title: Runoff, infiltration and soil erodibility studies in the Otutira catchment

authors: Selby, Michael J.

abstract: Yellow-brown pumice soils cover a large area of the central North Island of New Zealand. In the Waikato River basin these soils occupy over 7,000km². Since land development started in the mid-1930s approximately 4,000km² have been converted from the native vegetation to exotic forests (1,243km²) and pasture (2,740km²), and a further 500km² could be developed.

Since about 1959 gully erosion has become more common and widespread. The causes of this erosion were not known, although many hypotheses attempting to account for erosion have been put forward. The research reported in this thesis was undertaken in an attempt to isolate the most important causes of erosion.

Three experiments have been completed.
(1) A study of runoff from plots placed in areas of pasture grass, ungrazed grass and scrub vegetation has been made. Climatic, soil, vegetation, and slope variables were studied and as a result of statistical analysis it is concluded that surface water runoff is greater from developed land in pasture and less from areas covered by scrub and ungrazed grass vegetation. The major causes of runoff from pastures are very intense rainfall on a soil with low moisture content.

(2) Infiltration studies with an infiltrometer, designed and built for the purpose, reinforce the conclusions drawn from runoff studies. They also show that modifications of soil properties, especially compaction caused by animals and vehicles, decrease infiltration and hence promote runoff.

(3) Flume studies of the erodibility of pumice soils indicate that soil particles are easily entrained by running water, but that plant roots inhibit this process. Analysis of data from the three experiments indicates that land development should be carried out so that: (a) a close vegetation cover is kept on all soils; (b) channel development is avoided; (c) vulnerable areas such as valley floors and steep valley sides are kept as water absorption areas; (d) animals and vehicles are excluded from water absorption areas to prevent soil compaction; (e) plants with strong and dense root systems are used to protect surface soils.

text: Runoff, infiltration and soil erodibility studies in the Otutira catchment Yellow-brown pumice soils cover a large area of the central North Island of New Zealand. In the Waikato River basin these soils occupy over 7,000km². Since land development started in the mid-1930s approximately 4,000km² have been converted from the native vegetation to exotic forests (1,243km²) and pasture (2,740km²), and a further 500km² could be developed.

Since about 1959 gully erosion has become more common and widespread. The causes of this erosion were not known, although many hypotheses attempting to account for erosion have been put forward. The research reported in this thesis was undertaken in an attempt to isolate the most important causes of erosion.

Three experiments have been completed.
(1) A study of runoff from plots placed in areas of pasture grass, ungrazed grass and scrub vegetation has been made. Climatic, soil, vegetation, and slope variables were studied and as a result of statistical analysis it is concluded that surface water runoff is greater from developed land in pasture and less from areas covered by scrub and ungrazed grass vegetation. The major causes of runoff from pastures are very intense rainfall on a soil with low moisture content.

(2) Infiltration studies with an infiltrometer, designed and built for the purpose, reinforce the conclusions drawn from runoff studies. They also show that modifications of soil properties, especially compaction caused by animals and vehicles, decrease infiltration and hence promote runoff.

(3) Flume studies of the erodibility of pumice soils indicate that soil particles are easily entrained by running water, but that plant roots inhibit this process. Analysis of data from the three experiments indicates that land development should be carried out so that: (a) a close vegetation cover is kept on all soils; (b) channel development is avoided; (c) vulnerable areas such as valley floors and steep valley sides are kept as water absorption areas; (d) animals and vehicles are excluded from water absorption areas to prevent soil compaction; (e) plants with strong and dense root systems are used to protect surface soils.

year: 1971

title: Road User Interactions: Patterns of Road Use and Perception of Driving Risk

authors: Charlton, Samuel G.

subjects: driving

abstract: The goal of the Road User Interactions research programme is a better understanding of the human factors of our road transport system: road user demographics, risk perceptions of road users, and the driving attitudes of various road user groups. Our analysis of the 1989 and 1999 New Zealand Household Travel Surveys identified several fundamental road user differences and consistent demographic trends over the past 10 years. The driver characteristics of gender, age, and area of residence (urban, secondary urban, and rural) are the demographic factors which most clearly differentiate New Zealand road user groups. Analysis of the patterns of road use suggests that, although these road user groups do drive at distinctly different times, there are periods of conflict which are also associated with the greatest crash risk for these drivers. Our analysis of a sample of road user groups in Hamilton, Auckland, Gisborne, New Plymouth, and Palmerston North found significant differences in their perceptions of risk and driving behaviours. Rural drivers and women drivers rated a range of driving situations as having greater risk than did the other road user groups, and they rated the high risk scenarios as being much riskier. Men indicated the greatest willingness to accept the risk in driving situations and rated their own driving skill as higher. Older drivers also rated driving situations as having higher risk, and young drivers generally rated low risk situations much lower than other drivers. In the survey of driving behaviour, young men in our sample reported very high levels of violations and aggressive violations. The male drivers’ rates of violations and aggressive violations were significantly higher than the women drivers’ and the number of both decreased significantly with age. Finally, inspection of crash data show that young drivers’ and older drivers’ crashes have some characteristics in common; both groups have a disproportionate number of crossing, turning, and manoeuvring crashes at intersections in the mid-afternoon.

text: Road User Interactions: Patterns of Road Use and Perception of Driving Risk The goal of the Road User Interactions research programme is a better understanding of the human factors of our road transport system: road user demographics, risk perceptions of road users, and the driving attitudes of various road user groups. Our analysis of the 1989 and 1999 New Zealand Household Travel Surveys identified several fundamental road user differences and consistent demographic trends over the past 10 years. The driver characteristics of gender, age, and area of residence (urban, secondary urban, and rural) are the demographic factors which most clearly differentiate New Zealand road user groups. Analysis of the patterns of road use suggests that, although these road user groups do drive at distinctly different times, there are periods of conflict which are also associated with the greatest crash risk for these drivers. Our analysis of a sample of road user groups in Hamilton, Auckland, Gisborne, New Plymouth, and Palmerston North found significant differences in their perceptions of risk and driving behaviours. Rural drivers and women drivers rated a range of driving situations as having greater risk than did the other road user groups, and they rated the high risk scenarios as being much riskier. Men indicated the greatest willingness to accept the risk in driving situations and rated their own driving skill as higher. Older drivers also rated driving situations as having higher risk, and young drivers generally rated low risk situations much lower than other drivers. In the survey of driving behaviour, young men in our sample reported very high levels of violations and aggressive violations. The male drivers’ rates of violations and aggressive violations were significantly higher than the women drivers’ and the number of both decreased significantly with age. Finally, inspection of crash data show that young drivers’ and older drivers’ crashes have some characteristics in common; both groups have a disproportionate number of crossing, turning, and manoeuvring crashes at intersections in the mid-afternoon.

year: 2002

title: Maori and psychology: Indigenous psychology in New Zealand

authors: Nikora, Linda Waimarie

subjects: Maori

abstract: Maori have their own approaches to health and well-being, which stem from a world view that values balance, continuity, unity and purpose. The world view is not typically thought of as 'psychology', yet it is a foundation for shared understandings and intelligible action among Maori. Maori behaviours, values, ways of doing things and understandings are often not visible nor valued. However, through these opening years of the twenty-first century, psychologists are slowly turning their attention to addressing this invisibility with the explicit agenda of building 'indigenous psychologies'

text: Maori and psychology: Indigenous psychology in New Zealand Maori have their own approaches to health and well-being, which stem from a world view that values balance, continuity, unity and purpose. The world view is not typically thought of as 'psychology', yet it is a foundation for shared understandings and intelligible action among Maori. Maori behaviours, values, ways of doing things and understandings are often not visible nor valued. However, through these opening years of the twenty-first century, psychologists are slowly turning their attention to addressing this invisibility with the explicit agenda of building 'indigenous psychologies'

year: 2007