Application and evaluation of sediment fingerprinting techniques in the Manawatu River catchment, New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Geography at Massey University, Palmerston North, New Zealand

Suspended sediment is an important component of the fluvial environment, contributing not only to the physical form, but also the chemical and ecological character of river channels and adjacent floodplains. Fluvial sediment flux reflects erosion of the contributing catchment, which when enhanced can lead to a reduction in agricultural productivity, effect morphological changes in the riparian environment and alter aquatic ecosystems by elevating turbidity levels and degrading water quality. It is therefore important to identify catchment-scale erosion processes and understand rates of sediment delivery, transport and deposition into the fluvial system to be able to mitigate such adverse effects. Sediment fingerprinting is a well-used tool for evaluating sediment sources, capable of directly quantifying sediment supply through differentiating sediment sources based on their inherent geochemical signatures and statistical modelling. Confluence-based sediment fingerprinting has achieved broad scale geochemical discrimination within the 5870 km2 Manawatu catchment, which drains terrain comprising soft-rock Tertiary and Quaternary sandstones, mudstones, limestones and more indurated greywacke. Multiple sediment samples were taken upstream and downstream of major river confluences, sieved to 40 and > 35 respectively. The revised mixing model estimated Mudstone terrain to contribute 59.3 % and 61.8 %, with significant contributions estimated from Mountain Range (12.0 % and 11.4 %) and Hill Surface (11.5 % and 11.3 %) respectively, indicating that Tm, Ni, Cu, Ca, P, Mn and Cr have an influence on these sediment source estimations

Resolving neutrino mass hierarchy from supernova (anti)neutrino-nucleus reactions

We introduce a hybrid method to determine neutrino mass hierarchy by simultaneous measurements of detector responses induced by antineutrino and neutrino fluxes from accretion and cooling phase of type II supernova. The (anti)neutrino-nucleus cross sections for $^{12}$C, $^{16}$O, $^{56}$Fe and $^{208}$Pb are calculated in the framework of relativistic nuclear energy density functional and weak Hamiltonian, while the cross sections for inelastic scattering on free protons, $p(\bar{\nu}_{e},e^{+})n$, are obtained using heavy-baryon chiral perturbation theory. The simulations of (anti)neutrino fluxes emitted from a protoneutron star in a core-collapse supernova include collective and Mickheev-Smirnov-Wolfenstein effects inside star. The emission rates of elementary decay modes of daughter nuclei are calculated for normal and inverted neutrino mass hierarchy. It is shown that simultaneous use of (anti)neutrino detectors with different target material and time dependence of the signal allow to determine the neutrino mass hierarchy from the ratios of $\nu_e /$ $\bar{\nu}_e$ induced particle emissions. The hybrid method favors detectors with heavier target nuclei ($^{208}$Pb) for the neutrino sector, while for antineutrinos the use of free protons and light nuclei ($\text{H}_2\text{O}$ or $\text{-CH}_2\text{-}$) represent appropriate choice.Comment: 4 pages, 2 figures, 1 tabl