Effect of development and cultivation on physical properties of peat soils in New Zealand

Geoderma ◽  
1992 ◽  
Vol 54 (1-4) ◽  
pp. 23-37 ◽  
Author(s):  
C.D.A. McLay ◽  
R.F. Allbrook ◽  
K. Thompson
Keyword(s):  
New Zealand ◽  
Physical Properties ◽  
Peat Soils

scholarly journals Assessing the Eutrophic Susceptibility of New Zealand Estuaries

2020 ◽  
Vol 43 (8) ◽  
pp. 2015-2033 ◽  
Author(s):  
David R. Plew ◽  
John R. Zeldis ◽  
Bruce D. Dudley ◽  
Amy L. Whitehead ◽  
Leigh M. Stevens ◽  
...  
Keyword(s):  
Land Use ◽  
New Zealand ◽  
Physical Properties ◽  
Nutrient Loading ◽  
Management Strategies ◽  
Nutrient Concentrations ◽  
Intertidal Area ◽  
Land Use Patterns ◽  
Regional Patterns ◽  
Nitrogen Concentrations

Abstract We developed a method to predict the susceptibility of New Zealand estuaries to eutrophication. This method predicts macroalgae and phytoplankton responses to potential nutrient concentrations and flushing times, obtained nationally from simple dilution models, a GIS land-use model and physical estuary properties. Macroalgal response was based on an empirically derived relationship between potential nitrogen concentrations and an established macroalgal index (EQR) and phytoplankton response using an analytical growth model. Intertidal area was used to determine which primary producer was likely to lead to eutrophic conditions within estuaries. We calculated the eutrophication susceptibility of 399 New Zealand estuaries and assigned them to susceptibility bands A (lowest expected impact) to D (highest expected impact). Twenty-seven percent of New Zealand estuaries have high or very high eutrophication susceptibilities (band C or D), mostly (63% of band C and D) due to macroalgae. The physical properties of estuaries strongly influence susceptibility to macroalgae or phytoplankton blooms, and estuaries with similar physical properties cluster spatially around New Zealand’s coasts. As a result, regional patterns in susceptibility are apparent due to a combination of estuary types and land use patterns. The few areas in New Zealand with consistently low estuary eutrophication susceptibilities are either undeveloped or have estuaries with short flushing times, low intertidal area and/or minimal tidal influx. Estuaries with conditions favourable for macroalgae are most at risk. Our approach provides estuary-integrated susceptibility scores likely to be of use as a regional or national screening tool to prioritise more in-depth estuary assessments, to evaluate likely responses to altered nutrient loading regimes and assist in developing management strategies for estuaries.

Physical properties of peat soils under different land use options

2016 ◽  
Vol 32 (3) ◽  
pp. 400-410 ◽  
Author(s):  
P. Mustamo ◽  
M. Hyvärinen ◽  
A.-K. Ronkanen ◽  
B. Kløve
Keyword(s):  
Land Use ◽  
Physical Properties ◽  
Peat Soils

Harmotome from the Tokatoka district, New Zealand

1969 ◽  
Vol 37 (288) ◽  
pp. 453-458 ◽  
Author(s):  
Philippa M. Black
Keyword(s):  
New Zealand ◽  
Chemical Composition ◽  
Physical Properties ◽  
Alkaline Solutions

SummaryHarmotome, associated with analcime, is described from andesite dykes at Rehia and Maungarahu in the Tokatoka district, New Zealand. The Maungarahu harmotome has the composition: (Na1·03K0·23)(Ba1·54Ca0·18)Al4·66Si11·31 12·39 H2O; physical properties: α 1·498, β 1·503, γ 1·506, 2Vγ 75–82° β:[001] 28° D 2·378; and cell constants: a 9· 906±0·006, b 14·119 ±0·003, c 8·712±0·007 Å, β 124° 57′ ± 3′. The harmotome is Ba-poor, and 2 Na+ has substituted for Ba2+ on a valency basis. Analcime associated with the Maungarahu harmotome has chemical composition: (Na15·16 K0·03Ca0·09)Al15·52Si32·47 15·93 H2O and physical properties: n = 1·483, D = 2·257, a = 13·708 Å. The zeolites are believed to have crystallized from Na and Ba-rich alkaline solutions at approximately 200°C The source of the Ba is baryte concretions in adjacent limestones.

Fate of urine nitrogen on mineral and peat soils in New Zealand

1996 ◽  
Vol 178 (1) ◽  
pp. 141-152 ◽  
Author(s):  
T. J. Clough ◽  
R. R. Sherlock ◽  
K. C. Cameron ◽  
S. F. Ledgard
Keyword(s):  
New Zealand ◽  
Peat Soils

Impact of development and cultivation on hydro-physical properties of tropical peat soils

Tropics ◽  
2006 ◽  
Vol 15 (4) ◽  
pp. 383-389 ◽  
Author(s):  
Ahmad KURNAIN ◽  
Tejoyuwono NOTOHADIKUSUMO ◽  
Bostaug RADJAGUKGUK
Keyword(s):  
Physical Properties ◽  
Peat Soils ◽  
Tropical Peat

Physical properties of titanomagnetite sands

Geophysics ◽  
1980 ◽  
Vol 45 (3) ◽  
pp. 394-402 ◽  
Author(s):  
D. C. Lawton ◽  
M. P. Hochstein
Keyword(s):  
Magnetic Susceptibility ◽  
New Zealand ◽  
Binary Mixture ◽  
Electric Field ◽  
Physical Properties ◽  
Magnetic Permeability ◽  
Induced Polarization ◽  
Laboratory Measurements ◽  
Relative Magnetic Permeability ◽  
Polarization Response

Laboratory measurements of density, magnetic susceptibility, remanence, resistivity, and induced‐polarization response of New Zealand titanomagnetite sands (“ironsands”) were made for different volume concentrations [Formula: see text] of titanomagnetite in the range 10 to 100 percent. Both density ρ and magnetic susceptibility κ of these sands increase monotonically with [Formula: see text]; the observed variation of κ as a function of [Formula: see text] can be explained by changes of the resultant relative magnetic permeability μ of a binary mixture of magnetic and nonmagnetic grains. The natural remanence of titanomagnetite sands is small (Koenigsberger ratio Q < 0.2). No significant induced‐polarization response could be observed even for mixtures of almost pure titanomagnetite. When placed in an electric field, the titanomagnetite sands were found to be nonconductive.

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