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2022 ◽  
Vol 3 (1) ◽  
Author(s):  
Katharine M. Grant ◽  
Udara Amarathunga ◽  
Jessica D. Amies ◽  
Pengxiang Hu ◽  
Yao Qian ◽  
...  

AbstractDark organic-rich layers (sapropels) have accumulated in Mediterranean sediments since the Miocene due to deep-sea dysoxia and enhanced carbon burial at times of intensified North African run-off during Green Sahara Periods (GSPs). The existence of orbital precession-dominated Saharan aridity/humidity cycles is well known, but lack of long-term, high-resolution records hinders understanding of their relationship with environmental evolution. Here we present continuous, high-resolution geochemical and environmental magnetic records for the Eastern Mediterranean spanning the past 5.2 million years, which reveal that organic burial intensified 3.2 Myr ago. We deduce that fluvial terrigenous sediment inputs during GSPs doubled abruptly at this time, whereas monsoon run-off intensity remained relatively constant. We hypothesize that increased sediment mobilization resulted from an abrupt non-linear North African landscape response associated with a major increase in arid:humid contrasts between GSPs and intervening dry periods. The timing strongly suggests a link to the onset of intensified northern hemisphere glaciation.


Geosciences ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 20
Author(s):  
Bébhinn Anders ◽  
Shane Tyrrell ◽  
David Chew ◽  
Gary O’Sullivan ◽  
Chris Mark ◽  
...  

Sediment delivery and supply are explicitly controlled by variations in broad-scale processes such as climate, tectonics and eustasy. These in turn influence fluvial processes and hinterland evolution. A bespoke multi-proxy approach (integrating apatite and zircon U-Pb geochronology, trace elements in apatite, and Pb-in-K-feldspar provenance tools) coupled with outcrop investigation is used to constrain the temporal trends in sediment delivery to channel sandstones of the fluvio-estuarine mid-Viséan Mullaghmore Sandstone Formation, Ireland. Provenance data indicate unique detrital signatures for all sampled horizons, indicating the fluctuating nature of sediment supply to this medium-sized basin. Tectonism and/or abrupt relative sea-level fall likely caused fluvial rejuvenation, resulting in local basement sourcing of the initial fill. Older and more distal sources, such as the Nagssugtoqidian Belt of East Greenland, become more prominent in stratigraphically younger channel sandstones suggesting catchment expansion. Paleoproterozoic to Mesoproterozoic sources are most dominant, yet the detrital grain cargo varies in each channel sandstone. Proximal sources such as the Donegal Batholith and Dalradian Supergroup are variable and appear to switch on and off. These signal shifts are likely the result of channel migration and paleoclimatic fluctuation. A monsoonal climate and large-scale wildfire events (evidenced by fusain) likely contributed to modify plant cover, intensify erosion, and increase run-off and sediment delivery rates from specific areas of the hinterland.


2022 ◽  
Vol 7 (1) ◽  
pp. 7
Author(s):  
Suliman Gargoum ◽  
Lloyd Karsten ◽  
Karim El-Basyouny ◽  
Xinyu Chen

Fatalities and serious injuries still represent a significant portion of run-off-the-road (ROR) collisions on highways in North America. In order to address this issue and design safer and more forgiving roadside areas, more empirical evidence is required to understand the association between roadside elements and safety. The inability to gather that evidence has been attributed in many cases to limitations in data collection and data fusion capabilities. To help overcome such issues, this paper proposes using LiDAR datasets to extract the information required to analyze factors contributing to the severity of ROR collisions on a localized collision level. Specifically, the paper proposes a new method for extracting pole-like objects and tree canopies. Information about other roadside assets, including signposts, alignment attributes, and side slopes is also extracted from the LiDAR scans in a fully automated manner. The extracted information is then attached to individual collisions to perform a localized assessment. Logistic regression is then used to explore links between the extracted features and the severity of fixed-object collisions. The analysis is conducted on 80 km of roads from 10 different highways in Alberta, Canada. The results show that roadside attributes vary significantly for the different collisions along the 80 km analyzed, indicating the importance of utilizing LiDAR to extract such features on a disaggregate collision level. The regression results show that the steepness of side slopes and the offset of roadside objects had the most significant impacts on the severity of fixed-object collisions.


Author(s):  
Patricia L. Gillis ◽  
Joanne L. Parrott ◽  
Paul Helm
Keyword(s):  

2022 ◽  
pp. 1592-1610
Author(s):  
Abdelkrim Ben Salem ◽  
Souad Ben Salem ◽  
Kholoud Kahime ◽  
Mohammed Messouli ◽  
Mohammed Yacoubi Khebiza

Moroccan ecosystems are considered endangered due to climate change that affects directly or indirectly different key features (biodiversity, snow cover, run-off processes, and water availability). The chapter describes the strategy for achieving collaboration between natural and social scientists, stakeholders, decision makers, and other societal groups in order to carry out an integrated assessment of climate change in the 12 Moroccan regions, with an emphasis on vulnerability and adaptation, and evaluate the vulnerability of human population to climate change applying the socioeconomic vulnerability index (SeVI) that measures socioeconomic vulnerability by regions. Result suggest that three southern and one north region are relatively more vulnerable, which are the most exposed to natural hazard. Furthermore, significant adaptive capacity scores are recorded in in the remaining regions, and average sensitivity for all. Therefore, societies and economies at all levels and on every region have to prepare for and adapt to impacts of climate change.


2021 ◽  
Vol 14 (6) ◽  
pp. 3635
Author(s):  
Flávio Alves Sousa ◽  
Hildeu Ferreira Da Assunção

O estudo avalia a capacidade de armazenamento de água dos solos (CAD), utiliza como objeto de avaliação os latossolos da alta bacia do ribeirão Santo Antônio no município de Iporá-Goiás. O objetivo do estudo foi avaliar a dinâmica da água da chuva na manutenção do fluxo de água na bacia. Utilizou de dados de umidade dos solos em período de déficit hídrico e de excedente para comparar o comportamento dos solos na retenção de água e na permeabilidade. Utilizou a metodologia padrão na definição do CAD, porém com ajustes específicos na obtenção da umidade e na capacidade de campo (CC) e no ponto de murcha permanente PMP, que aqui foi denominado de ponto de menor umidade residual (PMUR). Informações como dados de chuva do período, balanço hídrico climatológico no período analisado (maio de 2018 a abril de 2019) e valores de vazão obtidos mensalmente no exutório durante o período de referência fizeram parte da análise. Um total de 43,5% da água disponibilizada pela chuva escoam superficialmente, 9,5% escoam em subsuperfície, 47% da água infiltra e/ou permanece retida nos solos. Os solos apresentaram boa drenagem e, cerca de 42% da água das chuvas garantem a perenidade da bacia.    Soil Water Storage Capacity (AWSC) and Physical Characteristics of Soils in the Evaluation of Rainwater Distribution in the High Basin of  Santo Antônio Stream.  A B S T R A C T         The study evaluates the water storage capacity of soils (AWSC). It use like object of evaluation the oxissoils located at the high Santo Antônio basin. The objective of the study was to evaluate the dynamics of rainwater in maintaining the flow of water in the basin through laboratory evaluations, in addition to testing a new methodology to define the destinations of the water that reached the surface. Was used soil moisture data in a period of water deficit and surplus to compare the behavior of soils in water retention and permeability. It used the standard methodology in the definition of the AWSC but with specific adjustments in obtaining the humidity and in the field capacity (FC) and in the permanent wilting point PWP, which here was called the point of lowest residual moisture (PLRM). Information such as rainfall data for the period, climatological water balance in the period analyzed (May 2018 to April 2019) and flow values obtained monthly in the exutory during the reference period were part of the analysis. A total of 43.5% of the water provided by the rain run off superficially, 9.5% seeps in subsurface, 47% of the water seeps and / or remains trapped in the soil. The soils had good drainage and about 42% of the rainwater guarantees the basin's perpetuity.   Keywords: AWSC. Permeability. Moisture. Storage.


MAUSAM ◽  
2021 ◽  
Vol 43 (3) ◽  
pp. 315-320
Author(s):  
O. N. DHAR ◽  
S.S. NANDARGI

Onset of monsoon for each year of the period from 1961 to 1986 over the Upper Mahanadi basin has been studied taking into consideration the sharp increase in water levels of the Hirakud reservoir. This study has shown that .there are positive and negative time-lags in the arrival of monsoon run off into the reservoir. It has been seen that positive time lags are due to antecedent condition of the basin before the onset of monsoon while negative time-lag appears to be due to pre-monsoon thunderstorm activity which causes reservoir levels to increase before the onset of monsoon. Attempt has been made to discuss all these cases briefly. It has been seen that on  a majority of occasions monsoon runoff has reached the reservoir with a time-lag of 1 to 4 days.  


Significance This appears to reflect high levels of disillusionment with established political parties, possibly exacerbated by several public sector corruption scandals that have emerged in recent months. A run-off looks the most likely outcome of the first presidential round on February 6. Impacts A surge in COVID-19 cases, potentially linked to Omicron, could disrupt the presidential race, particularly affecting the ruling PAC. Further arrests in anti-corruption investigations could influence voting intentions. More details of policies will be released over the coming weeks, especially focused on socio-economic issues.


2021 ◽  
Author(s):  
Benti D. Gelalcha ◽  
Getahun E. Agga ◽  
Oudessa Kerro Dego

Mastitis is the most frequently diagnosed disease of dairy cattle responsible for the reduction in milk quantity and quality and major economic losses. Dairy farmers use antibiotics for the prevention and treatment of mastitis. Frequent antimicrobial usage (AMU) undeniably increased antimicrobial resistance (AMR) in bacteria from dairy farms. Antimicrobial-resistant bacteria (ARB) from dairy farms can spread to humans directly through contact with carrier animals or indirectly through the consumption of raw milk or undercooked meat from culled dairy cows. Indirect spread from dairy farms to humans can also be through dairy manure fertilized vegetables or run-off waters from dairy farms to the environment. The most frequently used antibiotics in dairy farms are medically important and high-priority classes of antibiotics. As a result, dairy farms are considered one of the potential reservoirs of ARB and antimicrobial resistance genes (ARGs). To mitigate the rise of ARB in dairy farms, reducing AMU by adopting one or more of alternative disease control methods such as good herd health management, selective dry-cow therapy, probiotics, and others is critically important. This chapter is a concise review of the effects of antimicrobials usage to control mastitis in dairy cattle farms and its potential impact on human health.


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