Hydrologic and hydrodynamic modelling of extreme flood events to assess the impact of climate change in a large basin with limited data

2015 ◽  
Vol 11 ◽  
pp. S147-S157 ◽  
Author(s):  
M.S.I.I. Amir ◽  
M.M.K. Khan ◽  
M.G. Rasul ◽  
R.H. Sharma ◽  
F. Akram
Mycorrhiza ◽  
2021 ◽  
Author(s):  
P. W. Thomas

AbstractVery little is known about the impact of flooding and ground saturation on ectomycorrhizal fungi (EcM) and increasing flood events are expected with predicted climate change. To explore this, seedlings inoculated with the EcM species Tuber aestivum were exposed to a range of flood durations. Oak seedlings inoculated with T. aestivum were submerged for between 7 and 65 days. After a minimum of 114-day recovery, seedling growth measurements were recorded, and root systems were destructively sampled to measure the number of existing mycorrhizae in different zones. Number of mycorrhizae did not display correlation with seedling growth measurements. Seven days of submersion resulted in a significant reduction in mycorrhizae numbers and numbers reduced most drastically in the upper zones. Increases in duration of submersion further impacted mycorrhizae numbers in the lowest soil zone only. T. aestivum mycorrhizae can survive flood durations of at least 65 days. After flooding, mycorrhizae occur in higher numbers in the lowest soil zone, suggesting a mix of resilience and recovery. The results will aid in furthering our understanding of EcM but also may aid in conservation initiatives as well as providing insight for those whose livelihoods revolve around the collection of EcM fruiting bodies or cropping of the plant partners.


2021 ◽  
Vol 13 (16) ◽  
pp. 8979
Author(s):  
Serey Sok ◽  
Nyda Chhinh ◽  
Sanara Hor ◽  
Pheakdey Nguonphan

Climate change is unequivocal. Farmers are increasingly vulnerable to floods and drought. In this article, the negative impact of climate hazards on rice cultivation in the Tonle Sap and Mekong River influenced by climatic variability between 1994 and 2018 are analyzed. A cohort of 536 households from four Cambodian districts participated in household surveys designed to consider how various vulnerability factors interacted across this time series. It was found that: (i) The major climate hazards affecting rice production between 1994 and 2018 were frequent and extreme flood and drought events cause by rainfall variability; (ii) In 2018, extreme flood and drought occurred in the same rice cultivation cycle. The impact caused by each hazard across each region were similar; (3) An empirical model was used to demonstrate that drought events tend to limit access to irrigation, impact rice production, and result in an increased prevalence of water-borne diseases. Flood events cause reduced rice production, damage to housing, and impede children from accessing education. The impact of drought events on rice production was found to be more severe than flood events; however, each climatic hazard caused physical, economic, social, and environmental vulnerabilities. It is recommended that sufficient human and financial resources are distributed to local authorities to implement adaptation measures that prepare rice farmers for flood and drought events and promote equitable access to water resources.


Author(s):  
N. Maidanovych ◽  

The purpose of this work is to review and analyze the main results of modern research on the impact of climate change on the agro-sphere of Ukraine. Results. Analysis of research has shown that the effects of climate change on the agro-sphere are already being felt today and will continue in the future. The observed climate changes in recent decades have already significantly affected the shift in the northern direction of all agro-climatic zones of Europe, including Ukraine. From the point of view of productivity of the agro-sphere of Ukraine, climate change will have both positive and negative consequences. The positives include: improving the conditions of formation and reducing the harvesting time of crop yields; the possibility of effective introduction of late varieties (hybrids), which require more thermal resources; improving the conditions for overwintering crops; increase the efficiency of fertilizer application. Model estimates of the impact of climate change on wheat yields in Ukraine mainly indicate the positive effects of global warming on yields in the medium term, but with an increase in the average annual temperature by 2 ° C above normal, grain yields are expected to decrease. The negative consequences of the impact of climate change on the agrosphere include: increased drought during the growing season; acceleration of humus decomposition in soils; deterioration of soil moisture in the southern regions; deterioration of grain quality and failure to ensure full vernalization of grain; increase in the number of pests, the spread of pathogens of plants and weeds due to favorable conditions for their overwintering; increase in wind and water erosion of the soil caused by an increase in droughts and extreme rainfall; increasing risks of freezing of winter crops due to lack of stable snow cover. Conclusions. Resource-saving agricultural technologies are of particular importance in the context of climate change. They include technologies such as no-till, strip-till, ridge-till, which make it possible to partially store and accumulate mulch on the soil surface, reduce the speed of the surface layer of air and contribute to better preservation of moisture accumulated during the autumn-winter period. And in determining the most effective ways and mechanisms to reduce weather risks for Ukrainian farmers, it is necessary to take into account the world practice of climate-smart technologies.


2012 ◽  
Vol 20 (1) ◽  
pp. 108-115 ◽  
Author(s):  
Wu Weiwei ◽  
Xu Haigen ◽  
Wu Jun ◽  
Cao Mingchang

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