2,768 research outputs found

    An assessment of the impact of water impoundment and diversion structures on vegetation in Southern Arizona

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    High-altitude color infrared photography was used to survey existing conditions, both upstream and downstream, from nineteen diversion structures in Southern Arizona to determine their effect upon vegetation health, vigor, and cover. A diversion structure is defined as a man/made feature constructed to control storm runoff. The results are used to determine the policy for future structure design

    Hyperspectral monitoring of green roof vegetation health state in sub-mediterranean climate: preliminary results

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    In urban and industrial environments, the constant increase of impermeable surfaces has produced drastic changes in the natural hydrological cycle. Decreasing green areas not only produce negative effects from a hydrological-hydraulic perspective, but also from an energy point of view, modifying the urban microclimate and generating, as shown in the literature, heat islands in our cities. In this context, green infrastructures may represent an environmental compensation action that can be used to re-equilibrate the hydrological and energy balance and reduce the impact of pollutant load on receiving water bodies. To ensure that a green infrastructure will work properly, vegetated areas have to be continuously monitored to verify their health state. This paper presents a ground spectroscopy monitoring survey of a green roof installed at the University of Calabria fulfilled via the acquisition and analysis of hyperspectral data. This study is part of a larger research project financed by European Structural funds aimed at understanding the influence of green roofs on rainwater management and energy consumption for air conditioning in the Mediterranean area. Reflectance values were acquired with a field-portable spectroradiometer that operates in the range of wavelengths 350–2500 nm. The survey was carried out during the time period November 2014–June 2015 and data were acquired weekly. Climatic, thermo-physical, hydrological and hydraulic quantities were acquired as well and related to spectral data. Broadband and narrowband spectral indices, related to chlorophyll content and to chlorophyll–carotenoid ratio, were computed. The two narrowband indices NDVI705 and SIPI turned out to be the most representative indices to detect the plant health status

    Vegetation Health and vegetative drought conditions: Case Study of AVHRR/VIIRS Data in Tigray Region, Ethiopia

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    In this study, weekly mean of vegetation health index (VHI) for Tigray region from 1982 to 2016 was compared with mean VHI during 2017. The Vegetation Health index (VHI) is based on a combination of products extracted from vegetation signals, namely the Normalized Difference Vegetation Index (NDVI) and from the brightness temperatures, both derived from the NOAA Advanced Very High-Resolution Radiometer (AVHRR) sensor. The data and images have 4 km spatial and 7-day composite temporal resolution. VH is calculated based on strong inverse correlation between NDVI and land surface temperature, since increasing land temperatures are assumed to act negatively on vegetation and consequently to cause stress. The VHI values range from 0 to 100, the low values representing stressed vegetation health conditions, middle values representing fair health conditions, and high values representing optimal or above-normal vegetation health conditions. Vegetative drought conditions were calculated using vegetation health conditions as proposed by Kogan. Extreme Drought<10 VHI, Severe Drought<20 VHI, Moderate Drought<30VHI, Mild Drought <40 VHI, No Drought>40 VHI. The results showed during 1985, 1990 – 91, 2009 and 2015-16 there was large area covered under drought conditions in Tigray Region. Drought conditions were found in Tigray region during 32nd week to 42nd week of 2017. Results shows eastern and south eastern part of Tigray has not been as much affected as western and central part of Tigray during 2017

    Three undescribed pathogenic Phytophthora taxa from the south-west of Western Australia

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    The Phytophthora culture collection of the Vegetation Health Service of the Department of Environment and Conservation of Western Australia (WA) has been re-evaluated using DNA sequencing (Burgess et al., 2009). This has revealed many undescribed taxa previously classified as known morpho-species, one of which has recently been described as P. multivora (Scott et al., 2009). The aim of this study was to describe three of these taxa, all of which occur in WA native ecosystems. They were compared with both the morphological species to which they are most similar and their closest phylogenetic relatives. In addition, the pathogenicity of these taxa was assessed in glasshouse trials

    Meteorological drought analysis in the Lower Mekong Basin using satellite-based long-term CHIRPS product

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    Lower Mekong Basin (LMB) experiences a recurrent drought phenomenon. However, few studies have focused on drought monitoring in this region due to lack of ground observations. The newly released Climate Hazards Group Infrared Precipitation with Station data (CHIRPS) with a long-term record and high resolution has a great potential for drought monitoring. Based on the assessment of CHIRPS for capturing precipitation and monitoring drought, this study aims to evaluate the drought condition in LMB by using satellite-based CHIRPS from January 1981 to July 2016. The Standardized Precipitation Index (SPI) at various time scales (1-12-month) is computed to identify and describe drought events. Results suggest that CHIRPS can properly capture the drought characteristics at various time scales with the best performance at three-month time scale. Based on high-resolution long-term CHIRPS, it is found that LMB experienced four severe droughts during the last three decades with the longest one in 1991-1994 for 38 months and the driest one in 2015-2016 with drought affected area up to 75.6%. Droughts tend to occur over the north and south part of LMB with higher frequency, and Mekong Delta seems to experience more long-term and extreme drought events. Severe droughts have significant impacts on vegetation condition

    LINKING HISTORICAL, FIELD, AND SATELLITE DATA TO DETERMINE THE RELATIONSHIP BETWEEN GAS EMISSIONS AND VEGETATION CHANGE IN THE PUHIMAU GEOTHERMAL AREA EAST RIFT ZONE KILAUEA, HAWAII

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    The Puhimau geothermal area, located near the summit of the Kilauea volcano, Hawaii, has been suggested to represent a ‘window’ into the East Rift Zone. The quantification of CO2 and H2S soil gas emissions improves our understanding of its gas emission mode- including total emission and spatial distribution and contribute to a more accurate estimation of total CO2 and H2S in the thermal area – and how these gas emissions relate to observed vegetation health from satellite data. The total emission of CO2 and H2S was interpolated by the sequential Gaussian simulation method (SGS) using Stanford Geostatistical Modeling Software (SGeMS). Ranges for total flux emissions for CO2 are 14.09 to 14.21 t d-1 and 0.0759 to 0.0764 t d-1 for H2S. Results show that faults or fractures covered by sinter are very likely to exist at Puhimau, based on the similarity between the correlation of high flux areas and the trend of the regional faults. An analysis of images derived from satellite remote sensing data was also utilized to track changes in vegetation health in the Puhimau geothermal area through time. These results indicate changes in vegetation health occur that correlate with specific volcanic events. However, the precise source of these changes in vegetation health remain inconclusive and could be the result of changes in soil gas emissions, soil temperature, or both

    Application of machine learning to prediction of vegetation health

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    This project applies machine learning techniques to remotely sensed imagery to train and validate predictive models of vegetation health in Bangladesh and Sri Lanka. For both locations, we downloaded and processed eleven years of imagery from multiple MODIS datasets which were combined and transformed into two-dimensional matrices. We applied a gradient boosted machines model to the lagged dataset values to forecast future values of the Enhanced Vegetation Index (EVI). The predictive power of raw spectral data MODIS products were compared across time periods and land use categories. Our models have significantly more predictive power on held-out datasets than a baseline. Though the tool was built to increase capacity to monitor vegetation health in data scarce regions like South Asia, users may include ancillary spatiotemporal datasets relevant to their region of interest to increase predictive power and to facilitate interpretation of model results. The tool can automatically update predictions as new MODIS data is made available by NASA. The tool is particularly well-suited for decision makers interested in understanding and predicting vegetation health dynamics in countries in which environmental data is scarce and cloud cover is a significant concern

    Research paper on Vegetation Health Monitoring Using Agricultural IOT

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    Vegetation health monitoring project aims to measure and record data about crops in real time using the reflectance of light shined or water provided on the growing plants. Sensors can be installed across the application boom to collect information while the different span of time of the plant growth. The data is logged and mapped to be used in further analysis – or for real-time variable rate applications. This kind of data is the key to precision farming. Collect information in the fields, analyze and then make decisions based on the data..A Sensor Network (SN) is a group of sensor nodes work collaboratively to perform a common task. SensorNetworks plays a major role in the development of monitoring air, soil and water, habitat monitoring, agriculturalmonitoring, military surveillance, inventory tracking etc.Sensors are used in agriculture to monitor Temperature, Humidity, Soil moisture, Wind (speed and direction), Pressure. In the existing systemarduino,and the sensors are used to track the needs of the canopy growth. External server is used to collect the data.In proposed system, a plant growth will be monitored in terms of sunlight, temperature and soil moisture, and read values will be fed into the applicationon the user’s mobile phone.With this Project, plant breeders can evaluate the performance of different plant varieties using measurements taken from remote sensors. These sensors monitor things like soil moisture, atmospherictemperature, and soil moisture and are often used for crop variety trials. The system has a great advantage, that is expandable and so new type of sensors and controllers can be added without affecting the existing infrastructure; power and communication are made using a single cable This allows planning appropriate necessities for the vegetation, and monitoring the vegetation’s health

    Sea Level Rise and Public Perceptions of Climate Change at Otter Point Creek Estuarine Reserve, MD

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    Freshwater tidal marshes are essential stopover points for migratory birds traveling up and down the east coast of North America. Given the importance of these habitats, we examined the effects of sea level rise on vegetation health and vegetation migration at Otter Point Creek Estuarine Reserve. We aimed to test three predictions: 1) vegetation health will decline over time during vegetation growth periods, 2) vegetation migration of less water-tolerant species will occur with movement into higher elevation plots, 3) people will be aware that there are impacts of climate change on species around them and themselves. We used a combination of Google Earth Engine, ArcGIS, field-collected vegetation data analyzed in R, and a survey of visitor perceptions to test these predictions. Our results demonstrate that 1) vegetation health has increased in some areas but decreased in others over time; it is unclear which vegetation has grown over time, 2) there is a slow vegetation migration in low- to mid-marsh transects, 3) people are aware that climate change impacts plants, animals, and people, but fewer recognize that it will impact them personally. Our results also show that, with a 10ft increase in sea level, this system would disappear completely. Overall, this vital wildlife habitat will continue to change with increased extreme weather events that will negatively cause significant shifts within the marsh

    Innovative approaches for measuring organism stress and behavioural integrity in flume facilities: Deliverable D8-IV

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    HYDRALAB+ aims to improve the usefulness and value of hydraulic laboratory facilities and is developing experimental guidelines that will allow researchers to successfully investigate complex scenarios representative of natural environments in a context of climate change. Within this framework it is often important to incorporate relevant biological elements in physical experiments, including the use of live vegetation. Notwithstanding efforts to maintain their health by careful husbandry, plants typically degenerate when introduced to flume settings. Physiological responses to degenerating health can affect their interactions with the flow so that experimental conditions are not representative of healthy specimens in situ. There is therefore a need to measure and evaluate the health of plants being used in hydraulic facilities, especially since behavioural integrity might be reduced before there are obvious signs of degeneration. Such measurements are not routinely made so there is a need to identify measurement techniques and methodological protocols for assessing vegetation health status in hydraulic laboratories. This deliverable identifies a technique established in plant physiology and horticulture for monitoring vegetation health status and shows how it can be applied in hydraulic laboratories with minimal impact on organisms. A simple and suitable test among those established in the relevant literature is validated by conducting experiments on freshwater macrophytes. From the relevant literature and the results of experiments reported herein, this deliverable provides an overview of the technique identified and establishes practical guidance on how to properly apply it in hydraulic experiments. The methodological protocol developed can potentially be integrated into established protocols used in ecohydraulics studies as a simple proxy of vegetation health status
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