Coronavirus Disease 2019 (COVID-19) in Conakry, Republic of Guinea: Analysis and Relationship with Meteorological Factors

The coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), dates back to December 29, 2019, in Wuhan, China. It quickly spreads like wildfire to all continents in the following months. In Guinea, the first case of COVID-19 and death were all reported respectively on March 12 and April 16, 2020. Since then, several studies have found a relationship between certain environmental conditions such as the meteorological factors to have the potential of contributing to the spread of the virus. Thus, this study aims at examining the extent to which observed meteorological factors might have contributed to the spread of the coronavirus disease 2019 (COVID-19) cases in Conakry, from March 1 to May 31, 2020. Meteorological factors such as temperature (Tmin, Tmean and Tmax) and relative humidity (RHmin, RHmean and RHmax) were analyzed together with the data on the COVID-19. The dynamic of the COVID-19 in Guinea was analyzed along with that of some west African countries. The analysis on the dynamic of the COVID-19 pandemic in West Africa indicated Guinea as one of the most affected countries by the pandemic after Nigeria and Ghana. The study found that in general an increase in the temperature is linked to a decline in the COVID-19 number of cases and deaths, while an increase in the humidity is positively correlated to the number of cases and deaths. Nevertheless, from this study it was also observed that low temperature, mild diurnal temperature and high humidity are likely to favor its transmission. The study therefore, recommends that habitations and hospital rooms should be kept in relatively low humidity and relatively higher temperature to minimize the spread of the (SARS-CoV-2).

Evolution of Dam Lakes in the Kayanga/Geba Basin: Contribution of Remote Sensing and GIS

The Confluent and Niandouba dams were built in 1984 and 1997 respectively to better control water resources, increase agricultural production and promote local development. This article studies their evolution on the Kayanga/Geba River, a transboundary river between Guinea, Senegal and Guinea-Bissau, from its impoundment to the present day. The topographic characteristics analysed through the DTMs (Digital Terrain Models) show a flat shape for the Confluent Dam Lake and long plateaus for the Niandouba Dam Lake. The cross-sections present a variety of morphologies ranging from wide U-shaped valleys with sinuous bottoms to deep V-shaped valleys. The homogenisation and reconstruction of missing values were carried out using the regional vector method. The application of Pettitt’s statistical test on annual rainfall (1932-2019) indicates breaks of stationarity in 1967 or 1969. The post-breakage deficits range from 11.4% to 19.4%. The segmentation method corroborates the results of the Pettitt test. The variations of the surface area of the Confluent and Niandouba water bodies are linked to rainfall, evaporation and withdrawals for different uses. Their monitoring would allow for better management of available water resources but also for good planning of off-season crops.

Analysis of Rainfall Dynamics in Conakry,Republic of Guinea

Observed rainfall data of the National Meteorological Service of Guinea (NMS) exhibit that synoptic station usually records the largest rainfall amount in Guinea. Only few studies have been done on this rainfall peak observed in Conakry. This work better analyses the atmospheric dynamics leading to rainfall particularity. Using NMS data from 1981 to 2010, the monthly contribution and mean seasonal cycle of each station has been done. These findings of the study show that between July and August (rainfall season peak), the coastline particularly Conakry records the largest amount of rainfall. Using Era Interim data for the common period (1981-2010), we also investigate the rainfall dynamics in the lower level (1000 hPa - 850 hPa) from precipitable water, divergence, and moisture flow transport. There is a west and southwest moisture flow transport explained by a strong moisture convergence in the coastal region (Lower-Guinea). Furthermore, values of precipitable water in the same region are found, in agreement with the high moisture flow transport gradient. These incoming flow (west and south-west) undergo a return by blocking’s Kakoulima range (foehn effect) and Fouta Djallon massif to initiate convection clouds on the Guinean coast. These processes enhance a convergence of moisture associated with orographic origin convection. This has an important effect by increasing the rainfall amount in Conakry.