scholarly journals Relationships among man, environment and sediment transport

2013 ◽  
Vol 26 (3) ◽  
pp. 235-244 ◽  
Author(s):  
Gil Mahé ◽  
Hafzullah Aksoy ◽  
Yao Télesphore Brou ◽  
Mohamed Meddi ◽  
Eric Roose

In the Mediterranean the environment is under pressure from agricultural and urban development, changes in agricultural practices and international markets, and climate change. Moreover, many studies show a steady increase in the agro-pastoral pressure and land degradation and their impacts on water resources and soil, and ultimately the lives of local people. But few studies address these issues across the inclusive scale of large river basins. The conference held at Tipaza in Algeria, from which come several papers published in the Journal of Water Science in 2013, was intended to reflect on the topics, methods and tools available to study the relationships among humans, the environment and sediment transport at this large scale, with the result expected to improve the potential for dialogue between researchers and developers who make decisions for regional macro surfaces. The topics discussed at the conference that appear in the articles published here concern the factors responsible for the variability of sediment transport: climate change and anthropogenic changes, such as agricultural activity and water projects; relationships between land-cover/land-use, rainfall-runoff processes and sediment transport; modeling of sediment transport; and the interest of a multi-scale approach, predominantly a spatial one, for addressing the geographical realities of large basins and scale transfer issues, particularly in Mediterranean and semi-arid areas.

2020 ◽  
Vol 12 (20) ◽  
pp. 8369
Author(s):  
Mohammad Rahimi

In this Opinion, the importance of public awareness to design solutions to mitigate climate change issues is highlighted. A large-scale acknowledgment of the climate change consequences has great potential to build social momentum. Momentum, in turn, builds motivation and demand, which can be leveraged to develop a multi-scale strategy to tackle the issue. The pursuit of public awareness is a valuable addition to the scientific approach to addressing climate change issues. The Opinion is concluded by providing strategies on how to effectively raise public awareness on climate change-related topics through an integrated, well-connected network of mavens (e.g., scientists) and connectors (e.g., social media influencers).


2021 ◽  
Author(s):  
András Polgár ◽  
Karolina Horváth ◽  
Imre Mészáros ◽  
Adrienn Horváth ◽  
András Bidló ◽  
...  

<p>Crop production is applied on about half of Hungary’s land area, which amounts to approximately 4.5 million hectares. The agricultural activity has significant environmental impacts.</p><p>Our work aims the time series investigation of the impacts of large-scale agricultural cultivation<strong> </strong>on environment and primarily on climate change in<strong> </strong>the test area by applying environmental life cycle assessment (LCA) method.</p><p>The investigated area of Lajta Project can be found in the triangle formed by the settlements Mosonszolnok, Jánossomorja and Várbalog, in the north-western corner of Hungary, in Győr-Moson-Sopron county. The area has intense agri-environment characteristics, almost entirely lacking of grasslands and meadows.</p><p>We were looking for the answer to the question “To what extent does agricultural activity on this area impact the environment and how can it contribute to climate change during a given period?” The selection of the plants included in the analysis was justified by their significant growing area. We analysed the cultivation data of 5 crops: canola, winter barley, winter wheat, green maize and maize. Material flows of arable crop production technologies were defined in time series by the agricultural parcel register data. These covered the size of the area actually cultivated, the operational processes, records on seeds, fertilizer and pesticide use and harvest data by parcels. The examined environmental inventory database contained also the fuel consumption and lubricating oil usage of machine operations, and the water usage of chemical utilization.</p><p>In the life cycle modelling of cultivation, we examined 13 years of maize, 20 years of green maize, 20 years of winter barley, 18 years of winter wheat and 15 years of canola data calculated on 1 ha unit using GaBi life cycle analysis software.</p><p>In addition, we also calculated by an average cultivation model for all cultivated plants with reference data to 1 ha and 1 year period.</p><p>We applied methods and models in our life cycle impact assessment. According to the values of the impact categories, we set up the following increasing environmental ranking of plant cultivation: (1) canola has minimum environmental impacts followed by (2) green maize and (3) maize with slightly higher values, (4) winter barley has 6 times higher values preceded by (5) winter wheat with a slight difference. The previous environmental ranking of the specific cultivated plants’ contribution was also confirmed as regards the overall environmental impact: canola (1.0%) – green maize (4.9%) – maize (7.1%) – winter barley (43.1%) – winter wheat (44.0%).</p><p>Environmental impact category indicator results cumulated to total cultivation periods and total crop growing areas (quantitative approach) display the specific environmental footprints by crops. Increasing environmental ranking of environmental impacts resulted from cultivating the sample area is the following: (1) canola – (2) maize – (3) green maize – (4) winter barley – (5) winter wheat. The slight difference resulted in the rankings in quantitative approach according to the rankings of territorial approach on the investigated area is due to the diversity of cultivation time factor and the crop-growing parameter of the specific crops.</p><p>Acknowledgement: Our research was supported by the „Lajta-Project”.</p>


2020 ◽  
Author(s):  
Philip Kraaijenbrink ◽  
Emmy Stigter ◽  
Tandong Yao ◽  
Walter Immerzeel

<p>Meltwater from seasonal snow provides a substantial amount of runoff to many of the rivers that originate in the high mountains of Asia, yet the importance of snow in the region as streamflow component, its changes over the past decades, and its sensitivity to future climatic changes are relatively unknown. To understand future changes in the water supply to the millions of people living downstream, a better understanding of snow dynamics at large scale is key. Using a novel snow model, forced by ERA5 climate reanalysis and calibrated by MODIS remote sensing observations, we generate daily snow water equivalent output at 0.05° resolution covering all major river basins in Asia. We show that between 1979 and 2018 significant and spatially variable changes have occurred in snow meltwater availability and its timing, with melt peaks attenuating and/or advancing in time, and snowmelt seasons shortening. Additionally, our results reveal that snowmelt is a much more important contributor to streamflow than glacier melt in many of Asia's large river basins. In a bottom-up elasticity analysis we project strong changes in snowmelt in the future under changing temperature and precipitation. Sensitivity of snowmelt to climate change varies among basins, however, and actual losses are strongly dependent on the degree of future climate change. Limiting climate change in the current century is therefore crucial in order to sustain the role of seasonal snow packs in Asia’s water supply.</p>


2021 ◽  
Vol 1 (1) ◽  
pp. 65
Author(s):  
James Kimani

Purpose: Climate warming affects the phenology, local abundance and large‐scale distribution of bees. Despite this, there is still limited knowledge of how climate affect plant‐pollinator mutualisms and how changed availability of mutualistic partners influences the persistence of interacting species. This article reviews the evidence of climate warming effects on bee farming and discuss how their interactions may be affected by change in climate. Bees provide the majority of biotic pollination and are at risk from a multitude of factors; changes in land use, intensive agricultural practices, mono-cropping (growing a single crop year after year on the same land), and the use of pesticides have all contributed to large-scale losses, fragmentation and degradation of bee habitat. The general objective of the study was to establish the effect of effect of climate change on bee farming.    Methodology: The paper used a desk study review methodology where relevant empirical literature was reviewed to identify main themes and to extract knowledge gaps. Findings: The study found out Climate change is causing temperature shifts which are leaving bees unable to pollinate in time. Bees are severely vulnerable to extreme weather and climate change has caused flowers to emerge and bloom earlier. Changing temperatures have also reduced the size of their wild range by approximately five miles. Recommendations: The study recommends that the local community needs to be enlightened on the need to form self-help group. These will provide them a platform to access more incentives and be able to share more information in relation to honey yield and to put more emphasis on providing food and water to bees during dry season  


1996 ◽  
Vol 33 (4-5) ◽  
pp. 39-44
Author(s):  
J. Holas ◽  
M. Konvicková

Potential environmental impacts as a result of large-scale farming system in the Czech Republic have created a great deal of concern in recent years. This concern has led to several studies to identify the role of new regulations, directives and other legislative issues in the field of water pollution control. The set of legislative tools related to watershed management policy to promote better agricultural practices is shortly reviewed. The paper emphasises the running water law system amendment with respect to European community water quality regulations.


2021 ◽  
Author(s):  
Alba de la Vara ◽  
William Cabos ◽  
Dmitry V. Sein ◽  
Claas Teichmann ◽  
Daniela Jacob

AbstractIn this work we use a regional atmosphere–ocean coupled model (RAOCM) and its stand-alone atmospheric component to gain insight into the impact of atmosphere–ocean coupling on the climate change signal over the Iberian Peninsula (IP). The IP climate is influenced by both the Atlantic Ocean and the Mediterranean sea. Complex interactions with the orography take place there and high-resolution models are required to realistically reproduce its current and future climate. We find that under the RCP8.5 scenario, the generalized 2-m air temperature (T2M) increase by the end of the twenty-first century (2070–2099) in the atmospheric-only simulation is tempered by the coupling. The impact of coupling is specially seen in summer, when the warming is stronger. Precipitation shows regionally-dependent changes in winter, whilst a drier climate is found in summer. The coupling generally reduces the magnitude of the changes. Differences in T2M and precipitation between the coupled and uncoupled simulations are caused by changes in the Atlantic large-scale circulation and in the Mediterranean Sea. Additionally, the differences in projected changes of T2M and precipitation with the RAOCM under the RCP8.5 and RCP4.5 scenarios are tackled. Results show that in winter and summer T2M increases less and precipitation changes are of a smaller magnitude with the RCP4.5. Whilst in summer changes present a similar regional distribution in both runs, in winter there are some differences in the NW of the IP due to differences in the North Atlantic circulation. The differences in the climate change signal from the RAOCM and the driving Global Coupled Model show that regionalization has an effect in terms of higher resolution over the land and ocean.


Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1755
Author(s):  
Shuo Wang ◽  
Chenfeng Cui ◽  
Qin Dai

Since the early 2000s, the vegetation cover of the Loess Plateau (LP) has increased significantly, which has been fully recorded. However, the effects on relevant eco-hydrological processes are still unclear. Here, we made an investigation on the changes of actual evapotranspiration (ETa) during 2000–2018 and connected them with vegetation greening and climate change in the LP, based on the remote sensing data with correlation and attribution analysis. Results identified that the average annual ETa on the LP exhibited an obvious increasing trend with the value of 9.11 mm yr−1, and the annual ETa trend was dominated by the changes of ETa in the third quarter (July, August, and September). The future trend of ETa was predicted by the Hurst exponent. Partial correlation analysis indicated that annual ETa variations in 87.8% regions of the LP were controlled by vegetation greening. Multiple regression analysis suggested that the relative contributions of potential evapotranspiration (ETp), precipitation, and normalized difference vegetation index (NDVI), to the trend of ETa were 5.7%, −26.3%, and 61.4%, separately. Vegetation greening has a close relationship with the Grain for Green (GFG) project and acts as an essential driver for the long-term development trend of water consumption on the LP. In this research, the potential conflicts of water demanding between the natural ecosystem and social-economic system in the LP were highlighted, which were caused by the fast vegetation expansion.


Author(s):  
Christoph Schwörer ◽  
Erika Gobet ◽  
Jacqueline F. N. van Leeuwen ◽  
Sarah Bögli ◽  
Rachel Imboden ◽  
...  

AbstractObserving natural vegetation dynamics over the entire Holocene is difficult in Central Europe, due to pervasive and increasing human disturbance since the Neolithic. One strategy to minimize this limitation is to select a study site in an area that is marginal for agricultural activity. Here, we present a new sediment record from Lake Svityaz in northwestern Ukraine. We have reconstructed regional and local vegetation and fire dynamics since the Late Glacial using pollen, spores, macrofossils and charcoal. Boreal forest composed of Pinus sylvestris and Betula with continental Larix decidua and Pinus cembra established in the region around 13,450 cal bp, replacing an open, steppic landscape. The first temperate tree to expand was Ulmus at 11,800 cal bp, followed by Quercus, Fraxinus excelsior, Tilia and Corylus ca. 1,000 years later. Fire activity was highest during the Early Holocene, when summer solar insolation reached its maximum. Carpinus betulus and Fagus sylvatica established at ca. 6,000 cal bp, coinciding with the first indicators of agricultural activity in the region and a transient climatic shift to cooler and moister conditions. Human impact on the vegetation remained initially very low, only increasing during the Bronze Age, at ca. 3,400 cal bp. Large-scale forest openings and the establishment of the present-day cultural landscape occurred only during the past 500 years. The persistence of highly diverse mixed forest under absent or low anthropogenic disturbance until the Early Middle Ages corroborates the role of human impact in the impoverishment of temperate forests elsewhere in Central Europe. The preservation or reestablishment of such diverse forests may mitigate future climate change impacts, specifically by lowering fire risk under warmer and drier conditions.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mulalo M. Muluvhahothe ◽  
Grant S. Joseph ◽  
Colleen L. Seymour ◽  
Thinandavha C. Munyai ◽  
Stefan H. Foord

AbstractHigh-altitude-adapted ectotherms can escape competition from dominant species by tolerating low temperatures at cooler elevations, but climate change is eroding such advantages. Studies evaluating broad-scale impacts of global change for high-altitude organisms often overlook the mitigating role of biotic factors. Yet, at fine spatial-scales, vegetation-associated microclimates provide refuges from climatic extremes. Using one of the largest standardised data sets collected to date, we tested how ant species composition and functional diversity (i.e., the range and value of species traits found within assemblages) respond to large-scale abiotic factors (altitude, aspect), and fine-scale factors (vegetation, soil structure) along an elevational gradient in tropical Africa. Altitude emerged as the principal factor explaining species composition. Analysis of nestedness and turnover components of beta diversity indicated that ant assemblages are specific to each elevation, so species are not filtered out but replaced with new species as elevation increases. Similarity of assemblages over time (assessed using beta decay) did not change significantly at low and mid elevations but declined at the highest elevations. Assemblages also differed between northern and southern mountain aspects, although at highest elevations, composition was restricted to a set of species found on both aspects. Functional diversity was not explained by large scale variables like elevation, but by factors associated with elevation that operate at fine scales (i.e., temperature and habitat structure). Our findings highlight the significance of fine-scale variables in predicting organisms’ responses to changing temperature, offering management possibilities that might dilute climate change impacts, and caution when predicting assemblage responses using climate models, alone.


Author(s):  
Ihsan Jamil ◽  
Wen Jun ◽  
Bushra Mughal ◽  
Muhammad Haseeb Raza ◽  
Muhammad Ali Imran ◽  
...  

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