14,772 research outputs found

    A quest to quantify urban sustainability. Assessing incongruous growth

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    [EN] Urban planners, politicians and citizens need comprehensive and clear information in order to conduct or to get involved in successful evidence-based planning and policymaking. The objective to improve the quality of planning outcomes both at the local and regional level needs design mechanisms that can help verify and support urban planning approaches with quantitative analyses and simulation tools. While this issue has been explored through extensive literature on the topic, there is still plenty to research further, especially when dealing with the evaluation of plans, such as local plans of urban development, comprehensive plans, municipal studies or larger planning involving multiple municipal associations. The use of quantitative analyses may be applied to several aspects of the physical form, including connectivity, ecological system continuations, built structure conciseness and its urban boundary, urban tissue morphology, among others. Quantitative analyses completed by qualitative description and enriched with socio-cultural assessment can result in a comprehensive picture of an area’s current and planned state. This paper presents our experience with mapping residential structure typologies in Lodz, Poland and its surroundings. This mapping assessed the existing residential densities and planned development capacities considering the area’s demographic dynamics in the background. The method revision is completed by examples of open green space quality assessment.Hanzl, M.; Bezerra, LM.; Tomczak, A.; Warsza, R. (2018). A quest to quantify urban sustainability. Assessing incongruous growth. En 24th ISUF International Conference. Book of Papers. Editorial Universitat Politècnica de València. 623-632. https://doi.org/10.4995/ISUF2017.2017.5096OCS62363

    Quantifying Dynamics in Tropical Peat Swamp Forest Biomass with Multi- Temporal LiDAR Datasets

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    Tropical peat swamp forests in Indonesia store huge amounts of carbon and are responsible for enormous carbon emissions every year due to forest degradation and deforestation. These forest areas are in the focus of REDD+ (reducing emissions from deforestation, forest degradation, and the role of conservation, sustainable management of forests and enhancement of forest carbon stocks) projects, which require an accurate monitoring of their carbon stocks or aboveground biomass (AGB). Our study objective was to evaluate multi-temporal LiDAR measurements of a tropical forested peatland area in Central Kalimantan on Borneo. Canopy height and AGB dynamics were quantified with a special focus on unaffected, selective logged and burned forests. More than 11,000 ha were surveyed with airborne LiDAR in 2007 and 2011. In a first step, the comparability of these datasets was examined and canopy height models were created. Novel AGB regression models were developed on the basis of field inventory measurements and LiDAR derived height histograms for 2007 (r(2) = 0.77, n = 79) and 2011 (r(2) = 0.81, n = 53), taking the different point densities into account. Changes in peat swamp forests were identified by analyzing multispectral imagery. Unaffected forests accumulated on average 20 t/ha AGB with a canopy height increase of 2.3 m over the four year time period. Selective logged forests experienced an average AGB loss of 55 t/ha within 30 m and 42 t/ha within 50 m of detected logging trails, although the mean canopy height increased by 0.5 m and 1.0 m, respectively. Burned forests lost 92% of the initial biomass. These results demonstrate the great potential of repetitive airborne LiDAR surveys to precisely quantify even small scale AGB and canopy height dynamics in remote tropical forests, thereby featuring the needs of REDD+

    Measuring spatial separation processes through the minimum commute : the case of Flanders

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    The average distance covered by individual commuting trips increases year after year, regardless of the travel mode. The causes of this phenomenon are diverse. Although increasing prosperity is often invoked as the main reason, the discipline of spatial planning also points to the relevance of land-use policies that enable processes of suburbanization and sprawl. By calculating time series of spatially disaggregated theoretical minimum commuting distances, this paper offers a method to identify and quantify the process of spatial separation between the housing market and the job market. We identify the detected spatial separation as one of the possible indicators for the contribution of spatial processes to the growth of traffic. In the case study area of Flanders and Brussels (Belgium), it is found that over time the minimum commuting distance increased in many municipalities, especially where population is growing faster than job supply, or where traditionally high concentrations of employment still increase. Decreases are noticed in suburban areas that are getting a more urban character by acquiring a considerable functional mix. For the study area in its entirety, we do indeed register an increasing spatial separation between home and work locations. However, this separation evolves less rapidly than the increase in commuting distances itself. Regarding the methodology, we find that the use of municipalities as a spatial entity is suitable for grasping regional transformations of the economy and intermunicipal forms of suburbanization and peri-urbanization. However, a similar methodology, applied at a more detailed geographical scale, could be used to detect processes of sprawl in the morphological sense

    Written evidence submitted by Canterbury Christ Church University (SH0097) to the House of Commons Environment, Food and Rural Affairs Committee on Soil health. First Report of Session 2023–24, HC 245.

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    Executive summary Soils are fundamental to ecosystem functioning in agricultural soils and therefore their ability to provide public goods. Agri-environment policy measure progress towards improving soil health through various physio-chemical or biological means; however, these are no longer fit for purpose. This paper is split into two sections: soil health indicators, covering physio-chemical characteristics and biodiversity, and soil contamination, dealing with heavy metals, pharmaceuticals and microplastics. Within this document, we make a series of recommendations to improve monitoring and subsidy schemes under the new Environmental Land Management schemes. New policy frameworks also need to consider known and emerging contaminants if they are to be a true representation of the health of our soils. Recommendations are given below, split into: physio-chemical characteristics, biodiversity, heavy metals, pharmaceuticals and microplastics. Physio-chemical indicators: 1. Expand on the soil health indicators quantified under the ELMS to include several more that are mentioned under the Countryside Survey (i.e. pH, bulk density, soil carbon, organic matter, total nitrogen, mineralizable nitrogen and total phosphorous), and offer a set of relevant tests related to soil health, taking into account basic soil characteristics, cropping systems and/or climate. 2. Subsidise costs of soil testing under the ELMS so that farmers can collect good quality data on soil health before and after management interventions to demonstrate if soil health has been improved. 3. Ensure that all tests have a standardised method for soil sampling, storage and testing to enable comparisons and accurately track long-term changes. 4. There is a risk of low farmer participation due to the loosely defined soil assessment methods. There is a need for clear guidance and defined, but easy to use, methodologies and farmers need to have access to expert advice and guidance. 5. Soil quality indicators should be relatable to a specific ecosystem services/public goods, and farmers need clear guidance on how to interpret the results of their soil tests in this context. 6. Conduct a large-scale monitoring scheme to provide a reference dataset for farmers to compare their soil physio-chemical data to, or create a scoring system that is easy for farmers to interpret to use as a comparison or demonstrate changes in soil health. Biological indicators: 1. Any agreements attaching subsidy payments to improvements in soil biodiversity need to be long-term and might need to include staged and proxy payments. This is to account for the longer timeframe that soil communities may take to respond to new land management approaches compared to physio-chemical characteristics. 2. Current measurements of biological health are no longer appropriate. Since soil biodiversity – especially microbial biodiversity – drives soil functioning and is a key component of soil health, this needs to be included as a soil health indicator under the new ELMS. 3. Although methods for biodiversity assessment using metagenomics are complex, schemes ot monitor soil must be cooperative. Thus, farmers have to be able to on collecting soil samples and sending these for analysis. Similarly, the biodiversity data that is sent back to the farmer also needs to be easily interpreted (i.e. using a simple summary of findings or scoring system). Heavy metals: 1. Expand on heavy metals that are used as soil health indicators under the Countryside Survey (total copper, zinc, cadmium, and nickel) to include several more that are prevalent in agricultural soils. 2. Include contamination as a soil threat and add Action(s) within the ELMS that targets remediation of contaminated soils. Pharmaceuticals: 1. First, there is a need for prioritization: there are more than 1,900 active pharmaceutical compounds in use, making it a challenge to study all of them at once. Prioritization will allow identifying those compounds that can pose the greatest risk to the UK soil, plants, environment, and public health. 2. Soil microbiome is diverse and varies with location, soil type, plants, environmental conditions, and human activities. There is a need to understand the effect of prioritized CECs pharmaceuticals on soil microbiome and its interaction with the rhizosphere in different agroecological zones of the UK. 3. How the presence of prioritized CECs in the soil affects the growth, productivity, and nutritional quality of main UK crops needs to be assessed. This will be achieved by evaluating the mechanisms of absorption, plant uptake and metabolism of CECs in main UK crop species. 4. With the anticipated negative effects of the CECs on agriculture and the environment, strategies for the remediation of prioritized CECs from contaminated soils should be developed. Different available bioremediation approaches need to be tested to identify those who would work on those CECs and in the UK context. 5. Considering the current development of climate change and its impact on agriculture, it is inevitable to assess how climate change is affecting / will affect the prioritized CECs in their interaction with plants and soil. Microplastics: 1. Define ‘microplastics’ clearly as an environmental contaminant in policy documents. 2. More accurate estimates of deliberate and accidental release of plastics are required to reduce uncertainty in approximations of the quantity of plastics entering soils. 3. Well-aligned initiatives, best management practices, more stringent policies and co-operative efforts of the public, manufacturers and government officials are urgently needed to reduce illegal disposal of plastic waste, moderate improper use of plastic products in the agriculture and increase the proportion of plastics undergoing waste management or recycling processes. 4. Better characterisation of MPs (i.e. origin, shape, size, and composition) and evaluation of their in soils (i.e. distribution, transport and degradation) is required, with reference to specific soil characteristics, agricultural systems and climates. 5. Understand how the presence of MPs in the soil affects soil biota and the growth, productivity and nutritional quality of crops, and determine soil guideline values for MPs in soils. 6. Develop a standard set of low-cost, high-efficiency protocols to collect and process soil samples, and then to isolate, identify and quantify microplastics in soils, depending on both the soil characteristics and the type of MPs being quantified

    Population Biology and Interactions of Arbuscular Mycorrhizal Fungi and Their Benefits in Strawberry Cultivation

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    The diversity of arbuscular mycorrhizal fungi (AMF) and relative abundance among species may affect their ecological impact. Species-specific primers for qPCR quantification of Funneliformis geosporus and F.mosseae DNA were developed to quantify their relative abundance for use in studying mixed inocula in roots of strawberry under different conditions of water stress. Co-occupation of the same root by both species was shown to commonly occur but the relative abundance of the two species varied with water stress. Greater root colonisation was observed microscopically under water stress but this increased colonisation was often accompanied with decreased amounts of fungal DNA in the root. Funneliformis mosseae tended to become more abundant under water stress relative to F. geosporus. There was significant correlation in the fungal colonisation measurements from the microscopic and qPCR methods under some conditions, but the nature of this relationship varied greatly with AMF inoculum and abiotic conditions. Water stress experiments, undertaken with strawberry (Fragaria x ananassa) show a reduction of plant development when subjected to regulated deficit irrigation (RDI) conditions. The effect on growth of AMF colonisation and relative abundance of two co-occurring species of AMF, F. geosporus and F. mosseae, were determined in cultivated strawberry under conditions of water stress. Three AMF inoculation treatments (a single treatment either of F. mosseae BEG25, F. geosporus BEG11 or a 50:50 mixed inoculation treatment of both species) were compared to un-inoculated plants. This study demonstrated that in strawberry plants, under these experimental conditions, single species inoculation treatments gave similar benefits to the host as the mixed inoculation treatment regardless of irrigation regime, suggesting colonisation was of greater importance than mycorrhizal fungal species. The addition of AMF inocula to plants, subjected to reduced irrigation of up to 40%, restored plant growth to the same or higher values as the non-mycorrhizal, fully-watered plants. The water use efficiency of plants was greater under the RDI regime and in AMF-inoculated plants, but there were no significant differences between plants inoculated with the single or combined inoculum. The occurrence of multiple variant sequences within the rRNA genes of the AMF is now widely accepted; however the mechanisms for this are not currently clear. This work investigated the effect of different culture conditions (in vitro and in planta culture) on sequence diversity and relative abundance of a culture of Rhizophagus clarus. Next generation sequencing, using the Illumina platform, generated three major sequence variants that were the most common sequence variants in all conditions. All other sequences grouped phylogenetically about these three major sequence types along with an outgroup of less common sequence types. This study demonstrated that changes in the frequency of dominant sequence variants had occurred when AMF are maintained for two years under different culture conditions

    Validation and application of close-range photogrammetry to quantify ephemeral gully erosion

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    Agricultural soil erosion is a serious problem on farms because it contributes to crop yield declines and beyond farms because it is a source of sediment and chemical pollutants. Ephemeral gullies effectively convey runoff and connect agricultural uplands to off-site waters, so control of this phenomenon would benefit multiple societal sectors. Soil conservationists often employ predictive soil erosion models to develop conservation plans, but commonly used models cannot account for ephemeral gully erosion. Future models with the capability to simulate such concentrated flow erosion must be verified with field measurements. This work sought to quantify the measurement uncertainty of a recently developed tool based on geo-referenced close-range digital photogrammetry and to apply it to naturally evolving channels in agricultural fields. Repeated photogrammetric surveys were conducted to create a set of point clouds, which were compared to define the two standard deviation (2σ) uncertainty in average elevation change between two point clouds as ± 1.29 to ± 2.55 mm (depending on surface relief), the 2σ relative vertical uncertainty of individual point clouds as 0.916 mm, and the 2σ geo-referenced vertical accuracy of entire point clouds as 8.26 cm. Utilization of the method at field monitoring sites resulted in average watershed-scale (0.47 to 3.19 ha) estimates of ephemeral gully erosion rates of 3.93, 0.847, and 0.415 Mg ha-1 for three time intervals during 2013 and 2014. For the average soil bulk density of approximately 1.2 Mg m-3, the vertical change uncertainty applied to estimate soil mass moved by ephemeral gully erosion resulted in an average sediment flux uncertainty of ± 0.175 Mg. The small uncertainties determined in the validation study and the plausible rates of soil loss by topographically concentrated overland flow quantified in the field study reflect the reliability of the data, which contributes to their utility for future refinement of soil erosion models that explicitly predict ephemeral gully erosion

    Spreading of Antarctic Bottom Water in the Atlantic Ocean

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    This paper describes the transport of bottom water from its source region in the Weddell Sea through the abyssal channels of the Atlantic Ocean. The research brings together the recent observations and historical data. A strong flow of Antarctic Bottom Water through the Vema Channel is analyzed. The mean speed of the flow is 30 cm/s. A temperature increase was found in the deep Vema Channel, which has been observed for 30 years already. The flow of bottom water in the northern part of the Brazil Basin splits. Part of the water flows through the Romanche and Chain fracture zones. The other part flows to the North American Basin. Part of the latter flow propagates through the Vema Fracture Zone into the Northeast Atlantic. The properties of bottom water in the Kane Gap and Discovery Gap are also analyzed
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