Temporal GIS

This report summarizes research into the nature and sources of errors that occur in medium to small scale vegetation maps such as those used for statewide forestry and conservation planning. The objective of this research was to develop a coherent approach and specific methods for quantifying such errors by jointly analyzing ground observations and multiscale map data using Geographic Information Systems (GIS) operations. Section I of the report provides an overview of statistical approaches to assessing cartographic errors, including uncertainty in points, lines, irregular polygons and classified digital imagery. Techniques for assessing point errors and line digitizing errors are relatively well developed. By comparison, much research is still needed on methods for comparing polygon and image data to ground measurements. Another active research front deals with propagation of errors during GIS analyses involving multiple spatial data layers. Also, work is needed to find effective means of transmitting accuracy information to the user of spatial data. Section 2 describes an error analysis of the CALVEG map of vegetation in California. The purpose of the analysis was to demonstrate a variety of approaches to assessing map accuracy, rather than to provide a formal test of the CALVEG map. The map is compared to ground data, U.S. Forest Service photo plots and larger scale timber inventory maps using GIS operations of overlay and spatial analysis. Analyses proceed from contingency table comparisons to analyses of spatial properties of map errors, including spatial autocorrelation, boundary effects, map generalization and association of errors with environmental variables. The tests and their results are summarized in a table at the end of this section. In general, high error rates were documented for the CALVEG map, and these errors were shown to have a number of different sources, most importantly polygon misclassification and map generalization. The report concludes with a series of recommendations to CDF concerning changes in map accuracy assessment procedures. These recommendations pertain to data collection, sampling design, and methods for representing uncertainty in map products. Specific recommendations include the use of enhanced mapping procedures and measures of line quality, withinpolygon heterogeneity and within polygon vegetation texture. Section I of this report provides an overview of methods for determining the accuracy of thematic maps. In Section 2 we demonstrate some of these techniques in an accuracy assessment of conifer classes in the CALVEG map of the vegetation of California. We document the types of errors that occur in the production of digital vegetation maps, including non-random classification errors, boundary errors, errors introduced during digitizing and geometric rectification. Geographic Information System (GIS) operations such as map overlay, buffering, area and distance calculations are used to compare the CALVEG map to more detailed map and field survey data. Section 3 provides a summary of the research and recommends a strategy for assessing the accuracy of vegetation maps derived from remotely sensed data.

Real world is dynamic in its nature, so techniques attempting to model the real world should take this dynamicity in consideration. A well known Constraint Satisfaction Problem (CSP) can be extended this way to a so called Dynamic Constraint Satisfaction Problem (DynCSP) that supports adding and removing constraints in runtime. As Arc Consistency is one of the major techniques in solving CSPs, its dynamic version is of a particular interest for DynCSPs. This paper presents an improved version of AC|DC-2 algorithm for maintaining maximal arc consistency after constraint retraction. This improvement leads to runtimes better than the so far fastest dynamic arc consistency algorithm DnAC-6 while keeping low memory consumption. Moreover, the proposed algorithm is open in the sense of using either non-optimal AC-3 algorithm keeping a minimal memory consumption or optimal AC-3.1 algorithm improving runtime for constraint addition but increasing a memory consumption.

Real world is dynamic in its nature, so techniques attempting to model the real world should take this dynamicity in consideration. A well known Constraint Satisfaction Problem (CSP) can be extended this way to a so called Dynamic Constraint Satisfaction Problem (DynCSP) that supports adding and removing constraints in runtime. As Arc Consistency is one of the major techniques in solving CSPs, its dynamic version is of a particular interest for DynCSPs. This paper presents an improved version of AC|DC-2 algorithm for maintaining maximal arc consistency after constraint retraction. This improvement leads to runtimes better than the so far fastest dynamic arc consistency algorithm DnAC-6 while keeping low memory consumption. Moreover, the proposed algorithm is open in the sense of using either non-optimal AC-3 algorithm keeping a minimal memory consumption or optimal AC-3.1 algorithm improving runtime for constraint addition but increasing a memory consumption.

Numerous efforts are underway by public and private groups to assess the status of biodiversity in the state. Most are being conducted at local to subregional scales, and many are focused on species or communities of special concern. Currently lacking is an overview of the protection status of species and communities both statewide and in the western U.S. as a whole. This report describes a geographic information system (GIS) based Gap Analysis of biodiversity in the Southwestern California Ecoregion. The project is part of an ongoing effort by many groups, including the USFWS, the California Department of Fish and Game (CDF&G), Department of Forestry and Fire Protection (CDF&FP), The Nature Conservancy (TNC) and others to provide this regional overview by mapping the distributions of plant community types and vertebrate species habitats and relating these distributions to existing patterns of land ownership and land management. The work at UCSB is supported by the National Fish and Wildlife Foundation, the Southern California Edison Company (SCE), and the IBM Environmental Research Program and is part of a national program of state and regional gap analyses being coordinated by the USFWS. The term "Gap Analysis" refers to the evaluation of the protection status of plant communities, animal species and vertebrate species richness by GIS overlay of biological distribution data on a map of existing biological reserves. We are conducting a Gap Analysis of California in collaboration with a number of public and private groups. This entails preparing a statewide map of actual vegetation, supplemented with more detailed locality data for plant taxa of special concern. By compiling a statewide, albeit low resolution digital database, GIS capabilities can be used to identify and map landscapes in California that contain large numbers of potentially unprotected vegetation types and vertebrate species of interest. Such areas can then be studied in more detail as candidates for additional preservation and protection efforts to fill existing "gaps" in the protection network. This approach allows conservationists to be proactive rather than reactive in their efforts to preserve biodiversity. It should also result in fewer conflicts among developers and biologists. Because of the significant differences between parts of California in the ecology, land uses, and data availability, we have chosen to perforrn GIS-based analyses on ecologically-defined subareas of the state. The subdivision we have chosen is the region as defined for the forthcoming revision of the Jepson Manual of California's flora (Hickman, 1993). The Manual delineates ten regions in the state that roughly correspond to the bioregions proposed for state conservation planning. This report is limited to the Southwestern California Region, within the California Floristic Province. The gap analyses of the remaining nine regions will be reported separately as each is completed. Ultimately, a statewide gap analysis will be conducted with the data from the ten regions. The region includes 3,383,160 ha or roughly 8 percent of the area of California and is comprised of three subregions: South Coast, Transverse Ranges, and Peninsular Ranges. The region is bounded by the transition to the Sonoran and Mojave Desert regions on the east and the Santa Ynez Mountains on the north. Land Management: For the purposes of gap analysis, it is necessary to distinguish levels of management in order to determine the protection status of elements of biodiversity. Level 1 represents areas managed for the long-term protection of biodiversity, such as wilderness areas, research natural areas, National Wildlife Refuges, Areas of Critical Environmental Concern, state parks, ecological reserves, and private preserves and sanctuaries. Level 2 includes publicly-owned lands not specifically designated for Level 1 management, while Level 3 contains private lands with no formal management for biodiversity. A 1:100,000 scale management status map depicting these three levels and land ownership was compiled from many sources. Vegetation: A map of actual vegetation was produced using summer 1990 Landsat Thematic Mapper (TM) satellite imagery, 1990 high altitude color infrared photography (1:58,000 scale), Vegetation Type Mapping maps based on field surveys conducted between 1928 and 1940, and miscellaneous recent vegetation maps and ground surveys. Landscape boundaries were mapped subjectively by photointerpretation of patterns in the satellite imagery and air photos. Final delineation of a landscape unit was an iterative process based on lines of converging evidence obtained from the various source data. The map was produced using a minimum mapping unit of 100 ha (1 km 2 ), and the region was mapped into some 2,100 landscape units. 230 polygons (excluding urban and agricultural areas) were checked in the field, primarily by roadside reconnaissance. Based on our concept of landscape, we recorded a primary species complex, which was the most widespread vegetation type or land use/land cover type in the polygon, a secondary type, and the fraction of the landscape covered by each type. Each species complex was defined by up to three dominant species. Where possible, we also recorded the occurrence of minor overstory species of special conservation concern (e.g., Juglans californica, Quercus engeltnanii, Cupressus forbesii). Species composition was derived from field survey, air photos or from the VTM maps. VTM information was used for areas where air photos provided no evidence of recent disturbance, based on the assumption that canopy dominants observed by VTM field crews have not changed over the past 50-60 years. We also developed rules for assigning each species combination into Holland's classification of natural communities. We mapped 64 different communities (out of 89 recognized in the region). The premise of Gap Analysis is that biological resources at risk can be identified by their ownership/management profile as generated by GIS overlay of 1: 100,000 scale maps. Based on the profiles of communities already known to be at risk, we adopted the following criteria for identifying communities or dominant plant species at-risk: 1. Less than 10% of the distribution is in Level 1 areas, and the species or community type is endemic to the region, and the mapped distribution covers more than 100 km 2 or 2. over 70% of the mapped distribution is in Level 3 areas. Wildlife Distributions: Combining the California Wildlife Habitat Relationships (WHR) model with the vegetation map generated predicted distribution maps for native vertebrates. We used the WHR database to generate a set of presence/absence tables of species occurring within each of the major habitat types. Another component to the development of a set of predicted distribution maps is using a coarse-scale range map for general locality information. The maps used here are range outlines digitized from a state map at 1:3,500,000 scale and published as part of the VIM system ). The vegetation map was translated into the major habitat types used in the WHR system. The coarse-scale range map was then combined with the medium-scale vegetation map to produce a predicted distribution map for every species. By overlaying the predicted distribution maps with land management status, the proportion of a species' range in various levels of habitat protection was determined. The criteria for highest risk for breeding species whose habitats are rated either medium or high suitability or for migratory species with critical wintering habitat in the region are: 1. Less than 15% of the distribution is in Level I areas, and the species or a subspecies is endemic to the region, and the mapped distribution covers more than 100 km 2 and 2. The species does not find cropland, orchards/vineyards or urban habitats as either medium or high suitability, nor is it exclusively associated with wetlands. The species is not a marine mammal, shorebird, in the chiroptera order, introduced or intensively managed as either a harvest species or being translocated. Land Management: Level 1 areas total 324,773 ha or 9.6 percent of the region. Thirty percent is other public lands managed at Level 2, while the remaining 60 percent is Level 3. The area of level 1 managed areas is dominated by National Forest Wilderness Areas, with 226,185 hectares in 14 areas. State Parks, including Reserves and Wilderness Areas, are the second largest category of Level 1 areas, totaling 56,204 hectares. Lower elevations where most urban and agricultural development are located are predominately private land and therefore Level 3 management. Mid-elevations, between 1500 and 2500 meters are primarily public lands, with about 25 percent being Level 1 management, but most being Level 2. The majority of land above 2500 meters is in Level 1 management, and in fact more than 90 percent of the highest elevation zone is in Level I management (usually National Forest wilderness areas). Vegetation: Based on the GAP criteria, communities restricted largely to the lower elevations , such as nonnative grasslands and the coastal sage scrub types, are at considerable risk (Table ). Roughly 88% of areas below 500 rn are in Level 3 management (i.e. privately owned). A majority of the lands at these elevations have already been converted to agricultural or urban uses and most of the remaining lands are threatened with future urbanization. Especially alarming is the condition of the California black walnut woodlands. The southern variety of this species is endemic to this region and its current distribution is highly fragmented and reduced compared with its original distribution. Sagebrush steppe shrublands, although widespread elsewhere in California, appear vulnerable in this region. A significant proportion of the sagebrush steppe habitat is on Level 2 lands, and conservation concern for these communities can...

A number of reasoning problems involving the manipulation of temporal information can be viewed as implicitly inducing an ordering of decisions involving time (associated with durations or orderings of events) on the basis of preferences. For example, a pair of events might be constrained to occur in a certain order, and, in addition, it might be preferable that the delay between them be as large, or as small, as possible. This paper explores problems in which a set of temporal constraints is specified, each with preference criteria for making local decisions about the events involved in the constraint. A reasoner must infer a complete solution to the problem such that, to the extent possible, these local preferences are met in the best way. Constraint-based temporal reasoning is generalized to allow for reasoning about temporal preferences, and the complexity of the resulting formalism is examined. While in general such problems are NP-complete, some restrictions on the shape of the preference functions, and on the structure of the set of preference values, can be enforced to achieve tractability. In these cases, a generalization of a single-source shortest path algorithm can be used to compute a globally preferred solution in polynomial time.

Management accounting practices play an important role in business management and help companies survive in a competitive and ever-changing world. Appropriate measures of management accounting practices allow academics and practitioners to effectively evaluate the adoption of management accounting practices by companies. In this study, based on the qualitative information disclosed in the annual reports of 175 companies listed on the Tehran Stock Exchange from 2013 to 2022, new and comprehensive criteria for management accounting practices at the company level have been designed using the Word2Vec word embedding model. In measuring textual metrics, using this method is very useful because it can capture the nuances of language and identify patterns in textual data. After developing textual measurement criteria, a series of validations including content validity, convergent validity, discriminant validity and reliability have been performed to confirm that the measurement criteria of management accounting practices really reflect the actual choices of companies. The results show that the fit and approval of the developed measures with the representative indicators of each management accounting practices' dimensions in the industry indicate the effectiveness of the proposed measures. The new measurement of management accounting practices not only provides a solid foundation for empirical analysis in management accounting research, but also paves a new way to examine the status of companies regarding the extent of using management accounting practices.

We studied in this article a topic that focused on two areas of research: Constraint Satisfaction Problems (CSP) and genetic algorithms. The problem is that this type of algorithm is recognized to be greedy in terms of CPU time. To solve this problem, we tried to integrate the arc consistency (AC) at the initial population in a way that it would be the result of this filtering. First, we generated the genetic algorithm without integrating the arc consistency. Then, we considered that each chromosome is a CSP, each gene is a variable of the problem and each allele represents the taken value. We randomly generated the CSP to obtain the inconsistent values of each pair of variables. To remove these values, we used the technique of arc consistency as a technique for solving this type of problem, that means we have worked to eliminate from each variables domain the values which violate the constraint specific and make the CSP inconsistent. The aim of this work is to reduce performance in terms of execution time of the genetic algorithm.

Since the 1930s, California’s Sierra Nevada has warmed by an average of 1.2∘C. Warming directly primes forests for easier wildfire ignition, but the change in climate also affects vegetation species composition. Different types of vegetation support unique fire regimes with distinct probabilities of catastrophic wildfire, and anticipating vegetation transitions is an important but undervalued component of long-term wildfire management and adaptation. Vegetation transitions are more likely where the climate has become unsuitable but the species composition remains static. This vegetation climate mismatch (VCM) can result in vegetation conversions, particularly after a disturbance like wildfire. Here we produce estimates of VCM within conifer-dominated forests in the Sierra Nevada. Observations from the 1930s Wieslander Survey provide a foundation for characterizing the historical relationship between Sierra Nevada vegetation and climate before the onset of recent, rapid climate chang...

This paper addresses urban block densification in a simulation context. The simulation of such a process requires several spatial analysis tools and specific knowledge on the types of objects accounting for the increased urban density. In this paper, only buildings creation is considered. The method proposed hereby takes into account the existing spatial organisation of an urban block in order to respect it while creating new buildings.

La simulation des évolutions des villes suppose une certaine compréhension et une modélisation des lois qui gouvernent les dynamiques urbaines. L'approche présentée dans ce papier utilise un système multi-agent pour modéliser les propriétés auto-organisatrices des systèmes complexes urbains et vise à fournir un outil permettant d'étudier les évolutions des systèmes modélisés. Le système multi-agent proposé comporte une hiérarchie d'agents topographiques (e.g. les bâtiments, routes, cours d'eau, îlots) qui peuvent être construits, modifiés, fusionnés, découpés, restructurés et détruits au cours du temps. Le comportement de chaque agent est contrôlé par un ensemble de règles d'évolution, de contraintes et d'actions associées.

Recent research projects led in Cluny have focused on interoperability issues between computer-aided design (CAD) and geographic information system (GIS). In one of these projects, the Gunzo project went through a complete digital restitution of what was the largest church in the world during five centuries. In another project, a 3D GIS of the Cluny region was set up and led to the idea of designing an online historical and archaeological 3D database. This involves the development of time-based 3D data management functionalities in which both CAD and GIS could exchange information. Thanks to the close collaboration between interdisciplinary fields, the team managed to formulate the basis of a joint workflow. These steps are promising and could meet in the future this long-time dream of the scientific community: to be able to tie together CAD and GIS models with temporality on a single georeferenced collaborative platform, so closely that it will be possible to navigate through the history of a city in 3D.

The goal of geographic information retrieval (GIR) is to provide information about geo-entities to end-users and assist their spatial decision making. In the current means of GIR interfaces, users could easily visualize the geo-entities of interest on a map interface via sequential querying or browsing of individual categories. However, there are several decision making scenarios when the user needs to explore and investigate the geospatial database with multiple criteria of interests, which is not well supported by the sequential querying or browsing functionality of current GIR interfaces. There is a need for more sophisticated visual interfaces to enable end-users in discovering knowledge hidden in multidimensional geospatial databases. In this paper we discuss some of the HCI issues in realizing such multi-criteria decision making scenario based on the user requirement analysis. To tackle the human centered aspects we propose different heatmap based interfaces to support multi-criteria visualizations in GIR, i.e., to facilitate the knowledge based exploration of geospatial databases with less information overload.

The goal of geographic information retrieval (GIR) is to provide information about geo-entities to end-users and assist their spatial decision making. In the current means of GIR interfaces, users could easily visualize the geo-entities of interest on a map interface via sequential querying or browsing of individual categories. However, there are several decision making scenarios when the user needs to explore and investigate the geospatial database with multiple criteria of interests, which is not well supported by the sequential querying or browsing functionality of current GIR interfaces. There is a need for more sophisticated visual interfaces to enable end-users in discovering knowledge hidden in multidimensional geospatial databases. In this paper we discuss some of the HCI issues in realizing such multi-criteria decision making scenario based on the user requirement analysis. To tackle the human centered aspects we propose different heatmap based interfaces to support multi-criteria visualizations in GIR, i.e., to facilitate the knowledge based exploration of geospatial databases with less information overload.

Proposed causes of the latitudinal-propagule size gradient invoke differences among biome structures or seed dispersal syndromes. Latitudinal seed-size gradients so far have been predominantly investigated using entire floras, prompting the question of whether such trends exist at smaller scales. Here we consider effects of latitude and elevation on fruit size between and within species in Arctostaphylos L. (Ericaceae), a zoochorous, primarily Californian chaparral shrub genus. We measured fruit size, strongly correlated with seed size in Arctostaphylos, in three species of this genus from multiple localities in the Sierra Nevada foothills, and conducted a character analysis of fruit size across the genus using the standard California flora plant manual (Baldwin et al. 2012). Across the genus we found a weak negative correlation between fruit size and latitude (0.0026 mm diameter/km) and a weak positive correlation between fruit size and elevation (1.3 mm diameter/ km). AIC indicates that these trends are not explained by autocorrelation between fruit size and other variables such as maximum plant size. By contrast, intraspecific field data revealed a positive relationship between fruit size and both elevation and latitude. Propagule size gradients within Arctostaphylos oppose those reported for angiosperms globally. This contrast may result from uniformity of fruit structure and animal dispersal, disturbance ecology of chaparral, or local precipitation gradients characteristic of Mediterranean-type climates. Studies of propagule size gradients within taxa can uncover ecological mechanisms behind this trend that remain obscure at global scales.

Traditionally, national mapping agencies produced datasets and map products for a low number of specified and internally consistent scales, i.e. at a common level of detail (LoD). With the advent of projects like OpenStreetMap, data users are increasingly confronted with the task of dealing with heterogeneously detailed and scaled geodata. Knowing the scale of geodata is very important for mapping processes such as for generalization of label placement or land-cover studies for instance. In the following chapter, we review and compare two concurrent approaches at automatically assigning scale to OSM objects. The first approach is based on a multi-criteria decision making model, with a rationalist approach for defining and parameterizing the respective criteria, yielding five broad LoD classes. The second approach attempts to identify a single metric from an analysis process, which is then used to interpolate a scale equivalence. Both approaches are combined and tested against well-known Corine data, resulting in an improvement of the scale inference process. The chapter closes with a presentation of the most pressing open problems

La généralisation de données géographiques vectorielles est un problème spatialisé complexe qui consiste à simplifier des données géographiques (bâtiments, routes, etc.) pour satisfaire au mieux des contraintes de lisibilité. Il existe beaucoup de processus automatiques (dont certains reposent sur des SMA) spécialisés sur une partie du problème. Nous proposons une approche de résolution par agents, que nous appelons généralisation collaborative, pour réaliser l'orchestration de ces processus automatiques dans le but de généraliser une carte complètement. Notre approche combine des techniques de résolution spatiale, utilisées dans les SMA dédiés à la généralisation cartographique, avec des agents processus, choisis selon leurs capacités, pour traiter une partie de l'espace. Un prototype a été développé et des expérimentations de généralisation collaborative sont présentées.

Abstract. Dechter et al. [5] proposed solving the Temporal Constraint Satisfaction Problem (TCSP) by modeling it as a meta-CSP, which is a finite CSP with a unique global constraint. The size of this global constraint is exponential in the number of time points in the original ...

In 1995, the Manual of California Vegetation introduced a quantitatively based method for classifying and mapping vegetation in California. We used this method to develop a classification of vegetation types for Napa County, which we then used to attribute the polygons of a new vegetation map. The new map was produced by on-screen digitizing over USGS Digital Orthophoto Quarter Quads (DOQQ's) with the aid of ancillary digital maps. We identified the distribution of 56 landcover types, 48 dominated by natural vegetation, at the alliance or aggregated alliance level, in 28,456 polygons across 2042 km 2. The effective minimum mapping unit is below one hectare. The methods used, the mapping classification system developed, and the extents of landcover types mapped are presented. In a comparison with two previous digital vegetation maps for the area, the US Forest Service's CalVeg and the Gap Analysis Program's GAP maps, the MCV map had finer spatial and floristic resolution. The MCV map has 15 more vegetation types than CalVeg and 22 more vegetation types than GAP. The MCV map contains more riparian corridors and isolated wetlands, identifying 157 km 2 of these types, compared to 7 km 2 for CalVeg and a non-spatial result for GAP.

Ce numero traite des activites de recherche de l'Institut Geographique National-France en 1997. Il dresse un bilan des progres realises en traitement d'images et de cartes scannees, en photogrammetrie, en instrumentation, en base de donnees geographiques, en cartographie et en geodesie. Il aborde plus particulierement les sujets suivants : le filigrane pour proteger des cartes scannees, la restitution automatique des bâtiments sur photos aeriennes, les images aeriennes numeriques en couleur, la mise a jour des bases de donnees geographiques, la generalisation cartographique du reseau routier, l'appariement geometrique de surfaces, une nouvelle generation de realisation du Systeme International de Reference Terrestre, la determination des variations du centre des masses de la Terre, la synergie entre la maregraphie et la geodesie spatiale.

A wealth of digital data are produced during an archaeological excavation and because so much of the fieldwork is unrepeatable, once the site is fully excavated, the digital records must be archived in a manner that best facilitates reuse. This paper presents three case studies of users wishing to reuse digital archaeological data from online repositories, with a specific focus on absolute and relative dating evidence. We discuss the problems encountered and how they reflect the wider issues of the reuse of digital archaeological data. Additionally, we provide recommendations specific to chronological data that seek to address the problems encountered.

Primarily driven by current advances in web, web service and sensors technologies, and the expressed needs from geospatial and broader communities, the webbased sensors and geoprocessing service fields have evolved rapidly over the last 10 years. Geoprocessing services greatly facilitate the process of transforming geospatial data to geoinformation, exposing the powerful analytic capability of geographic information system (GIS) and empowering the public in today's "electronic" decision-making over the worldwide web, particularly within spatial data infrastructure frameworks, through service composition, utilization of advanced grid/cloud computing, and well-designed client-side applications. The research topics and issues range from discovery, accessibility, usability to interoperability, which require standards support, and cooperation among academia, industry, government, commercial, and open source communities. This special issue builds on the extended version of seven papers selected from the papers submitted to the first International Workshop on Pervasive Web Mapping, Geoprocessing and Services, which was successfully held on the Politecnico di Milano campus in Como, Italy from August 26 to 27, 2010. The workshop was organized by ISPRS WG IV/5 on "Distributed, Web-based Geoinformation Services and Applications" and Politecnico di Milano, and coorganized by ISPRS WG WG IV/1 on "Geospatial Data Infrastructure", WG IV/4 on "Virtual Globes and Context-Aware Visualization", and ICWG IV/II on "Geo-Sensor Networking and GEOGRID". The main theme of the workshop focused on Sensor Web Enablement and Geoprocessing Services. Some of the particular topics and issues addressed in the technical sessions

The framework of Temporal constraint Satisfaction Problems (TCSP) has been proposed for representing and processing temporal knowledge. Deciding consistency of TC-SPs is known to be intractable. As demonstrates in this paper, even local consistency algorithms like path-consistency can be exponential due to the fragmentation problem. We present t wo new polynomial approximation algorithms, Upper-Lower-Tightening (ULT) and Loose-Path-Consistency (LPC), which are ecient y et eective in detecting inconsistencies and reducing fragmentation. The experiments we performed on hard problems in the transition region show that LPC is the superior algorithm. When incorporated within backtrack search LPC is capable of improving performance by orders of magnitude.

Uncontrolled exploitation of groundwater in many parts of the world has led to a sharp drop in groundwater levels. In this study, changes in Ardabil plain groundwater level were studied using geographic information system (GIS). For this purpose, the interpolation table method was used, the intrinsic data as table data of piezo metric wells was used. In order to implement the model, the Majol Geoestatical in geographic information system software was used. The data entered as regions into the geographic information system, and then done for the entire zoning area, due to zoning 8 models, the IDW, GPI, RBF, LPI, KO, KS, KU and EBK in geostatical extension were evaluated. The ordinary kriging method (KO) with the lowest RMSE, was determined as the most accurate one, and finally, as the ultimate method for zoning and map providing for the changes in groundwater levels drop of the region. The results of classification showed that the biggest drop of about 40 meters was in the areas close to the southeastern parts of the study region and in other areas, little changes were observed, this rate of the change and decline in some parts of the desert like southern regions is very tangible and specified.

Since its inception in Reston, VA in 1974, the AutoCarto biennial conference series has brought together leading researchers in cartography and geographic information systems and science to their present cutting-edge research in cartography, geospatial science and visualization. AutoCarto 2018 was held jointly with the University Consortium for Geographic Information Science (UCGIS) at the Historic Concourse Hotel in Madison, Wisconsin, USA on May 22-24. This is the second time that the UCGIS Symposium and AutoCarto have been coordinated for participants, the first being in 2006 in Vancouver, Washington. We received 1 position paper, 26 extended abstracts to be considered for both presentation at the conference and publication consideration in the CaGIS Journal, 23 short abstracts to be considered for presentation only, 3 abstracts for lightning talks, 3 abstracts for poster presentations and 14 abstracts for the student poster competition. Each submission was reviewed by at least two Program Committee members.

Human interactions with geographical information are contextualized by problem-solving activities which endow meaning to geospatial data and processing. However, existing spatial data models have not taken this aspect of semantics into account. This paper extends spatial data semantics to include not only the contents and schemas, but also the contexts of their use. We specify such a semantic model in terms of three related components: context knowledge, contextualized ontology base, and context-sensitive interpretation. Such contextualization of spatial data semantics allows the same underlying data to take multiple semantic forms, and disambiguate spatial concepts based on localized contexts. We demonstrate how such a semantic model supports contextualized interpretation of vague spatial concepts during human-GIS interactions. We employ conversational dialogue as the mechanism to perform collaborative diagnosis of context and to coordinate sharing of meaning across agents and contexts.

Recently, many studies have investigated the effect of climate change on groundwater resources in semiarid and arid areas and have shown adverse effects on groundwater recharge and water level. However, only a few studies have shown suitable strategies for reducing these adverse effects. In this study, climate conditions were predicted for the future period of 2020-2044, under the emission scenarios of RCP2.6, RCP4.5, and RCP8.5, for Isfahan-Borkhar aquifer, Isfahan, Iran, using MODFLOW-2000 (MODFLOW is United States Geological Survey product). Results showed that the average groundwater level of the aquifer would decrease to 13, 15, and 16 m in 2012 to 2044 approximately under RCP2.6, RCP4.5, and RCP8.5 scenarios, respectively. Then, three groundwater sustainability management scenarios were defined that included 10%, 30%, and 50% reduction in groundwater extraction. These strategies simulated the reduced negative effects of climate change on the aquifer. The results showed that decreases in water withdrawal rates of 10%, 30%, and 50% under RCP8.5 scenario (critical scenario) could decrease the mean groundwater level by 14, 11, and 7 m, respectively. The main result of the study showed that 50% reduction in groundwater withdrawal may increase the groundwater levels significantly in order to restore the aquifer sustainability in the study area. In this study, with assuming that the current harvest of wells in the future period is constant, so the results of studies showed that for the aquifer's sustainability management, the water abstraction from the aquifer should reduce up to 50% of the existing wells. Changing the irrigation method from surface to subdroplet irrigation plays an important role in reducing the withdrawal from the aquifer. The results of a study in Iran have shown that the change in the irrigation method from surface to subdroplet irrigation causes a 40% reduction in water use for agriculture.

User-generated contents are developing rapidly through VGI and contributors create the tags through the Web applications in a free mechanism. Semantic Knowledge in VGI like other user-generated contents needs to be combined with other authoritative data sources. One of the main challenges of integration is the semantic heterogeneity of user-generated contents which are describing the geographical objects as POIs. Geographical objects can be described in different semantic levels such as purpose or function. Significance of semantic levels defines the importance of related attributes. Analysis of significance for semantic levels of different POIs can be considered as a base to enhance the semantic quality of VGI. This paper proposes an approach based on the notions of rough set theory to measure the significance of semantic levels of tags which are applied to describe the buildings in OpenStreetMap. The proposed approach is implemented for tags which are applied to describe buildings in OpenStreetMap. Results show the high significance for tags which describing the semantic levels of geographic information constructs and purpose/ function for buildings.

Keeping this species in check at this time will prevent the spread of the species. The banks of the Stanislaus River are prime habitat for this species and may be a focal point for control. Carduus pycnocephalus (Italian Thistle) Cal-IPC List B. Carduus pycnocephalus is an annual thistle, introduced from the Mediterranean with reports of its occurrence as early as 1912 (Bossard et al. 2000). It is widespread in the grasslands and oak woodlands within the study area. It is considered less invasive than some other species of thistle but once established it can come to dominate a site. It is the most abundant of the exotic thistles within the study area. It was found in 30 associations, ranging in absolute cover from <1% to as high as 40%. Control may center on identifying those areas of heaviest infestation. Research of the literature seems to indicate that mechanical control and grazing are the most effective methods. Treatment, however, requires being persistent over a period of several years. Centaurea melitensis (Maltese Star-thistle) Cal-IPC List B Centaurea melitensis is an annual thistle, first introduced to California during the Spanish mission period. Dense infestations can displace native plants and animals (Bossard et al. 2000). Though placed on Cal-IPC List B, it is noted that this species may be more widespread than realized. It is often mistaken for C. solstitialis. The plant can be toxic to horses if ingested over long periods. Little work has focused on the control of C. melitensis with more focus given to C. solstitialis. With similar life-forms and habit, control methods used for C. solstitialis may be effective on C. melitensis (Bossard et al. 2000). Control may center on identifying those areas of heaviest infestation. It is the second most abundant of the exotic thistle species. It occurs in 24 associations ranging in absolute cover from <1% to as high as 20%. Centaurea solstitialis (Yellow Star-thistle) Cal-IPC-List A-2 Centaurea solstitialis is considered one of the most noxious weeds in the state. It can form dense impenetrable stands diminishing the quality of rangelands and displacing other vegetation. It has spread rapidly since the mid-1900s and has come to infest 15-20 million acres throughout California. It is believed to have begun invading the Sierra foothills in the 1930s and 1940s (The Nature Conservancy 2004). Like C. melitensis, the plant is toxic to horses. 5000-Deciduous Shrubland 5400-Winter Rain Drought Deciduous Shrubland 5401-Poison Oak Alliance 5500-Seasonally Flooded Deciduous Shrubland 5501-Mixed Riparian Shrub Mapping Unit (including Salix spp., Calycanthus occidentalis, Rhamnus tomentella, etc) 6000-Perennial Herbaceous (Graminoid-Forbs) 6100-Bunch Forming Grasses 6101-Serpentine Native Wet Perennial Grassland (Hordeum brachyantherum, Carex spp., Juncus spp.

Ce numero traite des activites de recherche de l&#39;Institut Geographique National-France en 1997. Il dresse un bilan des progres realises en traitement d&#39;images et de cartes scannees, en photogrammetrie, en instrumentation, en base de donnees geographiques, en cartographie et en geodesie. Il aborde plus particulierement les sujets suivants : le filigrane pour proteger des cartes scannees, la restitution automatique des bâtiments sur photos aeriennes, les images aeriennes numeriques en couleur, la mise a jour des bases de donnees geographiques, la generalisation cartographique du reseau routier, l&#39;appariement geometrique de surfaces, une nouvelle generation de realisation du Systeme International de Reference Terrestre, la determination des variations du centre des masses de la Terre, la synergie entre la maregraphie et la geodesie spatiale.

Introduction: Studies have demonstrated that the presence of standard amount of fluoride in drinking water can prevent tooth decay. Meanwhile, higher concentration than permitted amount in drinking water causes bone disease and dental fluorosis. Given the importance of fluoride in drinking water as well as GIS ability in spatial analysis of various factors in the groundwater, this study aimed to evaluate concentration of fluoride in the plain of Yazd-Ardakan using two IDW (Inverse Distance Weighting) and

Questions: Has tree density changed consistently across vegetation types? Do changes in component species correspond with changes across vegetation types? Do patterns of changes suggest potential drivers of change? Location: Northern two-thirds of the Sierra Nevada, CA, USA, ca. 45 000 km 2. Methods: Using two data sets that cover the span of elevations and land jurisdictions in the study area, we classified 4321 historical plots and 1000 modern plots into nine broad groups of vegetation types that are widely used by land managers and researchers in the region. We compared tree density and composition between historical and modern plots across and within these nine types. Results: In the modern data set, tree density was significantly higher in eight of nine vegetation types. Total density was significantly higher in modern plots for all west slope types, especially for montane hardwood, where modern forests are 128% denser, and mixed conifer forests, which are 69% denser. Relative density of component species was also very different between data sets in these forests, and suggests a shift in dominance toward shade-tolerant conifers and evergreen oaks. Fire suppression is likely a driving factor in these types but density was also significantly higher in high-elevation types such as sub-alpine forest (+20%), where neither fire suppression nor logging have had major impacts on structure. East slope forest types (eastside P. jeffreyi forest and piñon-juniper woodland) were very similar in both modern and historical data sets, with no significant differences in density or composition. Conclusion: West slope forest types, especially montane hardwood and mixed conifer forest, appear the most altered types of the mountain range. These types are more productive but have also been subject to greater disturbance than high-elevation and east slope forest types. Climate change may also be driving changes across the study area. Species such as Quercus chrysolepis and Calocedrus decurrens, which have each increased markedly in abundance, appear well positioned to dominate in the near future, especially under continued fire suppression and a warmer climate.

Iran, being located in arid and semi-arid regions, faces an increase in human demand for water, and the global climate change has led to the excessive use of groundwater. China, India and Iran were ranked from first to third, respectively, in excessive groundwater consumption in 2005. The effects of effective parameters on groundwater recharge such as precipitation, surface recharge and well water harvesting in the Karvan aquifer are assessed. Groundwater flow models have typically been and are being adopted since the beginning of this millennium to better manage groundwater resources. The decrease in groundwater level and the potential environmental hazards thereof have made the researchers here to apply the Groundwater Modelling System (GMS software) in 3D in the subject area. This modelling is calibrated and validated for 86 months at steady and unsteady states. In this study, six scenarios are defined as both an increase and a decrease of 30% in precipitation, both an increase a...

Studies have demonstrated that the presence of nitrate and nitrite in drinking water can cause some disease such as cancer and blu baby in the infant. The Environmental Protection Agency (EPA) has since adopted the 10 mg/L standard as the maximum contaminant level (MCL) for nitrate-nitrogen and 1 mg/L for nitrite-nitrogen for regulated public water systems. Given the importance of nitrate and nitrite in drinking water as well as GIS ability in spatial analysis of various factors in the groundwater, this study aimed to evaluate concentration of nitrate and nitrite in the drinking water wells of Yazd using two IDW (Inverse Distance Weighting) and Kriging models. In this descriptive study, the applied data on the water quality of underground water of Yazd Environmental Health Office and the average annual nitrate and nitrite in 2015 were related to 24 wells in the studied area. The nitrate and nitrite rate in groundwater in wells was compared to the standard amount of Institute of Standard and Industrial Researches and then was analyzed via Arc GIS software using IDW and Kriging interpolation methods. The mean concentration of nitrate was 17.62 ± 3.08 mg/l and for nitrite was 0.011 ± 0.003 mg/l in the wells. In the all studied zone, the nitrate and nitrite rate was in the standard range according to the National Standard of Iran (No.

Stands of montane chaparral are an integral component of the mixed conifer forest in the Cascade Mountains of northern California. In this region, chaparral stands found on sites that could support trees are thought to have established following high severity fire. The exclusion of fire for over a century may have allowed trees to invade chaparral. The conversion of chaparral to forest has reduced chaparral in the mixed conifer landscape. This study investigated the timing and spatial dynamics of chaparral and tree establishment in six chaparral stands in Lassen Volcanic National Park, California. Findings include that the oldest chaparral established after a fire event and were older than most trees in the stand. The chaparral were multi-aged, indicating continued resprouting in the absence of fire. Tree density (trees hectare-1) was higher closer to the forest edge than further into the chaparral, suggesting gradual tree invasion from the forest. Pinus jeffreyi were older at the f...

Geographic information systems (GIS) have considerable potential for extending the study of spatial processes in archaeology. However, the present structure of GIS is currently atemporal and consequently only able to deal with spatial phenomena in a single instant of time. If past events and processes cannot be linked to each other, or to the present, we cannot hope effectively to model trends in the past, nor understand fully the nature of dynamic process. This is a problem which has been recognised within the GIS community and a considerable degree of research is currently being directed toward the operational development of a temporal dimension in GIS (cf. Langran 1989a, 1989b, forthcoming; Barrera & AlTaha 1990; Barerra et al. 1990). Because archaeologists are beginning to make considerable use of GIS (cf. Kvamme 1986a, 1986b, 1989; Peregrine 1988; Wansleeben 1988; Allen et al. 1990), and because archaeologists have a significant interest in cultural change over time, the search...

Beyond the relational database: managing the variety and complexity of archaeological data. . 1 Nick Ryan 1.1 Introduction j 1.2 Integrated systems: current possibilities 1.3 Adding new data types 3 1.4 Conclusions References ^ 2. The archaeological database-new relations? P.N. Cheetham & J.G.B. Haigh 2.1 Introduction 2.2 The problem 2.3 Temporal databases ^ 2.3a Rollback databases 3 2.3b Historical databases g 2.4 Null values 9 2.4a Archaeological 'unknowns' J^Q 2.4b Internal representation of null values \\ 2.5 Abstract Data Types i\ 2.6 Procedures as database extensions 12 2.7 Expert systems and relational databases 13 2.8 Concluding notes 13 6. Object-oriented design for excavation simulation programming 39 Leonor Barroca & Sebastian Rahtz 6.1 Introduction 39 6.2 Object-Oriented languages 39 6.2a A bit of history 39 6.2b Object-Oriented databases 40 6.2c Smalltalk 40 6.3 The SYASS project 6.4 The Smalltalk implementation of SYGRAF 6.4a Object-Oriented design methodology 6.4b The model 6.4b (i) The objects/classes 6.4b (ii) Formalizing the Model 42 6.4b (iii) The hierarchy 42 6.4c The implementation 43 6.4d The SMALLSY implementation 44 6.5 Comparison 44 6.6 Conclusions Acknowledgements 47 References 47 7. An experiment in electronic exchange and publication of archaeological field data 49 Neel Smith 7.1 Archaeology as rhetoric 49 7.2 Publication of field research 7.3 The Southern Euboea Exploration Project 50 7.4 Perseus 7.4a Electronic information interchange in Perseus 7.4b Standard Generalized Markup Language 51 7.5 Example of implementations 51 7.6 Perseus site catalogue 7.7 SEEP material in Perseus 7.8 Structures underlying implementations 7.9 A possible evolution away from the unpublished archive 7.10 Conclusions

Developing intelligent and interactive systems with visual user interfaces is essential for any website and mobile device. In this study, we propose a new web-based shopping system to elicit buyer's requirements and preferences and to provide a set of suggestions accordingly. This process is achieved by first representing the elicited information through graphical models and then solving the underlying constrained problem. More precisely, we have used the Weighted CP-nets (WCP-net) graphical model to allow the user to express finegrained preferences on the product attributes and their values in a quantitative or a conditional qualitative form. The latter has been extended in this paper to include constraints between attributes. A backtrack search algorithm is then performed to solve the constrained WCP-net and to return a set of Pareto optimal solutions satisfying all the constraints and maximizing all the preferences.

Proposed causes of the latitudinal-propagule size gradient invoke differences among biome structures or seed dispersal syndromes. Latitudinal seed-size gradients so far have been predominantly investigated using entire floras, prompting the question of whether such trends exist at smaller scales. Here we consider effects of latitude and elevation on fruit size between and within species in Arctostaphylos L. (Ericaceae), a zoochorous, primarily Californian chaparral shrub genus. We measured fruit size, strongly correlated with seed size in Arctostaphylos, in three species of this genus from multiple localities in the Sierra Nevada foothills, and conducted a character analysis of fruit size across the genus using the standard California flora plant manual (Baldwin et al. 2012). Across the genus we found a weak negative correlation between fruit size and latitude (0.0026 mm diameter/km) and a weak positive correlation between fruit size and elevation (1.3 mm diameter/ km). AIC indicates that these trends are not explained by autocorrelation between fruit size and other variables such as maximum plant size. By contrast, intraspecific field data revealed a positive relationship between fruit size and both elevation and latitude. Propagule size gradients within Arctostaphylos oppose those reported for angiosperms globally. This contrast may result from uniformity of fruit structure and animal dispersal, disturbance ecology of chaparral, or local precipitation gradients characteristic of Mediterranean-type climates. Studies of propagule size gradients within taxa can uncover ecological mechanisms behind this trend that remain obscure at global scales.

Recent trends in information technology show that citizens are increasingly willing to share information using tools provided by Web 2.0 and crowdsourcing platforms to describe events that may have social impact. This is fuelled by the proliferation of location-aware devices such as smartphones and tablets; users are able to share information in these crowdsourcing platforms directly from the field at real time, augmenting this information with its location. Afterwards, to retrieve this information, users must deal with the different search mechanisms provided by the each Web 2.0 services. This paper explores how to improve on the interoperability of Web 2.0 services by providing a single service as a unique entry to search over several Web 2.0 services in a single step. This paper demonstrates the usefulness of the Open Geospatial Consortium's Open Search Geospatial and Time specification as an interface for a service that searches and retrieves information available in crowdsourcing services. We present how this information is valuable in complementing other authoritative information by providing an alternative, contemporary source. We demonstrate the intrinsic interoperability of the system showing the integration of crowd-sourced data in different scenarios.

Volunteered Geographic Information (VGI) projects such as OpenStreetMap (OSM) have been growing in users and edits in the past few years, resulting in more accurate, complete and up-to-date datasets. As a result, governments are now interested in VGI as a source of information that could help to improve their own datasets. Integrating geographic information requires solving semantic heterogeneity in a way that allows the identification of features in different datasets representing the same real phenomena. This paper presents a method that uses ontologies for identifying sets of homologous features in VGI and authoritative geographic sources. The method is based on two steps. First, a domain ontology is used as a common knowledge among datasets. Second, direct mapping from the datasets to the domain ontology is done, resulting in new datasets using the same vocabulary.

A wealth of digital data are produced during an archaeological excavation and because so much of the fieldwork is unrepeatable, once the site is fully excavated, the digital records must be archived in a manner that best facilitates reuse. This paper presents three case studies of users wishing to reuse digital archaeological data from online repositories, with a specific focus on absolute and relative dating evidence. We discuss the problems encountered and how they reflect the wider issues of the reuse of digital archaeological data. Additionally, we provide recommendations specific to chronological data that seek to address the problems encountered.

A wealth of digital data are produced during an archaeological excavation and because so much of the fieldwork is unrepeatable, once the site is fully excavated, the digital records must be archived in a manner that best facilitates reuse. This paper presents three case studies of users wishing to reuse digital archaeological data from online repositories, with a specific focus on absolute and relative dating evidence. We discuss the problems encountered and how they reflect the wider issues of the reuse of digital archaeological data. Additionally, we provide recommendations specific to chronological data that seek to address the problems encountered.