1. Introduction
The phenomenon of urban sprawl has become a focal point of scrutiny and critique from various vantage points [
1], spanning concerns related to urban efficiency such as infrastructure management [
2,
3,
4,
5,
6,
7] and environmental risk management [
8,
9,
10,
11,
12,
13]. Simultaneously, it has drawn attention from an environmental perspective, eliciting discussions about its ramifications on surrounding ecosystems [
14,
15,
16,
17,
18,
19,
20,
21] and the imperative need for the preservation of agricultural land [
22,
23]. The multifaceted nature of these critiques underscores the complexity and far-reaching consequences associated with unchecked urban expansion. Urbanization, spurred by burgeoning populations and the allure of modern life, paints a complex narrative across continents, often accompanied by uncontrolled expansion [
24]. Unchecked growth poses a formidable challenge [
25,
26,
27,
28], encroaching upon fertile agricultural lands and venturing into risky areas such as those prone to flooding.
Soil, fundamental to human survival, demands judicious use [
29,
30,
31,
32]; yet, unbridled urbanization jeopardizes farmlands and delves into environmentally precarious frontiers. In Bni Bouayach, the clash between rapid expansion and fragile ecosystems necessitates a nuanced understanding and strategic interventions. Navigating a path that harmonizes urban aspirations with environmental and agricultural viability is imperative [
33,
34,
35].
By 2030, an additional 1.2 billion people are expected to reside in urban areas globally [
36], and more than 66% of the global population is projected to reside in urban areas by 2050 [
37,
38]. Numerous studies have highlighted the far-reaching consequences of rapid urban growth. For instance, research conducted in Pensacola, Fl, between 1989 and 2002 revealed significant ecological damage caused by urban sprawl, highlighting the need for sustainable development practices [
39]. Similarly, a comprehensive Indonesian study (1995–2015) demonstrated a direct correlation between urban expansion and the decline of agricultural lands, underscoring the importance of land use planning [
40]. These findings resonate with broader concerns about the impact of urbanization on natural landscapes, as exemplified by a European study (1958–2018) showing a substantial decrease in green spaces due to human structures [
41]. Moreover, research focusing on West Africa (2007–2020) offers a specific case study of rapid urban expansion, with Greater Lomé experiencing a 33% increase in built area within just 13 years [
42]. These examples highlight the urgency of developing sustainable urban planning strategies that address the environmental and social challenges associated with rapid urban growth.
Recent years have witnessed a significant evolution in decision-making methodologies [
43,
44,
45,
46], focusing on the integration and refinement of Multi-Attribute Decision-Making (MADM) analysis and the Analytic Hierarchy Process (AHP) [
47,
48]. GIS and AHP have emerged as a powerful synergy in urban planning, providing a comprehensive framework for sustainable land use decisions [
49,
50,
51,
52,
53,
54]. Originally conceptualized by Saaty in the late 1970s, AHP has evolved into a structured methodology for multi-criteria decision-making [
55,
56,
57,
58]. It enables systematic evaluation and prioritization by breaking down complex decisions into hierarchical structures. GIS technology, transforming spatial data collection and analysis, provides a powerful platform for mapping, modeling, and managing spatial information, indispensable for urban planners [
59,
60,
61]. The integration of GIS and AHP, as showcased in this study, allows for the incorporation of spatial considerations into decision-making, empowering planners to visualize consequences and identify sustainable development pathways.
This research delves into the intricate knotwork of Bni Bouayach’s urban sprawl, wielding GIS-AHP as a compass for meticulously navigating land suitability for sustainable development and identifying optimal directions for urban sprawl with the main goal of balancing environment–human relationships. Armed with historical data, aerial photographs, and satellite imagery, this study traces the city’s growth and weaves ten distinct criteria into its landscape. Unlike generic solutions, GIS-AHP offers a context-specific strategy for harmonizing urbanization with environmental stewardship.
Through the proposed approach, spatial analysis unpacks the fabric of land suitability, revealing that 39.5% of the commune falls into suitable and highly suitable categories. This detailed analysis identifies key candidates for informed land use planning, offering a concrete roadmap for policymakers. This research transcends academic inquiry, aiming to provide actionable insights, steering Bni Bouayach towards a future where sustainable development is a tangible reality. It strives to guide the city toward a resilient and sustainable future amidst the forces of urban sprawl.
2. Materials and Methods
2.1. Overview
Bni Bouayach Town is located in northern Morocco near the emerging city of Al Hoceima (
Figure 1). It is nestled on the gentle slopes at the foothills of two prominent hills, defining its topographical setting. Several years ago, it was promoted from a rural town. However, it still maintains a clear rural imprint due to the presence of an irrigation sector fed by the lake of the MBA Al-Khattabi Dam (adjacent), the flows of the Nekor and Saftoula rivers, and dozens of irrigation wells exploiting the Ghis-Nekor aquifer.
The town’s development is notably influenced by its geographical context. Positioned on the lower terrace, Bni Bouayach has experienced urban growth over the years. It has evolved responding to economic activities, the establishment of a local market, and the influx of rural populations. Over the decades, Bni Bouayach has witnessed phases of rapid urban expansion, particularly along the National Road No. 2, contributing to the transformation of once-agricultural areas into urbanized zones.
2.2. Data Sources for Analyzing Historical Urban Growth in Bni Bouayach (1964–2014)
Based on an extensive array of tools, including aerial photographs, satellite imagery, and meticulously preserved archival documents, this research delves into the historical growth of Bni Bouayach. The town’s evolution was explored across four important phases—1964, 1982, 1994, and 2014. Aerial photography missions related to the study area are available through the National Agency for Land Conservation, Cadaster, and Cartography (Rabat, Morocco) (
Table 1). Landsat satellite images are accessible through the Earth Explorer platforms (
Table 1):
The analysis initiates with a meticulous examination of high-resolution aerial photographs spanning these phases, offering a visual narrative that captures the changing landscape and spatial intricacies shaping Bni Bouayach’s urban environment. Complementing this visual exploration, this research harnesses urban planning documents, municipal archives, and satellite imagery to delineate the city’s footprint in each phase, providing a dynamic layer to our understanding of its growth trajectory.
Employing a phased analysis, the historical timeline is dissected into distinct periods, each representing a snapshot capturing pivotal forms that have significantly molded the city’s spatial layout, demographic distribution, and land use patterns. The integration of these diverse datasets is achieved through a Geographic Information System (GIS) to facilitate the creation of comprehensive maps illustrating the evolving morphology of Bni Bouayach throughout each identified phase.
2.3. Delineating Suitable Land for Built-Up Growth: Criteria Selection and Justification
The cornerstone of identifying appropriate land for built-up development lies in the judicious selection of pertinent criteria. This critical process demands a dual focus: ensuring both relevance to the specific study area and correspondence with available data [
62]. While notable variability exists in the chosen criteria across studies—often influenced by local characteristics and resource limitations [
63]—a general trend emerges, leading to the categorization of criteria into two broad groups: accessibility–socioeconomic factors and physical–environmental factors.
This research builds upon a comprehensive synthesis of the existing literature [
16,
52,
62,
64,
65,
66,
67,
68,
69] to present a refined set of criteria (
Table 2). Recognizing the substantial influence of accessibility–socioeconomic factors on suitability determination, these elements take precedence, followed by physical–environmental factors. This prioritization reflects both their prevailing importance in academic discourse and their direct impact on development feasibility. By adopting these criteria, this study aims to enhance the precision and efficacy of identifying suitable land for built-up growth within the defined context.
Through meticulous consideration, five centrals physical–environmental factors have been chosen for this study: elevation (E), slope (S), aspect (A), Environmental Context Map (ECM), and Land Use/Land Cover (LULC). Similarly, five key accessibility–socioeconomic factors have been incorporated: distance from the main (national in this context) road (DNR), distance from schools (DS), from health centers (DHC), from residential zones (DRZ), and from industry/commerce zones (DIC). Each factor was carefully selected and classified based on a critical analysis of the existing literature, as described in
Table 2.
Here, this section demonstrates more details about the methodology employed to assess land suitability for development within the study area (
Table 2 and
Table 3). The assessment considers two primary categories of factors: physical–environmental and accessibility–socioeconomic.
2.3.1. Physical–Environmental Factors
Five key physical–environmental factors were evaluated to determine their influence on development suitability (
Table 2):
Elevation (m): lower elevations (Score 7) are considered more suitable due to easier accessibility and construction feasibility compared to higher elevations (Score 1).
Slope (°): gentle slopes (0° to 2°, Score 7) are ideal for development, while steeper slopes (>25°, Score 1) present significant challenges due to stability concerns.
Aspect (°): south-facing slopes (Score 135–225) receive more sunlight and are considered more desirable (Score 7) for development compared to north-facing slopes (Score 315–45) due to reduced sunlight exposure.
The Environmental Context Map plays a pivotal role, encompassing a plethora of geomorphological and geological elements. Rocky and hard formations, like conglomerates, are categorized as highly suitable (score 7), clay has medium suitability (score 4), and shale falls in between (score 5). Main channel flood zones (V-shaped valleys and badlands) and badlands are assigned the lowest possible suitability score (1) due to their high risk. Areas susceptible to ground movement and scree have moderately low suitability (score 2–3), together with rill and gully erosion areas. Additionally, there is a 15 m buffer zone around cliffs.
Land Use/Land Cover: Different Land Use/Land Cover (LULC) maps were generated using aerial photographs and satellite imagery (
Table 1). The LULC map, used in the AHP, categorizes land cover into distinct classes: built-up land, bare land, water bodies, forests, irrigated areas, agriculture, and arboriculture. Built-up areas and riverbeds are excluded from analysis due to their unsuitability for new development. Conversely, marginal and rare land uses like irrigated zones and forests are prioritized (moderate scores) to minimize environmental impact and encourage sustainable urban planning.
2.3.2. Accessibility–Socioeconomic Factors
This study also considers the influence of accessibility and socioeconomic factors on development suitability. Five key factors are evaluated (
Table 2):
Distance from the main road (m): proximity to the National Road No. 2 (high score) enhances connectivity and economic potential (Figure 4c).
Distance from schools (m): accessibility to educational facilities receives a high score, reflecting their importance for residents.
Distance from health centers (m): likewise, proximity to healthcare facilities is important and receives a high score.
Distance from residential zones (m): areas near existing residential zones score highly due to their attractiveness for new residents and potential for cost-efficient development.
Distance from industry/commerce zones (m): proximity to commercial and industrial areas is considered beneficial and receives a moderate score.
2.4. The Weighting of the Criteria by AHP
The AHP emerges as a widely acknowledged and universally employed subjective method within the domain of multi-criteria decision-making [
22]. Its renowned versatility lies in its ability to assign weights to data, fostering robust and comprehensive decision analyses [
40]. Rooted in expert opinions collected through structured questionnaires, AHP leverages Saaty’s 1-to-9 ratio scale for pairwise comparisons, where experts quantify the relative influence of one criterion over another [
11,
38].
During pairwise comparisons, experts assign scores from 1 to 9, reflecting the degree of influence one criterion holds over another. A score of 1 denotes equal influence, while 9 signifies extreme dominance. Normalization of these values is achieved by dividing each value by its respective column sum, ultimately leading to the derivation of criterion weights through the arithmetic mean method, as detailed in Table 6.
Following weight calculation, assessing the consistency of expert judgments becomes paramount. This critical step is accomplished through the determination of the Consistency Ratio (CR) [
30]. Introduced by Saaty [
41], the CR serves as a vital index for evaluating the coherence of the comparison matrix. The formula for computing the CR value is pivotal in validating the internal consistency of expert-derived judgments, adding an important layer of rigor to the AHP process.
The Consistency Ratio (Equation (1)) is an important metric in the evaluation of the reliability of pairwise comparisons. Defined as the ratio of the Consistency Index (CI) to the Random Consistency Index (RI), the latter is derived from randomly generated pairwise comparison matrices of order 1 to 10, computed by approximating random indices through a sample of 500 [
39].
Expressed mathematically, the formula for calculating CR involves CI, which is determined by Equation (2):
where λ represents the average of the consistency vector, and “n” denotes the total number of criteria considered. The structure of the Consistency Ratio is crafted to interpret results effectively (a value below 10% designates a sufficiently consistent matrix, affirming its acceptance, while a CR exceeding 10% signals a potential inconsistency in judgments). This stringent criterion ensures the robustness and reliability of the comparative judgments made during the Analytic Hierarchy Process.
2.5. Preparing and Rasterizing Criteria Thematic Maps
Following the rigorous selection of criteria for identifying optimal locations for future urban development, a comprehensive set of ten thematic maps was meticulously crafted. Leveraging the capabilities of a Geographic Information System (GIS) platform, these maps reflected each chosen criterion. To enable more intricate spatial analyses, the raster format was selected to enhance the analytical capabilities, facilitating a robust and versatile approach.
2.6. Synthesizing Suitability: Integrating Criteria Maps into the Final Assessment
The derivation of the final suitability map involves a structured integration of the thematic criteria maps. Once obtained, the maps were combined using a weighted overlay to assess the individual influences of each criterion, resulting in a single, comprehensive suitability map. The latter helped in understanding the spatial variation in the built-up suitability, thus serving as a critical tool guiding future urban development endeavors by clearly identifying areas with the highest potential for sustainable and successful urban growth.
2.7. Radar Chart for Suitability Visualization
A Radar Chart was employed to visualize the spatial distribution of suitability levels for urban expansion in Bni Bouayach Town. This method involved the following steps:
Center definition and area delineation: The geometric center of Bni Bouayach Town, representing both its historical core and current central area, was identified. A study area encompassing this center was delineated as a circle for further analysis.
Directional polygon creation: The circle was segmented into a series of directional zones radiating outward from the geometric center. This division allowed for the evaluation of suitability within specific directions.
Suitability distribution extraction: Within each directional zone, the distribution of suitability categories derived from the comprehensive analysis of physical–environmental factors (elevation, slope, aspect, Environmental Context Map, Land Use/Land Cover…) was extracted.
Quantification of suitability: The surface area for each suitability category within each directional zone was calculated. This provided a detailed breakdown of the spatial distribution of suitability within each direction.
Radar Chart construction: Utilizing Microsoft Excel, the calculated surface areas for each suitability category and direction were plotted as data points on a Radar Chart. This visual representation highlighted variations in suitability across different directions, providing insights into the suitability levels for urban expansion in Bni Bouayach Town.
3. Results
The results of this study provide a detailed assessment of land suitability for sustainable development in Bni Bouayach, Morocco, using a multi-criteria GIS-AHP approach, focusing on accessibility, economic, social, geomorphological, and environmental factors. It promotes a delicate balance between environment and human well-being, recognizing the importance of urban development that harmonizes with ecological needs. The following sections present findings and discuss their importance for sustainable urban planning.
3.1. Understanding Land Use Dynamics: A Chronological Analysis of Change over Five Decades (1964–2014)
Table 4 presents a comprehensive chronological breakdown of land use categories across the five decades (1964–2014), and
Figure 2 offers a visual representation of these changes through spatiotemporal maps. This allowed us to discern four evolution periods:
Pre-1960s (
Figure 2a): a predominantly agrarian landscape and the seeds of urbanization. This period paints a picture of a commune firmly rooted in agricultural practices. The lower abundance of the “built-up land” category highlights the pre-urban character of the landscape, showcasing the organic growth of the initial urban core. Notably, cereal cultivation reigns supreme, encompassing 78.70% of the total area (1731.2 ha), followed by olive tree plantations at 14.4% (316.7 ha) and irrigated areas at 3% (66.3 ha). This pre-urban baseline serves as a critical reference point for understanding the subsequent transformations.
Between 1964 and 1982 (
Figure 2b): initial phases of urban expansion and land use changes. Bni Bouayach’s first wave of urbanization occurred between 1964 and 1982. This period witnessed a significant doubling of built-up land area, reaching 57.2 hectares (
Table 4). This expansion, primarily focused on the Nekor plain, came at an environmental cost. Agricultural land use declined sharply, with cereal cultivation experiencing a substantial 17.36% reduction (381.9 hectares) and olive tree plantations decreasing by 3.9% (85.9 hectares) (
Table 4). These losses can be partly attributed to land conversion for urban construction. Notably, forest cover remained relatively stable during this period, suggesting that the initial urban sprawl primarily impacted agricultural lands. These land use shifts highlight the early stages of Bni Bouayach’s urban growth and the resulting transformation of its landscape.
Between 1982 and 1994 (
Figure 2c): navigating a phase of relative stability and evolving urban areas. This period was marked by the continuity of expansion of the built-up areas at a slower pace, with a 28.9 ha increase (
Table 4). An observed more controlled sprawl of the built-up areas was likely guided by evolving urban planning policies. The remaining categories exhibit minimal fluctuations, showcasing a continuation of the downward trend in cereal cultivation and irrigated areas.
Between 1994 and 2014 (
Figure 2d): acceleration of urban expansion and the continuous regression of natural spaces. This period witnessed an acceleration of urbanization, evidenced by a pronounced 13.03% increase in built-up land area, reaching 286.7 ha (
Table 4). This significant urban expansion was at the expense of natural space. In proof of this, cereal cultivation suffered a substantial decline of 23.40% (−514.7 ha), and irrigated areas also experienced a 14.12% loss (−30.9 ha) (
Table 4). This phase demonstrates the acceleration of urban space and the continuous regression of natural spaces, underscoring the importance of the current study. This study utilizes a GIS-based Analytical Hierarchy Process (GIS-AHP) framework to assess land suitability for sustainable development, aiming to balance environmental and human needs and ensure sustainability.
3.2. Influential Factors in Transformation
Drawing upon the preceding analysis, the town’s development initially traced a road-centric linear trajectory (National Road No. 2), subsequently spilling over into agricultural lands despite the inherent environmental risks. This intricate tapestry of urban growth was studied according to two group of factors (accessibility–socioeconomic factors and physical–environmental ones) to depict the optimal patterns of urban expansion to be followed.
3.2.1. Physical–Environmental Factors
The identification of development-suitable locations demands a rigorous consideration of physical–environmental factors, paramount for ensuring sustainable construction practices and environmental preservation. Five key factors were considered to discern optimal locations for sustainable development projects in urban areas: elevation, slope, aspect, Environmental Context Map (ECM), and Land Use/Land Cover (LULC) (
Figure 3).
The analysis pinpoints key factors shaping land suitability for development. North-facing slopes, dominant in the southeast (
Figure 3a), receive less sunlight, making them less desirable. Conversely, south-facing slopes, although less frequent, are more suitable due to increased sun exposure. Gentle slopes, concentrated in the central area (
Figure 3b), are ideal for construction, while steeper slopes, prevalent in the southwest, present development challenges. Finally, elevation (
Figure 3e) plays a significant role. Lower areas, dominant in the central and northeastern regions, are considered more adaptable due to easier accessibility compared to higher elevations. These findings align with the general preference for comfortable and accessible living environments.
The Environmental Context Map (
Figure 3d) plays an important role in land suitability assessment by considering various geomorphological and geological features. Shale formations, found primarily in the northwest and south, are the most prevalent, covering 52% of the study area and classified as moderately suitable. Clay formations, concentrated in the west-central region, exhibit medium suitability and account for 19% of the area. The areas with the lowest suitability (18%) are the main channel flood zones (V-shaped valleys and badlands) due to high risks associated with development. Areas prone to ground movement, scree, and rill and gully erosion, along with a 15 m buffer zone around cliffs, are categorized as having moderately low suitability and collectively cover 8% of the study area. Finally, rocky and hard formations, such as conglomerates, are considered highly suitable for development but are the least common, occupying less than 3% of the area and primarily located in the northwest.
The LULC map (
Figure 3c) plays an important role in identifying suitable locations for development. Built-up land and riverbeds are logically excluded from further analysis, as they are not viable options for new development. Conversely, this study prioritizes rare and marginal areas such as irrigated zones and forests. This approach minimizes the environmental impact and promotes sustainable urban planning principles.
3.2.2. Accessibility and Socioeconomic Factors
Identifying development-suitable locations necessitates an examination of both accessibility and socioeconomic factors. Five key factors influencing land suitability were addressed: distance from the mean (National) road, from schools, health centers, residential zones, and industry/commerce zones (
Figure 4). Recall that, for each factor, the distance was measured based on buffers depending on the factor, as reported previously in
Table 2.
The National Road No. 2 (
Figure 4c) serves as an important artery for Bni Bouayach, connecting it to neighboring cities like Imzouren and Al Hoceima. Proximity to this axis signifies high suitability due to enhanced connectivity and the potential economic benefits of catering to travelers and offering commercial services. Similarly, proximity to residential zones (
Figure 4b) also emerges as an important determinant, with areas within close vicinity receiving a high suitability score (6). This high score reflects the attractiveness of such locations for new residents and the cost-efficient development opportunities they present for decisionmakers.
Interestingly, certain residential cores within Bni Bouayach have organically developed around educational (
Figure 4a) and health establishments (
Figure 4d), highlighting the importance of accessibility to these services. Accordingly, areas close to these facilities are assigned a very high suitability score, reflecting observed urban planning patterns that prioritize accessibility to essential amenities. This nuanced analysis unveils the intricate interplay between accessibility and socioeconomic factors in shaping land suitability for urban development, offering valuable insights for informed decision-making and sustainable urban planning practices.
3.3. Pairwise Comparison Matrix Analysis
The Analytic Hierarchy Process stands out as a more effective method in comparison to its alternatives for determining weights. This superiority stems from its unique ability to measure and control inconsistency, particularly in situations involving conflicting criteria [
73,
74].
This study is based on a questionnaire previously conducted with experts. Among them, two are professors and three hold doctoral degrees, specializing in geography and regional planning, with a wealth of experience in implementing diverse future projects. Two additional experts are real estate developers, having successfully executed multiple projects related to residential buildings. The remaining six participants are residents aspiring to purchase residential homes.
The evaluation process involved the consideration of ten standards, with expert opinions gathered through questionnaires utilizing the nine-point Thomas Saaty scale: 1—equal importance; 3—moderate importance; 5—strong importance; 7—very strong importance; and 9—extreme importance (2,4,6,8 values in between) [
75,
76]. The selection of the most appropriate viewpoints, based on expert consensus, formed the basis for subsequent analysis. The resulting pairwise comparison matrix table (
Table 5) comprised 100 entries with 45 comparisons where the diagonal values consistently held a unitary value, representing the equality of effects between identical parameters.
The generation of the standard pairwise comparison matrix table (
Table 6) constituted the subsequent step in determining the final weight for each criterion. This involved the normalization of values by dividing each array element by the total column value. The weight for each criterion was then calculated using the arithmetic average method for each row, as outlined in
Table 6.
Notably, proximity to residential areas emerged as the most influential criterion, attaining a weighted value of 23%. This was followed by the significance of LULC considerations (17%), proximity to the National Road No. 2 (14%), the overall environmental context (13%), slope (9%), and proximity to schools (9%). The impact of proximity to economic and commercial activities ranked fifth at 7%, followed by proximity to health services (4%). Conversely, the aspect (2%), and elevation (2.7%) demonstrated a minimal impact, collectively accounting for only 4% of the weighted criteria (
Table 6).
The normalized pairwise matrix table underscored the paramount importance of the accessibility and socioeconomic (57%) factor in decision-making for new construction, affirming its pivotal role in shaping the prioritization of criteria for urban development projects (
Table 6).
3.4. Ensuring Consistency in Decision-Making
In the pursuit of robust decision-making, it is imperative to assess the degree of consistency in the judgments. Prior to computing the Consistency Ratio (CR), the Consistency Index (CI) and λ values are essential components. The obtained result for the Consistency Ratio (CR) is 1.4% (<10%), indicating that the judgments exhibit consistency. This validates their suitability for further analysis, underscoring the reliability of the decision-making process.
3.5. Analyzing the Conclusive Land Suitability Map
3.5.1. Urban Growth Suitability
Table 7 and
Figure 5 present a comprehensive breakdown of land suitability for Bni Bouayach. The category of “prohibited or unsuitable” (375 hectares) encompasses areas deemed unsuitable for construction due to environmental restrictions (riverbeds, badlands, and cliffs) or being already collapsed by urbanization. This extensive area highlights the presence of significant challenges for development or specific land uses.
The “extremely unsuitable” category, at 339 hectares (
Table 7), designates land with exceedingly low suitability. This suggests severe limitations or unfavorable conditions, such as proximity to flood zones and watercourses or challenging geomorphological features. Additionally, these areas are often distant from public services and economic activities, rendering them highly unsuitable for their intended purpose. The considerable extent of this category underscores the need for careful consideration and potentially alternative uses for these lands.
Moving to the “moderately unsuitable” category (660 hectares) (
Table 7 and
Figure 5), the analysis reveals areas with a moderate level of unsuitability due to certain constraints or challenges likely to impact optimal land use. These lands include irrigated areas (rare in this region) and less accessible areas with lower exposure to natural risks. The substantial area in this category warrants further examination to identify specific limitations and explore potential strategies for sustainable land use and development.
The “adequately suitable” category (692 hectares) indicates areas reasonably suitable for their intended use (
Table 7 and
Figure 5). These lands exhibit a balance of accessibility, socioeconomic, and environmental factors, including proximity to economic activity, built-up areas, and major roads and more solid bedrock. While some constraints and natural hazards, such as land movement risks, may exist, their degree of suitability suggests they could be effectively used with appropriate planning and management strategies to address existing limitations and further improve their suitability. This category presents valuable opportunities for land use planners and developers to optimize these areas.
Finally, the “very suitable” category, encompassing only 206 hectares, designates land with exceptional suitability (
Table 7 and
Figure 5). These areas present optimal conditions for their intended use, characterized by favorable characteristics such as proximity to existing developments, minimal constraints, flat surfaces, and low exposure to natural hazards. The limited but significant extent of this category highlights pockets of land prime for specific developments or uses requiring optimal conditions and minimal intervention. Careful exploitation and preservation of these highly suitable areas are crucial, potentially prioritizing them for projects demanding such conditions.
3.5.2. Future Direction Preferences
The analysis of the Land Suitability Map identifies optimal directions for urban expansion, considering both favorable conditions and significant constraints. Choosing the right direction for urban growth is important to managing sprawl and building sustainable cities [
77,
78]. Planners can guide development towards areas that fit with environmental, economic, and social needs. This prevents haphazard sprawl and creates resilient cities that complement the surrounding landscape. Choosing suitable directions is therefore essential for well-planned, sustainable urban development.
This direction emerges as the most suitable for urban growth due to its advantageous combination of factors where the suitable area (adequately and highly) represents 299.43 ha (66.98% of the total surface of direction) (
Figure 6). First, the lithological characteristics present fewer geological concerns compared to other directions. Second, proximity to the major road axis connecting Bni Bouayach to other central-oriental Rif agglomerations (Imzouren and Al Hoceima) enhances accessibility and connectivity, fostering economic and social integration. Additionally, the presence of existing built-up areas serves as a valuable foundation for further development, minimizing disruption and optimizing infrastructure utilization.
The southeast direction exhibits moderate suitability for urban expansion where the suitable area represents 169.08 ha (60.39% of the total surface of direction) (
Figure 6). Similar to the northwest, favorable lithology minimizes geological challenges. Furthermore, proximity to the National Road No. 2 connecting Bni Bouayach to nearby villages strengthens accessibility and potential economic linkages. This strategic location aligns well with the existing geographical and infrastructural layout of the region, making it a viable option for controlled and sustainable development.
- 2.
Unsuitable directions:
This direction is deemed highly unsuitable for urban growth due to the presence of important irrigated lands and flood zones, particularly in close proximity to existing settlements. Areas with significant constraints for development in this direction, categorized as extremely unsuitable and moderately unsuitable, cover 180.92 hectares (58% of the direction’s area) (
Figure 6). These natural constraints pose both environmental risks and limitations on development potential, rendering this direction significantly less attractive for expansion.
The southwest direction faces significant challenges due to the combination of unfavorable geomorphological conditions and limited access to essential services and economic activities. This direction also comprises 361.70 hectares (76.74% of the direction’s area) (
Figure 6). These areas are characterized by challenging terrain, remoteness from essential infrastructure, and lack of economic hubs, making them largely unviable for urban expansion in the immediate future.
Description of Planche 1 (
Figure 7): The agglomeration of Bni Bouayach is situated on the left bank of the Nekor Wadi, downstream of the Mohamed Ben Abdelkrim El Khattabi Dam, located between hills and low folded mountains (
Figure 7a,c). These physical and natural constraints have driven urban sprawl from the emerged town of Bni Bouayach towards the plains of Nekor, leading to construction in risk-prone areas (
Figure 7b). The soils of the left bank of Nekor are developed soils, which are rare in a mountainous region typically characterized by undeveloped soils. These soils have been formed by water erosion processes over thousands of years in a young mountainous landscape. This pedological heritage, historically designated for irrigated agriculture in urban planning documents, has been increasingly encroached upon by urban development over the last three decades (
Figure 7d). The observations of this study highlight the gradual encroachment of urbanization on these valuable agricultural lands, posing significant risks to both the environment and sustainable land use.
4. Discussion
A historical analysis of aerial and satellite images, plans, and maps reveals the dynamic narrative of Bni Bouayach’s urban evolution. From its birth as a strategic core serving the Spanish military, the city organically expanded around a bustling weekly market, catering to surrounding rural communities. This early phase laid the foundation for future growth, etching the city’s initial footprint. The next era witnessed a surge in expansion, driven by migration, economic diversification, and unplanned sprawl. Residential neighborhoods blossomed alongside evolving urban planning policies, guiding development along key transport arteries and encroaching upon agricultural areas. However, unchecked growth also led to construction in flood-prone zones, revealing the challenges of managing rapid urban expansion within limited land resources. Finally, facing constrained urban boundaries, Bni Bouayach’s trajectory shifted. Houses spilled over into irrigated agricultural lands, highlighting the complex interplay between socioeconomic pressures, land constraints, and evolving development strategies. This shift ultimately shaped the city’s current form: a line running along the National Road No. 2 and a dense core surrounded by residential areas, stretching toward agricultural lands and flood-prone zones. Bni Bouayach’s urban evolution offers valuable lessons for managing urban growth in developing contexts. Understanding its historical trajectory can inform future planning strategies that prioritize sustainable land use, balanced growth, and resilience to environmental challenges.
This study leverages a comprehensive GIS-AHP framework, offering an approach that systematically prioritizes development zones, strategically identifies potential challenges, and informs the formulation of sustainable land use practices. Integrating both Geographic Information Systems and Analytic Hierarchy Process techniques enhances the precision and reliability of the results, fostering informed decision-making. Environmental factors are important for sustainable urban development [
79]. The GIS-AHP framework facilitates a nuanced examination of urban growth directions and integrates all factors responsible for the development of urban areas [
80]. Unlike previous studies that often neglect geomorphological characteristics and certain environmental factors [
50,
64,
81], this approach prioritizes factors like geomorphological characteristics, infrastructural accessibility, and natural constraints, ensuring a holistic understanding of how these complex elements influence land suitability for development. This comprehensive approach lays a foundation for sustainable and balanced urban expansion. The prioritization of directions, particularly the emphasis on the northwest, exemplifies a strategic approach to urban planning in Bni Bouayach. This direction offers optimal conditions for development while minimizing inherent challenges, providing a blueprint for future growth initiatives. This aligns with current trends in the urban planning literature, advocating for the integration of advanced spatial analysis like GIS-AHP to optimize decision-making and contribute to sustainable urban development [
80]. In short, by integrating the GIS-AHP framework, this study delivers a robust analysis of land suitability in Bni Bouayach, contributing valuable insights for informed planning and sustainable urban development. The prioritization of efficient expansion and responsible land use practices aligns with broader trends in research, ultimately positioning Bni Bouayach for a future of balanced and resilient growth.
Urban construction suitability assessments are shaped by a multifaceted ecological system, encompassing a blend of natural and human-made factors. This implies that the ultimate outcome of urban land suitability hinges on the cumulative impact of all factors influencing the evaluation process. The interplay of these diverse elements contributes to the complexity of the suitability assessment, highlighting the intricate relationship between the natural environment and human interventions in determining the appropriateness of land for urban construction.
The suitability analysis conducted in this study reveals vital insights for informed urban planning in Bni Bouayach, contributing significantly to the development of a sustainable city. Identifying both suitable and unsuitable directions for expansion underscores the importance of aligning development with environmental, economic, and social needs [
82]. This approach ensures well-rounded growth that prioritizes long-term sustainability.
Analysis identified the northwest and southeast as particularly favorable options for controlled and sustainable urban expansion. Favorable topography, existing infrastructure networks, proximity to neighboring Imzouren and Al Hoceima, and the proximity to the National Road No. 2 make these areas attractive choices. Additionally, suitable geological conditions and the absence of natural hazards like flooding and landslides further enhance their development potential. The possibility of integrating green spaces strengthens the appeal of these directions for balanced growth. Focusing expansion here can minimize the environmental impact and promote social well-being. Conversely, the northeast and southwest present significant challenges. The northeast is dominated by irrigated agricultural land and susceptible to flooding, while the southwest features rugged terrain, potential for landslides, and a lack of existing infrastructure. In the southwest direction, planting and afforestation efforts can be intensified to increase vegetation cover and mitigate environmental risks associated with soil erosion and terrain movements. Concerns regarding floodplains, rugged terrain, sensitive ecosystems, and limited infrastructure necessitate careful consideration and, in some cases, the avoidance of immediate urban development in these areas [
83]. Prioritizing the protection of such ecological features is important for building a resilient and environmentally responsible city [
84,
85]. This nuanced understanding of direction preferences lays the groundwork for well-planned urban expansion that harmonizes with the surrounding landscape. By adopting a sustainable approach that prioritizes environmental considerations, economic opportunities, and social well-being, Bni Bouayach can navigate its future growth trajectory with confidence, ensuring a prosperous and resilient future for its inhabitants.
Limitations
While the GIS-AHP framework offers valuable insights for Bni Bouayach’s land suitability analysis, acknowledging its limitations is important for responsible interpretation and future research. These limitations provide avenues for continued exploration and ensure a more comprehensive understanding of urban development dynamics. The foundation of any GIS analysis rests on the quality of its input data. In this study, the factor maps are based on a spatial resolution of 30 m. The geological map, Digital Elevation Model (DEM), and accessibility maps, if inaccurate or lacking detail, can introduce uncertainties into the results. Employing higher-resolution datasets [
86] and advanced data validation techniques will be vital for future studies seeking greater precision in land suitability assessments. The AHP’s reliance on subjective weight assignments for different criteria introduces an element of human judgment. While expert and stakeholder involvement minimizes bias, variations in opinion can influence outcomes. Exploring sensitivity analyses and alternative weighting scenarios in future research will strengthen the robustness of the results and enhance confidence in decision-making [
86,
87]. Additionally, to address this limitation, future research could explore incorporating the following:
Machine learning models: Algorithms like Random Forest, Support Vector Machines, and Neural Networks can analyze vast datasets and identify complex relationships between variables. This could lead to more objective and precise suitability assessments.
Weighted statistical models: Weighted statistical models, such as the approach by Xiao et al. [
88], offer a systematic way to analyze and explain results from different methods. These models leverage statistical rigor and comprehensive data analysis to mitigate biases inherent in expert-driven methods.
Urban environments are dynamic, and factors influencing land suitability evolve over time. This study’s static nature may not fully capture these temporal changes. Future research could explore dynamic GIS-AHP models that account for temporal shifts, enabling a more adaptive and responsive approach to urban planning. This research focuses primarily on geomorphological, physical, accessibility, economic, and some social aspects (schools and health centers), potentially overlooking important social dimensions. Community preferences, cultural aspects [
89,
90] such as public spaces with cultural significance and cultural amenities and activities, and demographic trends significantly impact the success of development initiatives. Integrating social considerations into future iterations of the GIS-AHP framework will contribute to a more holistic understanding of land suitability and its implications for urban development.
In Bni Bouayach, the challenges associated with land availability and acquisition are particularly pronounced, primarily characterized by the prevalence of private land with limited plot sizes. The constraints are compounded by the high cost of land and the involvement of land dealers in the exploitation of available parcels. The predominance of small-sized private plots often poses logistical challenges for large-scale urban development initiatives. Additionally, the elevated cost of land, driven by market dynamics, becomes a significant hurdle in acquiring suitable areas for planned expansion. The influence of land dealers further complicates the acquisition process, introducing complexities in negotiations and potentially impeding strategic land use planning. As urban development endeavors progress, addressing these key constraints becomes imperative for successful land acquisition and the realization of sustainable urban growth in Bni Bouayach.
5. Conclusions
The historical trajectory of Bni Bouayach’s urban fabric reveals a compelling narrative of dynamic growth interwoven with ecological considerations and socioeconomic realities. While the town’s rapid expansion, particularly between 1994 and 2014, effectively addressed urgent housing demands, it simultaneously triggered concerns regarding environmental sustainability and optimal land use management. This complex interplay of factors necessitates further investigation to illuminate Bni Bouayach’s future spatial configuration, enabling policymakers to formulate strategies for balanced development that prioritize both environmental preservation and prudent resource allocation.
The present study, through a multifaceted land suitability analysis and the integration of the GIS-AHP framework, unveils invaluable insights for urban planners and decisionmakers. This comprehensive approach allows for the systematic prioritization of development zones, the strategic identification of potential challenges, and the formulation of sustainable land use practices. Notably, the nuanced examination of urban growth directions underscores the pivotal role played by geomorphological characteristics, infrastructural accessibility, natural constraints, and proximity to essential services in determining land suitability for development. By prioritizing directions like the northwest that offer optimal conditions while minimizing inherent challenges, Bni Bouayach can strategically orchestrate efficient urban expansion and concurrent responsible land use practices.
Importantly, the methodological framework employed in this study champions a holistic approach that considers both environmental and socioeconomic dimensions. This balanced perspective is particularly important in the context of developing nations, where the substantial costs associated with infrastructure development for urban expansion necessitate careful resource optimization. The integration of environmental considerations with socioeconomic factors aligns with the imperative to maximize resource utilization, ultimately fostering a sustainable and resilient urban development trajectory for Bni Bouayach.