Spatial Comparison Research Articles

Has the Free Trade Zone Construction Promoted the Upgrading of the City’s Industrial Structure?

Based on the panel data of 250 prefecture-level cities from 2006 to 2019, we adopted the idea and method of a “quasi-natural experiment” with difference-in-difference to assess the industrial-structure-upgrading effect of FTZ construction, analyze the factors and mechanisms influencing the effect, and further compare and analyze the regional heterogeneity and differences in spatial and temporal characteristics. We also propose policy recommendations to promote the orderly development of the FTZ. Empirical results show that, (i) compared with non-FTZ cities, the level of rationalization for industrial structures in FTZ cities increased by 9.69%, and the level of the advanced industrial structures increased by 7.01%. (ii) The innovation effect and the foreign investment effect enhance the effect of FTZ policy on industrial structure upgrading. (iii) Heterogeneity analysis found that the eastern and central FTZ have more significant roles in promoting industrial structure upgrading. (iv) Further spatial and temporal comparison analysis found that the promotion effect of the FTZ on industrial upgrading is temporally sustainable but with a certain lag. From the spatial perspective, the FTZ inhibits the level of advanced industrial structure in neighboring cities.

Temporal and spatial comparison of food web structure in marine pastures in the Pearl River Estuary: Implications for sustainable fisheries management.

The biological and ecological integrity of marine ecosystems in the Pearl River Estuary (PRE) has been compromised due to overfishing and water pollution. Fishing moratorium and artificial reef construction have been implemented in Wanshan and Miaowan for resource protection and restoration. Therefore, food web structure and trophic pathways of Wanshan, Miaowan, and Wailingding in different temporal and spatial situation will be determined using the Ecopath model, as well as the keystone species affecting these ecosystems, which can provide a basis for fishery management. The results showed that the energy transfer efficiency of IV and V trophic levels (TL) was higher than that of II and III‐TL before and after fishing moratorium, and the energy transfer efficiency of artificial reefs II and III‐TL was only slightly higher than that of nonartificial reefs in Wanshan. In addition, the mean values of ecosystem property indicators (consumption, respiration flow, total system throughput, and total biomass) after the fishing moratorium were significantly higher than those before the fishing moratorium. The average value of the ecosystem attribute indicators (consumption, respiration flow, total system throughput, and total biomass) of artificial reefs is lower than those of nonartificial reef areas, which may be related to the differences in community composition between artificial reefs and non‐artificial reefs. Finally, Nemipterus japonicus and Gastrophysus spadiceus are keystone species that distinguish the Wanshan and Miaowan artificial reefs from other areas. Overall, the fishing moratorium has a positive effect on the short‐term restoration of fishery resources, mainly restoring short‐life cycle organisms. However, the construction of artificial reefs will be more conducive to the persistence of ecosystem restoration. In addition, reasonable proliferation, release and fishing of N. japonicus and G. spadiceus will be beneficial to the sustainable utilization of fishery resources.

A low-cost, durable, submersible light trap and customisable LED design for pelagic deployment and capture of fish parasite Salmincola sp. copepodids

Documenting species invasions and assessments of ecological changes depend on detection. Here, we present a simple design of a plankton light trap with specific wavelength LEDs and modifications. We used PVC pipe to create standardised small, rigid, low-cost traps that can be deployed in lentic habitats. With a cost of under $30 US each, including lights and rechargeable batteries, our traps are affordable without the need for disposable chemical lights. These small traps rely on a vacuum to retain contents upon retrieval, eliminating complicated closing mechanisms and allowing bottom entry. Our design includes submersible LED lights that can withstand pressures of at least 5 atm. We expect that the included instructions for underwater light construction and rubber weights using sand may be broadly applicable. However, we designed and field-tested our traps focusing on the detection and capture of the infective copepodid lifestage of a freshwater parasitic copepod, Salmincola californiensis. This lifestage had previously only been observed by rearing in a laboratory setting and is of concern due to continued spread outside of its native range and detrimental impacts on salmonids, especially in freshwater reservoirs. We used a 445–450 nm wavelength LED light for capturing Salmincola copepodids, but the light design can be modified to any readily available LED and heat sink to attract other target organisms. In our case, the overall affordability of the trap and components allowed for the extensive trapping needed to capture and map the occurrence of rarely-observed species and lifestages, such as the copepodids of S. californiensis. In general, increasing the number of traps that can be deployed within or across sites can aid in the spatial comparisons of plankton distributions needed in studies of ecology and species life histories. Light traps may aid in the detection of introduced zooplankton, such as S. californiensis, outside of their native range and associated plankton community changes.

Performance of gridded precipitation products in the Black Sea region for hydrological studies

Gridded precipitation products are becoming good alternative data sources for regions with limited weather gauging stations. In this study, four climate gridded precipitation products were utilized, namely Climate Forecast System Reanalysis (CFSR), European Centre for Medium-Range Weather Forecasts (ECMWF) ERA-Interim/land, the Asian Precipitation-Highly-Resolved Observational Data Integration Towards Evaluation of Water Resources (APHRODITE), and Multi-Source Weighted-Ensemble Precipitation (MSWEP). The key novelty of this study is to fill the gap in one of important areas of the transcontinental region of Eurasia, namely Rize province in the Black Sea region being selected as a study area since it has complex topography and climatology in addition to a limited number of gauging stations. A set of precipitation products were assessed for performance with the observed precipitation data before using a hydrological model (SWAT) to evaluate the basin response for the climate products. Three methods were considered in this study: (i) spatial comparison and (ii) hydrological and (iii) statistical evaluations. Along with precipitation forcing, the SWAT model simulations were analyzed in conjunction with streamflow observations. In an overall evaluation, the percentage bias of ERA-Interim/land, CFSR, APHRODITE, and MSWEP mean monthly precipitation is 19.9%, 33.4%, 41.4%, and 85.0% respectively. For the flow simulations, the CFSR and MSWEP have resulted in exaggerated peak flows in the high flow season due to overestimated precipitation forcing (Nash Sutcliffe efficiency [NS] equal to 0.22 and −0.73, respectively). On the contrary, the APHRODITE underestimated the peak flows due to lower precipitation estimates (NS = 0.38). The ERA-Interim land showed good agreement with the observed flows (NS = 0.53). From these readings, we stated that the ERA-Interim land exhibited improved performance with the observed precipitation whereas the CFSR showed the worst performance. The study suggests that gridded precipitation products could supplement observed precipitation data for observational data scarcity in mountainous regions.

Coastal marine biodiversity in the western Canadian Arctic

Establishing a baseline of Arctic marine biodiversity is necessary for monitoring impacts of climate change in the vulnerable Canadian Arctic and protecting sensitive regions that are of significant importance to Inuit culture and socioeconomics. Under the goals of improving documentation of Arctic marine communities and creating a tool for assessing coastal Arctic biodiversity across different regions, relative abundance data of fishes, benthic invertebrates, and prey items found in fish stomach contents from coastal areas near Paulatuk and Sachs Harbour, Northwest Territories, and Kugluktuk, Nunavut were used to calculate Shannon–Wiener Biodiversity Indices. Biodiversity varied among and within regions and trophic groups; fish and stomach content biodiversity were highest in Kugluktuk, whereas benthic biodiversity was highest near Paulatuk. The methods presented here can be used as a tool for assessing low- to mid-trophic Canadian Arctic coastal biodiversity and would also facilitate spatial comparisons and long-term monitoring as climate warming impacts Arctic ecosystems.

Geogenic manganese and iron in groundwater of Southeast Asia and Bangladesh – Machine learning spatial prediction modeling and comparison with arsenic

Naturally occurring, geogenic manganese (Mn) and iron (Fe) are frequently found dissolved in groundwater at concentrations that make the water difficult to use (deposits, unpleasant taste) or, in the case of Mn, a potential health hazard. Over 6000 groundwater measurements of Mn and Fe in Southeast Asia and Bangladesh were assembled and statistically examined with other physicochemical parameters. The machine learning methods random forest and generalized boosted regression modeling were used with spatially continuous environmental parameters (climate, geology, soil, topography) to model and map the probability of groundwater Mn > 400 μg/L and Fe > 0.3 mg/L for Southeast Asia and Bangladesh. The modeling indicated that drier climatic conditions are associated with a tendency of elevated Mn concentrations, whereas high Fe concentrations tend to be found in a more humid climate with elevated levels of soil organic carbon. The spatial distribution of Mn > 400 μg/L and Fe > 0.3 mg/L was compared and contrasted with that of the critical geogenic contaminant arsenic (As), confirming that high Fe concentrations are often associated with high As concentrations, whereas areas of high concentrations of Mn and As are frequently found adjacent to each other. The probability maps draw attention to areas prone to elevated concentrations of geogenic Mn and Fe in groundwater and can help direct efforts to mitigate their negative effects. The greatest Mn hazard is found in densely populated northwest Bangladesh and the Mekong, Red and Ma River Deltas of Cambodia and Vietnam. Widespread elevated Fe concentrations and their associated negative effects on water infrastructure pose challenges to water supply. The Mn and Fe prediction maps demonstrate the value of machine learning for the geospatial prediction modeling and mapping of groundwater contaminants as well as the potential for further constituents to be targeted by this novel approach.

Spatial comparisons of carbon sequestration for redwood and radiata pine within New Zealand

Accurate spatial characterisation of plantation carbon will become increasingly important as countries look to offset anthropogenic emissions and growers seek fair payment for carbon. Although much research has characterised carbon in existing forests, estimates are often required for unplanted areas to gain insight into the suitability of greenfield sites for carbon forests. Ideally, these predictions should be made for multiple species as matching of species to site is critical for maximising carbon sequestration. Using a novel prediction method that leverages stand level carbon prediction models, and utilises previously developed geospatial productivity surfaces, our objectives were to (i) develop national surfaces for New Zealand of carbon sequestration for redwood (Sequoia sempervirens) and radiata pine (Pinus radiata) and (ii) compare carbon sequestration between these two species across a range of ages (30, 40 and 50 years) and stand densities (planting densities of 400, 650 and 900 stems ha−1).Spatial predictions of volume productivity show that suitable areas for radiata pine covered, respectively, 98% and 71% of the total land area in the North and South Islands of New Zealand. The suitable range for redwood was more restricted, and a subset of the radiata pine range, with 87% and 28% of total land area suitable for redwood, respectively, within the North and South Islands. Within regions suited to both species (i.e. the redwood range), the mean carbon for redwood growing for 40 years at 650 stems ha−1 (mid-range scenario), exceeded that of radiata pine by 23% (636 vs. 519 tonnes C ha−1) and 35% (540 vs. 399 tonnes C ha−1), respectively, within the North and South Islands. When compared across the larger range suitable for radiata pine, mean carbon for redwood, under the mid-range scenario, was 12% higher (569 vs. 508 tonnes C ha−1) than radiata pine within the North Island but 49% lower (204 vs. 402 tonnes C ha−1) within the South Island, as large areas of the South Island are too cold or dry for redwood, but still suitable for radiata pine. Averaged across all regions, within the area suitable for both species, percentage gains in carbon were markedly higher for redwood than radiata pine between ages of 30 and 50 years and between stand densities of 400 and 900 stems ha−1. Our results highlight the potential of redwood for further afforestation as this species is capable of high and sustained rates of carbon sequestration on suitable sites within New Zealand.

Spatial Expansion of Built-Up Areas in the Beijing-Tianjin-Hebei Urban Agglomeration Based on Nighttime Light Data: 1992-2020.

Built-up areas are one of the most intuitive and important indicators used to assess urbanization, the spatial expansion of which is of great significance in depicting the evolution of urban spatial structures. Based on the harmonized Defense Meteorological Satellite Program (DMSP) nighttime light dataset, this paper extracts the spatial distribution of built-up areas and explores the spatial expansion patterns and spatiotemporal evolution regularity of the Beijing–Tianjin–Hebei urban agglomeration from 1992 to 2020. The results show that the spatial comparison method, comparing the extracted area with the government’s statistical area, can accurately determine the optimal threshold of nighttime light and extract urban built-up areas. According to the spatial comparison method, the built-up areas of the Beijing–Tianjin–Hebei urban agglomeration are expanding rapidly from 1992 to 2020, and both expansion speed and expansion intensity have experienced an inverted “U-shaped” growth process. As the core cities of the Beijing–Tianjin–Hebei urban agglomeration, Beijing and Tianjin have been in the later stage of spatial expansion with slower expansion speed but better quality. In contrast, prefecture-level cities and other node cities have rapid expansion speed. The urban space structure of the Beijing–Tianjin–Hebei urban agglomeration has changed from a “monocentric model” to a “polycentric model” to a “metropolitan model”. High-tech industry parks around node cities have become important strongholds of urban space development, leading cities to evolve from monocentric structures to polycentric structures of downtown and industrial parks. The radiation range of core cities expands and spreads to surrounding districts and counties, which inevitably lead to the formation of metropolitan areas.

Combined Small- and Large-Scale Geo-Spatial Analysis of the Ruhr Area for an Environmental Justice Assessment

This paper investigates spatial relationships regarding the accessibility of urban green space, the overall yearly vitality of the surrounding vegetation, and additional indicators such as air and noise pollution, in urban areas. The analysis uses socio-economic data sets derived from a sophisticated disaggregation approach. It results from applying a new tool that processes data from coarse and small-scale data sets to smaller spatial units in order to derive more fine-grained insights into the characteristics of the smallest suburb. The consequent data sets are then augmented by comprehensive raster-based accessibility network analysis and the incorporation of measured data on air and noise pollution. Gaining an overview over the whole area on the one hand, and looking at smaller city districts in detail on the other, unveils whether there is an imbalance regarding all combined indicators. After correlating two socio-economic indicators, a spatial comparison of the preliminary results determines whether this approach reveals neighborhoods wherein residents of a lower socio-economic status are exposed to multiple threats at once. As a result, the paper presents a workflow to obtain a broader and, at the same time, more small-scale overview of polycentric agglomeration. Simultaneously, it provides a large-scale insight into single sites, right down to the city block level. Consequently, this study provides a sophisticated approach that helps to assess the quality, quantity and characteristics of the specific spatial distribution of environmental justice in small- to large-scale urban areas at a glance. The results help to identify regions of inequalities and disadvantages. They allow for querying additional values assigned to large-scale spatial units. These versatile variables provide a means to reveal other noticeable indicators. Furthermore, this entails the opportunity to evaluate the distinct living conditions of locally affected demographic groups, and improve them with tailored approaches. Finally, the results can enhance the perception of these living conditions, and be used to promote the capacity for organizing the lives of the respective residents more sustainably, helping the neighborhood to grow accordingly.

Quantifying Fundamental Vegetation Traits over Europe Using the Sentinel-3 OLCI Catalogue in Google Earth Engine.

Thanks to the emergence of cloud-computing platforms and the ability of machine learning methods to solve prediction problems efficiently, this work presents a workflow to automate spatiotemporal mapping of essential vegetation traits from Sentinel-3 (S3) imagery. The traits included leaf chlorophyll content (LCC), leaf area index (LAI), fraction of absorbed photosynthetically active radiation (FAPAR), and fractional vegetation cover (FVC), being fundamental for assessing photosynthetic activity on Earth. The workflow involved Gaussian process regression (GPR) algorithms trained on top-of-atmosphere (TOA) radiance simulations generated by the coupled canopy radiative transfer model (RTM) SCOPE and the atmospheric RTM 6SV. The retrieval models, named to S3-TOA-GPR-1.0, were directly implemented in Google Earth Engine (GEE) to enable the quantification of the traits from TOA data as acquired from the S3 Ocean and Land Colour Instrument (OLCI) sensor.Following good to high theoretical validation results with normalized root mean square error (NRMSE) ranging from 5% (FAPAR) to 19% (LAI), a three fold evaluation approach over diverse sites and land cover types was pursued: (1) temporal comparison against LAI and FAPAR products obtained from Moderate Resolution Imaging Spectroradiometer (MODIS) for the time window 2016-2020, (2) spatial difference mapping with Copernicus Global Land Service (CGLS) estimates, and (3) direct validation using interpolated in situ data from the VALERI network. For all three approaches, promising results were achieved. Selected sites demonstrated coherent seasonal patterns compared to LAI and FAPAR MODIS products, with differences between spatially averaged temporal patterns of only 6.59%. In respect of the spatial mapping comparison, estimates provided by the S3-TOA-GPR-1.0 models indicated highest consistency with FVC and FAPAR CGLS products. Moreover, the direct validation of our S3-TOA-GPR-1.0 models against VALERI estimates indicated with regard to jurisdictional claims in good retrieval performance for LAI, FAPAR and FVC. We conclude that our retrieval workflow of spatiotemporal S3 TOA data processing into GEE opens the path towards global monitoring of fundamental vegetation traits, accessible to the whole research community.

Linking human activity to spatial accumulation of microplastics along mangrove coasts

Microplastics (MP) in mangrove coasts are threating ecological health and seafood safety. However, quantitative evidence on the effects of different coastal human activities on microplastic accumulation in mangrove sediments is lacking, thereby impeding the policy development of evidence-based waste management. In this study, continuous geographical sampling (N = 50) was applied to collect sediments from the largest mangrove coast, namely the Leizhou Peninsula in China. Similar worldwide research data (16 mangrove coasts) were collected from the Science Citation Index Expanded (SCIE) database of the Web of Science. The connections between human drivers and microplastic accumulation were evaluated by spatial comparison, multi-correspondence analysis, and multiple differences analysis. The microplastic abundance fluctuated widely along the mangrove coasts (average value was 51.24, ranged from 6.40 to 255.57 items·kg−1 dry weight; coefficient of variation = 97%) with a globally lower-middle concentration in sediments of the Leizhou Peninsula. Densely populated urban residents and the floating population of tourists largely contributed to the high abundance of microplastics in mangrove sediments, of which large-sized (1–5 mm) white foams were the dominant type. Although suburbs had less crowds, both onshore and offshore fishery production could cause high accumulation of microplastics in neighboring mangrove coasts, which were characterized by small-sized (<1 mm) fragments with fresh color. Small microplastics (80%) with fresh color (44%) were dominant. Weathering may break down more toxic particles in urban areas neighboring mangrove coasts. Larger mangrove patches could partly block ocean-based microplastics; however, coasts surrounded by more geographical barriers had intensified pollutant accumulation. It was suggested that foam packaging of commodities for urban residents and tourists in popular tourism areas should be reduced and restrictions of fishery waste plastics are needed along shores with mangroves, especially in coasts surrounded by more geographic barriers.

The relationship between tree size and tree water-use: is competition for water size-symmetric or size-asymmetric?

Relationships between tree size and water use indicate how soil water is partitioned between differently sized individuals, and hence competition for water. These relationships are rarely examined, letalone whether there is consistency in shape across populations. Competition for water among plants is often assumed to be size-symmetric, i.e., exponents (b1) of power functions (water use ∝ biomassb1) equal to 1, with all sizes using the same amount of water proportionally to their size. We tested the hypothesis that b1 actually varies greatly, and based on allometric theory, that b1 is only centered around 1 when size is quantified as basal area or sapwood area (not diameter). We also examined whether b1 varies spatially and temporally in relation to stand structure (height and density) and climate. Tree water use ∝ sizeb1 power functions were fitted for 80 species and 103 sites using the global SAPFLUXNET database. The b1 were centered around 1 when tree size was given as basal area or sapwood area, but not as diameter. The 95% confidence intervals of b1 included the theoretical predictions for the scaling of plant vascular networks. b1 changed through time within a given stand for the species with the longest time series, such that larger trees gained an advantage during warmer and wetter conditions. Spatial comparisons across the entire dataset showed that b1 correlated only weakly (R2<12%) with stand structure or climate, suggesting that inter-specific variability in b1 and hence the symmetry of competition for water may be largely related to inter-specific differences in tree architecture or physiology rather than to climate or stand structure. In conclusion, size-symmetric competition for water (b1≈1) may only be assumed when size is quantified as basal area or sapwood area, and when describing a general pattern across forest types and species. There is substantial deviation in b1 between individual stands and species.

Scratching the Surface: Integrating Low-Visibility Zones and Large Rural Sites in Landscape Archaeology Using Point Sampling

ABSTRACT Whereas archaeological field survey is relatively fast and effective for the mapping of surface finds in Mediterranean landscapes, two challenges limit its potential for reconstructing ancient settlement patterns. First, field survey usually excludes portions of the landscape that are inaccessible or present low ground visibility due to vegetation or the terrain, and second, including large settlements sites poses logistical problems, as these tend to produce unmanageably high frequencies of finds. In this paper, we explore the potential value of point sampling for integrating these areas in standard transect field survey projects. For this experiment, we sampled a large rural Archaic–Roman period site and its off-site environs in Molise, central-southern Italy. We present a systematic statistical and spatial comparison between data derived from both methods on the same areas. As such, the experiment contributes to the current debate on how to compare and integrate data from survey projects that apply different techniques.

Process integrated monitoring of spatially resolved particle emissions of a baghouse filter using a network of low-cost PM-sensors

In industrial applications of baghouse filters, emission sources other than direct penetration contribute greatly to the overall outlet dust emission. Spatio-temporal process monitoring could enable the detection of local particle emission hotspots and facilitate maintenance procedures by offering new insights regarding the emission behavior of baghouse filters. This publication shows the spatial emission behavior measured by low-cost sensors in a small scale baghouse filter with nine filter bags. After initial cleaning cycles, which cause clogging of the seams and a decrease of the particle emission level, the emission behavior corresponds to ideal filter operation. However, seemingly random continuous particle emissions are temporarily measured at individual filter bags within the baghouse. Via spatial monitoring and comparison with the total dust emission of the process, measured by a state-of-the-art precision laboratory optical particle counter, these events can be allocated to a corresponding filter bag, which serves as the source of temporary increase in dust emission. An increase in tank pressure shows a rise of the intensity and frequency of temporarily occurring continuous emissions. This behavior can be directly linked to a release of particles from previously clogged seams, thus enabling renewed particle penetration through the stitching holes of the seams.

Performance Comparison of Repetition Coding MIMO Optical Wireless Communications with Distinct Light Beams.

In current optical wireless communications (OWC) oriented research works, the various multiple input multiple output (MIMO) techniques are introduced and utilized to enhance the coverage performance. Objectively, this Lambertian light beam based MIMO research paradigm neglects the light beam diversity and the potential performance gains. In this work, the distinct non-Lambertian light beams of commercially available light emitting diodes (LEDs) were adopted to configure MIMO OWC links. Specifically, the homogenous and heterogeneous non-Lambertian MIMO configurations were constituted in typical indoor scenarios. Moreover, applying the repetition coding (RC) MIMO algorithm with low complexity, a spatial coverage performance comparison was made between the several above mentioned non-Lambertian configurations and the well-discussed Lambertian MIMO configuration. Numerical results illustrate that the homogeneous NSPW light beam configuration could provide a more than 30 dB average signal to noise ratio (SNR), while the achievable average SNR of the heterogeneous light beam configuration was up to 28.77 dB. On the other side, the counterpart of the Lambertian configuration achieved just about 27.00 dB. Objectively, this work paves the fundamental and essential way for the further design and optimization of MIMO OWC in this novel light beam dimension.

Evaluation of Sentinel-1, SMAP and SMOS surface soil moisture products for distributed eco-hydrological modelling in Mediterranean forest basins

Reliable distributed hydrological modeling, especially in semi-arid areas, must consider the inclusion of surface soil moisture (SSM) spatial information during the calibration process. This variable plays a key role in the evapotranspiration processes that determine the hydrological cycle. The coarse resolution of the SSM estimates by satellite remote sensing has restricted the application of this approach to only large basins, focusing most of the studies in the consideration of simply the temporal dynamics of this variable. The growing efforts in providing higher spatial resolution through disaggregating methodologies or new sensor estimates facilitates the application of this spatial approach to small basins. This paper explores the applicability of the currently available satellite surface soil moisture estimates for distributed eco-hydrological modelling in Mediterranean forest basins. On one hand, this study contributes to fill the existing research gap on the use of remote sensing SSM spatial patterns within the distributed hydrological modelling framework in small basins. On the other hand, it serves as an indirect validation method for the spatial performance of satellite SSM products. To achieve this goal, we implemented the eco-hydrological model TETIS in three case studies named: Hozgarganta (southern Spain), Ceira (western Portugal) and Carraixet (eastern Spain). The SSM estimates selected for comparison were Sentinel-1 SSM provided by the Copernicus Global Land Services (CGLS), SMAP SSM disaggregated using Sentinel-1 (SPL2SMAP_S) provided by the National Aeronautics and Space Administration (NASA), SMOS SSM provided by the Barcelona Expert Center (BEC), and SMOS and SMAP SSM disaggregated using the DISPATCH algorithm provided by Lobelia Earth. The methodology employed involved a multi-objective and multi-variable calibration in terms of remote sensing SSM spatial patterns and in-situ streamflow, using the Spatial Efficiency Metric (SPAEF) and the Nash-Sutcliffe efficiency index (NSE) respectively. Before model calibration a sensitivity analysis of the most influent variables was performed. The temporal and spatial comparison of the reference SSM products revealed inconsistencies amongst products. The disaggregating methodology determined the spatial agreement to a greater degree than the sensor itself (i.e. SMAP, SMOS). In spite of the differences amongst products, the multi-objective calibration approach proposed increased the robustness of the hydrological modelling.

An Earthquake Simulator for New Zealand

ABSTRACTWe present an earthquake simulator for New Zealand. It uses the Rate-and-State Earthquake Simulator engine based on approximations of the rate-and-state friction equations. The full set of faults considered in the most recent New Zealand national seismic hazard maps are included in the simulator. New simulator methods are introduced that allow for the inclusion and interaction between upper plate faults and a subduction interface fault below them. The simulator generates sequences of complex slip events and a catalog of finite ruptures hundreds of thousands of years in length. Results from the simulator are evaluated through statistical testing and comparison with geological and geophysical observations. These evaluations include a spatial comparison against historical earthquakes, a comparison against rates of events in the instrumental catalog, and a comparison against scaling relations. Consistency of the model with these measures is generally found, though some differences with productivity is noted, due to incomplete modeling of subducting slab features like geodetically inferred spatially dependent creep and dense faulting in Bay of Plenty faults. Significant emergent aspects of the resulting synthetic catalog are discussed. These include substantial variability over instrumental catalog timescales, clustering of large events in space and time, and spontaneous ruptures that break both the upper crustal faults and subduction interface coseismically. An online repository provides the model output, and an additional site provides python code for reproducing some of the figures in this article and tools for further model output analysis.

A feedforward model of spatial lightness computation by the human visual system

Last year at HVEI, I presented a computational model of lightness perception inspired by data from primate neurophysiology. That model first encodes local spatially-directed local contrast in the image, then integrates the resulting local contrast signals across space to compute lightness (Rudd, J Percept Imaging, 2020; HVEI Proceedings, 2021). Here I computer simulate the lightness model and generalize it to model color perception by including in the model local color contrast detectors that have properties similar to those of cortical &#x201C;double-opponent&#x201D; (DO) neurons. DO neurons make local spatial comparisons between the activities of L vs M and S vs (L + M) cones and half-wave rectify these local color contrast comparisons to produce psychophysical channels that encode, roughly, amounts of &#x2018;red,&#x2019; &#x2018;green&#x2019;, &#x2018;blue&#x2019;, and &#x2018;yellow.&#x201D

Coordinated interactions between economy and atmospheric environment: temporal–spatial comparisons from China

Coordinated interactions between economy and atmospheric environment: temporal–spatial comparisons from China

Comparing contemporaneous hunter-gatherer and early agrarian settlement systems with spatial point process models: Case study of the Estonian Stone Age

Inductive locational models have been used for decades to map the probability of past settlements and identify the preferred environmental conditions for habitation. In this study we apply inductive modelling to compare the spatial structure of the settlement systems of hunter-fisher-gatherer groups (Narva and Combed Ware Culture) and early agrarian communities (Corded Ware Culture) in Stone Age Estonia.We conceptualise settlement system formation as a point process and develop a first order point process model representing the environmental suitability for habitation based on geomorphological, soil and proximity to water. We use MaxEnt and the SDMTune machine learning framework for building the model, variable selection and estimation. The model is applied to the two communities and the effects of the variables and the resulting spatial patterns compared.The statistical analysis indicated higher predictive power for hunter-fisher-gatherer sites, which might result from higher variety of agrarian activities, different socio-economic organization or effects of spatial structure of the landscape.The spatial comparison indicates significant differences between the suitable environments for habitation between the two groups. While the hunter-fisher-gatherer population had an entirely shoreline connected settlement system the Corded Ware people inhabited the areas further away from water bodies. This resulted in significantly expanded potential space with differing spatial configuration for the incoming agrarian groups, possibly allowing tolerated immigration. The results also indicate there was a certain overlap of areas considered suitable habitation by both cultural groups, which might have caused a competition for land.