Evaluating the Impact of Urban Growth on the Design of Storm Water Drainage Systems

Urban growth is one of the major causes of flooding in urban areas. This affects the runoff coefficients, which is among the most important factors that affect the design of storm water drainage systems. Changing the runoff coefficient will affect the design parameters of the drainage network, including outfall discharge, velocity, lag time and cost of construction. This study aims to assess the effect of changing the runoff coefficient due to urban growth on the design of a storm water drainage system. The hydrological models Hyfran, StormCAD and GIS are used to analyze different runoff coefficients. This study examines three zones in Dammam in the Kingdom of Saudi Arabia (KSA). The data developed from the models for the current case studies are used to develop an empirical equation to predict the max discharge for other catchments. The discharge is a function of the return period, runoff coefficient, drainage density, longest path, rainfall intensity and catchment area. To validate the developed equation, we use it to estimate the discharge in a real case study in South Korea. A comparison between the measured discharge and estimated discharge shows that the empirical equation is capable of predicting the maximum discharge for different catchments with high accuracy. Then, the validation of the models is carried out to determine the effect of the runoff coefficient on the design of a storm water drainage system in a case study in KSA. The results show that an increasing runoff coefficient due to urban growth increases the outfall discharge and velocity of storm water drainage systems, as well as affecting the cost of construction and decreasing the lag time. The cost increases by two to three times with increasing urbanization. This study provides a new perspective on the hydrologic impact of urban growth on the design of storm water drainage systems, which are essential for flood management. Moreover, the relationship between urban growth and the cost of storm drainage networks is explored, which could help decision makers to make appropriate judgements

Effects of Aquifer Bed Slope and Sea Level on Saltwater Intrusion in Coastal Aquifers

The quality of groundwater resources in coastal aquifers is affected by saltwater intrusion. Over-abstraction of groundwater and seawater level rise due to climate change accelerate the intrusion process. This paper investigates the effects of aquifer bed slope and seaside slope on saltwater intrusion. The possible impacts of increasing seawater head due to sea level rise and decreasing groundwater level due to over-pumping and reduction in recharge are also investigated. A numerical model (SEAWAT) is applied to well-known Henry problem to assess the movement of the dispersion zone under different settings of bed and seaside slopes. The results showed that increasing seaside slope increased the intrusion of saltwater by 53.2% and 117% for slopes of 1:1 and 2:1, respectively. Increasing the bed slope toward the land decreased the intrusion length by 2% and 4.8%, respectively. On the other hand, increasing the bed slope toward the seaside increased the intrusion length by 3.6% and 6.4% for bed slopes of 20:1 and 10:1, respectively. The impacts of reducing the groundwater level at the land side and increasing the seawater level at the shoreline by 5% and 10% considering different slopes are studied. The intrusion length increased under both conditions. Unlike Henry problem, the current investigation considers inclined beds and sea boundaries and, hence, provides a better representation of the field conditions

Spatial and Temporal Effects of Irrigation Canals Rehabilitation on the Land and Crop Yields, a Case Study: The Nile Delta, Egypt

Shortage of surface water is considered an international problem that has even extended to countries that have rivers, in particular countries sharing the same river basins and downstream countries, such as Egypt. This issue requires intensive management of available water resources. Irrigation Canals Rehabilitation (ICR) has become essential to protect surface water in irrigation canals from losses due to seepage. Egypt is one of the countries that has started using this technique. This paper aims to evaluate the impact of ICR using concrete on the land and on crop yields. The SEEP/W model is used in the current study to estimate changes in the groundwater table and moisture in the root zone. Three cases studies have been simulated and compared including unlined, lined, and lined canals with a drainage pipe. The methodology is applied to three canals in the Nile Delta: Sero, Dafan, and New-Aslogy. The results demonstrate that ICR has decreased the losses from canals which resulted in lowering the groundwater, where the case of lining gave a higher reduction than the case of lining with a drainage pipe. In addition, the water table underneath the embankment was lowered. Decreasing the groundwater table could help to protect the land from logging and increase crop yields, but it may reduce the recharging of groundwater aquifers. Such a study is highly recommended in arid regions to decrease water losses where many countries are suffering from water shortage

Spatial and Temporal Effects of Irrigation Canals Rehabilitation on the Land and Crop Yields, a Case Study: The Nile Delta, Egypt

Shortage of surface water is considered an international problem that has even extended to countries that have rivers, in particular countries sharing the same river basins and downstream countries, such as Egypt. This issue requires intensive management of available water resources. Irrigation Canals Rehabilitation (ICR) has become essential to protect surface water in irrigation canals from losses due to seepage. Egypt is one of the countries that has started using this technique. This paper aims to evaluate the impact of ICR using concrete on the land and on crop yields. The SEEP/W model is used in the current study to estimate changes in the groundwater table and moisture in the root zone. Three cases studies have been simulated and compared including unlined, lined, and lined canals with a drainage pipe. The methodology is applied to three canals in the Nile Delta: Sero, Dafan, and New-Aslogy. The results demonstrate that ICR has decreased the losses from canals which resulted in lowering the groundwater, where the case of lining gave a higher reduction than the case of lining with a drainage pipe. In addition, the water table underneath the embankment was lowered. Decreasing the groundwater table could help to protect the land from logging and increase crop yields, but it may reduce the recharging of groundwater aquifers. Such a study is highly recommended in arid regions to decrease water losses where many countries are suffering from water shortage

Floating Photovoltaic Plants as an Effective Option to Reduce Water Evaporation in Water-Stressed Regions and Produce Electricity: A Case Study of Lake Nasser, Egypt

Water resources are considered one of the most critical and indispensable elements to ensure the survival of all living organisms on the planet. Since there is a close relationship between water, energy, and food security, this interdependence presents a major global societal challenge. While Egypt is one of the countries that suffers the most from water poverty, it has Lake Nasser which is considered one of the largest artificial lakes in the world, with an estimated area of about 5250 km2. Hence, this work aims to conserve such water resources while addressing two critical issues related to water and energy. To achieve this goal, this study proposed the use of partial coverage technology on Lake Nasser with floating photovoltaic (FPV) panels. The results of the study showed that the partial coverage of Lake Nasser with FPV panels represents a very effective proposal to preserve the water resources of Egypt, which suffers from water poverty. The savings in water evaporation in Lake Nasser reached 61.71% (9,074,081,000 m3/year) and the annual rate of electricity production was 467.99 TWh/year when 50% of the area of Lake Nasser was covered with FPV panels

Value Engineering Approach to Evaluate the Agricultural Drainage Water Management Strategies

Excessive irrigating water that has not been adequately drained may cause more water to enter the crop root zone than is necessary. As a result, issues with increasing water table levels, waterlogging, and salinity get worse and cause crop productivity losses. Agricultural drainage water management strategies (ADWMS) can be used to protect the quality of groundwater, guarantee that crops have better moisture conditions, and provide irrigation water by reusing agricultural water drainage and using sub-irrigation practices. In order to decrease the effects of poor drainage, mitigate climate change, conserve the environment, and achieve food security, this study proposes a framework for choosing the most effective ADWMS in Egypt’s Nile Delta as well as the new lands. The value engineering approach is used to ensure the strategy’s functionality and to present some innovation in the process of developing alternative solutions that are financially evaluated using the life cycle cost technique. According to the study results, the most effective strategy (ADWMS-3) prioritizes improving drainage effectiveness, controlling groundwater table rise, and providing another irrigation water source while maintaining environmental protection. This strategy encompasses the use of a control drainage system, timing of fertilizer application, regulating groundwater table variation, and using sub-irrigation practices. ADWMS-3 achieves the highest values for the technical score of 8.06 and the value index of 18.59. This study advances the understanding of the topic by providing policymakers with a tool to (i) evaluate ADWMS and (ii) incorporate the added value and functionality into their policies regarding agricultural drainage water

Assessment of Changing the Abstraction and Recharge Rates on the Land Subsidence in the Nile Delta, Egypt

The majority of residential, agricultural, and industrial areas are situated on cohesive soil in the Nile Delta, Egypt. Excessive pumping from the Nile Delta aquifer to meet the increasing demands for water could lead to aquifer system compaction and land subsidence. Land subsidence endangers infrastructure such as buildings, bridges, canals, and roads, as well as deteriorating lands and agricultural resources. The objective of this research is to investigate the land subsidence and predict the future behavior of the middle Nile Delta. The study goals are met by using a numerical model (MODFLOW) to simulate groundwater flow and an analytical solution to calculate land subsidence conditions. In this study, three scenarios are considered including; decreasing aquifer recharge, increasing abstraction and combination of the two. The results reveal that decreasing recharge by 94.4%, 88.8%, and 83.2% led to 30-, 60-, and 90-mm land subsidence, respectively, while increasing abstraction by 146%, 193%, and 233% led to land subsidence by 190, 380, and 560 mm, respectively, in the Nile delta. However, the combination of the two scenarios led to 220-, 440-, and 650-mm land subsidence. According to the results the future land subsidence due to over pumping from the Nile Delta should be considered in the future development plans of the country which intend to increase the abstraction from the Nile Delta aquifer. Increasing abstraction could increase the land subsidence that may cause many damages in different properties

Identification of Extreme Weather Events Using Meteorological and Hydrological Indicators in the Laborec River Catchment, Slovakia

This study used the standardized precipitation index (SPI) and the standardized runoff index (SRI) to analyze dry and humid conditions in the hill-country catchment area of the Laborec River (Slovakia) over a period of 50 years (1970–2019). Analysis of the SPI and SRI over various time scales showed the occurrence of wet periods (index > 1.0) that were associated with precipitation exceeding the long-term norm, and dry periods (index below −1.0), which were the result of small amounts of precipitation. Analysis of the correlation between the SPI and SRI on different time scales revealed that the catchment showed a weaker response to precipitation over short time scales (1 and 3 months) and a stronger response over longer accumulation periods (6, 9, and 12 months). The highest annual correlation coefficient (r = 0.72) was recorded between SRI-6 at the Humenne hydrometric station and SPI-9 at the Medzilaborce meteorological station in the upper part of the catchment area. The strongest annual correlation (r = 0.69) was obtained between the Izkovce and Kamenica stations in the lower part of the catchment area. As shown by the cross-relationships examined over different periods of accumulation of flows and precipitation, hydrological droughts appeared as a result of the occurrence of meteorological droughts with a three-month delay. The conducted analysis showed that in the case of the Laborec river catchment area, there was a strong correlation between the occurrence of meteorological drought and hydrological drought

Management of Seawater Intrusion in Coastal Aquifers: A Review

Seawater intrusion (SWI) is one of the most challenging and widespread environmental problems that threaten the quality and sustainability of fresh groundwater resources in coastal aquifers. The excessive pumping of groundwater, associated with the lack of natural recharge, has exacerbated the SWI problem in arid and semi-arid regions. Therefore, appropriate management strategies should be implemented in coastal aquifers to control the impacts of SWI problems, considering acceptable limits of economic and environmental costs. The management of coastal aquifers involves the identification of an acceptable ultimate landward extent of the saline water body and the calculation of the amount of seaward discharge of freshwater that is necessary to keep the saline–freshwater interface in a seacoast position. This paper presents a comprehensive review of available hydraulic and physical management strategies that can be used to reduce and control SWI in coastal aquifers. Advantages and disadvantages of the different approaches are presented and discussed