Hydrology of humid tropical regions — Aspects of tropical cyclones — Hydrological effects of agriculture and forestry practice

1985 ◽  
Vol 10 (2) ◽  
pp. 185-187
Author(s):  
P.M. Fleming
2021 ◽  
Author(s):  
Indrajit Pal ◽  
Parameshwar Udmale ◽  
Sylvia Szabo ◽  
Malay Pramanik ◽  
Satya Venkata Sai Aditya Bharawaz Ganni

<p>Across the world, health and disaster managers face the challenge of responding to natural hazards such as cyclones, floods, and droughts while minimizing the impacts of Covid-19. The tropical cyclones and floods affect vulnerable communities and result in losses of life and damages. The drought situations can weaken the agricultural economy and local livelihoods. How these impacts could be amplified by the Covid-19, mainly during the monsoon season, is of great importance for informed-planning. The present study aims to assess exposure to hydro-meteorological hazards (tropical cyclones, floods, and droughts) in terms of the number of people affected, economic activities exposed, and how these hazards superimposed over the Covid-19 pandemic could impact the different phases of disaster risk management cycle. The study focuses on three deltas, namely, Ganges-Brahmaputra-Meghna (GBM) delta spanning over India and Bangladesh, and Red River (RR) and Mekong River (MK) deltas in Vietnam.</p><p>Present research found that the GBM delta suffers from frequent cyclones and floods and less with coastal floods and droughts, whereas the MK delta suffers from riverine and coastal floods and droughts. The RR delta faces frequent tropical cyclones, riverine and coastal floods, and droughts. Populations living in Red delta (100%) exposed more to tropical cyclone as compared to GBM (2.22%) and the Mekong delta (0%) with 50-year return period (RP). Similarly, about 36.46 (0.28), 83.24 (47.23), and 72.76 (33.49) % population of the GBM, RR, and MK deltas are exposed to riverine (coastal) flood hazards with 10-year RP, respectively. During May-Aug 2020, a maximum of 0.76, 100, and 33.49 % population in a month was exposed to meteorological drought (SPI3 below -1) in the GBM, RR, and MK deltas, respectively.</p><p>The results include probabilistic exposure of urban area, cropland, livestock, and GDP to major hydro-meteorological hazards on a similar line. In the second part, the study explores the number of Covid-19 cases reported at the administrative level 2 and draws qualitative inferences on how tackling multi-hazards in the deltas could have become more challenging during the ongoing pandemic and vice versa.  The study recommends that the pandemic has resulted in an urgent need to incorporate health emergency disasters while designing hydro-meteorological disaster management plans.</p>


2020 ◽  
Vol 79 (2) ◽  
pp. 129-141
Author(s):  
M. E. Sanyaolu ◽  
Oluropo F. Dairo ◽  
A. A. Willoughby ◽  
L. B. Kolawole

2008 ◽  
Vol 6 (2) ◽  
Author(s):  
Iriwi Louisa S. Sinon

<p><em>Study dendrochronology or tree-ring dating is defined as the study of chronological sequence of annual growth rings in trees. Teak (Tectona grandis) is one of various tree species that has been identified for the use of tree-ring studies in tropical regions. Teak is found to be suitable for dendrochronology as it is long-lived and develops defined annual growth rings. In Java, teak cans growth naturally or intensively in plantation. The two silviculture conditions will give different sensitivity on climate effect. Therefore, the effect of silviculturer will on natural teak and plantation teak in Saradan, Madiun, and East Java. As a part of the study, ten core samples from natural- growth teak were measured. The samples of growth rings is spanned from 1832 – 2004. Using the COFECHA program, the correlation of the samples (r) was found to be 0.44 point, which is satisfactory to the standard used in dendrochronology. Thus, from this study it can be concluded that natural teak could still be used in dendrochronology, although the sensitivity are not as high as plantation teak. </em></p>


2017 ◽  
Author(s):  
Jocelyn Raude

Objectives: Although people have been repeatedly found to underestimate the frequency of risks to health from common diseases, we still do not know much about reasons for this systematic bias, which is also referred to as “primary bias” in the literature. In this study, we take advantage of a series of large epidemics of mosquito-borne diseases to examine the accuracy of judgments of risk frequencies. In this aim, we assessed the perceived versus the observed prevalence of infection by zika, chikungunya or dengue fever during these outbreaks, as well as their variations among different subpopulations and epidemiological settings.Design: We used data drawn from 4 telephone surveys, conducted between 2006 and 2016, among representative samples of the adult population in tropical regions (Reunion, Martinique, and French Guiana). The participants were asked to estimate the prevalence of these infections by using a natural frequency scale.Results: The surveys showed that (1) most people greatly overestimated the prevalence of infection by arbovirus, (2) these risk overestimations fell considerably as the actual prevalence of these diseases increased, (3) the better-educated and male participants consistently yielded less inaccurate risk estimates across epidemics, and (4) that these biases in the perception of prevalence of these infectious diseases are relatively well predicted by probability weighting function.Conclusions: These findings suggest that the cognitive biases that affect perception of prevalence of acute infectious diseases are not fundamentally different from those that characterize other types of probabilistic judgments observed in the field of behavioral decision-making. They also indicate that numeracy may play a considerable role in people’s ability to transform epidemiological observations from their social environment to more accurate risk estimates.


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