# Sense-making and shaping of temporary wetlands: A socio-hydrological analysis of dichotomous ontologies of merjas in Morocco

Hajar Choukrani, Guillaume Lacombe, Margreet Zwarteveen, Marcel Kuper, Abdelilah Taky, Ali Hammani

► To cite this version:

Hajar Choukrani, Guillaume Lacombe, Margreet Zwarteveen, Marcel Kuper, Abdelilah Taky, et al. Sense-making and shaping of temporary wetlands: A socio-hydrological analysis of dichotomous ontologies of merjas in Morocco. Journal of Hydrology, 2023, 627 (B), pp.130434. 10.1016/j.jhydrol.2023.130434. hal-04308835

HAL Id: hal-04308835

https://hal.science/hal-04308835v1

Submitted on 27 Nov 2023

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>
Sense-making and shaping of temporary wetlands: A socio-hydrological analysis of
dichotomous ontologies of merjas in Morocco

Hajar Choukrani a,b,*, Guillaume Lacombe a,b, Margreet Zwarteveen c, Marcel Kuper a,
Abdelilah Taky b, Ali Hammani b

<footnote>a University of Montpellier, AgroParisTech, Brgm, Cirad, Inrae, Institut Agro Montpellier, Ird, UMR G-Eau, Montpellier, France</footnote>

<footnote>b Hassan II Institute of Agronomy and Veterinary Medicine, Water resources management: water, irrigation and infrastructure, Rabat, Morocco</footnote>

<footnote>c IHE Delft Institute for Water Education, Water Governance Department, Delft, the Netherlands; University of Amsterdam (UvA), Amsterdam, the Netherlands</footnote>

<footnote>*Corresponding author: choukrani.hajar@gmail.com</footnote>
1 Abstract

2 There are quite different ways of making sense of wetlands: as wastelands to be drained and reclaimed,
3 as hotspots of biodiversity to be preserved or restored, or as hydro-social territories in which people live
4 and produce. We argue that such ontologies not only represent ‘a reality out there’ but help bring this
5 reality into being by shaping the way wetlands are developed and used. The present study was conducted
6 on temporary wetlands (merjas) in the Gharb plain (Morocco). Using a socio-hydrological approach,
7 this research probes the origin of these ontologies and how they shape field realities. Qualitative data
8 were collected during field surveys and focus groups and hydrological data were obtained by remote
9 sensing. There are two main ways of seeing merjas that have led to two different enactments – a ‘State’
10 one, that has drained and developed the land and re-distributed it to farmers of its choice; and a ‘local’
11 one, that of riverine people who have learned to live with land-water dynamics, who now also claim part
12 of this reclaimed land for their own children. The view of temporary wetlands as ecological systems has
13 been restricted to three particular merjas, thereby obliterating the ecological role of others. Since the
14 2009/2010 floods, the idea of merjas as buffer zones to protect agricultural and urban areas has been
15 under discussion. Although the idea is rejected by most actors, in practice, merjas will continue to play
16 this role during major floods in the future, as upstream dams are generally managed with the aim of
17 resilience to drought. We show how each ontology is connected to different networks of people,
18 resulting in different enactments that sometimes co-exist and sometimes clash. Creating space for
19 negotiation for the future of merjas remains challenging, given the changing water flows and the
20 persistent co-existence of ontologies, as the people connected to it aim to enact their own version of the
21 merja.

22 **Keywords:** seasonal wetlands, ontologies, stakeholders, buffer zone, agricultural land, Morocco
23

# 1. Introduction

24

25

26

27

28

29

30

31

32

33

34

35

36

37

"Instructed in March 1917 to do a reconnaissance of the Rharb for its agricultural development, he [an engineer of the Public Works Department] thought of carrying out his mission with the car and horse that the administration had put at his disposal...he had to give up the car very quickly...The horse itself was abandoned. And our engineer took place, like the Moroccan fellahs on a miserable boat... But let us imagine the dismay of the traveler who returns in September... He wonders if he was not victim of a mirage. The water has almost completely disappeared; no more boats, no more rafts; donkeys and camels circulate on already dusty tracks..." (Célérier, 1922: 109-110).

38

39

40

41

42

43

44

45

46

47

48

49

Temporary wetlands are intrinsically fluid and slippery environments that challenge dominant land-centered ways of making sense of such areas, but are also difficult to fit in water-centered frames, questioning how humans live (and should live) in places where there is dynamic interplay between land and water (Biggs, 2010). The dynamics and ambivalences of temporary wetlands, and more largely of delta environments are linked to the fact that these “vary between not quite firm land and not quite open water, or sometimes one and sometimes the other, with water periodically in excess and repeatedly scarce” (Krause, 2017: 403), as illustrated in the epigraph. In such hybrid environments, watery lands or muddy waters often escape or overflow theorizations – due to how difficult it is to fully understand and predict water-land dynamics, and to the agency of water – with water reacting to interventions in sometimes unexpected ways (Lahiri-Dutt & Samanta, 2013). As highlighted by the work of Cortesi (2022), this has led to recent calls for a shift from the binary ontology of land and water toward an “amphibious approach” to temporary wetlands that explicitly recognizes the dynamic interplay of land
and water, while paying particular attention to the intricate relations between the social and the natural (Krause, 2017: 404).

Wesselink et al. (2017) define sociohydrology as relational, where the social and the hydrology engage in a serious dialogue to clarify some of the complex and messy water situations currently encountered.

Sociohydrology aims to analyze “the dynamic interactions and feedbacks” between hydrology and societies (Sivapalan & Blöschl, 2015). This is particularly important in amphibious environments where “social relations must not be seen as add-ons to an assumed material, hydrological backdrop, and water flows must not be conceived of as external, pre-given dynamics” (Krause, 2017: 404). The way water flows (or does not flow) depends on socio-political relations, while water flows importantly shape social relations and practices.

The hydrological processes of wetlands have been extensively studied, particularly in relation to the ecological functions fulfilled by wetlands, including “water purification, flood reduction, streamflow maintenance, fish production and as a habitat for wild species” (Liang et al., 2020: 1). Such hydrological analyses are important, including when they report counterintuitive findings, for example when they show that some wetlands cause floods rather than attenuate them (Bullock & Acreman, 2003). In flat and complex wetlands, a spatial understanding of hydrology – both short-term changes and long-term trends – is important, thus explaining their decades-long investigation through remote sensing (Klemas, 2013; Tiner et al., 2015).

Making sense of what temporary wetlands are – their ontology – and why such ‘sense-making’ matters, has been the subject of multiple debates. (Cortesi, 2021: 872) showed that the simplification and “standardized description” of delta environments, stereotyping them as land to be reclaimed, played an important role in large-scale reclamation projects. Indeed, prevailing conceptualizations (theorizations, definitions) not only represent a ‘reality out there’ but help bring this reality into being. This is obvious when ‘sense-making’ of temporary wetlands, by conceiving them as land to-be-reclaimed, is so directly linked to reclamation projects. In the case of temporary wetlands, there is an additional fault line that is often exploited when planning their reclamation by questioning whether, given their “progressive disappearance in intensive farming landscapes”, they really are wetlands at all (Merot et al., 2006: 258).
Over the last century or so, there has been a massive worldwide drive to reclaim wetlands to separate land from water (Lahiri-Dutt & Samanta, 2013). At the heart of this drive was the quest for productive land (from the point of view of state revenues) linked to a hydraulic vision of regulated ‘modern’ water, “forcing a linked legal and technical arrangement - land as property and water as resource” (D’Souza, 2011: 5-6; see Linton, 2010, for the concept of modern water). Large scale drainage schemes and wetland reclamation into agricultural and urban systems have caused considerable damage to wetlands (Cooper & Moore, 2003). This has led to controversy about the massive decline of wetlands and the breakdown of biodiversity worldwide (MEA, 2005; Saha & Pal, 2019). We argue that at the heart of this controversy is a semiotic conflict about how wetlands should be considered (Cortesi, 2018) as useless wastelands and negative ecosystems that need to be drained and ‘reclaimed’ to turn them into profitable agricultural or urban lands, or as rich biodiversity hotspots of that need to be preserved, conserved, and, more recently, restored, for the ecosystem services they provide, including flood protection or purification of polluted water (Verhoeven, 2014).

Just as wetland reclamation was all about dominating their “obstinate natures” to transform them into “productive national assets” (D’Souza, 2011:1), policy makers and technocrats also gave much thought to who deserved to cultivate these newly created lands and how the land should be cultivated, as the way of life and practices of the people living in the wetlands were by and large illegible to the State (Lahiri-Dutt & Samanta, 2013). For instance, in Gambia, the explicit aim of the colonial administration in their swamp development projects was “drawing men into rice growing”, paradoxically leading to “loss of control over productive swampland” by women farmers, who previously cultivated these ecosystems, while increasing their burden of labor (Carney, 1993: 407, 412). Of course, the State and riverine populations often have diverging or even antagonistic “perspectives, values and interests” and “competing claims” about what wetlands are and should become, and call on and enroll science in their negotiations (Schut et al., 2010: 612). Although the inhabitants of wetlands have always intervened and modified these ecosystems, local stakeholder initiatives rarely become visible (Edelenbos et al., 2017).

This article focuses on temporary wetlands in the Gharb plain located in the delta of the Sebou River, Morocco’s largest river. Over the course of a century, a massive effort has been invested in land reclamation and agricultural development. The large-scale Gharb irrigation and drainage scheme now
105 extends over more than 100,000 ha plus another estimated 80,000 ha of privately irrigated land. Yet,
106 throughout the plain there remains an area of more than 30,000 ha of seasonal wetlands (Le Coz, 1964),
107 called merjas, that can be inundated from autumn to spring. Jean Célérier, author of the epigraph, would
108 certainly have recognized this part of the landscape, even though a boat was no longer needed for access
109 to the field during our study from 2021 to 2023. The starting point of our investigation was the aftermath
110 of the devastating floods of 2009-2010 that inundated more than 135,000 ha despite the numerous dams
111 upstream of the plain and an extensive drainage network. After the floods, one of the points of debate
112 was whether the merjas could serve as buffer zones to protect agricultural and urban areas, thus adding
113 yet another way of making sense of temporary wetlands.

114 Adopting a socio-hydrological approach, we seek to understand the reasons for the dichotomous
115 ontologies of merjas from the perspective of hydraulic and agricultural institutions as well as riverine
116 communities, and how these ontologies have shaped the merjas as we know them today.

## 2. Methodology

### 2.1. Description of the study site

119 The Gharb plain (Fig. 1) is located in the delta of the River Sebou in north-western Morocco. With its
120 micro relief and flat topography, the plain has the typical characteristics of delta regions. The plain has
121 a depression-like geomorphology, characterized by altitudes ranging from 4 to 40 meters and a slope of
122 less than 0.5%. The Gharb plain is marked by water flows that can occur in multiple directions and
123 stagnation of water during the rainy period or when the River Sebou overflows its banks.

124 Perhaps not surprisingly, little information is available about the merjas in the Gharb plain (Gharb means
125 land to the West) in the Sebou River Delta. At the beginning of the 20th century there were around 100
126 merjas in the Gharb plain (Le Coz, 1964) that accounted for about 60,000 ha or one-fifth of the plain
127 (Célérier, 1922: 111). Two geographical studies have been carried out in the Gharb plain that (partially)
128 concerned the merjas, at strategic moments of time. The first was conducted at the beginning of the
129 colonial project to reclaim the Gharb plain by Jean Célérier (1922), who clearly aimed to identify
130 possible "solutions to drain and reclaim these temporary wetlands". This colonial geographer considered
131 geography to be a science of action, "in the noble sense of creating wealth, transforming nature, patiently
creating landscapes that would remind one of one's country” (Naciri, 1983). The second study was conducted by Jean Le Coz (1964) during the last years of the colonial period and just after Independence to reflect on the rapid agrarian changes that had occurred during colonial times. In plans for the large-scale Sebou project, which would lead to the development of the large-scale Gharb irrigation scheme, he made a plea for a comprehensive overhaul of the dual agrarian structures, favoring the social emancipation of Moroccan peasantries (Le Coz, 1968).

In this paper, we focus on the central merjas located in the middle of the plain on the left bank of the River Sebou. The three central merjas are named (from east to west, in the general direction of the flow): Merja Jouad-Tidjina, Merja Kebira and Merja Sidi Ameur (Fig. 1). These merjas have an ambiguous status, as for many decades, they have been considered as lands to be reclaimed, but in practical terms, their reclamation is considered too difficult and costly. At the same time, riverine communities use the merjas for agriculture and grazing if they are connected to the drainage system. We also investigated Merja Bokka, an officially recognized protected natural area (Fig. 1). The extent of surface water in the central merjas varies seasonally from inundated to dry (Choukrani et al., 2023), making their dynamics difficult to manage and inviting different interpretations of the landscape where the borders between land and water are fluid and at times imperceptible. Together, they cover an area of about 20,000 ha, although clearly demarcating them is challenging. First, due to the only minute differences in altitude, major floods are never limited to the areas designated as merjas. Second, the different actors have different views of what and where merjas are, as we show in this paper. Several villages are located around these merjas, although there are no houses inside the merjas due to the risk of flooding, and the village inhabitants currently use the land for rainfed agriculture and pastoralism, taking advantage of the water retained in the soils.

The central merjas (Fig. 1) have a flat topography and geomorphology. They form a bowl-shaped receptacle for water inflows from different tributaries including Oueds Beht and Rdom, and other secondary affluents (Le Coz, 1964). Based on the reports to which we had access, it can be inferred that the floods in the Gharb plain are not torrential. Rather, they are likely caused by the gradual overflow of water from the Sebou and Beht rivers in areas where the river's flow capacity decreases. This type of flooding, where water gradually spreads to merjas through the force of gravity, is known as plain
flooding (FAO & MAPM, 2010). Additionally, the tributaries in this area are not regulated by dams,

and thus themselves also present a risk of overflowing water.
<figure><img src="image_2.png" /></figure>

162

163 **Fig. 1** Study site: Central merjas in the Gharb plain: (a) General overview, (b) Sebou watershed, (c) Gharb plain. (Geographic Coordinate System: WGS1984,

164 Decimal Degrees).
The bowl-shaped topography of the Gharb plain makes it difficult for the River Sebou to naturally evacuate the large volumes of water that originate from its 40 000 km² watershed. The raised riverbed of the Sebou river (caused by post-floods) created a topographic barrier near the estuary (Le Coz, 1964). The amount of rainfall in the Sebou watershed is significantly higher than the national average. The Sebou River Basin Agency (ABHS) reports that the watershed accounts for almost a third of Morocco's surface water (ABHS, 2019), making these water resources particularly important. As shown in Fig. 2, the seasonal distribution of rainfall in the Gharb is characterized by a relatively wet winter - 435.6mm from October to April (averaged from 1980 to 2019) and a dry summer - 40.6mm from May to September (averaged over the same period). This explains the description used by Le Coz (1964) to refer to the Gharb: lowlands in a semi-arid zone.

<figure><img src="image_3.png" /><figcaption>Fig. 2 Ombrothermal diagram of the Gharb plain (1980-2019).</figcaption></figure>

## 2.2. Field Surveys and focus groups

We used the following approach. First, we questioned the ontology that represents merjas as buffer zones, we cross-checked and compared the results of interviews with agents from the State water department with the results of our interviews with local communities. We also compared these results with the results of a hydrological analysis enabled by remote sensing. Second, we analyzed the agriculture of the merjas, triangulated quantitative data (remote sensing) with field surveys conducted

175

176

177

178

179

180

181

182
183

to examine access to irrigation water. We compared the results of our field surveys with data collected in focus groups when the participants were talking about the complexity of merjas land tenure and its impact on the agricultural development of the merjas.

184

185

186

To analyze the interplay between ontologies, we conducted semi-structured interviews with local communities, and six focus group discussions (four in merja Sidi Ameur, two in merja Kebira) (Fig. 3).

187

188

The interviewees belonged to diverse communities with diverse experience of merjas. We also conducted two semi-structured interviews with engineers from the State water department (Ministry of Equipment and Water), three semi-structured interviews with employees of the Ministry of Interior and with three employees from the Regional Office of Agricultural Development of Gharb (ORMVAG), between February 2021 and April 2023. The questions concerned agricultural practices, access to irrigation water, flood protection mechanisms, and strategies used to cope with floods and drought events. The aim of the interviews with ORMVAG employees was to understand State orientations concerning agriculture. The interviews with the agents of the Ministry of the Interior informed us about the land tenure of merjas. In addition to qualitative data (field surveys), we used secondary data from study reports and from the literature.

189

190

191

192

193

194

195

196

197

<figure><img src="image_4.png" /></figure>

198

199

<caption>Fig. 3 A focus group with members of a local community.</caption>

200

## 2.3. Satellite data processing

201

To understand the hydrological dynamics of the study area, we mainly used satellite images. Google Earth Engine (GEE) is a cloud computing platform "accessed and controlled through a web-accessible

202
application programming interface (API) and a web-based interactive development environment (IDE) that enables rapid prototyping and visualization of results” (Gorelick et al., 2017). All data processing was done in GEE Code Editor (https://code.earthengine.google.com/).

We calculated the water index MNDWI (Xu, 2006) to analyze the water dynamics of the merjas in wet and dry seasons and to monitor the dynamics that govern the presence of water (Yang et al., 2020). We also calculated the NDVI, which is used to distinguish vegetated from non-vegetated areas (Tuxen et al., 2008). The NDVI has already been used to identify irrigated areas in the Gharb plain (Lamhamedi et al., 2017).

$$MNDWI = \frac{Green-SWIR}{Green+SWIR}$$

$$NDVI = \frac{NIR-Red}{NIR+Red}$$

Using the maximum value of MNDWI of each pixel during the period of availability of Sentinel2 images (from 2018 to 2022) after excluding the years with extreme floods (1995-1996, 2009-2010), we delineated different types of waterbodies: permanent waterbodies (the River Sebou, dam reservoirs) and seasonal waterbodies (temporary flooded wetlands, paddy fields). We then calculated the spatial mean MNDWI and NDVI for each feature for each available date to produce time series. We also calculated the MNDWI value of the wet period (between October and April) averaged over different sections along the River Sebou for each year between 1984 and 2011.

We computed the Palmer Drought Severity Index (PDSI) (Palmer, 1965) for the Gharb plain and the Sebou watershed, using the GEE platform (Fig. 4). The PDSI considers other parameters like precipitation, temperature, and soil moisture.

We relied on CHIRPS (Climate Hazards Group InfraRed Precipitation with Station data) for data on precipitation, which can be accessed through the GEE platform.

# 3. Results and discussion

## 3.1. Different ontologies of merjas, different enactments

The presence/absence of water in the merjas lies at the heart of contrasting viewpoints and a dichotomy of ontologies related to a complex land and waterscape. Interestingly, the merjas of the Gharb have
229

followed very distinct trajectories, influenced, as we will argue, by the dichotomous ontologies that concern them.

230

231

First, over the past century, most of the merjas have been progressively incorporated in the large-scale Gharb irrigation scheme. At the beginning of the 20th century, the European settlers, in a close alliance with the colonial administration, assumed that, as semi-aquatic areas, merjas needed to be drained for agricultural purposes. Water in merjas was perceived as a natural disaster, and an obstacle for irrigation and modern agriculture. This "drain and develop" ontology underlines a binarization of water and land, as merjas were deemed valuable when drained of water. However, drainage alone was insufficient and was accompanied by the construction of dams, both for flood protection in winter and to provide irrigation water in spring and summer (Célérier & Charton, 1925). The Kansera dam (Fig. 1) was completed in 1935, enabling the development of the Beht irrigation scheme, intended by colonial settlers for citrus orchards (Swearingen, 1987). After Independence, over a period of 35 years (1972-2005), the Gharb irrigation scheme was progressively extended to 114,000 ha, including 12,000 ha of merjas. These merjas can still be identified indirectly because they were dedicated to rice production, considered particularly adapted to such low-lying areas. The remaining merjas, including the central merjas, are, even today, on stand-by, waiting to-be-reclaimed. On the one hand, they are part of the projected 250,000 ha Gharb irrigation scheme, constituting a land reserve for further State-led reclamation and the further development of irrigation schemes. On the other hand, feasibility studies have revealed the difficulties (topography, heavy clayey and hydromorphic soils) and the cost of land development in these low-lying areas (Choukrani et al., 2023).

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

Second, three merjas were dedicated to nature. Merja Zerga and merja Sidi Boughaba are permanent coastal wetlands (7,300 ha and 650 ha, respectively) which are protected and recognized by the international Ramsar convention since 1980. The third one, Merja Bokka (about 1,600 ha), is a national protected area – one of the 160 Sites of Biological and Ecological Interest (SIBE) in Morocco. According to official documents, since the 1980s it is no longer a permanent but rather a temporary wetland, under water from six to eight months a year. The fact that the idea of biodiversity was confined to a restricted area perhaps explains the absence of ecological studies and the lack of interest on the part

250

251

252

253

254

255
of environmental associations in any of the other merjas in the area, including the central merjas, except for the peri-urban merja Fouarat (Choukrani et al., 2023).

Third, a more conjunctural existence of merjas, generally after big floods, such as the recent 2009/2010 ones, is related to their supposed capacity to mitigate floods as buffer zones. We elaborate on this in the following section as the starting point of our investigation. The floods that occurred in 1996 and 2009-2010 served as a reminder of the limits of the current civil engineering infrastructure with nature reclaiming the upper hand. The floods that invaded the merjas and surrounding areas required the evacuation of many thousands of people and resulted in massive crop losses on agricultural lands (FAO & MAPM, 2010; MHUPV-IRHUPV, 2013). This prompted a contrasted debate on what to do next. The River Basin Agency and the agricultural services urged the creation of flood protection infrastructure, for example the construction of dams upstream of the Gharb plain, while pinpointing merjas as low areas that could serve as buffer zones when floods occur.

By contrast, local communities no longer consider the central merjas as wetlands but rather as agricultural lands that could be cultivated in most years if the drainage system is improved, and irrigation water provided. During our interviews, local communities stated that they even consider settling in the merjas and not only on the (higher) banks of neighboring rivers. The communities believe that they are protected by the dams built upstream of the Gharb plain. However, as demonstrated by Di Baldassarre et al. (2015), such measures can have unforeseen consequences because they reduce social preparedness.

**Table 1** summarizes the contrasted ways of making sense of merjas by different actors, linked to the spatial and temporal scales considered by the actors.

<table><caption>**Table 1.** Spatial and temporal dimensions of merjas through actors' lenses with a focus on water.</caption><thead><tr><td>Types of actors</td><td>Spatial scale</td><td>Hydrologic time scale of action</td><td>Amplitude of the hydroclimatic event</td><td>Roles of merjas</td></tr></thead><tbody><tr><td>Farmers</td><td>Local (merja)</td><td>Daily life</td><td>Moderate with very exceptional large floods</td><td>Agricultural and cultural services</td></tr></tbody></table>
<table><tr><td>Agricultural institutions</td><td>Gharb plain</td><td>Seasonal crop cycles</td><td>Dam-regulated mean seasonal river flow and water level determines irrigation water supply (pumping stations on Sebou River)</td><td>Agricultural production only in reclaimed merjas</td></tr><tr><td>Water department</td><td>Sebou watershed</td><td>Rare event (overflow of the Sebou river and its affluents in the plain)</td><td>Regular dam releases for hydro-electricity and agricultural demand. Exceptionally high during floods.</td><td>Regulation service: partial flood protection</td></tr></table>

**Table 1** emphasizes the different societal responses to flood events. The spatial and temporal scales are key determinants of the actors' responses.

### 3.1.1. Origin of the “buffer zone” ontology: are merjas a landscape or a waterscape?

According to an engineer we interviewed in the State water department, “Merjas are buffer zones”. The engineer explained that a study had been conducted after the devastating 2009-2010 floods in which more than 135,000 ha were inundated and many thousands of people had to be evacuated. Sixty days after the floods in 2010, more than 3,000 people who had lost their houses were still living in tents and major damage to crops had occurred in irrigated areas, for example to citrus orchards and agricultural enterprises<fnref n="1" />. Sugar factories for sugarbeet and sugarcane had been closed since the floods. Considering merjas as retention areas or buffer zones was not a recent idea, as we found out by immersing ourselves in the (often grey) literature on the study area. In fact, after devastating floods in 1960 and 1963, many flood protection studies of the Gharb plain were conducted as part of the large-scale integrated Sebou development project. The studies suggested that the merjas could serve as buffer zones or retention

<footnote n="1">¹ https://lematin.ma/journal/2010/Inondations-dans-le-Gharb-et-le-Souss_180-millions-de-DH-de-pertes-pour-les-agrumes/128689.html</footnote>
basins and the "temporary storage of floodwater in low-lying areas" was mentioned as one of the possible management scenarios for flood protection (Enneking & Vierhout, 1982). However, this option was not further explored by the State at the time, and attention was focused on alternative scenarios presenting a combination of interventions such as building dams upstream of the Gharb plain and constructing a drainage network in the plain itself. A total of 10 reservoirs (and 45 small or medium-sized hill reservoirs) have been constructed since the 1920s, including Al Wahda in 1996 (Fig. 1) which is the biggest reservoir in Morocco (regulated volume of 1.74 billion m³). A drainage network with a total length of 4,500 km was built to allow irrigated agriculture in the plain.

The construction of reservoirs had a double objective. First, the stored water was to be delivered to the expanding public irrigation scheme for agricultural intensification, but also serves privately irrigated land. An institutional interviewee stated that private irrigation accounts for approximately 50% of the water from dam releases. Second, the reservoirs protect the plain from flood damage in the rainy season from October to April.

The two objectives are, of course, at times contradictory as the River Basin Agency would like to store as much water as possible for dam releases in spring and summer for irrigation, without necessarily leaving sufficient storage capacity in the reservoir. In addition, the Sebou watershed has faced a cycle of consecutive years of drought in the past 30 years, as depicted in Fig. 4. The question of flood protection was consequently no longer a top priority on policy makers' and institutional stakeholders' agendas, making it difficult for the River Basin Agency to maintain a high level of protection for the plain. The entity responsible for dam managements did not release water before the 2009/2010 floods, as they foresaw a prolonged period of drought. As a result, the heavy rainfall in 2009-2010 far surpassed the capacity of Al Wahda reservoir. Flood control was not possible due to insufficient preliminary releases. The Gharb plain was submerged, and the River Sebou formed a "flood corridor", going through, but not limited to, the central merjas, as shown in the studies of this flood conducted by the FAO under the supervision of the Ministry of Agriculture (FAO & MAPM, 2010).
<figure><img src="image_5.png" /><figcaption>**Fig. 4** Palmer Drought Severity Index (PDSI) (1958-2021) of the Gharb plain.</figcaption></figure>

### 3.1.2 Local topography, geomorphology, and soil texture determine the submersion of merjas outside major floods

The graphs in **Fig. 5** show the different responses of the merjas to Sebou watershed precipitation over the course of three hydrological years: 1995-1996, 2009-2010, and 2020-2021. These years were selected because they were the wettest years in the period from 1984 to 2021. Total rainfall between October and April in the period 1995-1996 was about 638 mm. The year 2009-2010 stands out as the wettest year during this period, with total rainfall between October and April exceeding 746 mm. But, during the same period, cumulative rainfall in the year 2020-2021 was 469 mm, lower than in the two other years.

The MNDWI peaks differ from one merja to another over the years. These results suggest that local drivers such as topography, geomorphology, and soil texture play a role in determining the submersion of merjas during different hydrological years, as shown in **Fig. 5** (b), (c), and (d).
<figure><img src="image_6.png" /><figcaption>**Fig. 5** The responses of the merjas to different hydrological years: (a) Map of the central merjas, (b) Merjas responses to rainfall in the Sebou watershed in 1995-1996 rainfall, (c) Merjas responses to rainfall in the Sebou watershed rainfall in 2009-2010, (d) Merjas responses to rainfall in the Sebou watershed in 2020-2021.</figcaption></figure>
For instance, the merja Bokka is deeper and more bowl-shaped than the other merjas, leading to higher water levels. Additionally, the soil texture of merja Bokka is characterized by a mix of sandy and clayey soils, while the other merjas are made of clayey soils (Le Coz, 1964). The proximity of the merjas to the river and drainage network and overflow points is another factor. We conclude that flooding of the merjas depends on local factors and only in the case of extremely severe floods, like those in 2009-2010, do all the merjas come under the influence of the hydrology of the River Sebou due to overflow. One can infer from Fig. 5 (c) that there is a spatial homogeneity of MNDWI values among the merjas observed in 2009-2010 that contrasts with the values observed in the other two years. In the study of the 2010 flood, a total of 12 overflow points were identified along the banks of the River Sebou, explaining the massive floods during this event. These results suggest, first, the importance of dams, if managed with this objective, in reducing the impacts of major floods in the Gharb plain, including in the central merjas. Second, the results also indicate the importance of local rainfall events that, depending on topography and soil texture, lead to local submersion of the merjas and have a considerable impact on cropping systems.

### 3.1.3 Unpacking the impact of the Lalla Aicha dam on the potential risk of flooding

While analyzing the institutional ontology that considers the merjas as buffer zones, we identified an additional factor that may have influenced the flooding phenomenon. Our analysis of series of droughts, along with surveys and statements made by agents of the different State institutions, led us to envisage that Lalla Aicha dam was a possible contributor to the floods.

Lalla Aicha dam, which is located at the river mouth (Fig. 1, Fig. 6) and was put into service in 1991, was built to limit the amount of saltwater that enters the River Sebou and can adversely affect agricultural production.

The Lalla Aicha dam also ensures a sufficient and stable level of water upstream to facilitate the pumping of irrigation water for agriculture in public irrigation schemes and by private farmers along the River Sebou.

The results of our analysis showed that MNDWI values increased over time in three sections upstream of the dam (Fig. 6). The sections are PS6, PS7 and PS8 located respectively 3 km, 24 km, and 50 km upstream from the Lalla Aicha dam. Other sections located farther upstream or downstream of the dam showed no significant trend.
<figure><img src="image_7.png" /><figcaption>(a)</figcaption></figure>

<figure><img src="image_8.png" /><figcaption>(b)</figcaption></figure>

<figure><img src="image_9.png" /><figcaption>(c)</figcaption></figure>

<figure><img src="image_10.png" /><figcaption>(d)</figcaption></figure>

359

360 **Fig. 6** Assessment of the flood risk associated with the Lalla Aicha Dam: (a) Location of the Sebou sections
361 PS6, PS7 and PS8, (b) MNDWI values of PS6 (p value = 0,00013) located 3 km upstream of the dam, (c)
362 MNDWI values of PS7 (p value =0,000003) located 24 km upstream of the dam, (d) MNDWI values of PS8 (p
363 value = 0,03128) located 50 km upstream of the dam. (Trend analysis using the statistical Mann-Kendall test).

364 The positive trend in the MNDWI index observed upstream of the dam cannot be attributed to precipitation, as
365 can be seen in **Fig. 4** of the PDSI which, on the contrary, indicates a tendency to drought. To explain the
366 increasing value of MNDWI, we hypothesize that silting caused the bed of the River Sebou to rise thereby
367 increasing the risk of overflow. This hypothesis is in line with the results of studies undertaken in similar
368 contexts, which considered sedimentation as a non-climatic factor that amplifies flood risk (Abbasov &
369 Mahmudov, 2009; Liu et al., 2022).

370 This hypothesis is also supported by a study undertaken after the 2010 floods showing that the beds of the Rivers
371 Sebou and Beht have a roof-like structure making them vulnerable to deposits of sediment in the main riverbed
372 during flood periods (FAO & MAPM, 2010). When floods occur, even during ‘normal’ times, the water flow
373 exceeds the capacity of the riverbed, resulting in successive overflows that deposit large amounts of sediment
374 into the major riverbed. Consequently, the main riverbed progressively rises, forcing the minor bed to also rise
and dominate the plain. Due to the raised bed height, the volumes of water that overflow in the lower plain fail to join the minor bed downstream.

However, further research on sediment transport and deposition is needed to confirm this hypothesis and advance our understanding of the factors responsible for the observed increasing trend of MNDWI in some sections of the River Sebou due to changes in the water levels and in the flow patterns of the river. It is crucial to identify and understand these factors to design effective strategies to mitigate the risks of flood events.

## 3.2 Living with water-land dynamics: adapting agriculture to the “no longer merjas” paradigm

### 3.2.1 Supplying irrigation water from paddy fields to neighboring merjas

The large-scale reclamation projects implemented in the Gharb plain over the past century occurred at the expense of the merjas, which were progressively drained and reclaimed. The central merjas have been connected to the drainage network of the plain but are not supplied with irrigation water. The riverine populations observed these changes and adapted their agricultural practices to these new realities. Today, the merjas are mainly used for rainfed agriculture in winter and spring (cereals, fodder, and sunflower) and (some) irrigated agriculture in summer (melon, tomato, corn) (Choukrani et al., 2023). While some farmers told us “We miss the floods”, others said: “Thanks to El Wahda Dam, we are protected from floods”. They thus conclude that “It is no longer a merja”. These statements lead us to conclude that the farmers in the local communities have developed coping mechanisms and no longer perceive floods as a constant threat. They see the 2009/2010 events as exceptional floods that should be measured against the 15-20 years, they have been able to cultivate with no serious problems. During our interviews, farmers explained that the inhabitants of a village refused to be relocated to another village following the 2010 floods, and in other villages, some of the inhabitants returned to their original villages once the floods had subsided, to be near their plots.

We observed how farmers adapted their agricultural practices to the hydromorphic nature of the soils even though they are now rarely submerged. Farmers explained that after heavy rains, wild grasses grow in wheat fields thereby reducing yields. Consequently, the mixture of wheat and natural vegetation is harvested and fed to livestock as a forage crop. Moreover, in wet years when it is not possible to grow cereals, farmers use the residual soil moisture to cultivate sunflower, which is considered as a spring catch-up crop. Those who do not have access to irrigation water, practice rainfed agriculture and mainly cultivate wheat, barley, Alexandria clover, alfalfa, and sugar beet in winter (Choukrani et al., 2023).
The drop in NDVI values in winter in some years and in specific locations in the merjas, (represented by the green dot in **Fig. 7**), is an indicator of waterlogging of soils and explains why the vegetation is entirely covered by water. This was confirmed by our field observations in January 2021 where the sugar beet was under water following heavy rainfall (**Fig. 8**). The high value of MNDWI on the same date is represented by the red dot on the graph (**Fig. 7**).

<figure><img src="image_11.png" /></figure>

408

409

**Fig. 7** Water drained from paddy fields is used to irrigate neighboring plots in merja Kebira: NDVI and MNDWI graphs of some of the merja Kebira irrigated plots.

410

<figure><img src="image_12.png" /></figure>

411

412 **Fig. 8.** Partially flooded plot of sugar beet in merja Kebira (photo taken in January 2021).

413

414

415

A minority of farmers grow irrigated crops including melon, tomatoes, artichokes, and corn in summer. However, access to irrigation water is complicated. First, the merjas are not considered to be part of the public irrigation scheme and are consequently not supplied with irrigation water. Second, the phreatic aquifer is very
416 salty (up to 1.85 g/l)(El Mahmoudi et al., 2018), which is a constraint for agricultural intensification. Some
417 farmers have been able to drill (costly) boreholes to depths of between 60 and 100m to access the deeper and
418 less saline aquifer.

419 MNDWI (water index) and NDVI (vegetation index) were plotted for merja Kebira paddy fields which are not
420 part of the irrigation scheme (in green) (Fig. 1, Fig. 7). The graphs reveal peaks in MNDWI and NDVI during
421 summer (from July to September) that cannot be attributed to irrigation from boreholes or wells since there are
422 none in either area. In fact, the plots in the merjas located close to paddy fields (equipped by the State) in the
423 public irrigation scheme (Fig. 1), use their drainage water for irrigation. However, the paddy fields and the areas
424 of Merja Kebira are not irrigated systematically every summer. In drought years, no water is available to irrigate
425 the paddy fields, which in turn impacts the water supply to the areas neighboring merja Kebira. This information
426 was confirmed by the farmers during our field surveys, who want more reliable access to irrigation.

427

**3.2.2 Land tenure of Merjas: land of our children or land to develop?**

428 Land tenure of temporary wetlands is notoriously complex and de jure rights of states keen to appropriate and
429 reclaim wetlands often conflict with the de facto rights of riverine communities (Nguyen et al., 2017). The
430 merjas in the Gharb are no exception, because of the original intention to drain and develop these merjas. Before
431 the 20th century, merjas were used collectively by tribes, mainly for pastoralism. Merjas were declared to belong
432 to the State's Public Domain through the decree of November 8, 1919, thereby ignoring pre-existing land use
433 by qualifying the lands of the merjas as “property without owners” (Sonnier, 1935). Such “outright legal
434 chicanery” occurred in several places in Morocco not only concerning land but also water rights, whenever the
435 colonial administration coveted these resources for agricultural development (Swearingen, 1987: 46).
436 Recovering such resources generally involved their reallocation to more deserving people, be it European settlers
437 or Moroccan peasants who could be coerced into the modern agricultural project (Kuper et al., 2023).
438
439 According to the 1919 and 1956 laws, the merjas were first incorporated in the public domain of the State so
440 that it could plan its reclamation “for public purposes and utility” according to the official decree of July 1, 1914
441 (Fig. 9). This was thus a temporary tenure status. Once the merja was being reclaimed, it was incorporated in
442 the private domain of the State (Fig. 9), after which it becomes subject to all administrative acts and disposal
443 including sale, exchange, assignment and exploitation either directly by the State or indirectly by private
444 individuals through a long lease. The private domain of the State is managed by the Ministry of Economy and
Finance. On this basis, the State bears the costs of land development and recovers two thirds of the land that is then handed over to farmers of its choice, providing them with land use titles or even property rights. After Independence, the usual criteria for accessing land in merjas, explicitly intended for agricultural purposes, included being the head of a family (and therefore, implicitly, being male), residing in the area, being a farmer, and not possessing any land in the region.

On this same basis, the riverine communities obtained one third of the land (tulut). Because the land of the central merjas of Jouad-Tidjina, Kebira and Sidi Ameur have not been reclaimed, the situation concerning their land use rights is confusing. While the tulut is fully cultivated by the riverine communities, the remaining two thirds are rented by barani (outsiders, according to the riverine population), through the Ministry of Interior, either for rainfed agriculture in winter or for irrigated agriculture in summer. At times, this is fiercely contested by the villagers, who have even blocked part of the merja Sidi Ameur (1,200 ha) for cultivation since 2003. While officially, the private domain of the State is managed by the Ministry of Economy and Finance, according to the riverine population, it is currently managed by the Ministry of Interior, which is accustomed to dealing with confusing and conflicting situations. In the case of merja Bokka, which is an important site for biodiversity it remains part of the public domain of the State and farming is officially banned.

<figure><img src="image_13.png" /><figcaption>Fig. 9 Changes in merjas land tenure.</figcaption></figure>

According to the members of the communities we interviewed, after many years of hidden conflict in the Gharb plain, located at “the gates of Rabat” (Bouderbala, 1999), in 2003, open conflict emerged between the State and the riverine communities in the merja Sidi Ameur. The communities claimed access to the lands in the merja that were being exploited by outsiders (barrani), that is, on the two thirds of land taken by the State. The interviewees stated that the land rights they inherited from their ancestors were not recognized by the official
institutions. They insisted that the land in merja Sidi Ameur should be given to the local communities, particularly to the younger generation to develop the area, as there was not sufficient land for them.

These two contradictory points of view concerning land tenure in the merja Sidi Ameur led to the exclusion of outsiders from 1,200 ha of land by the communities. However, the land was not given to the communities for agricultural use. Each land tenure regime thus neutralised the other, which affected the agricultural development of the western part of the merja Sidi Ameur (represented by the red graph in **Fig. 10**). Instead, the local communities use the land for grazing, thus returning the land to its original use.

**Fig. 10** shows a NDVI graph of three merjas: merja Kebira, merja Bokka, and the conflictual area of merja Sidi Ameur (**Fig. 1**). Merja Kebira belongs to the private domain of the State. Merja Bokka belongs to the public domain of the State. The fought-over area of merja Sidi Ameur belongs to the private domain of the State but cannot be cultivated because of the above-mentioned conflict, and the area is now used as pasture for livestock.

<figure><img src="image_14.png" /><figcaption>**Fig. 10** Impact of land tenure on the agricultural development of merjas.</figcaption></figure>

**Fig. 10** shows the difference in the NDVI during irrigation period between the three above-mentioned merjas. There was an increase in the vegetation index in the merja Kebira during the irrigation season, because there was no land-tenure conflict. The NDVI did not increase in the fought-over part of the merja Sidi Ameur or in the merja Bokka where cultivation is not allowed by the State since it belongs to the public domain.
Local communities prioritize access to water and land for agriculture, while acknowledging the need to solve land tenure conflicts. They are accustomed to rare flooding events and do not perceive them as a serious risk. According to these communities, youth unemployment is a pressing issue that can be addressed by granting access to the fought-over area, which the communities perceive as an inherited right. The interviewees expressed concerns about the merja, which is a hot spot of tension due to land tenure insecurity. These riverine communities, who have learned to live with land-water dynamics in 'their' hydro-social territory (Boelens et al., 2016), now also claim part of the reclaimed land for their own children.

In a context of land tenure insecurity, interviewees in local communities frequently and spontaneously provided proof of their “right” to the merjas. For example, the land representative of one of the riverine communities referred to written proof of access to the merja Sidi Ameur dating back to the 19th century. The former laborers on colonial farms who obtained land in the merjas from the State (out of the two thirds recovered by the State) considered the receipts for the yearly payment they used to make to the State’s domain delegation, as proof of their ownership of the merja (Fig. 11). However, this payment stopped in the 1990s. When the communities approached the domain delegation to inquire about their situation, the State’s domain delegation denied such yearly rents, leaving them in a state of uncertainty and without a clear resolution.

<figure><img src="image_15.png" /><figcaption>Fig. 11 Receipt for annual community payment to the State domain delegation.</figcaption></figure>

## 4. Conclusion

This paper has shown how the different perceptions of what temporary wetlands (merjas) are – hotspots of biodiversity, lands to-be-reclaimed, buffer zones, or the land of our children – have produced at least three
different enactments in the Moroccan Gharb plain: a ‘State’ enactment that ‘drained and developed’ the land to
then re-distribute it to outsiders and former workers on colonial farms; a ‘local’ enactment by riverine people
who have learned to live with land-water dynamics and now also claim part of the reclaimed land as ‘their’
hydrosocial territory, for their own children; and limited natural reserves for biodiversity and migratory birds.

The fourth, a more conjunctural enactment of merjas as buffer zones did not gain much traction among actors,
but merjas will surely continue to play that role during major floods in the future. By combining hydrological
analyses to understand the complex water flows, and ethnographic observations to understand current ways of
practicing agriculture in these temporary wetlands, and using a sociohydrology analytical framework, we
questioned the ontologies concerning temporary wetlands. We showed how each of them is connected to
different networks of people, funds, political support, and result in different enactments that sometimes co-exist
and sometimes clash. Co-creating a conducive environment for negotiation remains challenging due to the
dynamic water flows and the existence of diverse ontologies. Creating a space where the voices of the people of
the merjas (*nas dial merja*) can be heard in negotiations concerning their still uncertain future is a priority, given
their essential role and experience in living and working in these spaces and their aim to enact their own version
of the merja.
518 References

519 Abbasov, R. K., & Mahmudov, R. N. (2009). Analysis of non climatic origins of floods in the downstream part of the Kura River, Azerbaijan. *Natural Hazards*, 50(2), 235–248. https://doi.org/10.1007/s11069-008-9335-2

522 Agence du Bassin Hydraulique du Sebou. (2019). *Plan Directeur d'Aménagement Intégré des Ressources en Eau du Bassin de Sebou*.

524 Biggs, D. (2010). *Quagmire: Nation-Building and Nature in the Mekong Delta*. University of Washington Press.

526 Boelens, R., Hoogesteger, J., Swyngedouw, E., Vos, J., & Wester, P. (2016). Hydrosocial territories: a political ecology perspective. *Water International*, 41(1), 1–14.
https://doi.org/10.1080/02508060.2016.1134898

529 Bouderbala, N. (1999). L'état et la modernisation des terres collectives. *Options Méditerranéennes. Série A: Séminaires Méditerranéens (CIHEAM)*, 38, 339–344.

531 Bullock, A., & Acreman, M. (2003). The role of wetlands in the hydrological cycle. *Hydrology and Earth System Sciences*, 7(3), 358–389.

533 Carney, J. (1993). Converting the Wetlands, Engendering the Environment: The Intersection of Gender with Agrarian Change in the Gambia. *Economic Geography*, 69(4), 329–348.

535 Célérier, J. (1922). Les merjas de la plaine du Sebou. *Hesperis*, 2, 109–138.

536 Célérier, J., & Charton, A. (1925). Les grands travaux d'hydraulique au Maroc. *Annales de Géographie*, 34(187), 76–80. https://www.jstor.org/stable/23440963

538 Choukrani, H., Kuper, M., Hammani, A., Lacombe, G., & Taky, A. (2023). Visions contrastées des services écosystémiques des zones humides saisonnières du Gharb, Maroc. *Cahiers Agricultures*, 32, 2.
https://doi.org/10.1051/cagri/2022031
541 Cooper, C. M., & Moore, M. T. (2003). *Wetlands and Agriculture* (pp. 221–235). M. M. Holland, E. R. Blood,
542 and L. R. Shaffer, editors.

543 Cortesi, L. (2018). The muddy semiotics of mud. *Journal of Political Ecology*, 25(1), 617–637.
544 https://doi.org/https://doi.org/10.2458/v25i1.22945

545 Cortesi, L. (2021). An ontology of water and land in North Bihar, India. *Journal of the Royal Anthropological
546 Institute*, 27(4), 870–889. https://doi.org/10.1111/1467-9655.13611

547 Cortesi, L. (2022). Hydrotopias and waterland. *Geoforum*, 131, 215–222.
548 https://doi.org/10.1016/j.geoforum.2021.11.014

549 Di Baldassarre, G., Viglione, A., Carr, G., Kuil, L., Yan, K., Brandimarte, L., & Blöschl, G. (2015). Debates -
550 Perspectives on socio-hydrology: Capturing feedbacks between physical and social processes. In *Water
551 Resources Research* (Vol. 51, Issue 6, pp. 4770–4781). Blackwell Publishing Ltd.
552 https://doi.org/10.1002/2014WR016416

553 D’Souza, R. I. (2011). Making Modern Flows: The Great Hydraulic Transition in South Asia. *125th Annual
554 Meeting American Historical Association*. https://www.researchgate.net/publication/267534945

555 Edelenbos, J., Van Buuren, A., Roth, D., & Winnubst, M. (2017). Stakeholder initiatives in flood risk
556 management: exploring the role and impact of bottom-up initiatives in three ‘Room for the River’
557 projects in the Netherlands. *Journal of Environmental Planning and Management*, 60(1), 47–66.
558 https://doi.org/10.1080/09640568.2016.1140025

559 El Mahmoudi, N., El Wartiti, M., Azelmad, R., Sadki, R., & Berred, S. (2018). Spatial Imaging of the Water
560 Resource and Natural Environment Coastal Gharb Basin: Downstream Part of the Hydraulic Basin of the
561 Sebou River (Morocco). *Sustainable Civil Infrastructures*, 169–175. https://doi.org/10.1007/978-3-319-61612-4_13

563 Enneking, J. J. L. M., & Vierhout, M. M. (1982). Design and construction of flood control dykes around
564 43,000 ha of irrigation areas in the Rharb plain, Morocco." . *Polders of the World*, 241–253.
565 https://library.wur.nl/WebQuery/wurpubs/fulltext/380812#page=251
566 FAO, & MAPM. (2010). *Plan d'action d'urgence pour le drainage et l'assainissement de la plaine du Gharb*.

567 Gorelick, N., Hancher, M., Dixon, M., Ilyushchenko, S., Thau, D., & Moore, R. (2017). Google Earth Engine: Planetary-scale geospatial analysis for everyone. *Remote Sensing of Environment*, 202, 18–27.

https://doi.org/10.1016/j.rse.2017.06.031

570 Klemas, V. (2013). Remote sensing of emergent and submerged wetlands: an overview. *International Journal of Remote Sensing*, 34(18), 6286–6320. https://doi.org/10.1080/01431161.2013.800656

572 Krause, F. (2017). Towards an Amphibious Anthropology of Delta Life. *Human Ecology*, 45(3), 403–408.

https://doi.org/10.1007/s10745-017-9902-9

574 Kuper, M., Mayaux, P.-L., & Benmihoub, A. (2023). The persistent appeal of the California agricultural dream in North Africa. *Water Alternatives*, 16(1), 39–64. www.water-alternatives.org

576 Lahiri-Dutt, K., & Samanta, G. (2013). *Dancing with the River* (J. C. Scott, Ed.). Yale University Press.

577 Lamhamedi, B. E., Jnah, N., Sebari, I., & Benbahria, Z. (2017). Extraction automatique des zones irriguées dans la région du Gharb par analyse d'image basée-objets des images Landsat 8. *Revue Marocaine Des Sciences Agronomiques et Vétérinaires*, 5(2), 170–177.

https://www.agrimaroc.org/index.php/Actes_IAVH2/article/view/495

581 Le Coz, J. (1964). *Le Rharb Fellahs et Colons*.

582 Le Coz, J. (1968). The third era of Moroccan agriculture. *Annales de Géographie*, 77(422), 385–413.

https://doi.org/10.3406/geo.1968.15689

584 Liang, D., Lu, J., Chen, X., Liu, C., & Lin, J. (2020). An investigation of the hydrological influence on the distribution and transition of wetland cover in a complex lake–floodplain system using time-series remote sensing and hydrodynamic simulation. *Journal of Hydrology*, 587, 125038.

https://doi.org/10.1016/j.jhydrol.2020.125038

588 Linton, J. (2010). *What is water? the history of a modern abstraction* (UBC Press 2010).
589 Liu, H., Du, J., & Yi, Y. (2022). Reconceptualising flood risk assessment by incorporating sediment supply.
*Catena*, 217. https://doi.org/10.1016/j.catena.2022.106503

591 Merot, P., Hubert-Moy, L., Gascuel-Odoux, C., Clement, B., Durand, P., Baudry, J., & Thenail, C. (2006). A
method for improving the management of controversial wetland. *Environmental Management*, 37(2),
258–270. https://doi.org/10.1007/s00267-004-0391-4

594 MHUPV-IRHUPV. (2013). *Schema Regional D'Aménagement Du Territoire De La Région du Gharb*
595 *Chharda Beni Hssen: Options Stratégiques, espaces de projet et programmation*.

596 Millennium Ecosystem Assessment. (2005). *Ecosystems and Human Well-Being: Wetlands and Water*
597 *Synthesis*.

598 Naciri, M. (1983). L'aménagement de l'espace territorial au Maroc: lieux d'autonomie et centralisation
599 étatique. *Annuaire de l'Afrique Du Nord*, 22, 225-242.

600 Nguyen, H. H., Dargusch, P., Moss, P., & Aziz, A. A. (2017). Land-use change and socio-ecological drivers of wetland conversion in Ha Tien Plain, Mekong Delta, Vietnam. *Land Use Policy*, 64, 101–113.
601 https://doi.org/10.1016/j.landusepol.2017.02.019

603 Palmer, W. C. (1965). *Meteorological Drought* (W. C. Palmer, Ed.; Vol. 30).

604 Saha, T. K., & Pal, S. (2019). Emerging conflict between agriculture extension and physical existence of wetland in post-dam period in Atreyee River basin of Indo-Bangladesh. *Environment, Development and Sustainability*, 21(3), 1485–1505. https://doi.org/10.1007/s10668-018-0099-x

607 Schut, M., Leeuwis, C., & van Paassen, A. (2010). Room for the river: Room for research? The case of depoldering De Noordwaard, the Netherlands. *Science and Public Policy*, 37(8), 611–627.
608 https://doi.org/10.3152/030234210X12767691861173

610 Sivapalan, M., & Blöschl, G. (2015). Time scale interactions and the coevolution of humans and water. In *Water Resources Research* (Vol. 51, Issue 9, pp. 6988–7022). Blackwell Publishing Ltd.
611 https://doi.org/10.1002/2015WR017896

613 Sonnier, A. (1935). Les merjas de la plaine du Rharb. *Bulletin Économique et Social Du Maroc*, 8.
614 Swearingen, W. D. (1987). *Moroccan Mirages: Agrarian Dreams and Deceptions, 1912-1986*. Princeton University Press.

616 Tiner, R. W., Lang, M. W., & Klemas, V. V. (2015). *Remote Sensing of Wetlands: Applications and Advances*. CRC Press.

618 Tuxen, K. A., Schile, L. M., Kelly, M., & Siegel, S. W. (2008). Vegetation colonization in a restoring tidal marsh: A remote sensing approach. *Restoration Ecology*, *16*(2), 313–323. https://doi.org/10.1111/j.1526-100X.2007.00313.x

621 Verhoeven, J. T. A. (2014). Wetlands in Europe: Perspectives for restoration of a lost paradise. *Ecological Engineering*, *66*, 6–9. https://doi.org/10.1016/j.ecoleng.2013.03.006

623 Wesselink, A., Kooy, M., & Warner, J. (2017). Socio-hydrology and hydrosocial analysis: toward dialogues across disciplines. In *Wiley Interdisciplinary Reviews: Water* (Vol. 4, Issue 2). John Wiley and Sons Inc. https://doi.org/10.1002/WAT2.1196

626 Xu, H. (2006). Modification of normalised difference water index (NDWI) to enhance open water features in remotely sensed imagery. *International Journal of Remote Sensing*, *27*(14), 3025–3033. https://doi.org/10.1080/01431160600589179

629 Yang, X., Chen, Y., & Wang, J. (2020). Combined use of Sentinel-2 and Landsat 8 to monitor water surface area dynamics using Google Earth Engine. *Remote Sensing Letters*, *11*(7), 687–696. https://doi.org/10.1080/2150704X.2020.1757780