Aeolian Research 32 (2018) 24–34

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Aeolian Research

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Application of fuzzy logic approach for wind erosion hazard mapping in T Laghouat region () using remote sensing and GIS ⁎ Djouher Saadouda, Mohamed Hassanib, , Francisco José Martin Peinadoc, Mohamed Saïd Guettouchea a Faculty of Earth Science, Geographical and Territorial Planning, University of Sciences and Technology Houari Boumediene, (U.S.T.H.B), El Alia, BP 32, Bab Ezzouar, 16111 , Algeria b Center of Research in Astronomy, Astrophysics and Geophysics, Algiers, Algeria c Department of Soil Science, Faculty of Sciences, University of Granada, Campus Fuentenueva s/n, 18001 Granada, Spain

ARTICLE INFO ABSTRACT

Keywords: Wind erosion is one of the most serious environmental problems in Algeria that threatens human activities and Wind erosion socio-economic development. The main goal of this study is to apply a fuzzy logic approach to wind erosion Fuzzy logic sensitivity mapping in the Laghouat region, Algeria. Six causative factors, obtained by applying fuzzy mem- GIS bership functions to each used parameter, are considered: soil, vegetation cover, wind factor, soil dryness, land Remote sensing topography and land cover sensitivity. Different fuzzy operators (AND, OR, SUM, PRODUCT, and GAMMA) are Hazard applied to generate wind-erosion hazard map. Success rate curves reveal that the fuzzy gamma (γ) operator, with Laghouat γ equal to 0.9, gives the best prediction accuracy with an area under curve of 85.2%. The resulting wind-erosion sensitivity map delineates the area into different zones of five relative sensitivity classes: very high, high, moderate, low and very low. The estimated result was verified by field measurements and the high statistically significant value of a chi-square test.

− − 1. Introduction (Laghouat), is about 62 Mg ha 1 y 1 (Houyou et al., 2014), which is five times higher than the highest tolerable soil-loss rates by wind Wind erosion is an important environmental process causes land erosion (Li et al., 2009). degradation and desertification in arid and semi-arid regions (Shao, Research on wind erosion at regional scales is significantly devel- 2008; Li et al., 2015; Du et al., 2016; Mirmousavi, 2016; Al-Bakri et al., oped by linking erosion predicted models (methods), remote sensing 2016). This process is affected by several factors including atmospheric and advanced GIS technologies, which are becoming a standard map- conditions, soil properties, land-surface characteristics and human ac- ping tools of land degradation especially in arid and semi-arid areas tivities (Shao, 2008; Li et al., 2014; Borrelli et al., 2016). During a wind- (Gomes et al., 2003; Borrelli et al., 2016; Betz et al., 2015; Shao, 2008; erosion event, these factors interact with each other engendering the Du et al., 2015, 2016; Yang and Leys, 2014). Several researches im- impoverishment of the grounds and the reduction of their production. pelled wind-erosion science integrating fuzzy logic approach, having Dust emission is another effect generated by wind erosion, which is great development (Shi et al., 2010; Mirmousavi, 2016; Schmidt et al., considered as the largest source of aerosols influencing the atmospheric 2017; Saadatpour et al., 2011; Mezősi et al., 2015). Thanks to these radiation balance and hence global climatic variations (Shao, 2008). developments, fuzzy logic approach shows its relevance on wind-ero- In fact, wind erosion is also a phenomenon relevant for the Algerian sion hazard research than conventional analytical methods. arid and semi-arid regions, mainly in the steppe regions (Taibi, 1997; Our study is partly based on the previous research using fuzzy logic Bensaid, 2006; Houyou et al., 2014). In these regions, data show that approach but includes new controlling factors like soil properties (cal- this phenomenon have caused huge losses: nearly 600,000 ha of land cium carbonate (CaCO3), organic matter (OM) and total iron oxide (Fed) (Haut commissariat au développement de la steppe (HCDS, 2012)). In contents, exchangeable cations (Na+, Ca++ and Mg++) and available the Laghouat region, the focus of this research, wind erosion threatens water (AW)), and wind exposure. The main objective of this study is socio-economic development. The quantified net soil-loss rate by wind now to (i) apply a fuzzy logic approach to wind-erosion hazard in erosion in rainfed cropping, in the Mokrane agricultural perimeter Laghouat region; (ii) develop sensitivity maps of six causative factors by

⁎ Corresponding author. E-mail addresses: [email protected] (D. Saadoud), [email protected] (M. Hassani). https://doi.org/10.1016/j.aeolia.2018.01.002 Received 20 May 2017; Received in revised form 4 January 2018; Accepted 5 January 2018 1875-9637/ © 2018 Elsevier B.V. All rights reserved. D. Saadoud et al. Aeolian Research 32 (2018) 24–34

Fig. 1. OLI Landsat image of Laghouat region, showing the location of the study area with Sample distributions. applying fuzzy membership functions, then establish wind-erosion ha- 3. Field work, data used and laboratory analysis zard map using fuzzy combinations in GIS environment; and (iii) verify the obtained result by field measurements and statistical significance Three field missions were conducted within summer in the Laghouat using a chi-square test. region. The 40 collected soil samples were taken from 0 to 10 cm in depth and located by GPS in the field. Samples were collected to ensure regular samples distribution, according to the accessibility areas, in 2. Study area order to establish interpolated maps using Kriging method to reflect the entire study area and all soil types (Fig. 1). Laghouat region is one of the important socio-economical spots in The main environmental factors chosen as fuzzy parameters to Algeria, and its potential natural resources are strongly exposed to evaluate the spatial pattern of wind-erosion hazard include soil para- wind-erosion effects. It is located in an arid to semi-arid area inside the meters, vegetation cover, climatic parameter, topography and land steppe regions (Fig. 1), with a total area of 25,052 km2. Geologically, it cover. is characterized by structure in the north, which is + composed mainly of sandstones and limestones, and the Saharan Plat- 1. Soil parameters: texture (Tx), CaCO3, exchangeable cations (Na , ++ ++ form in the south, formed by the Hamada sand ergs. Topographically, is Ca and Mg ), Fed, OM and AW, strongly influence the soil characterized by abrupt reliefs (slopes between 12.5 and 25%) and erosion sensitivity. Tx is analysed on air dried and sieved to 2 mm elevations varying between 1000 and 1700 m in the Saharan Atlas and samples, by the Robinson pipette method (Soil Conservation a sub-plain surface (0–3%) of the Saharan platform with elevations Service, 1972) (Loveland and Whalley, 1991), and classified ac- from 500 to 1000 m (Houyou et al., 2014). The study area characterized cording to the USDA textural triangle. CaCO3 content were analysed by a semi-arid with rainfall varying between 200 and 300 mm by the Barahona (1984) method. OM was analysed basing on wet in the north, and arid climate with rainfall varying between 50 and oxidation using the method of Tyurin (1951). AW was calculated by 200 mm in the Saharan platform. The average monthly wind speed the difference between the water retention at 33 kPa and 1500 kPa blown from the north, is the highest in January–March and after in using the Richard membrane (Richards, 1965) method. Fed content October–December. The wind speed blown from the east, is the highest was extracted with citrate–dithionite, following Holmgren (1967). in June but in the Atlas domain is in April–September. However, in Exchangeable cations (Na+, Ca++and Mg++) were extracted by summer period the wind are hot and dry and blows from the southeast ammonium acetate according to methodology recommended by the and south. In this season, the average wind speed reaches the maximum Soil Conservation Service of the United States Department of Agri- in August, and the average number of days (59 days of Sirocco) on culture (Soil Conservation Service, 1972) and measured by absorp- − which the maximum wind speed is over 40 m s 1 is also the highest in tion atomic spectrometer (VARIAN SpectrAA 220FS instrument). this month (Office National Météorologique (ONM, 2014). 2. Vegetation cover. Four OLI images from January to September 2016 covering the Laghouat region were used. The average maximum

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