Integrating scientific assessment of wetland areas and economic evaluation tools to develop an evaluation framework to advise wetland management

Wetland ecosystems provide society with a range of valuable ecosystem services. However, wetlands worldwide are experiencing increasing pressure from a number of sources, caused by an interrelated combination of market failure and policy intervention failure. Whatever the cause, the result is massive degradation and loss of these ecosystems and ultimately, loss of their services. To better manage wetlands the availability of sufficient relevant and reliable scientific information is required together with an assessment tool capable of providing meaningful evaluations of the consequences of management. Current assessments of wetlands are often biased towards either economic or scientific issues, with limited attempts at integration. Evaluations that neglect integration overlook the complexity of wetland ecosystems and have failed to sufficiently protect these areas. This paper reviews the literature to propose an evaluation framework which combines a scientific assessment of wetland function with cost utility analysis (CUA) to develop a meaningful trade-off matrix. A dynamic approach to wetland assessment such as the hydro geomorphologic method (HGM), developed by the US Army Corps of Engineers, offers the opportunity to consider interrelationships between ecosystem process and functions and the resulting ecosystem services. CUA facilitates the evaluation of projects where the consequences of investment or no investment are complex and difficult to value in monetary terms. The evaluation framework described in this paper has the potential to deliver an integrated wetland management tool. However, for this potential to be realised, targeted interdisciplinary research by scientists and economists is required.

A salad bowl, salt and not a drop to drink: recipe for disaster? Three essays on the economic value of agricultural land in a changing environment

This dissertation contains three core chapters which share a common theme of natural resource management in Australia and a common analytical technique of Ricardian hedonic price theory applied to agricultural land values. Chapter 1: This chapter presents a Ricardian analysis of the impact of projected climate change on Australian broadacre agricultural land values. Using several years of farmlevel sales data, we estimate the value of agricultural land as a function of climate attributes. We leverage satellite imagery-based land use data to separate our analysis by cropping and grazing land. Making this distinction is particularly important due to choice based sampling (as a consequence of land sale frequency) that would otherwise severely bias our land value estimates. We base our damage estimates on CSIRO climate projections for the 21st century, as used by the Intergovernmental Panel on Climate Change. We find that projected climate change would erode agricultural land values by around 10 per cent by 2050, and nearly 40 per cent by the end of the century; and negatively impact at least 95 per cent of the existing agricultural resource base. This damage is unlikely to occur suddenly. Rather, it would be equivalent to taxing agricultural productivity by about 0.6 per cent per year for the next 85 years. Chapter 2: Australia’s northern area has vast but largely undeveloped land that would be arable if irrigated. We analyse the net economic benefits of allocating northern Australia’s divertible surface water to irrigation, a scheme that would require significant investment in infrastructure for dam and canal construction. We estimate the benefits to northern Australia, using a Ricardian hedonic approach to forecast the economic value of constructing major new irrigation schemes that would be capitalised into agricultural land values. We use publicly available information from existing and potential Australian irrigation schemes to define the cost of constructing large water storages and distribution infrastructure, as well as on-farm irrigation infrastructure. We find that the costs of turning northern Australia into an irrigated food bowl are likely to exceed even the most optimistic benefits that would be capitalised into land prices by a multiple of between 1.1 and 3.2. Chapter 3: This chapter explores the damage wrought on broadacre agricultural property values by dryland salinity in the south-west agricultural region of Western Australia – one of Australia’s most productive wheat growing areas. We use a Ricardian hedonic approach based on 20 years of farm sales data to estimate salinity damages. We find that the damage caused by salinity in the south-west varies from approximately 20 per cent for land that is slightly affected by salinity to as much as 87 per cent for land that is extremely saline. Using these estimates, we project that the upside from eliminating existing salinity on 5.3 million hectares of currently impacted land would be worth approximately $2.6 billion. Conversely, if left unchecked, we find that an additional 3.75 million hectares of land worth approximately$5.85 billion is likely to become saline at some point in the future

Assemblathon 2: evaluating de novo methods of genome assembly in three vertebrate species

Background: The process of generating raw genome sequence data continues to become cheaper, faster, and more accurate. However, assembly of such data into high-quality, finished genome sequences remains challenging. Many genome assembly tools are available, but they differ greatly in terms of their performance (speed, scalability, hardware requirements, acceptance of newer read technologies) and in their final output (composition of assembled sequence). More importantly, it remains largely unclear how to best assess the quality of assembled genome sequences. The Assemblathon competitions are intended to assess current state-of-the-art methods in genome assembly. Results: In Assemblathon 2, we provided a variety of sequence data to be assembled for three vertebrate species (a bird, a fish, and snake). This resulted in a total of 43 submitted assemblies from 21 participating teams. We evaluated these assemblies using a combination of optical map data, Fosmid sequences, and several statistical methods. From over 100 different metrics, we chose ten key measures by which to assess the overall quality of the assemblies. Conclusions: Many current genome assemblers produced useful assemblies, containing a significant representation of their genes and overall genome structure. However, the high degree of variability between the entries suggests that there is still much room for improvement in the field of genome assembly and that approaches which work well in assembling the genome of one species may not necessarily work well for another

Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

Ultralight vector dark matter search using data from the KAGRA O3GK run

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

Projected impacts of salinity on dryland property values in South West Australia

The goal of this analysis is to predict the impacts of salinity on property values in the unirrigated, predominately cropping land in the south-west agricultural region of Western Australia. The method applied is statistical analysis of the relationship between salinity and property values in data from the recent past. Estimates suggest that if we can avoid salinisation of salt free cropping land holding other factors constant, we can avoid a reduction in land values of anywhere between 30% and 95%. In terms of dollar values and relative to the average land value per hectare in this study of approximately $1500, that amounts to savings of between$450 and $1425 per hectare

Projected impacts of salinity on dryland property values in South West Australia

The goal of this analysis is to predict the impacts of salinity on property values in the unirrigated, predominately cropping land in the south-west agricultural region of Western Australia. The method applied is statistical analysis of the relationship between salinity and property values in data from the recent past. Estimates suggest that if we can avoid salinisation of salt free cropping land holding other factors constant, we can avoid a reduction in land values of anywhere between 30% and 95%. In terms of dollar values and relative to the average land value per hectare in this study of approximately $1500, that amounts to savings of between$450 and $1425 per hectare.

Projected impacts of salinity on dryland property values in South West Australia

The goal of this analysis is to predict the impacts of salinity on property values in the unirrigated, predominately cropping land in the south-west agricultural region of Western Australia. The method applied is statistical analysis of the relationship between salinity and property values in data from the recent past. Estimates suggest that if we can avoid salinisation of salt free cropping land holding other factors constant, we can avoid a reduction in land values of anywhere between 30% and 95%. In terms of dollar values and relative to the average land value per hectare in this study of approximately $1500, that amounts to savings of between$450 and $1425 per hectare.Environmental Economics and Policy,