Across the world, cities are stressed for water [1
] and depend on the water resources within peri-urban areas [2
]. The sustenance of these water resources is an important concern for the welfare of the increasing urban population [3
]. Existing water management systems in peri-urban areas have to contend with changes in their contexts due to developmental pressures, significantly fuelling the conflict over the land and water resources between rural and urban areas. A significant manifestation of this conflict is the change in the land use from agricultural (rural) to nonagricultural (urban) land uses [4
]. This change in the land use from agriculture to nonagricultural land uses is an important factor as agriculture usually was the major consumer of water in most peri-urban areas and the management of water resources was organized around this requirement [3
]. The selection of the management model that can ensure the sustenance of water resources, therefore, needs to take into cognition the situational reality of these systems [5
], especially under changed conditions as encountered in peri-urban areas [7
]. The problem of selecting an appropriate management model for sustaining water resources is complicated due to the dynamic nature of changes in the peri-urban areas, as peri-urban areas tend to be a mix of urban and rural, whereas institutions and management systems tend to be organized based on rural and urban administrative boundaries [8
]. Water management in complex situations such as these needs alternative strategies. However, it is difficult to decide which of these strategies will be the most effective [9
]. Governance approaches for resource management systems that have existed over a long time have to be selected based on the context in which they are placed [10
]. Understanding the relationship between the land use change of agricultural lands to nonagricultural land uses and related changes in the water resources management is the first step in evaluating the effectiveness of a water management system and proposing an appropriate water management system.
Various forms of water management system in India had sustained the supply of water to the people since ancient times [11
]. In the state of Tamilnadu, located in the southern part of India, the most prevalent system of water management is connected to ‘Tanks’ or reservoirs. Here, tank refers to water storage reservoirs of an area of a few hundred square meters to thousands of square meters. The term tank comes from the Portuguese ‘Tanque’ or the Latin ‘Stagnum’ [12
]. The water management systems are called ‘tanks systems’ [13
] or ‘tank irrigation systems’ [16
] based on their prominent feature, the tanks. Like many traditional water management systems of India, the tank systems have also declined and their components are in damaged condition [14
The traditional tank system was a complex and interdependent system managed by the community [18
]. The basis of this interdependency was the interrelationships within the system through benefits acquired by the people related to the existence of agricultural activity, especially paddy cultivation [12
] (Figure 1
). The decline of the tank systems was attributed to various factors in the past related to the transfer from community control to state control [5
] and to the lack in their maintenance and protection by these government agencies that control these water resources [14
]. The present management of the components of this interconnected system is by multiple government agencies [22
] (Figure 2
), supported in some cases by user associations that partially control and maintain some of the components of the system. To arrest the decline, the government had enacted laws and established organizations to protect the water resources [15
]. The Tamilnadu state government law, ‘Protection of Tanks and Eviction of Encroachment Act, 2007’ (Act 8 of TN G.O.dt.22.05.2007), prohibits the conversion of common lands related to water storage, conveyance and foreshore areas for any other developmental purposes. The state government had also set up a nodal agency WRO-Water Resources Organization under the P.W.D.—Public Works Department for protection and management of water resources. Two agencies of the government play a salient role in the management of the components of the tank systems. The P.W.D.—Public Works Department is a centralized state department with finances and trained personnel to maintain the tanks and its components. This agency, however, has under its control only tanks of water storage area more than 40 acres (16 hectares). Tanks with lesser water storage area and their components come under the control of the Panchayat—the village administrative council. This agency, in general, lacks funds and do not have enough trained personnel to maintain the tanks and related components [15
]. In spite of these measures, urbanization is known to have caused damage to the tank systems [2
The technology of the water management is a function related to ‘agroclimatic and agrarian contexts’ [27
] and agriculture also plays an important role in the social dynamics of the tank systems [12
]. Mizushima (1966) [20
] and Yanagisawa (2008) [31
] traced the connection between the changes in the water management systems and the change in land ownership and administration during the colonial period and after. Studies by Janakarajan et al. (2007) [2
], Rodrigo (2004) [26
], and Datchayani et.al (2013) [32
] further explored this connection between the change in the land use in peri-urban areas and their impact on the changes in the social dynamics of water resources management. However, very few studies have analyzed the relationship between agricultural land use change and the changes in the functioning mechanisms of the tank systems. The aim of this research was to explore this relationship between change in the land use of agricultural lands to nonagricultural land uses and the change in the functioning mechanisms of the tank systems.
This research started with the proposition that change in the land use of agricultural lands to nonagricultural land uses is an important determinant in the success or failure of the water management system. To establish the role of land use change as a determinant, this research undertook two lines of enquiry:
The first line of enquiry was related to the existence of the components and interrelationships of the community management system under the context of change in agricultural land use. This line of enquiry was conducted to evaluate the possibility of reviving community management.
The second line of the enquiry was related to the current management system. This line of enquiry was conducted to evaluate the effectiveness of the current management system by the government.
4.1. Role of Land Use Change as a Determinant in the Evaluation and Selection of the Water Management System
Water management consists of the set of actions that ensure the sustenance of the water resources. The governance system that undertakes the water management collectively manages both the allocation of the resources and the possible conflicts. This governance system is generally negotiated by social institutions in traditional water management systems [10
]. Therefore, the question of the appropriate management system has been primarily addressed as a factor of social relations in previous literature, especially the dynamics of the social relations as a result of changes such as urbanization [2
]. The sustenance of the water resources was also addressed as a factor of maintenance activities in previous literature [13
]. The role of land use change in affecting both these aspects however had not been previously addressed. In peri-urban areas consisting of a mosaic of both urban and rural land uses [8
], the extent and intensity of land use change is an important factor to be considered for management of water resources. The results of this study had indicated that the intensity and extent of land use change are closely related to the changes in the functioning mechanisms of the water management systems. This results from this research indicate that land use change of agricultural lands can be thus be an important determinant to analyze the appropriateness of the existing water management systems.
This research acknowledges that factors, such as demography, policies of the government, market factors, among others, influence land use change and are influenced by land use change and these factors also can influence the water management systems, however they have not been dealt with in this paper as they were beyond the scope of this paper. Further research on the relationship between these factors, land use change and the changes in the water management systems will be of help to evolve more efficient management actions for the sustenance of water resources.
Previous literature on the relationship between land use change and water resources have been with reference to the groundwater depth and quality [39
], water quality in terms of pollution [46
], and water quantity due to overextraction [47
]. These studies have used remotely sensed data at a large regional scale. The methods used in these studies are not best suited to analyze small variations within a village level that create changes within the functioning mechanisms of local water management systems such as the tank systems. The method used in this research for integration of spatial data and the administrative data sources, such as land use records as well as the data about the actual status of the system through survey and structured interviews, can be applied to other studies of similar scale and complexity. The method used in this research will be of use also to other researchers working with the integration of cadastral and small-scale data into thematic land use maps for analysis. Integration of different types of data has been known to impart clear social understandings and solutions that can provide valuable insights for policy, governance, and management actions [10
]. Analysis of spatial patterns over time with the help of GIS [48
], in this research, had led to the isolation of events that caused the change in the water management systems. The spatial analysis combining land use maps and data from the survey had imparted clear understanding of the underlying spatial aspects of the land use change. Thus, the method used in this research had primarily enabled the understanding of the functioning mechanisms of the system and the changes in them. The advantage of this method is that it proposes a way through which land use change data can be combined with the data on the status of the system at a micro-level that can provide valuable insights for the decision regarding management policy and actions.
4.2. With Change in the Agricultural Land Use the Functioning Mechanisms of both Community Management and State Control are Ineffective
The break up in the functioning mechanisms of the tank systems was less in case 2 and high in case 1. In case 2, there were only a few instances of common land conversions, and the components of the community management had also not sustained notable damage. There was the presence of a nominal social institution in the form of tank user association, dependence on small tanks for drinking water and other purposes in this case 2. In this case, the conversion of agricultural lands in terms of the area was higher than in case 1, but the conversion was less intensive. The agricultural lands had been only converted to vacant plots which have not been developed. In case 1, with a higher intensity of change in the land use of agricultural lands, there were significant instances of common land conversions. The components of the community management had sustained significant damage too in this case. The secondary activities that had helped in the maintenance of the system in the form of product extraction had been abandoned and do not exist. Social institutions are absent and there is no dependence on tanks for drinking water. Even though a few of the tanks were being used for recreational purposes, this had not led to any social initiative to protect the tanks.
The findings of this research support the argument proposed by Wade [5
] and Shah [27
]: that need for water and the benefits attained from the system are the basis of the community controlling mechanisms. When there is no need for water from tanks and there is no interest in the extraction of benefits or if the extraction of benefits is denied, the people are no longer interested in protecting the system, making the system vulnerable to exploitation and damage. The conversion of agricultural lands to other land uses is thus a significant factor in the survival of the system, as it controls both the need for the water and the benefits from the system [19
]. The state protection through legislation that should have replaced the community protection is hampered by weak enforcement in the cases studied, resulting in the illegal conversion of common land required for the water management to other land uses. Similar issues related to weak state control have been reported by others [20
]. However, this research has brought attention to the fact that land use change plays a significant role in the breaking up of the linkages within the system that supported community management by exploiting the weak enforcement of the legislation by the state.
Even though the ownership and control of the tanks and related areas were with the government, whether the community is still dependent on the resources in terms of acquiring benefits from the components was analysed to evaluate the probability of restoring community control. The analysis of the components of the tank systems in terms of the presence of institutions and usage of the tanks in both cases had shown that change in the agricultural land use is strongly related to the breaking up of linkages within the system that had protected the system. In Case 1, with intensive land use change of agricultural lands, there is no presence of social institutions and there is no dependency on the water resources, and this is reflected in the poor status of the water storage, conveyance, and protective structures. In case 2, the status of the water resources is in better condition. The reasons for this are less intensive change in the agricultural land use, the presence of paddy cultivation, the existence of a nominal user association, high dependence on the tanks for water, and extraction of products aiding the maintenance of the tanks. As the need for the water and the benefits to people in terms of products extracted are both connected with agriculture, the change in the land use effectively removes the balance that had ensured the sustenance of the tank systems. The role of some of the tanks had changed to open spaces for recreation. Though it could be argued that this connection with the people can create a new balance of need and costs, it has not led to the formation of any community associations in the study area. Thus, it can be concluded that with an intense change in the agricultural land use, the likelihood of reviving the community management model of the tank systems becomes improbable.
In case 2, with less intensive change in agricultural land use, the illegal land use conversion of common lands was lower in number, leading to the interpretation that the protection afforded by the state through legislation had prohibited the conversion especially in water storage and conveyance areas. Such an argument is further supported by the fact that the conversion had happened predominantly in the common grazing land under the category protective areas in case 2, which are not specifically protected by the law. However, when the intensity of the change in agricultural land use was higher, as in case 1, this protection had not prevented the conversion of common lands in all three categories. In addition, the trajectories of change (see Figure 8
and Figure 9
) in case 1 clearly showed that the change in water resources was preceded by or concurrent to the changes in the agricultural land to other land uses that surround them, especially the conversion of agricultural land from paddy cultivation. Another salient aspect is that in the cases studied, the tanks and their components come under two agencies and two different maintenance protocols. The tanks that come under the P.W.D (Public Works Department) with a more active role in maintenance are in better condition than those that come under the panchayat, which has fewer resources to maintain the tanks. Therefore, it is clear that an agency which has an active role in the maintenance of the tanks is required to protect them.
This research had shown that in peri-urban areas with significant land use change, both the traditional model of management and the current management model of the government are ineffective. However, to an extent, the water resources under P.W.D, as the government agency, are in a relatively better condition. The condition of the tanks under P.W.D also cannot be sustained in the long term as the tanks are linked and even though the tanks under P.W.D are free from encroachment, they are affected by the changes in the tanks under panchayat, which act as the feeders for the larger tanks. Therefore, it is proposed that for the sustenance of water resources in peri-urban areas, active involvement of the government is required for all the tanks, channels, and protective areas of the tank system. The agencies that have ownership and control need to be present and engaged in the maintenance of water resources. These agencies require financial and administrative resources to implement measures that can protect and maintain water resources.