This work presents a sinkhole susceptibility and risk assessment mapping in Guidonia-Bagni di Tivoli plain (Italy), a travertine sinkhole-prone area where sudden occurrences of sinkholes have happened in past and rece...
详细信息
This work presents a sinkhole susceptibility and risk assessment mapping in Guidonia-Bagni di Tivoli plain (Italy), a travertine sinkhole-prone area where sudden occurrences of sinkholes have happened in past and recent times. We collected a point-like sinkhole inventory and we considered a series of different sinkhole-controlling and precursory factors over the study area, related to its geo-litho-hydrological setting and to its terrain deformational scenario, i.e. ground motion rates derived from InSAR COSMO-SkyMed imagery. A sinkhole susceptibility map was produced through a machine learning model, namely maximum entropy algorithm (MaxEnt). Results highlight that the most determining factors for sinkhole formation are the lithology, the travertine thickness, groundwater and the land use. The sinkhole susceptibility map was then combined with data on vulnerability and elements-at-risk economic exposure in order to provide a sinkhole risk map of the area. The outcomes show that areas at higher risk covers about 2% of the total study area and primarily relies on the zoning of the main urban fabric. In particular, it is worth to highlight that 5% of the whole road-network pavement and 27% of all the residential buildings fall into High and Very High risk classes. Overall, results of this work demonstrate capabilities of machine learning models to assess sinkhole susceptibility for predicting potential sinkhole areas, and provide a sinkhole risk map, along with information on urban environment, as a useful tool for urban planning and geohazard risk management.
Metzgeriaceae are a cosmopolitan family that is particularly diverse in the Neotropics. In Brazil, the species of Metzgeria Raddi preferentially inhabit the coastal ecosystem Atlantic Rain Forest (from northeastern to...
详细信息
Metzgeriaceae are a cosmopolitan family that is particularly diverse in the Neotropics. In Brazil, the species of Metzgeria Raddi preferentially inhabit the coastal ecosystem Atlantic Rain Forest (from northeastern to southern Brazil). For bryophytes, the IUCN distribution criteria are of critical importance to evaluate threat status. In this study, we propose the use of ecological niche modeling methods to estimate the extent of potential occurrence of five Metzgeria species. Herbarium collection data were used to estimate the potential distribution of the species based on the method MAXENT. Understanding the spatial distribution of species is essential for the conservation of biodiversity, and the use of potential distribution models in biogeographic analysis is an important tool for the conservation of rare or endangered species. Modeling the distribution of five Metzgeria species endemic and/or threatened reveals that the species are currently not known from several areas that are, however, predicted to provide suitable environments. From these areas of forest fragments, 52% are under environmental protection, which is very important for the conservation of these species typical of the Atlantic Rain Forest domain. When we intersect this information with future areas of environmental protection, proposed by the Ministry of Environment of Brazil in 2010, we observed that 93% of forest fragments will be protected.
We combined distribution data of bryophyte species with protected areas in the Brazilian Atlantic Forest, using models of potential distribution of species, in order to assess the effectiveness and representativeness ...
详细信息
We combined distribution data of bryophyte species with protected areas in the Brazilian Atlantic Forest, using models of potential distribution of species, in order to assess the effectiveness and representativeness of Conservation Units for bryophyte species. We performed potential distribution models for ten bryophyte species classified as bio-indicators for environmental quality and/or endemic to the Atlantic Forest, or endemic to Brazil (key species). Data from online herbarium collections, literature, and sampling were used to estimate the potential distribution of the species, based on the MAXENT method. We performed an intersection between the maps with > 50% of environmental suitability for the occurrence of the studied species and the maps of the Brazilian protected areas. Areas with the greatest potential presence of bryophyte species not superimposed on protected areas were considered areas of gaps in protection. The habitat suitability of the models for nine species was explained by the Mean Diurnal Temperature Range. The consensus map of high environmental suitability for all species showed significant gaps in knowledge about their distribution. However, three centers of potential distribution were recognizable: one in the Northeast, one Central and another one in the Southeast. The total potentially suitable area overlapped with 83 Conservation Units (only 27%), less than adequate for efficient conservation of the species. The Central Corridor was the region with the highest environmental suitability but also has only a few Conservation Units in the Atlantic Forest, and is therefore a priority for conducting inventories and creating reserves.
In this work, a robust thresholding algorithm framework based on reconstruction and dimensionality reduction of the three-dimensional (3-D) histogram is proposed with the consideration of the poor anti-noise performan...
详细信息
In this work, a robust thresholding algorithm framework based on reconstruction and dimensionality reduction of the three-dimensional (3-D) histogram is proposed with the consideration of the poor anti-noise performance in existing 3-D histogram-based segmentation methods due to the obviously wrong region division. Firstly, our method reconstructs the 3-D histogram based on the distribution of noisy points which reduce its segmentation performance. Secondly, we transfer the region division in 3D histogram from eight partitions into two parts, thus reducing the searching space of threshold from 3-dimension to 1-dimension, which saves a lot of processing time and memory space. Thirdly, we apply the presented framework to global thresholding algorithms such as Otsu method, minimum error method, and maximumentropy method and so on, and propose corresponding robust global thresholding algorithms. Finally, segmentation result and running time are given at the end of this paper compared with those of 3-D Otsu's method, Otsu method, minimum error method and maximumentropy method. The experimental results show that the presented method has better anti-noise performance and visual quality compared with the above four approaches, and has lower time complexity than 3-D Otsu's method.
Knowledge of the phase space density distribution in details is useful to understand subsequent evolution of the charged particle beam in a transport *** makes the beam tomography very useful in the application for be...
详细信息
Knowledge of the phase space density distribution in details is useful to understand subsequent evolution of the charged particle beam in a transport *** makes the beam tomography very useful in the application for beam *** application is not limited by the beam energy,as opposed to the emittance *** paper presented the simulations and measurements we undertook in TRIUMF beam-lines to validate the maximumentropy(MENT)technique for the tomographic reconstruction of beam density distribution in the 2-dimensional transverse phase *** profiles were taken with a single wire scanner while changing an upstream quadrupole’s ***,the phase space plots were directly measured with emittance scanner.A close comparison was made on the resulting phase space density distribution and the emittance value at the same location of the *** show good agreement.
Image segmentation is the pre-step of multi-target tracing in Computer Assisted Sperm Motion Analysis System (CASMA). As a special sperm-tracing problem, a fast, automatic, unsupervised segmentation algorithm is requi...
详细信息
ISBN:
(纸本)0819446564
Image segmentation is the pre-step of multi-target tracing in Computer Assisted Sperm Motion Analysis System (CASMA). As a special sperm-tracing problem, a fast, automatic, unsupervised segmentation algorithm is required. In this paper, we utilize four segmentation algorithms to segment three different kinds of sperm images sampled from our actual system. By making an overall comparison between them, a conclusion is reached that the Otsu's maximum between-class variance algorithm is the most suitable for the special sperm microscopic image segmentation and this segmentation algorithm has been successfully applied to our developed system.
Habitat assessment of species is one of the most important strategies to conserve biodiversity in the protected areas. The main objective of this study is to present an ecological assessment model for habitat manageme...
详细信息
Habitat assessment of species is one of the most important strategies to conserve biodiversity in the protected areas. The main objective of this study is to present an ecological assessment model for habitat management of brown bears using the MaxEnt algorithm in Oshtorankooh protected area, Lorestan. 55 presence points of brown bear and seven environmental variables including slope, elevation, distance from river, distance from road, distance from forest and grassland, distance from cropland and vegetation, and distance from rural area were applied for habitat assessment process. The importance of these variables was investigated by the Jaknikfe test and their predictive rate was assessed by response curves. The distance from the rural area and elevation were respectively the most important factors for modeling the distribution of brown bears in Oshtorankooh protected area. The final suitability map of habitat for brown bear species was classified into four categories: more suitable, suitable, less suitable and unsuitable. An area of 22566.7 ha was determined as a more suitable habitat for brown bears in the study area. The result indicates that the southern and central areas of the study area are more suitable for the species. The result of the model validity was obtained as 0.92, showing that the integrated model was very efficient in the habitat assessment process.
暂无评论