1,721,041 research outputs found
Durum wheat irrigation research trends on essential scientific indicators: a bibliometric analysis
Full text linkNowadays irrigation of durum wheat represents a key point to provide food security in a context of climate change. Although this topic has caught on particu-lar attention from the global scientific community, many issues and aspects remains understudied. To fill the knowledge gap and collate present evidences, this analysis used a combined bibliometric and thematic approach to synthesize the peer-review literature from SCOPUS main collection, covering the period 1977-2023, resulting in including 332 documents. The main findings of this work are as follows: (1) Spain and Tunisia hosts the most productive institutions in this field; (2) the journal Agricultural Water Management emerged as the most prolific, with the largest number of articles and citations; (3) a wide range of topics and approaches on durum wheat irrigation has been iden-tified, with particular emphasis on controlled water deficit and remote sensing driven management; (4) the mapping of bibliographic data coupling with co-occurrence map remains a poorly examined area of study. The results suggest the need of strengthened institutional partnerships and synergi-ze the research on durum wheat irrigation, particularly in the most vulnerable areas where climate change are acting heavily. Future studies should aim to contribute to the understanding of the impacts of climate change through innovative techniques in order to improve our understanding of the durum wheat water needs and their application in crop management, while ensuring ongoing updates to the existing collection of knowl-edge to face future challenges
Morphometric terrain analysis to explore present day geohazards and paleolandscape forms and features in the surroundings of the Melka Kunture prehistoric site, Upper Awash Valley, Central Ethiopia
No full textMorphometric Terrain Analysis was successfully applied in different sectors of environmental studies. However, other disciplines, such as archaeology, might also profit from spatially distributed high-resolution terrain information. In this paper, we show how detailed topographic analysis and simple hydrological modelling approaches help to explain complex terrain pattern and to assess geohazards affecting archaeological sites. We show that Melka Kunture, a cluster of Pleistocene sites in the Upper Awash valley of Ethiopia, is affected by flooding and erosion/sedimentation processes. Moreover, we identified paleo-landscape features, such as changes in drainage pattern and evidences of tectonic activity. The topographic indices indicate especially a different paleo-drainage pattern with a lake or palustrine environment in the upstream areas. Furthermore, a different drainage of the paleo-lake via the Atabella tributary is likely and might be also stressed by the dimensions of the lower Atabella valley with quite large cross sections not corresponding to the present-day drainage situation
Bibliometric Analysis of Soil and Landscape Stability, Sensitivity and Resistivity
Full text linkIn times of global change, it is of fundamental importance to understand the sensitivity, stability and resistivity of a landscape or ecosystem to human disturbance. Landscapes and ecosystems have internal thresholds, giving them the ability to resist such disturbance. When these thresholds are quantified, the development of countermeasures can help prevent irreversible changes and support adaptations to the negative effects of global change. The main objective of this analysis is to address the lack of recent studies defining terms like sensitivity, resistivity and stability in reference to landscapes and ecosystems through a Bibliometric analysis based on Scopus and Web of Science peer-reviewed articles. The present research also aims to quantify landscape statuses in terms of their sensitivity, stability and resistivity. The term “landscape stability” is mainly related to quantitatively measurable properties indicating a certain degree of stability. In contrast, the term “landscape sensitivity” is often related to resilience; however, this definition has not substantially changed over time. Even though a large number of quantification methods related to soil and landscape stability and sensitivity were found, these methods are rather ad hoc. This study stresses the importance of interdisciplinary studies and work groups
Matching legacy estimation of soil organic carbon changes from non-paired data with measured values in paired soil samples after two decades: a case study
No full textLegacy data are frequently unique sources of data for the estimation of past soil properties. With the rising concerns about greenhouse gases (GHG) emission and soil degradation due to intensive agriculture and climate change effects, soil organic carbon (SOC) concentration might change heavily over time. When SOC changes is estimated with legacy data, the use of soil samples collected in different plots (i.e., non-aligned data) may lead to biased results. The sampling schemes adopted to capture SOC variation usually involve the resampling of the original sample using a so called paired-site approach. In the present work, a regional (Sicily, south of Italy) soil database, consisting of N=302 georeferenced soil samples from arable land collected in 1993 [1], was used to select coinciding sites to test a former temporal variation (1993-2008) obtained by a comparison of models built with data sampled in non-coinciding locations [2]. A specific sampling strategy was developed to spot SOC concentration changes from 1994 to 2017 in the same plots at the 0-30 cm soil depth and tested. To spot SOC changes the minimum number of samples needed to have a reliable estimate of SOC variation after 23 years has been estimated. By applying an effect size based methodology, 30 out of 302 sites were resampled in 2017 to achieve a power of 80%, and an a=0.05. After the collection of the 30 samples, SOC concentration in the newly collected samples was determined in lab using the same method A Wilcoxon test applied to the variation of SOC from 1994 to 2017 suggested that there was not a statistical difference in SOC concentration after 23 years (Z = -0.556; 2-tailed asymptotic significance = 0.578). In particular, only 40% of resampled sites showed a higher (not always significant) SOC concentration than in 2017. This finding contrasts with a previous SOC concentration increase that was found in 2008 (75.8% increase when estimated as differences of 2 models built with non-aligned data) [2], when compared to 1994 observed data (Z = -9.119; 2-tailed asymptotic significance < 0.001). Such a result implies that the use of legacy data to estimate SOC concentration changes need soil resampling in the same locations to overcome the stochastic model errors. Further experiment is needed to identify the percentage of the sites to resample in order to align two legacy datasets in the same area
Italy - nitrogen fertilization based on prescription maps and on-the-go variable rate crop sensors in northern Italy maize cultivation
No full textAssessment of suspended sediment dynamics in a small ungauged badland catchment in the Northern Apennines (Italy) using an in-situ laser diffraction method
No full textThe volumes and dynamics of suspended sediments drained from a watershed are often unknown, especially in small creeks and tributaries where continuous discharge measurements are seldom available. The objective of this study was to assess in a qualitative and quantitative way the sediment dynamics of a small ungauged watershed in the Northern Apennines, Italy. We analysed and correlated the sediment volume concentration and grain-size distribution of the suspended sediments with the precipitation pattern. The study area is a small ungauged watershed (0.15 km(2)) that is dominated by intensive soil erosion processes and related landforms. The basin is oriented East-West with the south-facing slopes characterized by badland erosion processes. The north-facing slopes are cultivated and dominated by rill-interrill erosion phenomena. An morphometrical characterization of the basin was performed using a high-resolution DTM with a 1 x 1 m resolution. Subsequently, the physical characteristics of the topsoil were investigated based on grain size laboratory analysis. A detailed NDVI analysis of the vegetation was performed using Sentinel-2A images. Finally, we assessed the suspended sediments at the outlet of the basin using a laser diffraction technique. The Suspended Sediment Volume Concentration (SSC) and the Sauter Mean Diameter (SMD) of the eroded sediments, provide insights into the morphogenetic processes and the sediment transport dynamics of the basin. The measurements were conducted in autumn 2018 after an intense precipitation period and in spring 2019 after a dry phase. The results show a direct relationship between precipitation and SSC with a delay of about 2 h after the most intense precipitation events. Moreover, we reveal that the SMD values are inversely related to the precipitation due to turbidity effects. The SSC and SMD measurements allow for a detailed assessment of the dynamics between precipitation and suspended sediment load even though discharge volumes were not measured directly
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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