 2.2.2.5 Climate 31 2.2.2.6 Vegetati
Page 17 and 18: 5.10.1.3 Crown Width 78 5.10.1.4 Ve
Page 19: 8.5 Cross Tabulation of Perceived C
Page 23 and 24: Ntchenachena Area by goats, contrib
Page 25 and 26: Table 8.10 : Repetition of Landslid
Page 27 and 28: 1.1 Background CHAPTER ONE INTRODUC
Page 29 and 30: these factors. It also aimed at est
Page 31 and 32: Msilimba and Holmes, 2005). Norther
Page 33 and 34: 1.7 Organisation of the Thesis This
Page 35 and 36: Figure 2.1a: The Physiography of th
Page 37 and 38: To these divisions, may be added th
Page 39 and 40: Figure 2.2: Erosion surfaces of Mal
Page 41 and 42: Figure 2.3: The Geology of Malawi.
Page 43 and 44: Figure 2.4: Land use and land cover
Page 45 and 46: seasonal maximum and minimum temper
Page 47 and 48: Figure 2.5: Location of the Ntchena
Page 49 and 50: Figure 2.6: Part of the Ntchenachen
Page 51 and 52: 2.2.1.5 Climate The temperatures on
Page 53 and 54: Figure 2.10: Tobacco curing shed in
Page 55 and 56: sequence includes beds of modular l
Page 57 and 58: 2.2.2.3 Topography The Chiweta Area
Page 59 and 60: 2.2.3 Mvai/Livilivi Catchment Areas
Page 61 and 62: 2.2.3.3 Geology The rocks of the ca
Page 63 and 64: CHAPTER THREE LANDSLIDES: CLASSIFIC
Page 65 and 66: 1982). Topples have been observed t
Page 67 and 68: 3.4 Classification of Slopes In slo
Page 69 and 70: angle and hence greater values of g
Page 71 and 72:
3.6.5 Implications of Joints and Ro
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movement (Crozier, 1984). Preparato
Page 75 and 76:
containing a high percentage of cla
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largest landslides occur most frequ
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Mshali, 1989; Gondwe and Govati, 19
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avalanche Abefan, Wales 21/9/1966 F
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environmental problems (Taun, 1974)
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Malawi, emphasise only the causes.
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short of the identification and con
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Ingaga et al., 2001; Msilimba, 2002
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CHAPTER FOUR LANDSLIDES INVENTORY I
Page 93 and 94:
4.2 Analysis of the Previous Studie
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4.4 Proposed Mitigation Measures fr
Page 97 and 98:
CHAPTER FIVE METHODOLOGY The curren
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Ground reference data was acquired
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density of drainage network, and th
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weathered. Samples were collected f
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5.11 Soil Analyses Soil samples wer
Page 107 and 108:
5.11.1.4 Determination of Bulk Dens
Page 109 and 110:
5.11.1.8 Determination of Liquid Li
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The questionnaire was coded for eas
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and impacts of landslides and seeki
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CHAPTER SIX LANDSLIDE DISTRIBUTION,
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Ntcheu Livilivi Chiweta Lutowo 8c 2
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distribution was evenly among SE (3
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Figure 6.4: Mapped landslides in th
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6.3 Classification of the Mapped La
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Table 6.2: Landslides Classificatio
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Table 6.4: The Determination of the
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6.6 Discussion of the Landslides Ma
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Catchment where the rocks hang loos
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and the 1991 Phalombe landslides (G
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In Ntcheu District, the Livilivi/Mv
Page 137 and 138:
Figure 6.12: Position where landsli
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CHAPTER SEVEN ANALYSIS OF THE LANDS
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constructed, in the Ntchenachena Ar
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Chiweta Livilivi Mvai 3 53.29± 10.
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was confirmed by ANOVA test (p=0.00
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Table 7.9: Results of the Analysis
Page 149 and 150:
Table 7.11: Medium/Fine Sand Test R
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Mvai 55.8±6. 41 1 69.2±9. 34 67.8
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Rainfall (mm) 200 150 100 50 0 Dail
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The landslides of the Ntchenachena
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customary land tenure. Most of the
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Hoek’s critical angle for sliding
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esistance for these soils was proba
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acting as a lubricant (Crozier, 198
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cover of grasses and shrubs, record
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with major structural rock weakness
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disturbance caused by deforestation
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Figures 7.14 and 7.15). This has pa
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Figure 7.16: Highly weathered Chiwe
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CHAPTER EIGHT TRADITIONAL KNOWLEDGE
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majority of the respondents had att
Page 179 and 180:
Table 8.3: Types of Housing Distric
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Table 8.6: Knowledge of Past Landsl
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Table 8.9: Weather Conditions Befor
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Table 8.11: Level of Education and
Page 187 and 188:
Table 8.13B: Age of Respondents and
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with tertiary education were observ
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construction during the rainy seaso
Page 193 and 194:
Figure 8.3: Degraded agricultural l
Page 195 and 196:
out an assessment of the damage. La
Page 197 and 198:
2005). The results from these studi
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Table 8.23: Responsibility for Slop
Page 201 and 202:
This study, therefore, realises tha
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wanted the NGOs/Government to rehab
Page 205 and 206:
difficult and also reduces the area
Page 207 and 208:
8.17.1.4 Government Policy The majo
Page 209 and 210:
noise from drums. These spirits are
Page 211 and 212:
CHAPTER NINE ANALYSIS OF LANDSLIDE
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true for the entire East Africa reg
Page 215 and 216:
This explains why the majority of l
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damage from landslides. In areas wh
Page 219 and 220:
embankments may result in a build u
Page 221 and 222:
continued destruction of the vegeta
Page 223 and 224:
Furthermore, future research should
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esults have been encouraging (Mikke
Page 227 and 228:
landslides. Gender perceptions towa
Page 229 and 230:
The destruction of vegetation in al
Page 231 and 232:
stabilisation can also be achieved
Page 233 and 234:
knowledge on landslides in Malawi a
Page 235 and 236:
Badshah, A.: 1994, The Mega-Cities;
Page 237 and 238:
Briggs, J. Badri, M. and Mekki, M.:
Page 239 and 240:
Cooke, R.U and Doornkamp, J.C.: 199
Page 241 and 242:
Fairhead, J. and Scoones, I.: 2005,
Page 243 and 244:
Harlford, S. and Leonard, P.: 2001,
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Jibson, R.W. and Keefer, D.K.: 1968
Page 247 and 248:
Ludman, A. and Koch, N.I.: 1982, Ph
Page 249 and 250:
Mwafongo, K.W.M.: 1996, Rural Devel
Page 251 and 252:
Pitty, A.F.: 1984, Geography and So
Page 253 and 254:
Tsukamoto, Y. and Kusakabe, O.: 198
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Yamamuro, J.A and Lade, P.V.: 1998,
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v = volume of slope material involv
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APPENDIX 3: HOUSEHOLD QUESTIONNAIRE
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5. Are you employed? Yes (proceed t
Page 263 and 264:
15. What are the traditional belief
Page 265 and 266:
26. Which crops were affected by th
Page 267 and 268:
36. What was the most important for
Page 269 and 270:
APPENDIX 4: DISTRICT COMMISSIONERS,
Page 271 and 272:
13 How long does it take for inform
Page 273 and 274:
6. How far have you gone with lands
Page 275 and 276:
APPENDIX 6: MULTIPLE COMPARISON TES
Page 277 and 278:
Page 279 and 280:
Page 281 and 282:
APPENDIX 9: TESTS FOR THE EQUALITY
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Hydraulic conductivity cm/hr (>100
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Litowo 8 Pit 9 0615288 8819034 1445
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Mvai 2 Pit 8 0675274 8355428 1379 M
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RAINFALL DATA FOR MVAI/LIVILIVI FRO
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PIT 3 LUT 3 0-100 69..80 34.31 35.4
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KASFOR PIT 1 KASFOR >100 43.06 30.9
Page 295 and 296:
PIT 4 CHIKWE 0-100 81.42 43.45 37.9
Page 297 and 298:
PIT 5 MVAI 1 0-100 51.99 36.07 15.9
Page 299 and 300:
NTCHEU FIELD DATA APPENDIX 15: RESU
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Mchenje 167 130 5.7 4.1 Shallow ro
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CHIWETA U1-11 Dsh (mm) Dbh (mm) H (
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AVERAGE 125 93 5.5 3.6 LITOWO 1a-3
Page 307 and 308:
LITOWO 7a-u Dsh (mm) Dbh (mm) Mnthu
Page 309:
Mnthunu 50 Chi 1l 0615438 8819106 1
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A COMPARATIVE STUDY OF LANDSLIDES AND GEOHAZARD ...

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