Modeling Water Supply and Demand for Effective Water Management in the Sana’a Basin in Yemen

2021 ◽  
Vol 25 (2) ◽  
pp. 15-44
Author(s):  
Zamzam Mubarak ◽  
Wail Alderwish

Modelling system is the core for the evaluation of water related sectors in the Sana’a Basin. The numerical modelling (MODFLOW) has emerged as an effective tool for managing groundwater resources and predicting future responses, especially when dealing with complex aquifers systems and heterogeneous formations. MODFLOW model has been used herein as a management tool for the targeted sub- basins in Sana’a Basin such (Wadi Bani Hawat, Wadi Dhahr & Al-Ghayl, Wadi Hamdan & As Sabrahand Wadi Ghayman); the most important groundwater resources for domestic and agricultural sectors in Sana’a basin. A conceptual model was designed according to the actual groundwater dynamic flow system in the 2010 Hydrosult Sana’a Basin Model. Also, the governing partial parabolic differential equation was defined, including the vertical conductivity flow between the aquifers. Total groundwater abstraction values from previous studies were compiled, including the 2015 well inventory data of National Water Resources Authority –Sana’a Basin.In this study, three simulations of groundwater development scenarios were distinguished. The first scenario is applied for evaluation of the present status and till 2025. The second and thethird scenarios are focused on the effect of water augmentation i.e. decrease the present rate of groundwater abstraction to 30% and 50% respectively, with considering the highly intervention of IWRM structure of Sana’a basin on the on-going activities related to change land use, change crop pattern, value chain, marketing, modern irrigation techniques, water harvesting techniques, treated waste reuse etc…. Also other Modules were used in calculating the groundwater demand, deficit and unemployment in agricultural sector inSana’a Basin. Scenario 3 gives a remarkable improvement of the water resources system in the four sub-basins within a reasonable period (in the year 2025), thus, it will keep the water resources sustainability; but the unemployment in agricultural sector in Sana’a Basin in scenario 3 will be is the highest value if comparing with the other two scenarios. It will reachin 2025 under scenario 2 and scenario 3 to 10432 and 14762 respectively while in scenario 1 the unemployment will disappeared in 2025. This study is recommended that irrigation systems should be improved, usage of harvesting water methods and treated waste water reuse for agriculture to avoid the depletion of Sana’ Basin aquifer and to reduce unemployment in agricultural sector in Sana’a Basin. Keywords: Groundwater Flow Model, MODFLOW, Management Scenarios, Sana’a Basin, Targeted Sub-Basins.

2020 ◽  
Vol 28 (8) ◽  
pp. 2635-2656
Author(s):  
Samson Oiro ◽  
Jean-Christophe Comte ◽  
Chris Soulsby ◽  
Alan MacDonald ◽  
Canute Mwakamba

AbstractThe Nairobi volcano-sedimentary regional aquifer system (NAS) of Kenya hosts >6 M people, including 4.7 M people in the city of Nairobi. This work combines analysis of multi-decadal in-situ water-level data with numerical groundwater modelling to provide an assessment of the past and likely future evolution of Nairobi’s groundwater resources. Since the mid-1970s, groundwater abstraction has increased 10-fold at a rate similar to urban population growth, groundwater levels have declined at a median rate of 6 m/decade underneath Nairobi since 1950, whilst built-up areas have increased by 70% since 2000. Despite the absence of significant trends in climatic data since the 1970s, more recently, drought conditions have resulted in increased applications for borehole licences. Based on a new conceptual understanding of the NAS (including insights from geophysics and stable isotopes), numerical simulations provide further quantitative estimates of the accelerating negative impact of abstraction and capture the historical groundwater levels quite well. Analysis suggests a groundwater-level decline of 4 m on average over the entire aquifer area and up to 46 m below Nairobi, net groundwater storage loss of 1.5 billion m3 and 9% river baseflow reduction since 1950. Given current practices and trajectories, these figures are predicted to increase six-fold by 2120. Modelled future management scenarios suggest that future groundwater abstraction required to meet Nairobi projected water demand is unsustainable and that the regional anthropogenically-driven depletion trend can be partially mitigated through conjunctive water use. The presented approach can inform groundwater assessment for other major African cities undergoing similar rapid groundwater development.


2005 ◽  
Vol 5 (3-4) ◽  
pp. 17-25 ◽  
Author(s):  
J. Pasch ◽  
P. Macy

Jordan's population is projected to reach 6.5 million by 2010. Limited water does not meet present or projected demands, groundwater levels are dropping, and industrialization is increasing pressure on water resources and the environment. The agricultural sector alone uses approximately 70% of total water resources. Wastewater represents a resource that can help fill Jordan's gap between supply and demand. While approximately 80% of the over 80 MCM of wastewater/yr is currently reused, only a fraction is formalized with permitting and adherence to reuse guidelines. The Jordanian government seeks to embrace reclaimed resources in national water resources planning through recognized/regulated reuse implementation activities. A multi-sectoral project is being performed to help reach this goal in Jordan and worldwide, sharing lessons learned in increasing access to reused water, and involving performance of four demonstration projects with an aim toward developing replicable operational conditions that support sustainability/enhance expansion of treated wastewater reuse in Jordan.


2015 ◽  
Vol 73 (5) ◽  
Author(s):  
Intan Sazrina Saimy ◽  
Fauziah Raji

Most major cities in Malaysia face problems of clean and safe water supply. The blame is on the population boom, industrialisation, pollution plus climate change. It becomes more complicated with uncontrolled usage, public’s ignorance and ineffective water management. These problems have led to higher dependencies towards alternative usage of groundwater to serve the needs of public, agricultural sector and the industries. Groundwater usage must be abstracted sustainably to avoid short and long term effects. This exploratory qualitative study analyses several aspects: (a) existing documents on Malaysian water management (b) documents on Malaysian groundwater governance; (c) applications and enforcements of groundwater governance in states. The analyses are essential in recognising and providing appropriate and effective groundwater governance towards higher consumption in the country especially in industrial sector. Early finding reveals the current groundwater governance lack good management and there are legal vacuums. This paper promotes appropriate groundwater governance and management of policies and strategies at both federal and state level, relevant agencies, stakeholders and local communities in ensuring sustainable groundwater resources usage in Malaysia.


2021 ◽  
Vol 3 ◽  
Author(s):  
Ad De Roo ◽  
Ioannis Trichakis ◽  
Berny Bisselink ◽  
Emiliano Gelati ◽  
Alberto Pistocchi ◽  
...  

The Mediterranean is an area where the balance between water demand and abstractions vs. water availability is often under stress already, as demonstrated here with the Water Exploitation Index. In this work, model estimates on how different proposed measures for water resources management would affect different indicators. After a review of the current water resources status in the Mediterranean and the definition of indicators used in this study, aspects interlinked with water in the Water-Energy-Food-Ecosystems Nexus are briefly discussed, focusing on problems linked with water scarcity and depletion of groundwater resources as well as with climate change projections. Subsequently, the proposed measures for water efficiency are detailed—irrigation efficiency, urban water efficiency, water reuse and desalination—that might be effective to reduce the growing water scarcity problems in the Mediterranean. Their effects that result from the LISFLOOD model, show that wastewater reuse, desalination and water supply leakage reduction lead to decreased abstractions, but do not affect net water consumption. Increased irrigation efficiency does decrease consumption and reduces abstractions as well. We deduct however that the current envisaged water efficiency measures might not be sufficient to keep up with the pace of diminishing water availability due to climate change. More ambition is needed on water efficiency in the Mediterranean to keep water scarcity at bay.


2003 ◽  
Vol 3 (3) ◽  
pp. 63-70 ◽  
Author(s):  
P. Xu ◽  
F. Brissaud ◽  
M. Salgot

An integrated technical-economic modelling framework was developed to help planning and managing of water resources in a Mediterranean tourist area, Palma on Majorca island (Spain). Due to high water demand, groundwater resources are depleted and new water resources should be developed. Seawater desalination has become an important solution to water shortage, especially in the summer tourist season. Meanwhile, reclaimed water has been applied for agricultural and landscape irrigation. With regard to the treated wastewater not being effectively reused, further water reuse scenarios are envisaged in order to meet new water demand, restore over-exploited aquifers and reduce expensive seawater desalination. Three types of models were established and coupled: (i) hydrological models; (ii) water demand and/or need model; (iii) technical-economic model. In addition, a multi-criteria analysis completed the technical-economic modelling. The simulated water reuse scenarios are not alternative but complementary. They provide the possibilities for total reuse of wastewater in the Palma area. Compared with seawater desalination, water reuse is a cost-effective solution to address water scarcity issues in the Palma area. Using tertiary effluent for landscape irrigation allows over-exploited aquifers to recover. It is very attractive in terms of economic benefits and feasible with respect to technical and social aspects. Further water reuse for extending agricultural irrigation can greatly reduce seawater desalination but acquiring the farmers' agreement to give up pumping groundwater for irrigation would meet some difficulties. Water recharge would help to totally reuse wastewater but uncertainties related to public perception and the attitude or regulatory board and local authorities need dealing with. Because water reuse requires a long-term managing viewpoint in order to prepare and demonstrate its feasibility and security, seawater desalination was adopted as an emergency solution to meet peak demands during the tourist season and in case of drought.


Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2132
Author(s):  
Sanghyun Park ◽  
Hyeonjun Kim ◽  
Choelhee Jang

Groundwater withdrawal results in a significant depletion of groundwater storage due to the frequency and intensity of droughts and increasing irrigation demands. To ensure the sustainable use of groundwater resources, it is necessary to accurately simulate the groundwater behavior of catchments using a surface–groundwater integrated runoff model. Most of the existing catchment runoff models have been applied to surface water management; thus, integrated runoff analysis studies that consider the interaction between surface water and groundwater are required. Due to the intensive agricultural sector in Korea and the position of rice as the staple in the Korean diet, more than 50% of groundwater abstraction is used for irrigation. Therefore, it is very important to understand the hydrological interrelationships between agricultural areas and the entire watershed. This study aimed to compare and analyze the groundwater levels in the mountainous areas and paddy field areas in the Boryeong Dam catchment through a surface–groundwater integrated runoff simulation using the Catchment Hydrologic Cycle Assessment Tool model, and to compare the hydrological responses in wet years (2010–2012) and dry years (2014–2016). The maximum difference in the monthly groundwater level in the dry years compared to the wet years was 1.07 m at the forest catchment and 0.37 m at the paddy catchment. These results indicate that the impact of drought on the groundwater level of paddy catchments is not significant compared to the forest catchments; however, drought slows the recovery of the groundwater level before the rainy season, thereby limiting the agricultural groundwater use in the catchment.


Water ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 34 ◽  
Author(s):  
Yuanying Zhang ◽  
Yimin Chen ◽  
Min Huang

Water footprint (WF) is a measure of the actual appropriation of water resources. WF accounting can provide a scientific basis for the managements of water resources. In this study, a multi-regional input-output model is employed to measure the quantity of blue WF (WF) and inter-provincial virtual water (VW) flows in China for the years of 2007 and 2010. The results show that: (1) China’s total WF increased from 205.42 billion m3 in 2007 to 229.34 billion m3 in 2010. Approximately 42% of the WF was attributed to VW embodied in inter-provincial trade. Xinjiang is the largest province of VW export, whereas Shanghai had the largest net VW inflows. (2) From 2007 to 2010, the share of the agricultural sector in the entire VW trade declined, but was still as high as 82.78%, followed by the industrial sector. (3) The north-to-south and south-to-south patterns were witnessed in the domestic VW flows. The provincial WF variations are found to be affected by the per capital GDP, total water resources, per capita water resources, and urban population. (4) By linking VW with an integrated WAVE+ (water accounting and vulnerability evaluation) factor, it was found that virtual scarce water (VSW) was mainly exported by the provinces in northern China. At the national level, the amounts of VSW inflows were consistently greater than those of VSW outflows for both years, 2007 and 2010, implying an increased pressure on the provinces with water deprivation issues. Overall, these results can provide a basis for refining the spatiotemporal allocation of water resources and mitigating the conflict between water supply and demand in China.


2020 ◽  
Vol 202 ◽  
pp. 03002
Author(s):  
Wedo Aru Yudhantoro ◽  
Suyud Warno Utomo ◽  
Dwi Nowo Martono

The number of clean water needed will always increase when the number of the population still shows growth. It must have the same level from the supply and demand or the supply of clean water has higher than the demand for clean water. Some cities in Indonesia have problems with the fulfilment of clean water. Factors from climate change, behaviour, and management can affect the conditions of clean water resources. The development of technologies and science makes the reuse of the water process can be done for another resource of clean water fulfilment. Rainwater harvesting, membrane bioreactors, reverse osmosis, and filtration systems are some kind of processing systems for the water mechanism for the fulfilment of clean water. Sustainable clean water resources and supply is one of the indicators of sustainable development goals. This research was conducted to see how is the potential of water reuse for the fulfilment of clean water in Indonesia by using several systems or processing that have been installed and used. The control and evaluation is the best key to make sure the clean water resources still in the best condition and water reuse is one of the plan to support fulfilment of clean water.


2019 ◽  
Vol 5 (1) ◽  
pp. 18-25
Author(s):  
Isah Funtua Abubakar ◽  
Umar Bambale Ibrahim

This paper attempts to study the Nigerian agriculture industry as a panacea to growth as well as an anchor to the diversification agenda of the present government. To do this, the time series data of the four agriculture subsectors of crop production, livestock, forestry and fishery were analysed as stimulus to the Real GDP from 1981-2016 in order to explicate the individual contributions of the subsectors to the RGDP in order to guide the policy thrust on diversification. Using the Johansen approach to cointegration, all the variables were found to be cointegrated. With the exception of the forestry subsector, all the three subsectors were seen to have impacted on the real GDP at varying degrees during the time under review. The crop production subsector has the highest impact, however, taking size-by-size analysis, the livestock subsector could be of much importance due to its ability to retain its value chain and high investment returns particularly in poultry. Therefore, it is recommended that, the government should intensify efforts to retain the value chain in the crop production subsector, in order to harness its potentials optimally through the encouragement of the establishment of agriculture cottage industries. Secondly, the livestock subsector is found to be the most rapidly growing and commercialized subsector. Therefore, it should be the prime subsector to hinge the diversification agenda naturally. Lastly, the tourism industry which is a source through which the impact of the subsector is channeled to the GDP should be developed, in order to improve the impact of such channel to GDP with the sole objective to resuscitate the forestry subsector.


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