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Dtissibe Francis Yongwa Ari Ado Adamou Abba Titouna Chafiq Thiare Ousmane Gueroui Abdelhak Mourad 《Natural Hazards》2020,104(2):1211-1237
Natural Hazards - Nowadays, floods have become the widest global environmental and economic hazard in many countries, causing huge loss of lives and materials damages. It is, therefore, necessary... 相似文献
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Salif Diop Aliou Guisse Claude Sene Birane Cisse Ndeye Rokhaya Diop Sokhna Di Ka Amady Gnagna Cisse Saly Sambou Ousmane Ndiaye Adand Belarmain Fandohan FU Chao WANG Guoqin WANG Yongdong 《资源与生态学报(英文版)》2018,9(3):257-265
The Great Green Wall Initiative (GGWI) has an overall objective of fighting desert encroachment through proven practices of sustainable management of land, and the reinforcement and protection of natural resources and systems of production and transformation, while also ensuring socio-economic development of local communities through multi-purpose activity platforms. The activities described in the present study are designed to accomplish several goals: (1) generate wealth, (2) strengthen access to basic social services, (3) manage the transition to a green economy as a means of creating suitable conditions for the emergence of rural production centers, (4) integrate sustainable development in order to eradicate poverty and food insecurity, and (5) strengthen adaptation and resilience capacities of local populations. The present study was undertaken on the basis of a wide variety of available publications and documentation, including articles and scientific papers, thesis, meeting summaries and reports, concerning the implementation of the Great Green Wall Initiative/GGWI in Senegal. 相似文献
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ABSTRACTThere is great potential in Data Assimilation (DA) for the purposes of uncertainty identification, reduction and real-time correction of hydrological models. This paper reviews the latest developments in Kalman filters (KFs), particularly the Extended KF (EKF) and the Ensemble KF (EnKF) in hydrological DA. The hydrological DA targets, methodologies and their applicability are examined. The recent applications of the EKF and EnKF in hydrological DA are summarized and assessed critically. Furthermore, this review highlights the existing challenges in the implementation of the EKF and EnKF, especially error determination and joint parameter estimation. A detailed review of these issues would benefit not only the Kalman-type DA but also provide an important reference to other hydrological DA types.
Editor D. Koutsoyiannis; Associate editor F. Pappenberger 相似文献
4.
Guidah Chabi Bio Alassane Abdoukarim Kpegli Kodjo Apelete Raoul Lawson Fabrice Messan Amene Alassane Zakari Aoulatou Koukpohounsi Bénito Didier Boukari Ousmane Touré Vouillamoz Jean-Michel Yalo Nicaise Mama Daouda Boukari Moussa 《Hydrogeology Journal》2023,31(5):1229-1243
The Mio-Pliocene aquifer of the coastal sedimentary basin of Benin is the most exploited aquifer for water supply to the urbanised region in the southern part of the country. The population explosion is putting increasing pressure on quantitative and qualitative aspects of the groundwater resources. Preventing groundwater contamination caused by surface waters requires a thorough understanding of surface-water/groundwater interactions, especially the interactions between the Mio-Pliocene aquifer and surface waters. This study aimed to investigate the interactions between groundwater and surface waters along the major rivers (Sô River and Ouémé Stream) and brooks in the Ouémé Delta. Field campaigns identified 75 springs located in the valleys which feed the rivers, and thus maintain their base flow. The piezometric results indicated, through flow direction assessment, that the Mio-Pliocene aquifer feeds Ouémé Stream and Sô River. Chemical analyses of groundwater and surface waters show similar chemical facies, and changes in the chemical composition in groundwater are also observed in the surface waters. Moreover, the isotopic signatures of surface waters are similar to those of the groundwater and springs, which led to the identification of potential groundwater discharge areas. As a result of groundwater discharge into surface waters, the fraction of groundwater in the surface water is more than 66% in the brooks, regardless of the season. In the Ouémé Stream and Sô River, the fraction of groundwater is 0–21% between June and September, while from October to March it is 47–100%.
相似文献5.
Mamadou Adama Sarr Philippe Gachon Ousmane Seidou Christopher Robin Bryant Jacques André Ndione Jacques Comby 《水文科学杂志》2013,58(9):1538-1549
AbstractDaily precipitation data from 31 Senegalese stations spanning the period from 1950 to 2007 were used to examine the inter-annual variations of seven rainfall indices: the annual mean precipitation (MEAN); the annual standard deviation of daily precipitation (STD); the frequency of wet days (Prcp1); the maximum number of consecutive dry days (CDD); the maximum 3-day rainfall total (R3D); the wet day precipitation intensity (SDII); and the 90th percentile of rain-day precipitation (Prec90p). The indices were spatially averaged over three agro-climatic regions in Senegal. Trends in the time series of the averaged indices were assessed using both visual examination and a modified version of the Mann-Kendall (MM-K) test. Initially negative significant trends in all seven indices suggest gradually drier conditions over the three agro-climatic regions between 1950 and 1980. In contrast, no significant trends, or even positive significant trends, were observed from the mid-1980s to 2007. The MM-K test was applied to all available data (1950–2007) and the period from 1971 to 2000. While several indices were found to have significant trends towards drier conditions for the 1950–2007 period, only PRCP1 showed a positive significant trend for the 1971–2000 period. The MM-K test did not detect a significant trend for the other indices. It was found that the rainfall deficit and therefore drought is no longer intensifying, and that the region may even become wetter. However, the period covered by the observations is still too short to resolve the question of whether there is now a trend towards wetter conditions.
Editor Z.W. Kundzewicz; Associate editor K. Hamed 相似文献
6.
Sediment deposition in reservoirs is an important research topic in engineering practice. Reservoir sedimentation has the potential to affect ood levels, drainage for agricultural land, pump station and hydropower operation as well as navigation. This paper describes the development of a coupled fully three-dimensional (3D) numerical model for the prediction of the local sediment ushing scour upstream of the bottom outlet. The presented numerical model solves the Navier-Stokes equations in conjunction with the k- turbulence model which includes both sediment transport and hydrodynamic parameters. The proposed coupled fully 3D numerical model is used to simulate experimental tests based on non-cohesive sediment. The geometric features of the scour hole (temporal and spatial hole devel- opment) upstream of the bottom outlet were reasonably well predicted compared to the experimental data. Furthermore, the velocity eld upstream of the bottom outlet was in good agreement with mea- surements. The proposed numerical model for bottom outlet ushing was, therefore, validated because of its ability to accurately predict the scour hole development during the ushing process. The proposed numerical model can be considered reliable provided that the model is correctly calibrated and set up to re ect the conditions of a particular case study. 相似文献
7.
Flood quantiles are routinely used in hydrologic engineering to design hydraulic structures, optimize erosion control structure
and map the extent of floodplains. As an increasing number of papers are pointing out cycles and trends in hydrologic time
series, the use of stationary flood distributions leads to the overestimation or underestimation of the hydrologic risk at
a given time. Several authors tried to address this problem by using probability distributions with time-varying parameters.
The parameters of these distributions were assumed to follow a linear or quadratic trend in time, which may be valid for the
short term but may lead to unrealistic long-term projections. On the other hand, deterministic rainfall-runoff models are
able to successfully reproduce trends and cycles in stream flow data but can perform poorly in reproducing daily flows and
flood peaks. Rainfall-runoff models typically have a better performance when simulation results are aggregated at a larger
time scale (e.g. at a monthly time scale vs. at a daily time scale). The strengths of these two approaches are combined in
this paper where the annual maximum of the time-averaged outputs of a hydrologic model are used to modulate the parameters
of a non-stationary GEV model of the daily maximum flow. The method was applied to the Kemptville Creek located in Ontario,
Canada, using the SWAT (Soil and Water Assessment Tool) model as rainfall-runoff model. The parameters of the non-stationary
GEV model are then estimated using Monte Carlo Markov Chain, and the optimal span of the time windows over which the SWAT
outputs were averaged was selected using Bayes factors. Results show that using the non-stationary GEV distribution with a
location parameter linked to the maximum 9-day average flow provides a much better estimation of flood quantiles than applying
a stationary frequency analysis to the simulated peak flows. 相似文献
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Alodah Abdullah Seidou Ousmane 《Stochastic Environmental Research and Risk Assessment (SERRA)》2020,34(7):993-1021
Stochastic Environmental Research and Risk Assessment - While Stochastic Weather Generators (SWGs) are used intensively in climate and hydrological applications to simulate hydroclimatic time... 相似文献
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