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Map of main human activities in Wadi El Rayan  

Map of main human activities in Wadi El Rayan  

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Wadi El Rayan is located in the African Sahara ecoregion of the Palearctic eco-zone, the world's largest hot desert. The total area of Wadi El Rayan is 1759km². The objective of the present study is to enrich the knowledge on the vegetation cover along the shores of Wadi El Rayan lakes and to identify the different threats, underlying causes and re...

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... Comparisons between the classified images also showed that the major change was the desert changing into cultivated land. In addition, fish farms fed by the UL-WR's water have multiplied many times (Afefe et al., 2016;Aldabaa et al., 2010). ...
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The environmental changes in the wetlands are one of the major problems facing us in recent decades. Lately, many fluctuations have been observed in Wadi El-Rayan lakes. The geo-spatial analysis plays a great role in detecting the changes in Wadi El-Rayan lakes. The aim of the current study is to enrich the knowledge about Wadi El-Rayan Depression and to identify the changes in its lakes (Upper Lake and Lower Lake) and land cover by integration between RS and GIS techniques. The Upper Lake has become completely full with relative stability in its water area of around 53.61 (±2%) million m², but the Lower Lake is markedly decreasing by 1.92 million m² per year. It should be noted that it is hard to manage those artificial lakes because of human activities. These activities include reusing drainage water, land reclamation, and rapidly expanding aquaculture. Therefore, the optimum solution to this problem is to adjust water allocation within Wadi El-Rayan lakes by reducing the amount of water diverted for reuse, agriculture, and fish farms, or at least resecting the growth in these water uses to help stop or slow the decrease in Wadi El-Rayan lakes.
... However, the plant life in the Red Sea coastal shoreline and the Eastern Desert in Egypt is rather rich and interesting, where considerations of the exploitation and conservation of natural vegetation must take eco-logical principles into account (Afefe 2021). The sustainable management of natural vegetation in Egypt requires stopping the severe human impacts that lead to eliminating certain plant populations and modifying the complex plant communities into simple, fragile ones (Afefe 2020;Abbas et al. 2016;Afefe et al. 2016). ...
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Due to the importance of mangrove forests to the ecological system, environment, climate change adaptation, mitigation and ecosystem services, it is necessary to understand the status of the mangroves in Egypt (ecology and physiology). The present study aimed to obtain the basic information needed to evaluate the photosynthetic pigments and proline mechanisms of Avicennia marina and Rhizophora mucronata mangrove to the ambient salinity. The results reached that the free proline accumulated appreciably in leaves. The functional role of proline accumulation appears to be as a cytoplasmic osmoticum to lower cell water potential, provide hydration to bipolymer and serve as an energy source under high salinity environmental conditions. Mangroves showed variations in proline content between the two species. The highest value of proline was recorded 23.56 mg/g dry wt for R. mucronata and the minimum value was recorded 17 mg/g dry wt for A. marina. In addition, the mean value of proline was recorded 18.57 mg/g dry wt for A. marina and 23.98 mg/g dry wt for R. mucronata. The contents of chlorophyll-a in different analyzed mangroves was ranged from 4.46 to 6.05 mg/gf.wt. for A. marina, and from 3.69 to 4.29 mg/gf.wt. for R. mucronata. In addition, the chlorophyll-b content was ranged from 1.46 to 1.83 mg/gf.wt. for A. marina, and from 1.27 to 1.65 mg/gf.wt. for R. mucronata. The carotenoids contents in mangroves ranged from 2.94 to 2.29 mg/gf.wt for A. marina and from 2.04 to 2.09 mg/gf.wt for R. mucronata. In the present study, A. marina was relatively more tolerant and adapted to salinity, low rainfall and extreme temperature conditions than R. mucronata. This explains the more significant local distribution of A. marina in Egypt compared to R. mucronata.
... The tunnel was receiving about 8 m 3 /s in 1999, and this amount decreased to about 4.5 m 3 /s in 2008 [19]. Based on the reduction in total received drainage per year and the rainfall pattern, besides the fact that the Lower Lake is a closed basin with no outflow, these all led to the accumulation of salts in Wadi El-Rayan Lakes, particularly the Lower Lake [1]. Soil salinity is the most soil limitation factor for vegetation productivity [36]; however, other soil physical and chemical characteristics can also influence it. ...
... Results of soil texture analysis of Wadi El-Rayan wetlands during winter and summer showed that the main soil textures that can be found are mainly sandy loam, loamy sand (distributed around the Upper Lake) and sand (distributed around the Lower Lake), and these results are in accordance with Abbas and Afefe [1]. ...
... Results of soil chlorides analysis revealed that the soil chlorides content ranged from 20-700 mg/L to 100-1300 mg/L during winter and summer, respectively. According to [38] guidelines, most of the studied sites ranged from low during winter to moderate during summer and these results are in accordance with [1]. The four most abundant cations in soils are Calcium ( Ca +2 ) , magnesium ( Mg +2 ), Potassium ( K + ) and sodium ( Na + ). ...
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Wadi El-Rayan wetland is an inland Egyptian Ramsar site of international importance, due to its rich biodiversity. The wetland constitutes two man-made lakes. The lakes size, particularly the Lower Lake, is in continuous reduction, and the vegetation productivity pattern is changing as result of deteriorating water and soil quality, domestic and industrial activities. This research was carried out to map the spatial and seasonal distribution of certain physico-chemical parameters of geo-referenced soil samples covering the two lakes parts using ordinary kriging GIS technique. The study utilized ArcGIS ver.10.7 software, and 76 soil samples collected from representative sites; 38 samples during winter and 38 samples during summer seasons. Soil data were analyzed statistically and geo-statistically based on best fitted semivariogram model. The results indicated high concentrations of some soil physical and chemical parameters, especially in summer and in the Lower Lake of Wadi El-Rayan. The summary statistics for soil parameters had shown that the median of some soil parameters is higher than the mean which indicated the presence of abnormal data. This finding has been approved through the spatial distribution mapping which clearly showed the differences in spatial and temporal distribution between the upper and lower lakes of Wadi El-Rayan. The study concluded that the generated spatial distribution maps using ordinary kriging method can be used as an effective tool in Wadi El-Rayan wetlands’ soil management.
... The key threats to global desert ecosystems are anthropogenic. For example, urbanisation and industry increasingly encroach upon arid habitats, irresponsible tourism and habitat pollution/misuse causes direct environmental damage, soil erosion/salinization, overgrazing and nutrient depletion are caused by agriculture, introduced species alter habitats and prey upon or compete with native species, and, Chapter 1: General Introduction 8 climate change is causing increasingly severe and frequent droughts and wildfires in arid regions (Scott 2000, Martín-Queller et al. 2010, IPCC 2014, Brito et al. 2014, Doherty et al. 2015a, Afefe et al. 2016, CSIRO 2017). ...
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We are experiencing a global biodiversity and climate crisis that is rapidly causing the extinction of species. Mammal species have been disproportionately affected; however, this trend is considerably worse in Australia. Since Australia’s occupation by Europeans, 34 mammal species have been declared extinct. Australian mammals in deserts are particularly at risk of extinction. Many arid zone mammals have specialised adaptations to their hostile, unpredictable ecosystems. For example, they use thermally insulative refuges, prefer habitats that reduce predation risk, or have large home ranges and broad diets to maximise energy intake. Understanding these adaptations is essential for informed conservation management. However, little ecological data is known for the sandhill dunnart, Sminthopsis psammophila, an endangered and charismatic marsupial that now remains within just a few natural refugial habitats in Australia’s southern deserts. To address conservation biology knowledge gaps, an integrated, evidence-based approach (i) quantified the diurnal and nocturnal ecology of S. psammophila in the Western Australian Great Victoria Desert (WAGVD), (ii) estimated the past, present and future distributions of S. psammophila throughout Australia, (iii) examined the key threats to S. psammophila - particularly wildfires and anthropogenic climate change - and (iv) proposed conservation management solutions for a) S. psammophila and b) sympatric arid zone species. Between 2015 and 2019, radio tracking and global positioning system (GPS) technologies examined the sheltering, foraging, dietary and habitat preferences of S. psammophila in the WAGVD. In contrast to its previously reported habitat preferences, S. psammophila preferred burrowing within long unburned (32+ years since a wildfire) spinifex (Triodia spp.) grassland habitats. Dense lower stratum swale, sand plain and dune slope habitats were preferred, whereas habitats lacking spinifex and open dune crest habitats were rarely used. Hence, wildfires were identified as a significant threat to the species. The sheltering preferences of S. psammophila agreed with the premise that small desert mammals often use shelters with thermal advantages and anti-predation benefits, such as burrows, Lepidobolus deserti hummocks and logs. Conversely, spinifex hummocks were not found to be insulative against extreme temperatures and were not preferred. The foraging adaptations of S. psammophila agreed with the premise that arid zone species often have large home ranges to exploit resource patches or islands. The 100 % home ranges of S. psammophila [mean: 70 ha; range: 6-274 ha; minimum convex polygon (MCP)] were influenced by sex and reproductive status. In addition, a Formicine-rich diet indicated that ants are an important dietary resource for S. psammophila. Species distribution models (SDMs) predicted the past, present, and future distributions of S. psammophila, evaluated the environmental parameters that determine the species’ distribution and identified habitats of high conservation value. The past model supported evidence that S. psammophila was widespread but has recently contracted to more climatically favourable areas of its geographic range. Ground-validation of the present model’s predictions discovered a population 150 km north of the species’ known range. Future models identified that climate change is a potential catastrophic threat for S. psammophila. By 2050, under Representative Concentration Pathway (RCP) 8.5 (our current pathway) there is a predicted 95 % reduction in suitable habitat for S. psammophila in the WAGVD. By 2070 (RCP 8.5), only the Eyre Peninsula population may remain viable and the continental distribution of S. psammophila may contract by up to 80 %. However, this contraction is predicted to be halved if global greenhouse gas emissions peak in 2040 then reduce (RCP 4.5). Due to specific habitat preferences for long unburned habitats, S. psammophila is further restricted within its climatically and geographically suitable range. As a semi-arid specialist, it is also vulnerable to drought-related population crashes. Hence, S. psammophila should remain listed as endangered at the state and federal level, and its status should be revised by the International Union for Conservation of Nature.
... Species number gives an indication of the diversity of any community. A variation in species diversity among different locations was detected in this study, confirming the results recorded by Amin (1998), Abdou (2002), and Afefe et al. (2016). In this study transect 1 (Northeast of Lower Lake), transect 4 (Southwest of Lower Lake) and transect 9 (Northeast of Upper Lake) showed high species richness while transect 3 (Southeast of Lower Lake) revealed the lowest species richness, as presented in Table 3. ...
... Moreover, a high percentage of hemicryptophytes and therophytes in sandy dune habitats can be related to their ability to resist drought, sand accumulation and grazing (Danin and Orshan 1990;Danin 1996). Afefe et al. (2016) reported that the current pressures of human activities on natural vegetation include overgrazing, irresponsible tourism, land encroachment, water pollution, water over-use, fire, and habitat change and destruction. The reduction of water levels due to decreased water incoming is considered the main threat facing ecosystems and biodiversity in the lake area. ...
... However, we agree with Afefe et al. (2016) that most of the plant species that were recorded in the study area are of a perennial nature. The field observations found that there is low diversity and a number of plant species around the lakes. ...
Article
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Wadi El Rayan is located in Egypt in the Sahara ecoregion the Palearctic ecozone (the world’s largest hot desert). The total area of Wadi El Rayan is 1759km2. The aim of this work was to study the ecosystems, compare species composition, species richness and species diversity of the study sites in the Wadi El Rayan protected area and the distributions of plants in the different landform. The field observations found that there is a low diversity and number of plant species around the lakes, in particular a decline in vegetation cover in accordance with a dramatic decrease in the water level in the lakes compared to earlier studies. The reduction of water levels due to decreased water supply is considered the main threat facing ecosystems and biodiversity in the lake area which requires a continuous survey of flora and measures to be implemented to conserve the natural vegetation in the area. Based on investigations of the spontaneous flora of Wadi El Rayan in 2018, 18 taxa of vascular plants were recorded. This inventory was compared with published records of investigations made in 1998, 2002 and 2014. A total of 18 vascular plant species belonging to 14 families were recorded in the wetland and desert ecosystems around the lakes of Wadi El Rayan. The vegetation mainly consists of sparsely distributed xerophytic and halophytic plants except in the wetland ecosystem around the lakes where it is characterized by some hydrophytic and halophytic plants. The family with the highest number of species was Poaceae followed by Zygophyllaceae. The results showed that a higher number of species was recorded from the Lower Lake (13 species) than the Upper Lake (10 species) and (5 species) for the connecting channel. The most frequently recorded species were Phragmites australis, Tamarix nilotica, Juncus rigidus and Alhagi graecorum: the first two species were the most successful species as they grow in a variety of ecosystems and habitats.
... They also create a new opportunity for the development of various types of human activities including recreation, tourism, fishing, aquaculture, chemical industry, etc. (Black, 1988;El-Shabrawy and Dumont, 2009;Ramzy, 2013;Anufriieva, 2018;Shalloof, 2020). Due to climate aridity and human activities, in some man-made lakes, the salinity can gradually fluctuate and increase, which along with ecosystem changes, create a lot of the problems for people and their activities (Hussein et al., 2008;Cohen, 2009;Afefe et al., 2016;Shadrin et al., 2016;Voyles, 2016;Shalloof, 2020). ...
Article
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The Wadi El-Rayan is a depression in the Fayoum oasis collecting agricultural drainage water from the Fayoum. Since 1973, this drainage water formed two man-made lakes. Twenty years ago, a third lake, called Lake Magic was formed. Since this newly formed lake was not yet studied, in January of 2019 we conducted research related to its physico-chemical (ion composition, nutrients, heavy metals, etc.) and biological (phyto-, bacterio- and zooplankton) characteristics. The depth of the lake ranged from 1.5 to 9.0 m, water transparency was up to 4.0 m, and the water temperature was 13.6 °C. The average salinity was 29.1 g/l, and the salinity of drainage waters from agricultural fields was 2.9 g/l. A total of 28 phytoplankton species was identified belonging to Bacillariophyceae (eight species), Dinophyceae (three species), Cyanobacteria (seven species), Chlorophyceae (nine species) and Conjugatophyceae (one species). Chlorophyll a content varied from 14.3 to 24.2 μg/l. In zooplankton, there were three species of Ciliophora, five of Rotifera, and two Copepoda as well as Nematoda and Cirripedia larvae. Salinity in Lake Magic was much higher than in drainage waters coming in the lake. This is a result of a strong salinity increase in Lake Magic after its creation due to climate aridity, and salinity may markedly increase during the next 20 years along with the sharp changes of the lake's ecosystem.
... The main threat to the effective long-term protection of the Wadi El-Rayan protected area is seen to be the development of un-controlled economic activities within its boundaries. These activities include large-scale land reclamation schemes, an operating oil field, rapidly expanding aquaculture, commercial fishing and tourism, small-scale salt mining, tourism cafeterias, private tour boat owners, as well as human settlement in highly sensitive areas such as previously un-disturbed habitats used by gazelles and other key species (Paleczny et al. 2007;Afefe et al. 2016). As well as the declining water levels and water quality are also a threat to the economic values (fishing, agriculture, and tourism) supporting local communities within and outside of WRPA (Paleczny et al. 2007). ...
... According to Hereher (2015), about 20 Km 2 was reduced in the lower lake area from 2000 In general, the rate of water inflow is currently less than the total rate of water use and lost by evaporation, making the future of the lake system in WRPA in jeopardy. Accordingly, the salinity increases lead to problems for the ecosystem and biodiversity particularly for the second lake (Afefe et al. 2016). ...
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Wadi El-Rayan lakes are a crucial source of irrigation water and fisheries in El-Fayoum Governorate of Egypt. It is part of the Wadi El-Rayan Protected Area (WEPA) about 125 km Southwest of Cairo. The present study was carried out to assess the present status of the lakes’ water quality, especially after the increasing of un-controlled economic activities within its boundaries. The results demonstrated that the upper lake water may be suitable for irrigation utilization, and the water quality is categorized as fair (WQI = 67). The two lakes are classified as marginal for aquatic life habitat, with (WQI = 52 and 61) for the upper and lower lakes, respectively. Eight heavy metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) were studied to evaluate the metal pollution in the lakes’ water. Pollution index (PI) and metal index (MI) revealed that the water of the two lakes suffers from a different degree of metal contamination, especially for aquatic life utilization. In addition, the progressive increasing of salinity in the second lake enhances the remarkable deterioration of the lake aquatic environment that may restore the dramatic transformation story of Qarun lake.
... It consists of two basins (upper and lower) in the Fayoum depression. The upper lake is an open basin with about 63 km 2 , surrounded by a dense agricultural cover, while the lower is a closed basin of approximately 42 km 2 (Afefe et al. 2016). Al-Rayyan lakes are used to reduce the excessive accumulation of water drainage in the Qaroun Lake and to protect the nearby agricultural land from inundation (Hereher 2015). ...
... Many environmental obstacles hinder the progress of ecotourism and sustainable development in the study area. Examples of these obstacles are sand dune invasion (EEAA, 2008) and discharging of sanitary and agricultural wastewater (Donia 2012;Mohamed et al. 2015;Afefe et al. 2016). The study area is located under arid and semi-arid climatic conditions (Kotb et al. 2017), where the ecosystem is always considered to be fragile due to high temperatures and low precipitation. ...
Article
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The Qaroun Lake, Wadi El-Rayyan, and Wadi El-Hitan are some of the most promising ecotourism destinations in Egypt due to their natural mineral resources, wildlife, and biodiversity in addition to their historic heritage that dates back to the age of The Pharos. These natural resources should be managed and maintained without affecting the needs of future generations. Land use/land cover change is the most important factor in causing biodiversity loss. Accordingly, the objectives of this study are to identify, quantify, and model future land cover changes using remote sensing and GIS techniques. To fulfill the objectives of the study, a hybrid image classification is employed using the combination of unsupervised and supervised classification methods to detect land cover types. Post-classification comparison is used to map changes in land cover between 2000 and 2017. Markov model is applied to analyze, predict, and simulate future land cover changes from 2017 to 2050. This is in order to safeguard against the adverse effects and negative consequences of land cover changes, preserve the natural resources, and consequently achieve goals of sustainable development. The outcome of this study can provide policy makers and urban planners with the required information regarding the status of the environment and subsequently reduce pressure on natural resources in order to facilitate conservation planning and sustainable development.