Egyptian Expeditionary Inscriptions of the Fourth Dynasty and Ancient Natural Landscapes of the Western (Libyan) Desert

The Middle Holocene epoch in northeastern Africa was marked by a steady trend towards aridization. However, the transformation of ecosystems and natural landscapes was gradual and had a complex nature. This change directly affected the development of the first ancient Egyptian centralized state as well as the development of its resource base beyond the Nile Valley. This study addresses the problem of using ancient Egyptian epigraphic sources (expeditionary inscriptions) for the study of both paleolandscapes and ecosystems of the Western (Libyan) Desert and the possible socio-economic impact of their change. The author studies several graffiti, which are believed to have preserved information on natural conditions near the Dakhla oasis and in the region of Wadi Toshka during the time of construction of the great pyramids (Fourth Dynasty). The author concludes that it is quite easy to make misleading assumptions when interpreting expeditionary artefacts. At the same time, as an example with an unusual toponym from the quarries near Wadi Toshka demonstrates, even the shortest graffiti can provide researchers with important additional information on possible changes in the ancient climate and landscape.

Hamlet of ʽAin el-Gedida in Dakhla Oasis

This article discusses archaeological and documentary evidence from the late Roman settlement of ʽAin el-Gedida (located in the Dakhla Oasis of Upper Egypt), with a particular focus on the site’s likely identification as an epoikion, i.e., a small rural center associated with the management of a large agricultural estate. ʽAin el-Gedida was first excavated by an Egyptian mission in 1993–1995 and immediately raised interest among scholars working in the oasis, with the site being preliminarily identified either as a rural village or a monastic settlement. More recent excavations and study seasons, conducted (from 2006 to 2010) by a Columbia University (then New York University) mission directed by Roger Bagnall, has allowed investigators to gather a substantial amount of new data. This evidence, published in 2018 and more recently in 2020, supports the likely identification of ʽAin el-Gedida as an epoikion over other types of settlements. In this article, the data from ʽAin el-Gedida are discussed in light of what is known from documentary sources about epoikia, as well as modern Egyptian ezab. Worthy of note is that not many other agricultural hamlets of a comparable size have been extensively excavated and published thus far. It is also remarkable that, while written evidence on epoikia abounds, the site of ʽAin el-Gedida may provide the first available archaeological evidence for this type of settlement; therefore, it may offer new and useful data on the layout and organization of epoikia in late antique Egypt.

Modeling and Assessing Potential Soil Erosion Hazards Using USLE and Wind Erosion Models in Integration with GIS Techniques: Dakhla Oasis, Egypt

Soil erosion modeling is becoming more significant in the development and implementation of soil management and conservation policies. For a better understanding of the geographical distribution of soil erosion, spatial-based models of soil erosion are required. The current study proposed a spatial-based model that integrated geographic information systems (GIS) techniques with both the universal soil loss equation (USLE) model and the Index of Land Susceptibility to Wind Erosion (ILSWE). The proposed Spatial Soil Loss Model (SSLM) was designed to generate the potential soil erosion maps based on water erosion and wind erosion by integrating factors of the USLE and ILSWE models into the GIS environment. Hence, the main objective of this study is to predict, quantify, and assess the soil erosion hazards using the SSLM in the Dakhla Oasis as a case study. The water soil loss values were computed by overlaying the values of five factors: the rainfall factor (R-Factor), soil erodibility (K-Factor), topography (LS-Factor), crop types (C-Factor), and conservation practice (P-Factor). The severity of wind-driven soil loss was calculated by overlaying the values of five factors: climatic erosivity (CE-Factor), soil erodibility (E-Factor), soil crust (SC-Factor), vegetation cover (VC-Factor), and surface roughness (SR-Factor). The proposed model was statistically validated by comparing its outputs to the results of USLE and ILSWE models. Soil loss values based on USLE and SSLM varied from 0.26 to 3.51 t ha−1 yr−1 with an average of 1.30 t ha−1 yr−1 and from 0.26 to 3.09 t ha−1 yr−1 with a mean of 1.33 t ha−1 yr−1, respectively. As a result, and according to the assessment of both the USLE and the SSLM, one soil erosion class, the very low class (<6.7 t ha−1 yr−1), has been reported to be the prevalent erosion class in the study area. These findings indicate that the Dakhla Oasis is slightly eroded and more tolerable against water erosion factors under current management conditions. Furthermore, the study area was classified into four classes of wind erosion severity: very slight, slight, moderate, and high, representing 1.0%, 25.2%, 41.5%, and 32.3% of the total study area, respectively, based on the ILSWE model and 0.9%, 25.4%, 43.9%, and 29.9%, respectively, according to the SSLM. Consequently, the Dakhla Oasis is qualified as a promising area for sustainable agriculture when appropriate management is applied. The USLE and ILSWE model rates had a strong positive correlation (r = 0.97 and 0.98, respectively), with the SSLM rates, as well as a strong relationship based on the average linear regression (R2 = 0.94 and 0.97, respectively). The present study is an attempt to adopt a spatial-based model to compute and map the potential soil erosion. It also pointed out that designing soil erosion spatial models using available data sources and the integration of USLE and ILSWE with GIS techniques is a viable option for calculating soil loss rates. Therefore, the proposed soil erosion spatial model is fit for calculating and assessing soil loss rates under this study and is valid for use in other studies under arid regions with the same conditions.

Soil Quality Assessment Using Multivariate Approaches: A Case Study of the Dakhla Oasis Arid Lands

A precise evaluation of soil quality (SQ) is important for sustainable land use planning. This study was conducted to assess soil quality using multivariate approaches. An assessment of SQ was carried out in an area of Dakhla Oasis using two methods of indicator selection, i.e., total data set (TDS) and minimum data set (MDS), and three soil quality indices (SQIs), i.e., additive quality index (AQI), weighted quality index (WQI), and Nemoro quality index (NQI). Fifty-five soil profiles were dug and samples were collected and analyzed. A total of 16 soil physicochemical parameters were selected for their sensitivity in SQ appraising to represent the TDS. The principal component analysis (PCA) was employed to establish the MDS. Statistical analyses were performed to test the accuracy and validation of each model, as well as to understand the relationship between the used methods and indices. The results of principal component analysis (PCA) showed that soil depth, gravel content, sand fraction, and exchangeable sodium percentage (ESP) were included in the MDS. High positive correlations (r ≥ 0.9) occurred between SQIs calculated using TDS and/or MDS under the three models. Moreover, the findings showed highly significant differences (p < 0.001) among SQIs within and between TDS and MDS. Approximately 80 to 85% of the total study area based on TDS, as well as 70 to 75%, according to MDS, were identified as suitable soils with slight limitations on soil quality grade (Q3, Q2, and Q1), while the remaining 20 to 30% had high to severe limitations (Q4 and Q5). The highest sensitivity (SI = 2.9) occurred by applying WQI using MDS and indicator weights based on the variance of PCA. Furthermore, the highest linear regression value (R2 = 0.88) between TDS and MDS was recorded using the same model. Because of its high sensitivity, such a model could be used for monitoring SQ changes caused by agricultural practices and environmental factors. The findings of this study have significant guiding implications and practical value in assessing the soil quality using TDS and MDS in arid areas critically and accurately.

Electrical properties of the lithosphere in the western desert, Egypt, using magnetotelluric sounding

&lt;p&gt;We present electrical resistivity models of the crust and upper mantle estimated from 2D inversions of broadband magnetotellurics (MT) data acquired from two profiles in the western desert of Egypt, which can contribute to the understanding of the structural setup of this region. The first profile data are collected from 14 stations along a 250 km profile, in EW direction profile runs along latitude ~25.5&amp;#176;N from Kharga oasis to Dakhla oasis. The second profile comprises 19 stations measured along a 130 km profile in NS direction centered at longitude 28&amp;#176;E and crossing the Farafra. The acquisition for both profiles continued for 1 to 3 days at each station, which allowed for the calculation of impedances for periods from 0.01 sec up to &amp;#160;4096 sec at some sites. The wide frequency band corresponds to a maximal skin depths of up to 150 km that can provide penetration to the top of the asthenosphere. The inversion models display high-conductivity sediments cover at the near surface (&lt;1-2 km), which can be associated with the Nubian aquifer. Along the EW-profile from Kaharge to Dhakla, the crustal basement is overly highly resistive and homogeneous und underlain by a more conductive lithospheric mantle below depths of 30-40 km. Along the N-S profile across Farafra, only the southern portion exhibits a highly resistive crust, whereas beneath Farafra northwards, moderate crustal conductivities are encountered. A comparison has been made between the resultant resistivity models with the 1&amp;#176; tessellated updated crust and lithospheric model of the Earth (LITHO1.0) which was developed by &lt;em&gt;Pasyanos, 2014&lt;/em&gt; on the basis of seismic velocity data. The obtained results show a remarkable consistency between the resistivity models and the calculated crustal boundaries. Especially at the Kharga-Dakhla profile a clear matching can be noticed at the upper and lower boundaries of a characteristic anomaly with the Moho and LAB boundaries respectively.&lt;/p&gt;