scholarly journals Groundwater Depletion in an Urban Environment under Semiarid Climate and Persistent Drought–City of Marrakesh (Morocco)

Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3253
Author(s):  
Mohammed Analy ◽  
Nour-Eddine Laftouhi
Keyword(s):  
Water Table ◽  
Groundwater Resources ◽  
Shallow Aquifer ◽  
Arid Climate ◽  
Groundwater Depletion ◽  
Hydrodynamic Behaviour ◽  
General Decline ◽  
Persistent Drought ◽  
The Impact ◽  
Semi Arid

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).

scholarly journals The use of groundwater crustacean communities as indicators for aquifers quality in the semi-arid region of north-central Chile

2018 ◽  
Vol 1 ◽  
Author(s):  
Sanda Iepure ◽  
Nicolas Gouin ◽  
Angeline Bertin ◽  
Ana Camacho ◽  
Antonio González-Ramón ◽  
...  
Keyword(s):  
Negative Impact ◽  
Groundwater Resources ◽  
Economic Benefits ◽  
Nutrient Loads ◽  
Groundwater Temperature ◽  
Groundwater Levels ◽  
Water Abstraction ◽  
Over Exploitation ◽  
The Impact ◽  
Semi Arid

Chile has large extensions of arid and semi-arid regions throughout the whole country, where the intensive demands and use of water resources, especially groundwater for irrigations and mining activities, increased dramatically over the last decades. The aquifer depletions due to water abstraction for irrigation and nutrient loads, exert major alterations of water quality, groundwater recharge and the natural renewal rate. All these factors diminish the aquifer value for the users and contribute to the degradation of groundwater as environment and habitat for fauna. This intensive use of groundwater resources in Chile brought to significant social and economic benefits, but their inadequate management resulted in negative environmental, legal and socioeconomic consequences. In this study, we aimed at providing a first assessment of environmental alterations of groundwater ecosystems from agricultural watersheds in northern Chile by specifically evaluating the effects of nitrogen and pesticide loads on groundwater communities and identifing the ecosystem service alterations due to agricultural activities. The study has been performed in a glacial aquifer from Coquimbo region; 250 km north of Santiago de Chile, the floodplain of which is dominated by agriculture (fruits tress, vineyards). Due to low regional precipitations (100-240 mm/year) the aquifer is primarily recharged by snowmelt from the Andean chain and surface runoff. The relative groundwater levels, groundwater temperature, chemical analysis of nitrogen and total phosphorus and pesticide concentrations were examined, along with the evaluation of crustacean biodiversity and spatial distribution pattern. Stygofauna taxonomic richness and the presence of stygobites have been related more to groundwater level stability than to chemical water parameters indicating that over-exploitation has a negative impact on habitat suitability for groundwater invertebrates. Groundwater biota assessment is essential in understanding the impact produced by agriculture activities on groundwater as a resource and as ecosystem, a nexus that becomes more and more widely recognized. The rationale and the preliminary results of this study are summarized in the Suppl. material 1.

The Impact of Pavement Permeability on Time of Concentration in a Small Urban Watershed with a Semi-Arid Climate

2020 ◽  
Vol 34 (9) ◽  
pp. 2969-2988
Author(s):  
Mahya Sadat Ghazi Zadeh Hashemi ◽  
Masoud Tajrishy ◽  
Ehsan Jalilvand
Keyword(s):  
Arid Climate ◽  
Urban Watershed ◽  
Time Of Concentration ◽  
The Impact ◽  
Semi Arid

scholarly journals Using multiple methods to understand groundwater recharge in a semi-arid area

2020 ◽  
Author(s):  
Shovon Barua ◽  
Ian Cartwright ◽  
P. Evan Dresel ◽  
Edoardo Daly
Keyword(s):  
Groundwater Recharge ◽  
Water Table ◽  
Groundwater Resources ◽  
Land Use Changes ◽  
Arid Area ◽  
Plantation Forest ◽  
Land Clearing ◽  
Water Table Fluctuations ◽  
Recharge Rates ◽  
Semi Arid

Abstract. Understanding recharge in semi-arid areas is important for the sustainable management of groundwater resources. This study focuses on estimating groundwater recharge rates and understanding the impacts of land-use changes on recharge in a semi-arid area. Two adjacent catchments in southeast Australia were cleared ~180 years ago following European settlement; in one of these catchments eucalypt plantation forest was subsequently established ~ 20 years ago. Chloride mass balance yields recharge rates of 0.2 to 61.6 mm yr−1 (typically up to 11.2 mm yr−1). The lower of these values probably represent recharge rates prior to land clearing, whereas the higher likely reflects recharge rates following initial land clearing. The low pre-land clearing recharge rates are consistent with the presence of groundwater that has residence times that are up to 24,700 years (calculated using radiocarbon) and the moderate to low hydraulic conductivities (0.31 to 0.002 m day−1) of the clay-rich aquifers. Recharge rates estimated from tritium activities and water table fluctuations reflect those following the initial land clearing. However, recharge rates estimated using water table fluctuations (15 to 500 mm yr−1) are significantly higher than those estimated using tritium renewal rates (0.01 to 89 mm yr−1; typically

scholarly journals Improving estimates of water resources in a semi-arid region by assimilating GRACE data into the PCR-GLOBWB hydrological model

2016 ◽  
Author(s):  
N. Tangdamrongsub ◽  
S. C. Steele-Dunne ◽  
B. C. Gunter ◽  
P. G. Ditmar ◽  
E. H. Sutanudjaja ◽  
...  
Keyword(s):  
Water Resources ◽  
Hydrological Model ◽  
Hexi Corridor ◽  
Accurate Estimation ◽  
Groundwater Depletion ◽  
Correlated Errors ◽  
Grace Data ◽  
The Impact ◽  
Semi Arid

Abstract. An accurate estimation of water resources dynamics is crucial for proper management of both agriculture and the local ecology, particularly in semi-arid regions. Imperfections in model physics, uncertainties in model land parameters and meteorological data, as well as the human impact on land changes often limit the accuracy of hydrological models in estimating water storages. To mitigate this problem, this study investigated the assimilation of Terrestrial Water Storage (TWS) estimates derived from the Gravity Recovery And Climate Experiment (GRACE) data using an Ensemble Kalman Filter (EnKF) approach. The region considered was the Hexi Corridor of Northern China. The hydrological model used for the analysis was PCR-GLOBWB, driven by satellite-based forcing data from April 2002 to December 2010. In this study, EnKF 3D scheme, which accounts for the GRACE spatially-correlated errors, was used. The correlated errors were propagated from the full error variance-covariance matrices provided as a part of the GRACE data product. The impact of the GRACE Data Assimilation (DA) scheme was evaluated in terms of the TWS, as well as individual hydrological storage estimates. The capability of GRACE DA to adjust the storage level was apparent not only for the entire TWS but also for the groundwater component, which had annual amplitude, phase, and long-term trend estimates closer to the GRACE observations. This study also assessed the benefits of taking into account correlations of errors in GRACE-based estimates. The assessment was carried out by comparing the EnKF results, with and without taking into account error correlations, with the in situ groundwater data from 5 well sites and the in situ streamflow data from two river gauges. On average, the experiments showed that GRACE DA improved the accuracy of groundwater storage estimates by as much as 25 %. The inclusion of error correlations provided an equal or greater improvement in the estimates. No significant benefits of GRACE DA were observed in terms of streamflow estimates, which reflect a limited spatial and temporal resolution of GRACE observations. Results from the 9-year long GRACE DA study were used to assess the status of water resources over the Hexi Corridor. Areally-averaged values revealed that TWS, soil moisture, and groundwater storages over the region decreased with an average rate of approximately 0.2, 0.1, and 0.1 cm/yr in terms of equivalent water heights, respectively. A substantial decline in TWS (approximately −0.4 cm/yr) was seen over the Shiyang River Basin in particular, and the reduction mostly occurred in the groundwater layer. An investigation of the relationship between water resources and agriculture suggested that groundwater consumption required to maintain the growing period in this specific basin was likely the cause of the groundwater depletion.

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
Keyword(s):  
Human Activities ◽  
Arid Climate ◽  
The Impact ◽  
Semi Arid

scholarly journals Coastal Aquifer Salinization in Semi-Arid Regions: The Case of Grombalia (Tunisia)

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 129
Author(s):  
Siwar Kammoun ◽  
Rim Trabelsi ◽  
Viviana Re ◽  
Kamel Zouari
Keyword(s):  
Coastal Aquifer ◽  
Arid Regions ◽  
Groundwater Resources ◽  
Exchange Process ◽  
Shallow Aquifer ◽  
Return Flow ◽  
Rock Interaction ◽  
Freshwater Resource ◽  
Semi Arid ◽  
Groundwater Mineralization

Groundwater resources are facing increasing pressure especially in semi-arid regions where they often represent the main freshwater resource to sustain human needs. Several aquifers in the Mediterranean basin suffer from salinization and quality degradation. This study provides an assessment of Grombalia coastal aquifer (Tunisia) based on multidisciplinary approach that combines chemical and isotopic (δ2H, δ18O, 3H, 14C and δ13C) methods to characterize the relation between groundwater quality variation and aquifer recharge. The results indicate that total dissolved solids exceed 1000 mg/L in the most of samples excepting the recharge area. In addition to water–rock interaction, evaporation and nitrate pollution contributing to groundwater mineralization, the reverse cation exchange process constitute an important mechanism controlling groundwater mineralization with enhancing risk of saltwater intrusion. Environmental isotope tracers reveal that groundwater is evolving within an open system to close system. A significant component of recent water that is recharging Grombalia aquifer system is confirmed by applying correction models based on the δ13C values and 14C activities and tritium contents. However, this recharge, which is mainly associated to the return flow of irrigation water, contributes to the groundwater salinization, especially for the shallow aquifer.

Effects of water table management on soil salinity and alfalfa yield in a semi-arid climate

2009 ◽  
Vol 27 (5) ◽  
pp. 401-407 ◽  
Author(s):  
Hamideh Noory ◽  
Abdol-Majid Liaghat ◽  
Mohamad Reza Chaichi ◽  
Masoud Parsinejad
Keyword(s):  
Water Table ◽  
Soil Salinity ◽  
Arid Climate ◽  
Water Table Management ◽  
Semi Arid

scholarly journals Where to locate a tree plantation within a low rainfall catchment to minimise impacts on groundwater resources

2014 ◽  
Vol 11 (8) ◽  
pp. 10001-10041 ◽  
Author(s):  
J. F. Dean ◽  
J. A. Webb ◽  
G. E. Jacobsen ◽  
R. Chisari ◽  
P. E. Dresel
Keyword(s):  
Water Resources ◽  
Mass Balance ◽  
Groundwater Recharge ◽  
Water Table ◽  
Groundwater Resources ◽  
Chloride Mass Balance ◽  
Tree Plantation ◽  
Depth Analysis ◽  
Paired Catchment ◽  
The Impact

Abstract. Despite the fact that there are many studies that consider the impacts of plantation forestry on water resources, and others that explore the spatial heterogeneity of groundwater recharge in dry regions, there is little marriage of the two subjects in forestry management guidelines and legislation. Here we carry out an in-depth analysis of the groundwater and surface water regime in a low rainfall, high evapotranspiration paired catchment study to examine the impact of reforestation, using water table fluctuations and chloride mass balance methods to estimate groundwater recharge. Recharge estimations using the chloride mass balance method were shown to be more likely representative of groundwater recharge regimes prior to the planting of the trees, and most likely prior to widespread land clearance by European settlers. These estimations were complicated by large amounts of recharge occurring as a result of runoff and streamflow in the lower parts of the catchment. Water table fluctuation method estimations of recharge verified that groundwater recharge occurs predominantly in the lowland areas of the study catchment. This leads to the conclusion that spatial variations in recharge are important considerations for locating tree plantations with respect to conserving water resources for downstream users. For dry regions, this means planting trees in the upland parts of the catchments, as recharge is shown to occur predominantly in the lowland areas.

scholarly journals MODELING OF PATIO ARCHITECTURAL SOLUTIONS AND THEIR EFFECT ON THE THERMAL COMFORT OF URBAN HOUSING IN THE SEMI-ARID CLIMATE OF ALGERIA.

2021 ◽  
Vol 6 (9) ◽  
pp. 45-55
Author(s):  
F. Bouhezam ◽  
T. Kolesnikova
Keyword(s):  
Thermal Comfort ◽  
Urban Housing ◽  
Arid Climate ◽  
Climatic Zones ◽  
Thermal Environments ◽  
Space Cooling ◽  
L Value ◽  
The Impact ◽  
Semi Arid

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.

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