**2.2 Social aspect of irrigation schemes sustainability**

Naturally, human beings have inherent needs that they are aiming to satisfy. These needs describe in-born requirements that need to be satisfied for an individual to remain healthy – physically, emotionally and mentally [29]. The management of open-access resources such as irrigation water involved numerous stakeholders with diverse interests which posed a unique challenge to the managers. These interests are the factors that affect individuals' ethical practices including propensity to compliant or unlawful activities. Ethical awareness is the ability of an individual to identify his deliberate action and understand what consequences that action might cause to others. Thus, for an individual to make an ethically accepted action depends on a person's moral awareness, motives and the benefits that individual is expected to gain. This depends largely on value-related factors such as culture, knowledge, religious beliefs, public trust and social wellbeing [30]. One of the problems that devastate irrigation water users' social wellbeing is water scarcity which leads to poor crop production. Water scarcity represents a multidimensional state of human social deprivation characterized by a lack of access to affordable and safe water to satisfy societal needs or a condition in which these needs are met at the expense of the environment [10]. The mission for sustainable natural resource utilization is an essential part of the ongoing 2030 agenda for sustainable development goals (SDGs). It is one of the 169 agreed targets being aimed at monitoring and assessing the level of sustainability with which resources, such as irrigation water are being managed and utilized [31].

This creates a challenge of ensuring societal wellbeing through the supply of human basic needs including food security, income to the rural dwellers and national GDP of which water (through irrigation) plays an essential role [32, 33]. Thus, irrigation contributed immensely to the provision of a wide range of socio-economic benefits on which the wellbeing of society is based [34]. However, irrigation water is subjected to several challenges including climate change, poor management, chemical, wastage, overexploitation and other human-related influences [35–38].

The social setting can be a social group, a community, town, region or a nation, thus, any change that occur either as ideas, norms, values, roles and social habits can be referred to as social change. When alteration occurs in the rural social system, it is termed as rural social change, and such a change could be in all attributes of a societal unit such as number, quality and importance. Different changes come to the notice of the rural population of the developing countries, including Nigeria. For example, the introduction of large scale irrigation projects, use of the machine in farming practices, application of agrochemicals to control weeds, pests, diseases and increase and sustain the fertility of the soil lead to the transformation of sustainable agriculture and hence, the wellbeing of that society [20]. The attainment of a sustainable agricultural production system is becoming a major concern of agricultural researchers and policymakers all over the world [39]. Implementation of sustainable development, therefore, requires integrated policy, planning and social learning process. Irrigation practices provide employment and stabilization to the rural population and undoubtedly provide major social benefits. A typical example is how the Kano River Irrigation Project (KRIP) played an important role in limiting rural–urban migration by creating jobs for the rural dwellers [20].

#### **2.3 Environmental aspect of irrigation schemes sustainability**

Environmental impact refers to any change in the environment or in its components that may affect human health, flora, fauna, natural and cultural heritage as well as other physical structures, social, economic or cultural conditions [40]. For example, the challenges facing the irrigation sector in Nigeria is not only to attain food security and eradicate poverty among rural dwellers but also to ensure a healthy environment. Inappropriate management of irrigation schemes might lead to environmental problems such as high water tables, poor drainage, salinization and pollution [13]. The majority of irrigation schemes in northern Nigeria are characterized by environmental degradation such as salinity, waterlogging and declining groundwater resources which could adversely affect future demand for water [41]. Both quantity and quality aspects of water are important as these jointly affect the success of irrigation schemes and environmental sustainability [42]. Thus, in the process to establish any socio-economic projects such as irrigation schemes, there is a need to ensure longterm maintenance of valued environmental resources in an evolving human influence [43]. Studies revealed that the majority of the economic development of the developing countries often occur at the expense of overexploitation of water resources which ultimately leads to ecosystem degradation [19].

Even though the extent is different, several environmental-related problems including soil erosion, aquatic weeds infestation, sedimentation, infrastructural deterioration and overgrazing are observed in many irrigation schemes in Nigeria [43]. For example, despite the functioning of the Kano River Irrigation Project (KRIP), there was a serious decline in hectares of land due to environmental-related issues such as waterlogging, salt accumulation (salinity, sodicity, saline-sodic) and reduced fertility [20]. There is a gradually building up of salinity problems in KRIP, even though the threat from salinity is not alarming yet. This problem of salinity has been reportedly alleged to continue to increase as long as irrigation is practiced unless preventive and corrective measures are put in place [44]. Generally, irrigation schemes design, operation and management should seek to maximize not only crop productivity and economic and social gains but also to ensure environmental stability and health as shown on **Figure 2** [46]. Thus, irrigation scheme designs should consider using new technologies that ensure water allocation and application efficiencies such as micro irrigation methods (sprinklers and drip). In addition, in situ soil and water conservation methods such as mulch practices and deficit irrigation can significantly improve the overall ecosystem health.

#### **2.4 Technological aspect of irrigation schemes sustainability**

The development and improvement achieved so far in irrigation technologies are key to addressing the challenges of low agricultural productivity [47]. Availability and access to irrigation water and smart agricultural technologies were considered essential for crop production [48]. For instance, the success of the green revolution in Asia was achieved through the rapid expansion of irrigation areas with availability and access to new technologies including the development of high yielding varieties, fertilizers, micro irrigation techniques, tube-wells and water extraction mechanisms [49]. For example, technological advance provides irrigation sector
