652 research outputs found

    Kam-Kotia tailings reclamation by ecological engineering : feasibility evaluation : phase 1.

    Get PDF
    In fulfillment of P.O. # 12457Report examines the potential use of ecological engineering in the rehabilitation of mine tailings at the Kam-Kotia mine. The report outlines a program for rehabilitation

    Remote sensing in the Sudan

    Get PDF
    Report on a remote sensing pilot project in the Sudan, and the application of remote sensing in natural resources inventory - describes the project area within the savanna belt of the Sudan, field activity; examines images obtained through aerial surveying and from the Landsat communications satellite; outlines the training course undertaken by Sudanese scientists, computer-assisted technique for classification of images; includes an evaluation of the training programme, recommendations, statistical data

    Integrated Remote Sensing, Structural and Petroleum Systems Modeling of the Iraqi‐Kurdish Fold Belt

    Get PDF
    An integrated two‐dimensional remote sensing, structural and petroleum systems modeling study was carried out for the Iraqi‐Kurdish Fold Belt to analyze potential trap structures as well as the driving mechanisms of petroleum generation, migration and accumulation in the structural complex thrust belt area. Processing of Landsat‐7 ETM data has been used to create false color images, highlighting lithological differences, from which geological maps can be generated. Analysis of lineaments in these images is used to generate fault and fracture maps, producing a suite of geological surface maps. In addition, analysis of drainage patterns and erosional features is used to understand the relative age of the structures. Key regions were selected for ground‐truthing. Lastly, these maps were combined with published and proprietary subsurface data to create a structural cross‐section of the Qara Chauq to Bina Bawi transect of the Kurdish Folded Belt. The cross‐section indicates that a minimum of 20% shortening has occurred across this region. Twelve paleo‐sections, including pre‐ and post erosion geometries, were used for the model building process. The model features both, basement faults and surface folds as well as thrust geometries that accommodate the structural framework and its development. The strata were modeled as an alternating limestone and shale sequence. The Sargelu and the Kurra Chine Fm were considered as source rock intervals. The reservoir rocks include the Shiranish, Aqra‐Bekhme and the Sargelu Fm. The Gercus Fm acts as a regional seal horizon. Special focus was laid on the N‐S trending basement faults and their evolution through time since these faults appear to divide the petroleum system into areas of differing maturity. The influence of fault permeability evolution upon petroleum migration has been evaluated to unfold the charge history of the region. Temperature and vitrinite reflectance data derived from key wells and literature have been used for thermal calibration. The model results and a detailed petroleum systems analysis show the differential maturation and generation behavior of the source rock compartments and reveal the major influence of timing and fault migration for the oil & gas charge over time

    Use of structured expert judgment to forecast invasions by bighead and silver carp in Lake Erie

    Full text link
    Identifying which nonindigenous species will become invasive and forecasting the damage they will cause is difficult and presents a significant problem for natural resource management. Often, the data or resources necessary for ecological risk assessment are incomplete or absent, leaving environmental decision makers ill equipped to effectively manage valuable natural resources. Structured expert judgment (SEJ) is a mathematical and performance‐based method of eliciting, weighting, and aggregating expert judgments. In contrast to other methods of eliciting and aggregating expert judgments (where, for example, equal weights may be assigned to experts), SEJ weights each expert on the basis of his or her statistical accuracy and informativeness through performance measurement on a set of calibration variables. We used SEJ to forecast impacts of nonindigenous Asian carp (Hypophthalmichthys spp.) in Lake Erie, where it is believed not to be established. Experts quantified Asian carp biomass, production, and consumption and their impact on 4 fish species if Asian carp were to become established. According to experts, in Lake Erie Asian carp have the potential to achieve biomass levels that are similar to the sum of biomasses for several fishes that are harvested commercially or recreationally. However, the impact of Asian carp on the biomass of these fishes was estimated by experts to be small, relative to long term average biomasses, with little uncertainty. Impacts of Asian carp in tributaries and on recreational activities, water quality, or other species were not addressed. SEJ can be used to quantify key uncertainties of invasion biology and also provide a decision‐support tool when the necessary information for natural resource management and policy is not available.El Uso de Juicio Experto Estructurado para Predecir Invasiones de Carpas Asiáticas en el Lago ErieResumenIdentificar cuáles especies no‐nativas se volverán invasoras y predecir el daño que causarán es complicado y presenta un problema significativo para el manejo de recursos naturales. Con frecuencia los datos o recursos necesarios para la evaluación de riesgo ecológico están incompletos o son inexistentes, lo que deja mal equipados a quienes toman las decisiones ambientales para manejar efectivamente recursos naturales valiosos. El juicio experto estructurado (JEE) es un método con bases matemáticas y de desempeño para obtener, sopesar y agregar juicios expertos. En contraste con otros métodos de obtención y agregación de juicios expertos (donde, por ejemplo, se le pueden asignar pesos iguales a los expertos), JEE sopesa a cada experto con base en su asertividad estadística y capacidad de informar por medio de la medida de desempeño en un conjunto de variables de calibración. Usamos JEE para predecir los impactos de las carpas asiáticas no‐nativas Hypophthalmichthys spp. en el Lago Erie, donde se cree que no se ha establecido. Los expertos cuantificaron la biomasa, producción y consumo de la carpa asiática y su impacto sobre cuatro especies de peces si la carpa asiática se llegara a establecer en el lago. De acuerdo a los expertos, en el Lago Erie, la carpa asiática tiene el potencial de adquirir niveles de biomasa similares a la suma de biomasa de varios peces que se han cultivado comercialmente o recreativamente. Sin embargo, se estimó por los expertos que el impacto de la carpa asiática sobre la biomasa de estos peces sería pequeño, con poca incertidumbre. Los impactos de la carpa asiática sobre los tributarios y las actividades recreativas, la calidad del agua o sobre otras especies no se evaluaron. El JEE puede usarse para cuantificar incertidumbres clave de la biología de la invasión y también proporcionar una herramienta de apoyo para las decisiones cuando la información necesaria para el manejo de los recursos naturales y la política no está disponible.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110571/1/cobi12369.pd

    The Relative Influence of Habitat Amount and Configuration on Genetic Structure Across Multiple Spatial Scales

    Get PDF
    Despite strong interest in understanding how habitat spatial structure shapes the genetics of populations, the relative importance of habitat amount and configuration for patterns of genetic differentiation remains largely unexplored in empirical systems. In this study, we evaluate the relative influence of, and interactions among, the amount of habitat and aspects of its spatial configuration on genetic differentiation in the pitcher plant midge, Metriocnemus knabi. Larvae of this species are found exclusively within the water-filled leaves of pitcher plants (Sarracenia purpurea) in a system that is naturally patchy at multiple spatial scales (i.e., leaf, plant, cluster, peatland). Using generalized linear mixed models and multimodel inference, we estimated effects of the amount of habitat, patch size, interpatch distance, and patch isolation, measured at different spatial scales, on genetic differentiation (F ST) among larval samples from leaves within plants, plants within clusters, and clusters within peatlands. Among leaves and plants, genetic differentiation appears to be driven by female oviposition behaviors and is influenced by habitat isolation at a broad (peatland) scale. Among clusters, gene flow is spatially restricted and aspects of both the amount of habitat and configuration at the focal scale are important, as is their interaction. Our results suggest that both habitat amount and configuration can be important determinants of genetic structure and that their relative influence is scale dependent
    corecore