scholarly journals Effects of Underlay on Hill-Slope Surface Runoff Process of Cupressus funebris Endl. Plantations in Southwestern China

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 644
Author(s):  
Bingchen Wu ◽  
Shi Qi
Keyword(s):  
Spatial Pattern ◽  
Surface Runoff ◽  
Peak Flow ◽  
Pearson Correlation ◽  
Composite Index ◽  
Southwestern China ◽  
Near Surface ◽  
Long Duration ◽  
The Impact ◽  
Micro Topography

Clarifying the impact of underlay (i.e., the combination of near-surface vegetation and surface micro-topography) on the surface runoff process would provide a significant theoretical basis for the adjustment of vegetation patterns and the control of soil erosion on steep slopes in mountainous areas of southwestern China. In the current study, the runoff process under different rainfall characteristics was observed based on 10 natural runoff plots, and the correlation between the spatial pattern of cypress (Cupressus funebris), micro-topography, and runoff characteristic parameters was tested using the Pearson correlation coefficient method. The coupling effects of the spatial pattern of cypress and micro-topography on surface runoff also were analyzed using the Response Surface Method (RSM). The results showed that (1) under the conditions of long-duration moderate rainfall or long-duration rainstorm, topographic relief, surface roughness, runoff path density, contagion index of cypress, and stand density of cypress were the main reasons for the difference in the peak flow of each runoff plot, while under the condition of the short-duration rainstorm, the factors previously mentioned were no longer the dominant factors; (2) under the conditions of long-duration heavy rainfall or long-duration rainstorm, the common laws reflected by the response of the peak flow to the composite index of the spatial pattern of cypress and micro-topography were that (1) when the composite index of the spatial pattern of cypress (V) was below 21 and the composite index of micro-topography (U) was below 10.5, the peak flow would not be significantly affected; (2) when U > 10.5, increasing the composite index of the spatial pattern of cypress within a certain range would promote peak flow; (3) when U < 7.5 and V > 18, the increase of V value could significantly reduce the peak flow, and on this basis, adjusting the V value to 41, the reduction rate of peak flow could reach 84%.

scholarly journals Dampak Perubahan Penggunaan Lahan Terhadap Limpasan Permukaan dan Laju Aliran Puncak Sub DAS Gajahwong Hulu Kabupaten Sleman

2016 ◽  
Vol 11 (4) ◽  
pp. 127 ◽  
Author(s):  
Andiri Rahardian ◽  
Imam Buchori
Keyword(s):  
Flow Rate ◽  
Water Conservation ◽  
Surface Runoff ◽  
Open Space ◽  
Peak Flow ◽  
Watershed Hydrology ◽  
Peak Flow Rate ◽  
Landuse Change ◽  
Catchment Areas ◽  
The Impact

Upstream Gajahwong Sub-Watershed included in Yogyakarta Urban Agglomeration Region and regional development of tourism that utilizes the beauty of the slopes of Mount Merapi also the support accessibility (Solo-Magelang-Semarang road; this condition is assumed to be the cause of landuse changes, followed by vegetation land shrinkage. The shrinkage’s result is water catchment areas reduction that disrupts the Sub-Watershed hydrology function. One of indication is the increasing flood discharge that can be seen from the changes in surface runoff and peak flow rate. This research aims to assess the impact of landuse change on surface runoff and peak flow rate in Gajahwong Sub-Watershed using a quantitative method that consists of spatial and mathematic analysis with SCS and Rational Method. The results showed that the landuse changes impact on increasing surface runoff and peak flow rate. The surface runoff in year 2002 amounted to 3.073 mm with a peak flow rate of 98.02 m³/sec then increased to 3.901 mm with a peak flow rate of 101.65 m³/sec in year 2011. The landuse changes that occur tend to built landuse which was followed by vegetation shrinkage and impact on the increase in surface runoff and peak flow rate. Predictions in year 2031 also showed an increase in surface runoff and peak flow rate, if there is a tendency of landuse changes linearly as landuse changes in year 2002 – 2011. Alternative analytical efforts to handle surface runoff and peak flow rate showed that by combining the development of Green Open Space with water conservation technology (Biopori and Infiltration Wells) can reduce surface runoff and peak flow rate.

scholarly journals A Novel Approach for the Integral Management of Water Extremes in Plain Areas

Hydrology ◽  
2019 ◽  
Vol 6 (3) ◽  
pp. 70 ◽  
Author(s):  
Guevara Ochoa ◽  
Masson ◽  
Cazenave ◽  
Vives ◽  
Amábile
Keyword(s):  
Soil Moisture ◽  
Green Infrastructure ◽  
Surface Runoff ◽  
Peak Flow ◽  
Numerical Models ◽  
Management Strategies ◽  
Hydraulic Structures ◽  
Novel Approach ◽  
Event Based ◽  
The Impact

: Due to the socioeconomical impact of water extremes in plain areas, there is a considerable demand for suitable strategies aiding in the management of water resources and rainfed crops. Numerical models allow for the modelling of water extremes and their consequences in order to decide on management strategies. Moreover, the integration of hydrologic models with hydraulic models under continuous or event-based approaches would synergistically contribute to better forecasting of water extreme consequences under different scenarios. This study conducted at the Santa Catalina stream basin (Buenos Aires province, Argentina) focuses on the integration of numerical models to analyze the hydrological response of plain areas to water extremes under different scenarios involving the implementation of an eco-efficient infrastructure (i.e., the integration of a green infrastructure and hydraulic structures). The two models used for the integration were: the Soil and Water Assessment Tool (SWAT) and the CELDAS8 (CTSS8) hydrologic-hydraulic model. The former accounts for the processes related to the water balance (e.g., evapotranspiration, soil moisture, percolation, groundwater discharge and surface runoff), allowing for the analysis of water extremes for either dry or wet conditions. Complementarily, CTSS8 models the response of a basin to a rainfall event (e.g., runoff volume, peak flow and time to peak flow, flooded surface area). A 10-year data record (2003–2012) was analyzed to test different green infrastructure scenarios. SWAT was able to reproduce the waterflow in the basin with Nash Sutcliffe (NS) efficiency coefficients of 0.66 and 0.74 for the calibration and validation periods, respectively. The application of CTSS8 for a flood event with a return period of 10 years showed that the combination of a green infrastructure and hydraulic structures decreased the surface runoff by 28%, increased the soil moisture by 10% on an average daily scale, and reduced the impact of floods by 21% during rainfall events. The integration of continuous and event-based models for studying the impact of water extremes under different hypothetical scenarios represents a novel approach for evaluating potential basin management strategies aimed at improving the agricultural production in plain areas.

Data and visual displays in the Journal of Ecology 1996–2016

2020 ◽  
pp. 147387162098012
Author(s):  
Alon Friedman
Keyword(s):  
Best Practices ◽  
Pearson Correlation ◽  
Single Species ◽  
Data Type ◽  
Reliability Test ◽  
Visual Displays ◽  
Domain Type ◽  
Academic Publications ◽  
The Creation ◽  
The Impact

Scholars in scientific disciplines face unique challenges in the creation of visualizations, especially in publications that require insights derived from analyses to be visually displayed. The literature on visualizations describes different techniques and best practices for the creation of graphs. However, these techniques have not been used to evaluate the impact of visualizations in academic publications. In the field of ecology, as in other scientific fields, graphs are an essential part of journal articles. Little is known about the connections between the kind of data presented and domain in which the researchers conducted their study that together produces the visual graphics. This study focused on articles published in the Journal of Ecology between 1996 and 2016 to explore possible connections between data type, domain, and visualization type. Specifically, this study asked three questions: How many of the graphics published between 1996 and 2016 follow a particular set of recommendations for best practices? What can Pearson correlations reveal about the relationships between type of data, domain of study, and visual displays? Can the findings be examined through an inter-reliability test lens? Out of the 20,080 visualizations assessed, 54% included unnecessary graphical elements in the early part of the study (1996–2010). The most common type of data was univariate (35%) and it was often displayed using line graphs. Twenty-one percent of the articles in the period studied could be categorized under the domain type “single species.” Pearson correlation analysis showed that data type and domain type was positively correlated ( r = 0.08; p ≤ 0.05). Cohen’s kappa for the reliability test was 0.86, suggesting good agreement between the two categories. This study provides evidence that data type and domain types are equally important in determining the type of visualizations found in scientific journals.

scholarly journals Towards Including Dynamic Vegetation Parameters in the EUMETSAT H SAF ASCAT Soil Moisture Products

2021 ◽  
Vol 13 (8) ◽  
pp. 1463
Author(s):  
Susan C. Steele-Dunne ◽  
Sebastian Hahn ◽  
Wolfgang Wagner ◽  
Mariette Vreugdenhil
Keyword(s):  
Soil Moisture ◽  
Interannual Variability ◽  
Incidence Angle ◽  
Pearson Correlation ◽  
The United States ◽  
Research Network ◽  
Window Width ◽  
High Frequency Variability ◽  
Vegetation Parameters ◽  
The Impact

The TU Wien Soil Moisture Retrieval (TUW SMR) approach is used to produce several operational soil moisture products from the Advanced Scatterometer (ASCAT) on the Metop series of satellites as part of the EUMETSAT Satellite Application Facility on Support to Operational Hydrology and Water Management (H SAF). The incidence angle dependence of backscatter is described by a second-order Taylor polynomial, the coefficients of which are used to normalize ASCAT observations to the reference incidence angle of 40∘ and for correcting vegetation effects. Recently, a kernel smoother was developed to estimate the coefficients dynamically, in order to account for interannual variability. In this study, we used the kernel smoother for estimating these coefficients, where we distinguished for the first time between their two uses, meaning that we used a short and fixed window width for the backscatter normalisation while we tested different window widths for optimizing the vegetation correction. In particular, we investigated the impact of using the dynamic vegetation parameters on soil moisture retrieval. We compared soil moisture retrievals based on the dynamic vegetation parameters to those estimated using the current operational approach by examining their agreement, in terms of the Pearson correlation coefficient, unbiased RMSE and bias with respect to in situ soil moisture. Data from the United States Climate Research Network were used to study the influence of climate class and land cover type on performance. The sensitivity to the kernel smoother half-width was also investigated. Results show that estimating the vegetation parameters with the kernel smoother can yield an improvement when there is interannual variability in vegetation due to a trend or a change in the amplitude or timing of the seasonal cycle. However, using the kernel smoother introduces high-frequency variability in the dynamic vegetation parameters, particularly for shorter kernel half-widths.

scholarly journals Statistical Analysis and Machine Learning Prediction of Fog-Caused Low-Visibility Events at A-8 Motor-Road in Spain

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 679
Author(s):  
Sara Cornejo-Bueno ◽  
David Casillas-Pérez ◽  
Laura Cornejo-Bueno ◽  
Mihaela I. Chidean ◽  
Antonio J. Caamaño ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Probability Distributions ◽  
Pearson Correlation ◽  
Likelihood Method ◽  
Neural Network Approach ◽  
Event Duration ◽  
Full Characterization ◽  
Low Visibility ◽  
Learning Machine ◽  
The Impact

This work presents a full statistical analysis and accurate prediction of low-visibility events due to fog, at the A-8 motor-road in Mondoñedo (Galicia, Spain). The present analysis covers two years of study, considering visibility time series and exogenous variables collected in the zone affected the most by extreme low-visibility events. This paper has then a two-fold objective: first, we carry out a statistical analysis for estimating the fittest probability distributions to the fog event duration, using the Maximum Likelihood method and an alternative method known as the L-moments method. This statistical study allows association of the low-visibility depth with the event duration, showing a clear relationship, which can be modeled with distributions for extremes such as Generalized Extreme Value and Generalized Pareto distributions. Second, we apply a neural network approach, trained by means of the ELM (Extreme Learning Machine) algorithm, to predict the occurrence of low-visibility events due to fog, from atmospheric predictive variables. This study provides a full characterization of fog events at this motor-road, in which orographic fog is predominant, causing important traffic problems during all year. We also show how the ELM approach is able to obtain highly accurate low-visibility events predictions, with a Pearson correlation coefficient of 0.8, within a half-hour time horizon, enough to initialize some protocols aiming at reducing the impact of these extreme events in the traffic of the A-8 motor road.

scholarly journals Canonical Correlation Analysis and a New Composite Index on Digitalization and Labor Force in the Context of the Industrial Revolution 4.0

2020 ◽  
Vol 12 (17) ◽  
pp. 6812
Author(s):  
Ane-Mari Androniceanu ◽  
Irina Georgescu ◽  
Manuela Tvaronavičienė ◽  
Armenia Androniceanu
Keyword(s):  
Correlation Analysis ◽  
Labor Force ◽  
Canonical Correlation Analysis ◽  
Canonical Correlation ◽  
Structural Changes ◽  
Industrial Revolution ◽  
Composite Index ◽  
Developed Countries ◽  
World Economic ◽  
The Impact

The current phenomenon of the economy-accelerated digitalization, known as the “Industry 4.0”, will generate both an increased productivity, connectivity and several transformations on the labor force skills. Our research objectives are to determine the influence that digitalization has had on the workforce in several developed countries and to propose a new composite indicator that reflects these dynamics over time. We have used the Canonical Correlation Analysis (CCA) in order to identify and analyze the correlations between two sets of variables, an independent one and a dependent one. Data were collected from the World Bank and World Economic Forum for the years 2018–2019. Based on the results of our research we have determined and made a consistent analysis of the new composite index of digitalization and labor force in 19 countries. The results of our research are relevant and show not only the impact of digitalization on the labor force in different countries, but also the structural changes required by the new economic and social models. Our research can help decision-makers get in advance the necessary measures in the field of labor force in order to ensure a proper integration of these measures into the new economic model based on digitalization.

scholarly journals How Representative Are Snowball Samples? Using the Ethnosurvey to Study Guatemala-U.S. Migration

2016 ◽  
Vol 666 (1) ◽  
pp. 64-76
Author(s):  
David P. Lindstrom
Keyword(s):  
Rhode Island ◽  
Composite Index ◽  
The United States ◽  
Mexican Migration ◽  
Background Characteristics ◽  
Household Location ◽  
Sample Weighting ◽  
Migrant Integration ◽  
The Impact ◽  
The U.S

This analysis draws on binational data from an ethnosurvey conducted in Guatemala and in the United States in Providence, Rhode Island, to develop a refinement of the weighting scheme that the Mexican Migration Project (MMP) uses. The alternative weighting procedure distinguishes between temporary and settled migrants by using a question on household location in the Guatemala questionnaire that is not used in the MMP. Demographic characteristics and integration experiences of the most recent U.S. trip are used to assess the composition and representativeness of the U.S. sample. Using a composite index of migrant integration to compare the impact of alternative U.S. sample weights on point estimates, I find that although the U.S. sample is broadly representative across a range of background characteristics, the MMP sample weighting procedure biases estimates of migrant integration downward.

A Method for Evaluating Intensity of Water Cavitation Peening Processing

2011 ◽  
Vol 675-677 ◽  
pp. 747-750
Author(s):  
B. Han ◽  
Dong Ying Ju ◽  
Xiao Guang Yu
Keyword(s):  
Residual Stress ◽  
Process Capability ◽  
Diffraction Method ◽  
Spring Steel ◽  
Bubble Collapse ◽  
Plastic Layer ◽  
Process Conditions ◽  
X Ray Diffraction ◽  
Near Surface ◽  
The Impact

Water cavitation peening (WCP) with aeration, namely, a new ventilation nozzle with aeration is adopted to improve the process capability of WCP by increasing the impact pressure induced by the bubble collapse on the surface of components. In this study, in order to investigate the process capability of the WCP with aeration a standard N-type almen strips of spring steel SAE 1070 was treated byWCP with various process conditions, and the arc height value and the residual stress in the superficial layers were measured by means of the Almen-scale and X-ray diffraction method, respectively. The optimal fluxes of aeration and the optimal standoff distances were achieved. The maximum of arc height value reach around 150μm. The depth of plastic layer observed from the results of residual stresses is up to 150μm. The results verify the existence of macro-plastic strain in WCP processing. The distributions of residual stress in near-surface under different peening intensity can provide a reference for engineers to decide the optimal process conditions of WCP processing.

scholarly journals Assessing the regional impacts of Mexico City emissions on air quality and chemistry

2009 ◽  
Vol 9 (11) ◽  
pp. 3731-3743 ◽  
Author(s):  
M. Mena-Carrasco ◽  
G. R. Carmichael ◽  
J. E. Campbell ◽  
D. Zimmerman ◽  
Y. Tang ◽  
...  
Keyword(s):  
Air Quality ◽  
Mexico City ◽  
Ozone Production ◽  
Anthropogenic Aerosol ◽  
Near Surface ◽  
Mixing Ratios ◽  
Regional Impacts ◽  
Photolysis Rates ◽  
Regional Air Quality ◽  
The Impact

Abstract. The impact of Mexico City (MCMA) emissions is examined by studying its effects on air quality, photochemistry, and on ozone production regimes by combining model products and aircraft observations from the MILAGRO experiment during March 2006. The modeled influence of MCMA emissions to enhancements in surface level NOx, CO, and O3 concentrations (10–30% increase) are confined to distances <200 km, near surface. However, the extent of the influence is significantly larger at higher altitudes. Broader MCMA impacts (some 900 km Northeast of the city) are shown for specific outflow conditions in which enhanced ozone, NOy, and MTBE mixing ratios over the Gulf of Mexico are linked to MCMA by source tagged tracers and sensitivity runs. This study shows that the "footprint" of MCMA on average is fairly local, with exception to reactive nitrogen, which can be transported long range in the form of PAN, acting as a reservoir and source of NOx with important regional ozone formation implications. The simulated effect of MCMA emissions of anthropogenic aerosol on photochemistry showed a maximum regional decrease of 40% in J[NO2→NO+O], and resulting in the reduction of ozone production by 5–10%. Observed ozone production efficiencies are evaluated as a function of distance from MCMA, and by modeled influence from MCMA. These tend to be much lower closer to MCMA, or in those points where modeled contribution from MCMA is large. This research shows that MCMA emissions do effect on regional air quality and photochemistry, both contributing large amounts of ozone and its precursors, but with caveat that aerosol concentrations hinder formation of ozone to its potential due to its reduction in photolysis rates.

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