A theoretical and empirical investigation into the economic relationship between forested watersheds and water treatment costs

Forests around the world are believed to perform important chemical and nutrient retention functions. Chemical concentration levels have been found to be lower in surface water bodies located in areas with a higher forest cover. There is increasing interest from both academics and policymakers in understanding the economic value behind these nature-based services provided by forests. Including forest cover as green infrastructure in integrated source water protection and management strategies is believed to enhance their overall economic efficiency by improving water treatability. However, the empirical evidence base linking forest cover and forest management to water treatability and treatment costs is limited, and largely absent in Canada, one of the most resource-abundant regions in the world. In order to justify investments in forest cover as green infrastructure it is vital to understand the economic benefits involved, in particular in relation to drinking water treatment. The main objective of this PhD thesis is to further analyze the relationship between forest land and water treatment, both theoretically and empirically using Canada as a case study area. The first chapter of this PhD thesis aims to provide a theoretical framework for better understanding the costs and benefits of investment decisions in the provision of safe drinking water. More specifically, a cost minimization function is specified to reach a given water quality standard, for example based on World Health Organization guidelines. The costs are based on two possible treatment approaches that can be adopted, denoted as grey and green infrastructure, where grey infrastructure represents the traditional water treatment technologies and green infrastructure consists of forest cover (e.g. forest protection or re-afforestation). Compared to grey infrastructure, green infrastructure has been found to be less costly, but riskier to implement than grey infrastructure to improve water treatability due to the lack of engineering control and environmental uncertainties surrounding causal dose-response relationships between forest cover and water quality. An optimal control model is developed to guide social planners in combining these two complementary types of infrastructure in the most cost-effective way given assumptions about the age structure of forests, risk levels, risk aversion, and the discount rate used to value future water service delivery from green infrastructure. Any optimal allocation between grey and green infrastructure is based on balancing the marginal net benefits of both types of infrastructure. Including wildfires as an additional risk, makes green infrastructure less attractive, among others because of the introduction of additional costs such as forest protection costs and reforestation costs. More forest means a higher risk of forest fires and hence damage costs and increases the uncertainty surrounding the delivery of the water service. Accounting for the co-benefits of forests as a carbon trap increases the likelihood of investing in green infrastructure, because it reduces the risk of forest fire in the long term and hence the forest protection costs, but is highly dependent on the applied discount rate to factor these long-term benefits into present-day decision-making. The second chapter in this PhD makes use of available empirical data for the province of Ontario in Canada, and focuses on the potential role of forest cover in potentially reducing drinking water incidents, reflecting on concerns in the first chapter about the effectiveness of green infrastructure as a means of source water protection. The publicly available Ontario drinking water quality and enforcement data base contains all drinking water incidents over a particular fiscal year that failed existing water quality standards in Ontario. The database lists all incidents, so-called adverse events, related to municipal water sources. By linking this database (n=228) to geographical information retrieved from the Ontario Land Cover (GIS) database, a set of interconnected spatial regression models are estimated, aiming to assess the relationship between forest cover and drinking water rates and between drinking water rates and drinking water safety. In the latter case, the drinking water rates are used as a proxy for the drinking water treatment costs. To this end, a spatial instrumental variable model is estimated to improve our understanding about the aforementioned (reverse) causal relationships, i.e. how drinking water rates influence incidence rates and vice versa incidence rates in turn impact water rates. A key finding is that forest cover significantly reduces the number of adverse events and drinking water rates. In the third and final chapter of this PhD thesis, use is made of another important database, the biennial Drinking Water Plants Survey conducted by Statistics Canada for the country as a whole. The survey aims to gain insight into the financial treatment costs, water treatment characteristics, and water plant customers. The survey data are confidential and can only be accessed on-site in Statistics Canada in Ottawa after requesting permission and going through an extensive (legal) screening procedure of both student and supervisor. The collected data provides detailed insight in different treatment cost categories that can help to assess how specific cost categories are influenced by surrounding land cover across Canada. Using the detailed water treatment costs in similar spatial econometric regression models (n=1,373), accounting for potential spillover effects between neighbouring water service units, a significant negative relationship is found for Canada as a whole between forest cover and total drinking water treatment costs and the material costs incurred in drinking water treatment, whilst accounting for a range of individual water treatment plant characteristics, such as treatment capacity, treatment technology, and population served. In conclusion, in this PhD thesis I demonstrate that surrounding forest cover has a significant negative effect on water rates and incidence rates in Ontario and I show that surrounding forest cover significantly reduces water treatment costs across Canada as a whole. However, the regression models estimated in this PhD thesis are based on various far-reaching assumptions which could not be verified. These include, most importantly, the assumption that there exists a direct relationship between water rates and water treatment costs in Ontario and the assumption that the spatial analysis conducted at the level of census sub-divisions in both Ontario and Canada as a whole is able to capture upstream-downstream relationships between land cover upstream and the quality of the water intake downstream in the watersheds providing water to the drinking water treatment plants. More research is needed to validate these key assumptions

Research on the Penetration of Spudcan Foundation for Mobile Jack-Up Platform

[Introduction] The spudcan foundation is the key structure of the mobile jack-up platform, which displaces surrounding soil during its penetrating installation. In order to ensure the safety in the application of mobile jack-up platform to the offshore wind power installation works, it is particularly important to research the evolution of surrounding soil flow mechanism during spudcan penetration, and to evaluate the penetration resistance of spudcan reliably. [Method] The coupling Euler-Lagrange (CEL) method was used in this research to simualte the process of spudcan penetration under several typical seabed geological conditions (homogeneous and heterogeneous clay, sand, "clay-sand-clay" and "clay (hard)-sand (soft) and clay (hard)"), and to analyze the differences of penetration mechanisms. [Result] The simulation results show that in the process of spudcan penetration, the soil flow mechanism and penetration resistance of spudcan are closely related to the strength characteristics of seabed soil, while the friction coefficient of the interface between spudcan and seabed soil has little effect on the penetration mechanism and resistance. [Conclusion] From comparision with the results calculated in accordance current design specifications, the method combining large deformation finite element analysis and industry code design should be recommended to be applied in engineering design practice, as to provide a better basis for the assessment of punch-through risk and the prediction of penetrating depth in the process of spudcan penetration

Improvement of Phylogenetic Method to Analyze Compositional Heterogeneity

Background: Phylogenetic analysis is a key way to understand current research in the biological processes and detect theory in evolution of natural selection. The evolutionary relationship between species is generally reflected in the form of phylogenetic trees. Many methods for constructing phylogenetic trees, are based on the optimization criteria. We extract the biological data via modeling features, and then compare these characteristics to study the biological evolution between species. Results: Here, we use maximum likelihood and Bayesian inference method to establish phylogenetic trees; multi-chain Markov chain Monte Carlo sampling method can be used to select optimal phylogenetic tree, resolving local optimum problem. The correlation model of phylogenetic analysis assumes that phylogenetic trees are built on homogeneous data, however there exists a large deviation in the presence of heterogeneous data. We use conscious detection to solve compositional heterogeneity. Our method is evaluated on two sets of experimental data, a group of bacterial 16S ribosomal RNA gene data, and a group of genetic data with five homologous species. Conclusions: Our method can obtain accurate phylogenetic trees on the homologous data, and also detect the compositional heterogeneity of experimental data. We provide an efficient method to enhance the accuracy of generated phylogenetic tre

How the Unruh effect affects transition between classical and quantum decoherences

We investigate how the Unruh effect affects the transition between classical and quantum decoherences for a general class of initial states and find that: $(i)$ The quantum decoherence exists while $\lambda t\leq\lambda \widetilde{t}$ (the transition time) and the classical one can also affect the system's evolution while $\lambda t\geq\lambda\widetilde{t}$ for both the bit and phase-bit flips, which are different from the cases in inertial frame; $(ii)$ The classical correlations will be different constants corresponding to different Unruh temperature and the quantum decoherence still dominates the evolution of system as $\lambda t\geq\lambda\widetilde{t}$ for the phase flip; And $(iii)$ as the Unruh temperature increases, the $\lambda\widetilde{t}$, compared with that in inertial frame, will be bigger for phase flip but smaller for bit flip. However, the $\lambda\widetilde{t}$ does not change no matter what the Unruh effect is for phase-bit flip.Comment: 15 pages, 6 figure

Partitioning the contributions of glacier melt and precipitation to the 1971–2010 runoff increases in a headwater basin of the Tarim River

Glacier retreat and runoff increases in the last few decades characterize conditions in the Kumalak River Basin, which is a headwater basin of the Tarim River with a catchment area of 12,800 km2. To address the scientific question of whether, and to what extent, the observed runoff increase can be attributed to enhanced glacier melt and/or increased precipitation, a glacier evolution scheme and precipitation-runoff model are developed. Using the glacio-hydrological model, we find that both glacier cover area and glacier mass in the study area have decreased from 1971 to 2010. On average, the contribution to total runoff from rainfall, glacier melt and snowmelt are 60.6%, 28.2% and 11.2%, respectively. Despite covering only 21.3% of the basin area, glacier areas contributed 43.3% (including rainfall, snowmelt and glacier melt) to the total runoff from our model estimates. Furthermore, as primary causes of increased runoff in response to the warmer and wetter climate over the period 1971–2010, contribution from increases in rainfall and glacier melt are 56.7% and 50.6%, respectively. In comparison to rainfall and glacier melt, snowmelt has a minor influence on runoff increase, accounting for −7.3%. The research has important implications for water resources development in this arid region and for some similar river basins in which glacial melt forms an important part of the hydrological cycle

Dynamics of multipartite quantum correlations under decoherence

Quantum discord is an optimal resource for the quantification of classical and non-classical correlations as compared to other related measures. Geometric measure of quantum discord is another measure of quantum correlations. Recently, the geometric quantum discord for multipartite states has been introduced by Jianwei Xu [arxiv:quant/ph.1205.0330]. Motivated from the recent study [Ann. Phys. 327 (2012) 851] for the bipartite systems, I have investigated global quantum discord (QD) and geometric quantum discord (GQD) under the influence of external environments for different multipartite states. Werner-GHZ type three-qubit and six-qubit states are considered in inertial and non-inertial settings. The dynamics of QD and GQD is investigated under amplitude damping, phase damping, depolarizing and flipping channels. It is seen that the quantum discord vanishes for p>0.75 in case of three-qubit GHZ states and for p>0.5 for six qubit GHZ states. This implies that multipartite states are more fragile to decoherence for higher values of N. Surprisingly, a rapid sudden death of discord occurs in case of phase flip channel. However, for bit flip channel, no sudden death happens for the six-qubit states. On the other hand, depolarizing channel heavily influences the QD and GQD as compared to the amplitude damping channel. It means that the depolarizing channel has the most destructive influence on the discords for multipartite states. From the perspective of accelerated observers, it is seen that effect of environment on QD and GQD is much stronger than that of the acceleration of non-inertial frames. The degradation of QD and GQD happens due to Unruh effect. Furthermore, QD exhibits more robustness than GQD when the multipartite systems are exposed to environment.Comment: 15 pages, 4 figures, 4 table

Multidifferential study of identified charged hadron distributions in ZZ-tagged jets in proton-proton collisions at s=\sqrt{s}=13 TeV

Jet fragmentation functions are measured for the first time in proton-proton collisions for charged pions, kaons, and protons within jets recoiling against a $Z$ boson. The charged-hadron distributions are studied longitudinally and transversely to the jet direction for jets with transverse momentum 20 $< p_{\textrm{T}} < 100$ GeV and in the pseudorapidity range $2.5 < \eta < 4$. The data sample was collected with the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.64 fb$^{-1}$. Triple differential distributions as a function of the hadron longitudinal momentum fraction, hadron transverse momentum, and jet transverse momentum are also measured for the first time. This helps constrain transverse-momentum-dependent fragmentation functions. Differences in the shapes and magnitudes of the measured distributions for the different hadron species provide insights into the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb public pages

Study of the B−→Λc+Λˉc−K−B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-} decay

The decay $B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-}$ is studied in proton-proton collisions at a center-of-mass energy of $\sqrt{s}=13$ TeV using data corresponding to an integrated luminosity of 5 $\mathrm{fb}^{-1}$ collected by the LHCb experiment. In the $\Lambda_{c}^+ K^{-}$ system, the $\Xi_{c}(2930)^{0}$ state observed at the BaBar and Belle experiments is resolved into two narrower states, $\Xi_{c}(2923)^{0}$ and $\Xi_{c}(2939)^{0}$, whose masses and widths are measured to be $$m(\Xi_{c}(2923)^{0}) = 2924.5 \pm 0.4 \pm 1.1 \,\mathrm{MeV}, \\ m(\Xi_{c}(2939)^{0}) = 2938.5 \pm 0.9 \pm 2.3 \,\mathrm{MeV}, \\ \Gamma(\Xi_{c}(2923)^{0}) = \phantom{000}4.8 \pm 0.9 \pm 1.5 \,\mathrm{MeV},\\ \Gamma(\Xi_{c}(2939)^{0}) = \phantom{00}11.0 \pm 1.9 \pm 7.5 \,\mathrm{MeV},$$ where the first uncertainties are statistical and the second systematic. The results are consistent with a previous LHCb measurement using a prompt $\Lambda_{c}^{+} K^{-}$ sample. Evidence of a new $\Xi_{c}(2880)^{0}$ state is found with a local significance of $3.8\,\sigma$, whose mass and width are measured to be $2881.8 \pm 3.1 \pm 8.5\,\mathrm{MeV}$ and $12.4 \pm 5.3 \pm 5.8 \,\mathrm{MeV}$, respectively. In addition, evidence of a new decay mode $\Xi_{c}(2790)^{0} \to \Lambda_{c}^{+} K^{-}$ is found with a significance of $3.7\,\sigma$. The relative branching fraction of $B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-}$ with respect to the $B^{-} \to D^{+} D^{-} K^{-}$ decay is measured to be $2.36 \pm 0.11 \pm 0.22 \pm 0.25$, where the first uncertainty is statistical, the second systematic and the third originates from the branching fractions of charm hadron decays.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-028.html (LHCb public pages