Clinton Rissmann

19 Questions 36 Answers 0 Followers

Questions related from Clinton Rissmann

Does the biodegradability of fatty acids vary by plant species?

Some research has suggested that compound specific fatty acids may be used as tracers of soil erosion. My question is whether or not different plant species generate fatty acids with different...

22 March 2023 881 4 View

Are there published examples of aquifer denitrification capacity being overwhelmed?

Hi All, I wondered if anyone knows of published examples of the denitrification capacity (e.g., weakly reducing aquifers) of an aquifer being overwhelmed? I thought that weakly buffered (e.g.,...

08 September 2022 3,211 2 View

Are there any studies assessing the geological diversity between countries?

I'm interested to know if there have been any quantitative or semi-quantitative studies of geological diversity (complexity) between different countries? For example, New Zealand, Japan, Taiwan...

07 November 2021 9,483 2 View

What plotting software allows direct selection of data points from a graph?

I have been using Aabel (Gigawhiz) plotting and statistical software. However, it is Mac OS centric and cannot be installed on a PC. I like this software because it enables me to directly select a...

20 June 2020 3,560 4 View

What is the best method for unsupervised classification of large and multidimensional raster data sets?

We are attempting to generate a landscape classification of a large area using remote sensing data with a 20 x 20 m cell size and an area of 200,000 km2. We have 8 different rasters and want to...

13 February 2020 4,576 4 View

Hierarchical clustering of multiple raster images - is there an R script?

I'm working with a significant number of rasters (.tiff) as part of a landscape classification exercise. First I want to generate a dendrogram from the rasters (maximum of 7 different rasters) to...

26 January 2020 7,471 3 View

Where can I download daily rainfall rasters for the last ten years?

I'm wanting to build a library of daily precipitation rasters for NZ. Yes, 3650 rasters! Any guidance would be great. Thanks in advance.

10 January 2020 5,258 4 View

How is the electron density of an atom or molecular species calculated and is there a periodic table of electron density?

I'm applying airborne gamma ray spectroscopy to the mapping of wetlands and hydric soils. In terms of gamma rays emanating from the upper 300 mm - 1000 mm of the earth's surface the electron...

28 May 2019 2,407 1 View

How to back transform to raw data for a multi-driver geospatial model?

We have generated a predictive model of soil geochemical variation. The model utilises a training data set of soil geochemical variation and rasters of environmental covariates such as radiometric...

07 February 2019 429 0 View

Is it possible to weight the significance given to a raster during K-means or equivalent classification of raster imagery?

We are using multiple raster layers to produce a predictive classification of the landscape. Statistical modelling indicates that some of the layers we are using for the classification are more...

31 January 2019 5,200 1 View

Can positional data from airborne geophysical surveys be used to generate digital elevation models?

Airborne geophysical surveys collect positional data. Can this positional data be used to build digital elevation models (DEM)? Specifically, I have access to regional airborne aeromagnetics and...

20 March 2018 8,065 12 View

What reagent is best for detecting reduced iron (FeII) in soil or unsaturated zone cores?

We are interested in finding a reagent for testing, in situ, the presence or otherwise of reduced iron (FeII) in soil profiles or core. I have heard of Childs reagent being used for this purpose...

28 September 2017 2,135 1 View

Why do we continue to invest so heavily in poorly constrained empirical models for catchment water quality?

Dear Colleagues, I'm trying to better understand why we continue to invest in poorly constrained and often highly uncertain empirical models for estimating farm scale and catchment scale water...

22 July 2017 9,113 6 View

Is radon enriched or depleted in most marine limestones?

Groundwater baseflow to streams is often detected at low flows through measurement of radon concentrations. However, I note that a number of aquifers have potentially low uranium contents...

06 January 2017 8,394 3 View

How does one quantify methane oxidation from simultaneous CO2 and CH4 flux data?

I have a large data set of simultaneous CO2 and CH4 soil efflux data from across the surface of an active landfill. Data was collected using a West Systems Accumulation Chamber and infrared gas...

25 May 2014 9,580 2 View

Can anyone help with landfill pressure gradients - measurements of reservoir over pressure?

I’m hoping to simulate the role of air temperature and barometric pressure over landfill gas efflux and was wondering if anyone had information on landfill gas pressure gradients? The choice of...

25 May 2014 4,316 0 View

Parametric versus non-parametric analysis of soil gas measurements - any thoughts?

Many papers on soil gas fluxes use parametric tests, after log transformation, to assess the significance of temporally discrete data sets (see Giammanco et al., 2010). My question is: “why is...

26 April 2014 3,623 6 View

Why is there a difference between SGS and GSA uncertainty estimates for fugitive emissions?

Can anyone provide a technical explanation for why the uncertainties calculated by SGS (500 realisations) are often smaller than those determined by applying 95% confidence intervals to outputs...

21 December 2013 3,220 1 View

Why do some soils develop poor drainage?

Soils vary in their drainage status. Soil drainage status is a key control over redox and hydrological response. Can anyone explain why some soils evolve towards being poorly drained and others...

01 January 1970 7,796 8 View