The Impact of Human Activities on Flood Trends in the Semi-Arid Climate of Cheliff Basin, Algeria

2020 ◽  
Vol 47 (3) ◽  
pp. 409-420 ◽  
Author(s):  
Naima Zekouda ◽  
Mohamed Meddi ◽  
G. Thomas LaVanchy ◽  
Mohamed Remaoun
2020 ◽  
Vol 34 (9) ◽  
pp. 2969-2988
Author(s):  
Mahya Sadat Ghazi Zadeh Hashemi ◽  
Masoud Tajrishy ◽  
Ehsan Jalilvand

Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3253
Author(s):  
Mohammed Analy ◽  
Nour-Eddine Laftouhi

The quantitative monitoring of the shallow aquifer in Marrakesh and its surrounding area shows that the water table has been lowered gradually over the last 40 years, and attaining an acute decline in the early 2000s. This declining trend—if confirmed in the future—may lead to a water shortage, or even to a total aquifer depletion, which would be devastating for a region where economic activity and drinking water supply rely partly on groundwater resources. Two factors account for this situation: the hot semi-arid climate characterized by high temperatures and low precipitation, causing an inadequate groundwater recharge (deficit between rainwater supply and the potential evapotranspiration), and the over-pumping of groundwater from wells for intensive agricultural uses and some leisure activities (golf courses, waterparks and pools, for example). The objective of this study is to assess the hydrodynamic behaviour of the shallow aquifer in this context of persistent drought and semi-arid climate under intense use conditions. Based on earlier research studies and hydrological data recently collected from the field, a spatiotemporal analysis using a geographic information system has been conducted, allowing researchers to monitor the evolution of groundwater resources under the impact of intense exploitation. This study shows a general decline of groundwater level in the city of Marrakesh between 1962–2019. However, by dividing this period into three periods (1962–1985, 1986–2001 and 2002–2019), it is obvious that the main groundwater fall occurred during the two last decades, a period marked by highest recorded temperatures and decreased precipitation levels. This water table decline impacted 85% of the study area and is estimated at 0.9 m/year. The area most affected by the drawdown of the water table experienced a decline reaching 37 m between 2002 and 2019 (more than 2 m a year).


2021 ◽  
Author(s):  
Julie Collignan ◽  
Jan Polcher ◽  
Pere Quintana Seguí

<p>In a context of climate change, the stakes surrounding water availability and use are getting higher, especially in semi-arid climates. Human activities such as irrigation and land cover changes impact the water cycle, raising questions around the effects it could have on regional atmospheric circulation and how to separate the impact of climate change from the impact of anthropogenic activities to better understand their role in the historical records. The ORCHIDEE Land Surface Model from Institut Pierre Simon Laplace (IPSL) simulates global carbon cycle and aims at quantifying terrestrial water and energy balance. It is being developed at regional scale but does not include satisfying hypothesis to account for human activities such as irrigation at such scale so far.</p><p>We <span>propose</span> a methodology to semi-empirically separate the effect of climate from the impact of the changing catchment characteristics on river discharge. <span>It is based on</span> the Budyko framework and <span>allows to characterise the</span> annual river discharge of over 363 river monitoring stations in Spain. The Budyko parameter is estimated for each basin and <span>represents</span> its hydrological characteristics. Precipitations and potential evapotranspiration are derived from the forcing dataset GSWP3 (Global Soil Wetness Project Phase 3) – from 1901 to 2010 –. Two methods are used to estimate evapotranspiration : the first uses evapotranspiration from the ORCHIDEE LSM outputs while the second deduced evapotranspiration from river discharge observations and the water balance equation. The first method only accounts for the effects of atmospheric forcing while the other combines, through the observations, <span>climatic and non-climatic processes</span> over the watersheds. We then study the evolution over the <span>Budyko</span> parameter fitted with these two <span>estimates of evaporation</span>. Studying the watershed parameter allows us to free ourselves from some of the climate interannual variability compared to directly looking at changes in the river discharge and better separate anthropogenic changes from the effect of climatic forcing.</p><p>Our results show that for most basins tested over Spain, there is an increasing trend in the <span>Budyko parameter representing increasing evaporation efficiency</span> of the watershed which <span>can not be</span> explained by the climate forcing. This trend is consistent with changes in irrigation equipment and land cover changes over the studied period. However changes of the basin characteristics can not be fully quantified by this variables. Other factors as glaciers melting which derails the water balance over our time of study.</p><p>The methodology needs to be extended to other areas such as Northern Europe to see if the differences in response of the catchments to anthropogenic changes quantified by our methodology corresponds to known contrasts. Balance between climatic and anthropogenic changes of basin characteristics are different in semi-arid climate than in northern more humid regions.</p>


Author(s):  
F. Bouhezam ◽  
T. Kolesnikova

The article aims to substantiate the role of the patio and its effect on thermal comfort in urban housing, especially in the semi-arid climatic zones of Algeria. In semi-dry cities, the aim is always to avoid direct sunlight and to seek shade and freshness in the summer season. Indeed, the patio is one of the bioclimatic architectural devices that responds to the field of indoor thermal environments and contributes to the creation of comfortable atmosphere. In this study, authors tried to assess the impact of patio geometry on thermal comfort inside housing in the semi-arid climate of Oum El Bouaghi. The study is based on the method of mathematical modeling implemented in the program ECOTECT. It evaluates the impact of the proportional coefficient H/L (height/width) on the value of PMV (Predicted Mean Vote), and PPD (Predicted Percentage of Dissatisfied). The results of this study show that the patio plays an important role in thermal comfort in urban housing. The patio significantly improves the PMV value and reduces the PPD value, increasing sunlight in winter and providing passive space cooling in summer. However, for optimal thermal comfort, the proportional H/L value must be greater than 2.5.


2016 ◽  
Author(s):  
X. Guan ◽  
J. Huang ◽  
Y. Zhang ◽  
Y. Xie ◽  
J. Liu

Abstract. Anthropogenic dust is acknowledged as a product of human activities on disturbed soil, and is generated mainly from sensitive and fragile regions including croplands, pastures, and urbanized regions. In this study, we analyzed the behaviour of anthropogenic dust in semi-arid region of globe, and its relationship to human activities. An obvious peak in the total anthropogenic dust column, much higher magnitude than those of wet regions, was observed in semi-arid regions with population growth rates of more than 11.46 %. Four typical semi-arid regions, East China, India, North America and North Africa were selected to explore the local difference in anthropogenic dust production. The population growth rates in these areas were approximately 6.16 %, 17.71 %, 11.21 %, and 29.26 %, and the anthropogenic dust levels were 0.17 g m−2, 0.38 g m−2, 0.10 g m−2 and 0.21 g m−2, which are higher than the natural dust column burden. The anthropogenic dust column burden is positively correlated with the population and population change, indicating a contribution from human activities to the anthropogenic dust production. Based on the fact that anthropogenic dust can act as warming aerosol, the radiative effect of anthropogenic dust in semi-arid regions can not be ignored and requires further investigation.


2019 ◽  
Author(s):  
Kimberly Bowman ◽  
◽  
Eleana Brumage ◽  
Elizabeth Diaz ◽  
Daphne Kuta ◽  
...  

2021 ◽  
Vol 230 ◽  
pp. 111219
Author(s):  
Alae Azouzoute ◽  
Charaf Hajjaj ◽  
Houssain Zitouni ◽  
Massaab El Ydrissi ◽  
Oumaima Mertah ◽  
...  

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1608
Author(s):  
Salvatore Ivo Giano

This Special Issue deals with the role of fluvial geomorphology in landscape evolution and the impact of human activities on fluvial systems, which require river restoration and management [...]


Sign in / Sign up

Export Citation Format

Share Document