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THE DISTRIBUTION AND PROPERTIES OF SOILS I N RELATION TO EROS ION I N A SELECTED CATCHMENT OF THE SOUTHERN RUAHI NE RANGE , NORTH I S LAND , NEW ZEALAND
A thes is presented in par t ial fulf ilment o f the requirements f o r the degree of Haster o f Philosophy in Soil Sc ienc e
at Ma ssey University
Caro lyn Hubbard
1 9 7 8
FRONTISPIECE
A view o f the south-eastern fault -controlled f ront o f
the Ruahine Ran ge . Car Park Creek, a subcatchment o f
the West Tamaki River , is seen in the c entre o f photo .
In t he foreground , f er t ile floodplain s are seen . These
are t hreatened by the inunda t ion of ero sion produc t s
which are carri ed out of the mountainland by the r ivers ,
during s torm p e r iods.
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ABSTRACT
The soils o f a selected subca tchment of the Southern Ruahine Range have
been mapped a t a scale of 1 :5 , 000 .The soil mapping un its have been further charac t erised by measuremen t of a number o f soil physical and chemical
proper t i es , together with an invest igation of their sand and c lay minera 1- ogies .
The erosion history since 20 , 000 yrs B . P . when the Aokautere Ash wa s depo s i t ed in t he Wes t Tamaki River catchment, has been part ial ly recons truc ted
for this ca tchment . I t i s one o f erosive periods and resu l t ing aggrada tionalgrav e l deposi t s , al ternating with more s tabl e periods with soil development and vegetation growth. S tudies of a histoso 1 (organ ic so i l ) on the sum
fuit pla teau o f the Southern Ruahine Range , a t the head o f the catchment . suggest s tha t t his soil i s approxima tely 4 600 years o l d , and prio r to this t ime the summ i t pla teau wa s stripped by eros ion .
Present ero sion occurs predominan tly : ( 1 ) on c onvex creep slopes, j ust
below the summit plateau , and ( 2 ) on the steep va l l ey-sides. In the former zone, where Takapari hil l soils exis t , deep�sea ted creep and mass movements occur .
'In t he latter zone , where Ruahine steep1and so i l s exist, superfic ia lso il and rock s l ips are more common .
An inves t igation of the soil-wa ter relationships for each so il mapping uni t ind icat�that a number of factors render the Takapa r i hill soils and
Ruahine s teep1and soils par t icularly suscep tible to eros ion . A compa risonof soil proper t i es which a f fec t the e rosion susceptibil it ies of each soil mapping unit has enabled an ordering of the units with r espec t to ero sion r isk . Thu s , areas of high , medium and low risk to eros ion in the West
Tamaki River c a tchment have been del inea ted . Many o f the deep-s eated ero sion sur faces occur in t he high r i sk area . Thus , if stabil isation of these
s i t e s is pos s ib l e , by intens ive revegeta tion programmes , the resul t wil l
be a decrea s e in the amount o f gravels carr ied out of the mountain 1and by
rivers onto the surrounding fert ile floodplains .
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ii . ACKNOWLEDGE MENTS
My cour se of s tudy in New Zealand has been both benefic ial and
enj oyabl e .
I would like to express my s inc ere apprec ia tion to the following , who have helped to make it this way :
Drs . V. E . Nea l l and J . A . P ollok f or supervision of my study , and f or many plea surable times together .
.
Drs . D . Sc otter and J . H . Kirkman , Messrs D . G . Bowler and R . B . S tewart f or their a s s istanc e in vari ous parts of the study .
P r of e s so r J . K . Syers and many other member s of the Departmen t for help and fr iendship thr oughou t my course .
Mike Marden , my colleague , Keith McAuliffe and Mike Hedley f or accom
panying me in the field .
Messrs Rob Blakely , Dick Mar tin and Col in Hichie (Manawatu Ca tchment B oard) and Mr Peter S tephens (Min i s try of Works and Devel opment) for helping to acqua int me wi th the Ruahine situa tion. In particular , I would l ike to thank Mr Rob Blakely for arranging several rec onnaissanc e trips , and for many s timula ting d iscus s i ons .
Ro tary Interna ti onal , f or their generous f inanc ia l a s s i s tanc e ; wi thout whom I w ould have been unable to embark on this c ourse .
N. Z . Forest S ervice f or funding my sec ond year of s tudy; and especially to Mr A . Cunningham , f or his in terest and assistance throughou t the s tudy .
Judy f or speedy and skilful typing of the text;
and , f ina l l y , my family f or their unend ing supp ort.
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FRONTISPIECE ABSTRACT . .
ACKNOWLEDGEMENTS TABLE OF CONTENTS LIST OF F IGURES LIST OF TABLES .
INTRODUCTION
1 :1 Reasons for Study 1 . 2 Objectives of Study 1. 3 Choice of Study Area 1 . 4 Methodology of Study
TABLE OF CONTENTS
CHAPTER I
CHAPTER 2
LITERATURE REVIEH ON THE SOILS AND EROSION SITUATION OF THE SOUTHERN RUAHINE RANGE
2 . 1 Introduction
2 . 2
Landscape Evolution in the Southern Ruahine Range, Through Geological Time .2 . 2 . 1 Genesis of the Mountain Range
2 . 2 . 2 Landscape Evolution, during Plio-Pleistocene
times
2 . 2 .3
Post-glacial Climatic Changes2 . 3 Present Erosion Situation of the Southern Ruahine Range 2 . 3. 1 Erosion Situation
2 . 3 . 2 Erosion Types 2 . 3. 3 Causes of Erosion
2 . 3. 4
Future Control of Erosionj
iii
page i ii
iii viii xi
1 1 1 2 3
5
6 6
7 8 1 0 1 0 1 0 1 1 1 4
..
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2.4 Soils of the Southern Ruahine Range . . . . . 2.5 Soil Parameters, Relevant to Erosion Studies
2.5.1 Erosion Processes 2.5.2 Soil Mineralogy
2.5.3 Soil-Water Characteristics 2.5.4 Slope Stability Studies 2.6 Summary . . . .
CHAPTER 3
DESCRIPTION OF THE STUDY AREA 3.1 Location
3.2 Physiography 3.3 Geology 3.4 Soils 3.5 Vegetation 3.6 Climate
3.7 Introduced Wildlife 3.8 Erosion . . . .
CHAPTER 4
H ISTORY OF EROSION IN THE WEST TAMAKI R IVER CATCHMENT 4.1 Introduction
4.2 Method of Study 4.3 Erosion History
4.3.1 Deposits of the Last Stadial (Ohakean Substage) 4.3.2 Tephrostratigraphy of the Takapari peaty loam, and
Erosion History of the Summit P lateau
4.3.3 Depositional Surfaces in the West Tamaki River Catchment
4.3.4 Aerial Photographs (194 6 -1978 )
page 16 19 19 20 2 2 2 5 27
30 30 36 3 8 4 0 4 2 4 6 4 8
51 5 2 5 2
. . 54
5 9 6 8
iv
CHAPTER 5
A PEDOLOGICAL INVESTIGATION OF THE SOILS IN CAR PARK CREEK SUBCATCHMENT
5. 1 Introduction
5.2 Method of Approach
5.3 Soils (and Soils Legend)
5.3 . 1 The Ruahine steepland soils 5.3.2 The Takapari peaty loam 5.3.3 The Takapari hill soils 5.3.4 The Dannevirke soils 5.3.5 Recent soils
5.4 General Discussion
CHAPTER 6
AN INVESTIGATION OF SOIL PARAMETERS RELATED TO SOIL GENESIS AND ERODIBILITY
6. 1 Introduction
6.2 Soil Physical Properties
6.2. 1 Materials and Methods 6.2.1 . 1 Particle density 6.2 . 1 .2 Bulk density .
6.2. 1.3 Total Porosity and Macroporosity 6.2. 1 .4 Saturated Hydraulic Conductivity 6.2. 1 . 5 1 5 bar water retention (A . W . C . and
"drying effect") . . . 6 . 2. 1 . 6 Loss of weight on ignition
6.2. 1.7 Soil pH in ( 1 ) water and ( 2 ) sodium flouride .
6.2 . 2 Results and Discussion
6.2.2. 1 Particle density and Bulk density
page
70 74 76 7 9 8 5 8 8 9 6 1 0 1 103
105 107 1 0 7 108 108 109 1 10
1 1 2 1 1 3
1 1 3 1 14 1 14
v .
6.2.2.2 Total Porosity and Macroporosity 6.2.2.3 Saturated Hydraulic Conductivity
6.2.2.4 Soil Water Retention and Available Water- Holding Capacity . .
6.2.2.5 15 bar Soil Water Retention, and the Effect of Drying
6.2.2.6 Loss of weight on ignition
vi . page
116 119
121
126 130 6.2.2.7 pH values in (1) water and (2) sodium flouride 130
6.3 Soil Mineralogy . 133
6.3.1 Sand Mineralogy 133
6.3.1.1 Haterials and Methods 133
6.3.1.2 Results and Discussion 134
6.3.2 Clay Mineralogy . . . 137
6.3.2.1 Introduction 137
6.3.2.2 Haterials and Hethods 138
6.3.2.3 Results and Discussion 141
,6.4 Conclusions . 1 5 7
CHAPTER 7
F INAL DISCUSSION OF RESULTS AND EROSION PROCESSES, WITH CONCLUSIONS . 163
Bibliography . . 182
Abbreviations (used in soil profile descriptions) 191 Appendix I : Classification of Landslides : Abbreviated Version
(Varnes, 1 9 58) 1 9 2
Appendix II : Soil Chronosequence i n the West Tamaki River Catchment -
profile descriptions 19 3
• Appendix III: Soil Map of Car Park Creek (in pocket
inside rear cover) .
Appendix IV: Nitrogen Mineralisation Data from a Laboratory
vii .
page
. . (pocket)
Experiment for the Takapari Peaty Loam . . . . 196 Appendix V: Phosphate Retention Values for the Dannevirke
Taxadjunct, and Dannevirke Hill Soils 197
F IGURE
LIST OF F IGURES
l. Kumeti Gravel Reserve
2. Locality Map of Study Area
3. Longitudinal Profiles of (a) Car Park Creek;
(b) West Tamaki River, (Mosley, 1 9 7 7).
4. An idealised diagram of the land surface units which occur on a valley-side in the West Tamaki River
page 15 2 9
31
ca tchmen t . . . 3 3 5 . Landsurface Units at the head of Car Park Creek 3 5
6. Landsurface Units of a Valley-side in Car Park Creek. 3 5 7. A rockslide, and deep terracette features on the
convex creep slope of Car Park Creek . . . . 3 7 8. Downcutting in Hut Creek, since Cyclone Alison of
March, 1 9 7 5 . . . . . . . . 41 9. Altitudinal Distribution of four vegetational species
in the Southern Ruahine Range, compared with their
distribution further north 3 9
10. The Kamahi forest in Car Park Creek 41 11. Gully erosion in Car Park Creek . 4 3 12. Vegetation on a Slope in Car Park Creek 4 3
13. Rainfall Map for the Tamaki River area 4 5 14. Illustrations and Field Description of the Aokautere
Ash, as it occurs in the West Tamaki River catchment. 5 3 15. Takapari Peaty Loam: Particle-size and Organic
matter percentages. Profile Description (b) . 16. Depositional Surfaces in the West Tamaki River
5 5
ca tchment . . . . . . . . 5 8 17. A reconstruction of events forming the Whiteywood
Creek fan . . . 60
18. Whiteywood Creek fan deposit 61
19. A soil profile developed on the Whiteywood Creek fan
deposit . . . . . . . . . . 61 20. Old terrace, in the West Tamaki River channel 6 3 21. A Soil Profile developed on the old terrace system 6 3
viii.
page 2 2. An extensive gravel terrace, formed during Cyclo ne
Alison. and a 98 year old fan deposit at
Stanfield Hut . . . 65 2 3. Recent soil, formed in a gravel deposit, at the mouth
of Car Park Creek . . . . 65 24. Isopach Map of a Recent Gravel surface, associated
with Car Park Creek and Dry Creek . . . . . . . 67 2 5 . Car Park Creek - a subcatchment of the West Tamaki
River . . . . 7 1
26 . Diagrammatic Cross-section to show the distribution of Soil classes, in relation to the land surface
units, within Car Park Creek 7 3
2 7. Ruahine steepland soil (RuS) 80
28. Takapari peaty loam (Tp) 86
2 9. Takapari hill soil (TpH) 8 9
30. Iron and Aluminium distribution in the soil profile
of a Takapari hill soil . . . 9 4
31 . Dannevirkp. taxadjunct ( D tax) 98
32. Dannevirke hill soil (DH) . . 9 9
33. Native earthworm, and native earthworm burrows 100 34 . A Histogram to show the bulk density values for each
Soil Class . . . . . . . ll5 35. Total Porosity and Macroporosity of Selected Soil
Samples . . . 1 1 7 36 . Saturated Hydraulic Conductivity Values for three
3 7 .
38 .
3 9 .
40 .
4 1 .
42.
Selected Soil Profiles . . . 1 20 Water Retention Characteristics of Selected Soil
Profiles . ·
The Relationship between A . W . C. and bulk density in selected soil samples . ·
The i\elationship between A . W . C . and organic matter in selected soil samples · . . . . The Relationship of Organic Matter to the Effect of Drying on 1 5 bar Water Retention Values. for
selected soil samples . . " . . . . . X-ray diffraction patterns of NH4 saturated clay + samples . . . . . . . . . . X-ray diffraction patterns of a Dannevirke taxadjunct soil profile, indicating the presence of a small amount of pedogenic chlorite . . . .
1 2 3
1 2 5
1 2 5
1 2 9
1 4 2
1 4 4 ix.
4 3. + +
page X-ray diffraction patterns of NH4 and K saturated clay samples from a Bw horizon of a Ruahine steepland soil 1 4 5 44. D.T . A . Curves of Selected Soil Clay Samples 1 4 7 4 5. Infra-red Spectra of Selected Soil Clay Samples 1 50 4 6. Electron Micrograph showing kaolinite and halloysite 1 5 3 47.
4 8.
4 9.
50.
51.
52 .
11 11 11
the 2 forms of halloysite
11 11 11
weathering volcanic glass
11 11 11
amorphous gel
11 11 11 11 and crystalline
1 5 3 1 5 3 1 54
material in a Ruahine steepland soil (RuVS) . . 1 54 Representative electron micrograph of a Ruahine
steepland soil CRuS) . . . 1 54 Electron Micrograph showing imogolite and unidentifed
laths . . . 1 54 5 3. Representative electron micrograph of D tax (Ah horizon) 1 5 5
54. " 11 " 11 11 (C 11 ) 1 5 5
5 5. " 11 11 11 the clay fraction
of Aokautere Ash . . . . 1 5 5
5 6. Representative electron micrograph of the clay fraction
of a greywacke pebble . . . 1 5 5
57. An illustration of the Possible Origin of Terracettes, Observed at the Head of Car Park Creek . . . . 1 6 7 58. Erosion Potential Map for the West Tamaki River
Catchment . . . 1 78
x.
LIST OF TABLES
TABLE 1. Erosion Phases in the Southern Ruahine Range (Grant,
page
1978) . . . . . . 9 2 . Soils of the Mountain Range, i n Pohangina County
(Rijkse, 1977) . . . 18
3. Factors Contributing to Mass Movement in soils (Selby,
1970) . . . 2 6 4. Classification of landsurface units, according to the
NLne Unit Landscape Model, of Conacher and Dalrymple
(1977) . . . . . . . . . . . 33 5. Percentage Eroded Area in Car Park Creek and No . 1
Creek, from 194 6-1978 . . . 68 6. Variation of Properties in the Ruahine Steepland Soils
xi .
Mapping Unit . . . . . . . . 83-84 7. Bulk density and Particle density values for selected
soil profiles of the study area . . . 115 8. Saturated Hydraulic Conductivity Data for Selected Soils. 120 9. Soil Water Retention Values, and Available-Water Holding
Capacity (A . W . C . ) of Selected Soil samples . . . 1 2 2 10. The Effect of Drying on 15 bar Water Retention Values
of Selected Soil samples . . . 127 11. Loss of Weight on Ignition Data for Selected Soil
samples 131
12. pH values in (1) water, and (2) sodium flouride 1 3 2 13. Sand Mineralogy of Selected Sand Fractions of Samples
from the Study Area . . . . . l 3 5 14. Results of Transmission Electron Microscopy: Visual
Identification of Mineral and Amorphous Materials . 1 5 2 15. Average Soil and Tree Rooting Depths of each Soil Mapping
Unit . . . . . . . . . • 171 16. Factors Affecting the Erosion Susceptibility of the Soils
in Car Park Creek subcatchment . . . 17 5
