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Population in Egypt has significantly increased in the last four decades from ~36 million in 1976 to ~95 million in 2016 (Central Agency for Public Mobilization and statistics (CAPMAS), 2016). Most of the country's population tends to live in the main cities which have witnessed accelerated urbanization over the agricultural land. Citizens live within a few kilometres wide in the alluvial fertile fields along the Nile River and its Delta with a population density of ~89.2 per square kilometer in 2016 (CAPMAS), 2016), which has put pressure on the country's agricultural resources and food security (Abd-Elmabod, Fitch, Zhang, Ali & Jones, 2019). The national ministry of agriculture estimated the amount of the yearly agricultural land loss by 25 thousand acres due to the urban expansion during the period of 1984-2000 (Belal & Moghanm, 2011). The country continues to lose its fertile agricultural land due to urbanization, land fertility degradation, and agricultural land abandonment (Abou El-Magd, Hasan, & El Sayad, 2015; Abd-Elmabod, Fitch, Zhang, Ali & Jones, 2019). Similar cases have been found in other countries such as China and India. For instance, in China, urbanization has caused direct loss of agricultural land and has raised the agricultural density rates (Jiang, Deng & Seto, 2013; Zhou, Vermaat & Ke 2019). Similarly, in India, urban growth has resulted in the conversion of agricultural lands and has caused other forms of land degradation (Chadchan & Shankar, 2012; Rahman, Aggarwal, Netzban & Fazal, 2011; Bhatta, 2009; Varughese, Lakshmi, Kumar & Rana, 2009).
Currently, one of the country's strategic plans is to increase the agricultural productivity while controlling urbanization process. In this context, reviewing and monitoring the urban expansion versus agricultural land loss should have intensive and comprehensive understanding to build strong sustainable development policies. This can be made by monitoring the spatiotemporal pattern of urban expansion which can assist mitigating the impacts of urbanization on agricultural land and food security (Long et al. 2018; Gomes et al. 2019; Zhou, Vermaat & Ke, 2019).
The conventional surveying and mapping methods are of great value to provide detailed information; although, these methods are tedious and time, cost, and labour consuming. Alternatively, the use of geospatial technologies such as remote sensing (RS) and geographical information systems (GIS) have demonstrated promising results as they can provide, integrate, and analyze vast spatiotemporal data over large areas and time periods with less costs and time requirement. They become essential for mapping and monitoring landscape features (Gidado et al. 2018; Giri, 2016). Moreover, remote sensing can provide valuable historical imaging information regarding human activities.
Meanwhile, GIS techniques are effective for analyzing and identifying the dynamics and the spatial patterns of land use change including urban growth and agriculture land loss. Therefore, the synergy between remote sensing and GIS with ancillary data is very important in quantifying, monitoring, mapping, modelling and predicting land use and land cover changes (Gidado et al. 2018). These advantages have encouraged several researchers to study the rapidly growing cities such as Beijing, China (Tian, Yin, Lu, Hua, Zhao, & Wen, 2014); Tokyo, Japan (Bagan & Yamagata, 2012); Washington, D.C., USA (Masek, Lindsay & Goward, 2010); Cairo, Egypt (Hereher, 2012); Dhaka, Bangladesh (Ahmed & Ahmed, 2012). In this paper, we aim to implement the newly developed Built‑Up Delineation Index Set (BDIS; Hazaymeh, Mosleh & Al-Rawabdeh, 2019) for (i) characterizing the spatiotemporal dynamics of urban land expansion in Qena city, Egypt using three selected dates at approximately 15 years a part (i.e., 1986, 2000, and 2016), and (ii) evaluating the impacts of urbanization on the agricultural land loss.