rain precipitation
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2021 ◽  
Vol 10 (11) ◽  
pp. 25420-25430
Author(s):  
Sofiane HADJI

Modeling large-scale flood inundation requires weeks of calculations using complex fluid software. The state-of-the-art in operational hydraulic modeling does not currently allow flood real-time forecasting fields. Data driven models have small computational costs and fast computation times and may be useful to overcome this problem. In this paper, we propose a new modeling approach based on a coupled of Hydrodynamics finite element model and Multi-headed Deep convolutional neural network (MH-CNN) with rain precipitations as input to forecast rapidly the water depth reached in large floodplain with few hours-ahead. For this purpose, one first builds a database containing different simulations of the physical model according to several rain precipitation scenarios (historic and synthetic). The multi-headed convolutional neural network is then trained using the constructed database to predict water depths. The pre-trained model is applied successfully to simulate the real July 2014 flood inundation in an 870 km2 area of La Nive watershed in the south west of France. Because rain precipitation forecast data is more accessible than discharge one, this approach offers great potential for real-time flood modelling for ungauged large-scale territories, which represent a large part of floodplain in the world.


2021 ◽  
Vol 69 (4) ◽  
pp. 400-420
Author(s):  
Marc Muselli ◽  
Daniel Beysens

Abstract Biocrust sustainability relies on dew and rain availability. A study of dew and rain resources in amplitude and frequency and their evolution is presented from year 2001 to 2020 in southern Africa (Namibia, Botswana, South Africa) where many biocrust sites have been identified. The evaluation of dew is made from a classical energy balance model using meteorological data collected in 18 stations, where are also collected rain data. One observes a strong correlation between the frequency of dew and rain and the corresponding amplitudes. There is a general tendency to see a decrease in dew yield and dew frequency with increasing distance from the oceans, located west, east and south, due to decreasing RH, with a relative minimum in the desert of Kalahari (Namibia). Rain amplitude and frequency decreases when going to west and north. Short-term dew/rain correlation shows that largest dew yields clearly occur during about three days after rainfall, particularly in the sites where humidity is less. The evolution in the period corresponds to a decrease of rain precipitations and frequency, chiefly after 2010, an effect which has been cyclic since now. The effect is more noticeable towards north. An increase of dew yield and frequency is observed, mainly in north and south-east. It results in an increase of the dew contribution with respect to rain, especially after 2010. As no drastic changes in the distribution of biomass of biocrusts have been reported in this period, it is likely that dew should compensate for the decrease in rain precipitation. Since the growth of biocrust is related to dew and rain amplitude and frequency, future evolution should be characterized by either the rain cycle or, due to global change, an acceleration of the present tendency, with more dew and less rainfalls.


Author(s):  
Sazcha Olivera ◽  
María del Pilar Fuerte-Celis ◽  
Bernardo Bolaños

The worldwide number of migrants has had a rapid increase during the last fifteen years. Despite the extensive research studies that elucidate the increase in migrants' recipient countries, we know little about the relationship between the climate factors and human mobility in the countries of origin. Hence, this study focuses on the effects of weather and the propensity of individuals to leave a territory by measuring the importance of rain precipitation or the lack of it in one of the critical food corridors of Central America, formed by El Salvador, Honduras, and Guatemala. To study the mobility process, we develop a stochastic frontier model; the main result shows a greater propensity to migrate when there is a significant drought event in the place of origin. Some other factors that motivate people to leave their homeland are the effect of other climate events measured through the control system (ENSO), homicide levels, economic performance, and exchange rate. The findings allow differentiating between drought and excess precipitation on a population and mobility to other territories. In addition, these results permit us to derive observable implications of the different effects of flooding and drought and create public policies of prevention, mitigation, and resilience.


2021 ◽  
Vol 18 (2(Suppl.)) ◽  
pp. 1095
Author(s):  
Ibrahem Mahdi Al-Sudani

This study was performed on the Tigris River (Baghdad city section) during the period between December 2016 and December 2018 to assess seasonal variation in water quality using the Overall Index of Pollution (OIP). The OIP is one of the reliable tools for the assessment of surface water quality. To calculate OIP-values, eight parameters were measured ( pH, Dissolved Oxygen "DO", Biological Oxygen Demand "BOD", Total Dissolved Solid "TDS", Total Hardness "TH", calcium "Ca", Sulphate "SO4" and Alkalinity). The results showed the anthropogenic activities impact of Baghdad population that directly discharge of "inadequate treated" waste water to the river.  OIP values were acceptable (1˃OIP˃ 1.7) in 2011, 2012, 2013 and 2018. However, in 2014 and 2017,the OIP recorded values that were acceptable and tend to be slightly polluted (1.7˃OIP˃2.5). The impairment of water quality during 2014 and 2017 might be caused by the decrease in the water share feeding Tigris River from Turkey due to the construction of many dams. Also, markedly reduced rain precipitation rates were recorded in these periods.  The study suggests conducting continuous monitoring programs and establishing a reliable Iraqi classification system for water quality by a specialized scientific panel.


Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 769
Author(s):  
Neal McMullen ◽  
Isabella Annesi-Maesano ◽  
Jean-Baptiste Renard

As atmospheric particle matter (PM) pollution has been proven to be a public health risk, we investigated how PM concentrations of various particle diameters may be impacted by precipitation. Repeated measures over time of urban PM concentrations for particles of 0.2–50 µm in diameter were compared with precipitation data from Météo-France weather stations in Paris, Angers and Palaiseau from 2013 to 2019. A significant negative correlation, using Kendall’s rank correlation, was found between the amount of precipitation and concentrations of particles >3 µm. Distribution comparative analysis (Dunn’s test) of 154 events of 1 mm or more of rain demonstrated a decrease in concentrations for particles from 10 to 50 µm in diameter. Additionally, granulometric analysis of a typical heavy rain event showed a 10-fold decrease in concentrations of particles 10 to 30 µm in diameter one hour after rain compared with one hour before. We were able to show that measured concentrations of particles between 10 and 50 µm in diameter diminish when it rains, with a lasting effect of approximately 10–15 h.


2021 ◽  
Vol 24 (1) ◽  
pp. 32-41
Author(s):  
S. K. Kamzolov ◽  
S. M. Novikov ◽  
A. N. Razumovsky

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Qing-He Zhang ◽  
Yong-Liang Zhang ◽  
Chi Wang ◽  
Kjellmar Oksavik ◽  
Larry R. Lyons ◽  
...  

AbstractIn Earth’s low atmosphere, hurricanes are destructive due to their great size, strong spiral winds with shears, and intense rain/precipitation. However, disturbances resembling hurricanes have not been detected in Earth’s upper atmosphere. Here, we report a long-lasting space hurricane in the polar ionosphere and magnetosphere during low solar and otherwise low geomagnetic activity. This hurricane shows strong circular horizontal plasma flow with shears, a nearly zero-flow center, and a coincident cyclone-shaped aurora caused by strong electron precipitation associated with intense upward magnetic field-aligned currents. Near the center, precipitating electrons were substantially accelerated to ~10 keV. The hurricane imparted large energy and momentum deposition into the ionosphere despite otherwise extremely quiet conditions. The observations and simulations reveal that the space hurricane is generated by steady high-latitude lobe magnetic reconnection and current continuity during a several hour period of northward interplanetary magnetic field and very low solar wind density and speed.


Author(s):  
Jefferson Rodrigues dos Santos Silva ◽  
Matheus Kucmanski Taveira ◽  
Rodrigo Otávio Peréa Serrano ◽  
Anderson Azevedo Mesquita ◽  
José Genivaldo do Vale Moreira

Due to randomness in the occurrence of hydrological phenomena, the estimation of probable rain precipitation in a given region is important in assisting decision-making. This work aimed to adjust the probabilistic model of the Gamma distribution to the monthly and annual rainfall totals recorded in the city of Cruzeiro do Sul, Acre, for the period between 1970 and 2019, in addition to estimating the expected values at different probability levels. Using the maximum likelihood method, the distribution parameters were estimated, with adherence ratified by the Kolmogorov-Smirnov test. The results showed that the Gamma distribution was adequate to adjust the data; the region has two well-defined periods in its rainfall pattern; the mean precipitation values recorded in the locality are between 25% and 40% of probability. Finally, probable rainfall values were presented at different probability levels for the city of Cruzeiro do Sul.


Química Nova ◽  
2021 ◽  
Author(s):  
Fernanda Morro ◽  
Danielle Schnitzler

EVALUATION OF AGROCHEMICALS IN SOIL OF CONVENTIONAL AND AGROECOLOGICAL AGRICULTURAL PRODUCTION SYSTEMS. At the Contestado Settlement, Lapa, PR, soil samples from agroecological and conventional environments were evaluated against the agrochemicals alachlor, atrazine, chlorpyrifos and trifluralin. For sampling, 3 depths were considered, 10 points were selected, 5 in an agroecological and 5 in the conventional environment, with sampling frequency was at 2-month intervals. The samples were characterized according to textural, chemical and fertility parameters and the data were used in the chemometric study (PCA) demonstrating that the environments are different. The method of extraction, identification and quantification was validated at the trace level. The analytes were analyzed by GC-MS/MS, the recovery values were between 83 to 113%, RSD less than 14%, LD equal to 0.01; 0.0028; 0.004 and 002 μg kg-1, LQ equal to 0.04; 0.008; 0.011 and 0.05 μg kg-1, for alachlor, atrazine, chlorpyrifos and trifluralin, respectively. Chlorpyrifos was identified in the Conv3 and trifluralin in the Agro2 and 3 and Conv2 environments. Therefore, the application of pesticides in conventional environments can contaminate agroecological environments. The effect of rain/precipitation on the samples was evaluated by simulation and it was found that the physical-chemical properties of the compounds and the soil have an influence on their behavior in the soil profile.


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