Agent-based modeling for water resources allocation in an irrigation district of Red River Basin, VietNam
10:53 - 15/03/2018
Water is a common resource shared by many stakeholders, thus planning and managing water resources can present unique challenges beyond those of other engineering design problems. The management of water is therefore a highly complex social-value problem that lacks a definitive formulation and solutions to such problems are difficult to judge objectively. Decisions about the allocation of water typically affect a large group of stakeholders, a
Agent based modeling concept
Water is a common resource shared by many stakeholders, thus planning and managing water resources can present unique challenges beyond those of other engineering design problems. The management of water is therefore a highly complex social-value problem that lacks a definitive formulation and solutions to such problems are difficult to judge objectively. Decisions about the allocation of water typically affect a large group of stakeholders, and compromise solutions based on a simple understanding of stakeholder values and behaviors may not be satisfactory when implemented. Normally, water systems may be characterized as a complex system, where interactions among stakeholder’s behaviors lead to unexpected system performance. Stakeholders may resist or support changed policy, exchange with other stakeholders about water use, and make technological or behavioral changes to update their water use. Feedback in infrastructure and natural systems occurs as consumers adjust resource use in response to new regulation, policy from operators and other consumers will affect the availability of resources.
Water systems that involve the interaction of stakeholders, the management strategy, the technological capacity of the system will ultimately give rise to a complex problem whether the objective target is equitable distribution of resources, efficient use of water or simple economic value of water. In most of the cases, the problem often arises from the complex interaction of stakeholders that drive the management strategy and technological capacity. It can be seen as a bottom up system design where the interaction of the stakeholders will inform the decision maker of an efficient or effective management scheme. Agent-based modeling (ABM) is a unique tool that can be applied to define and simulate water resources as a complex adaptive system in order to address complexity in its planning and management.
The starting point of agent based modelling concept is not clear and can be considered diffusive. However, most of the early studied and uses of the method were to simulate and describe social phenomenon such as racial segregation, seasonal migration, transmission of disease. The main idea behinds the use of ABM for any social-technical problem is to explore how behavior at the local level interacts with nature or engineered processes to produce observable phenomenon at a higher level. The closest use of the model to water resources problem can be traced to the evolution of landscape from land use decision of farmers includes the heterogeneous characteristics of individual farmer as well as interdependencies between farmer and the landscape.
Typically, an ABM is one in which individual stakeholders are described as unique and autonomous entities that interact locally with one another and within a shared environment. The interaction can take different forms, including communication, exchange between agents, and lead to aggregated outcomes that would be unachievable for agents acting on their own. An ABM consists of three important parts: agents, the environment and rules. Agents are normally representing persons, but can also be representing groups as institutions. The environment is the geographical space or resources where agents act upon. The rules define how the agents interact with each other and with the environment.
ABM formulation for an irrigation district
With all the characteristics within an irrigation system and the ABM model describes above, it is reasonable to expect that an ABM that carefully designed with the agent interaction rule and the sphere of interaction is within an irrigation district, an ABM model can give the decision maker, irrigation system operation as well as stakeholders a better understanding/insights of how collective behavior at the household level can resonate to system wide parameter or likewise a decision at the top level will lead to a change or modification in behavior of stakeholder in the irrigation district.
Figure 1. North NamHa irrigation scheme (Nam Dinh province).
The study area is the North Nam Ha irrigation district located in the Red river basin - Vietnam (figure 1). The irrigation system is surrounded by 4 rivers Red river, Dao, Day and Chau Giang river, with Red river is the main water supply for the irrigation district. The whole system is a mixed of high ground and subsidence basin with rich soil to support the agricultural system, the total area of the irrigation district is 100.261 hectares with non-agriculture area accounts for about 37% of the area. The irrigation district is one of the main rice production areas of the province, this irrigation system was designed to irrigate for the whole cultivation area. The water extracted from the canal by the farmers is used to irrigate the number of fields determined by themselves or the authority at the beginning of each season. During the crop growing season, farmers irrigate their fields as it needs (determined by the availability of water and the experience or mostly following the schedule of the irrigation operator). They withdraw water according to the allocation schemes determined at the beginning of the season. If the amount of water actually reaching the fields is less than the amount needed to irrigate the given number of fields, then water stress occurs and accumulates over the season. Surveying of the irrigation district and discussion with stakeholders has revealed the following problems with the water management and water allocation scheme of the area as following:
- Years of land use and crop pattern change without consideration to the capacity of the system to supply water has led to lack of water at area of cultivation, especially at the ends of the irrigation canal (as shown in figure 1);
- Inefficient water use within the irrigation system (volume of water supply vs quantity of agriculture production);
- Water user groups are largely disconnected;
- Lacking a coherent interaction between the irrigation system management and stakeholders.
Discussion with the system operation and stakeholders enabled the co-development of a following management and behavior rules for the system taking account the future direction of the irrigation system. The rules have been carefully discussed and chosen as following:
- direct interactions for service or information exchanges
- A farmer who has the water intake may allow another farmer, whose plot is along the same watercourse, to take water at the same time.
- One farmer repairs the motorcycle of another farmer, who will work on his plot (exchange labor or water right through other social-economic activities).
- A farmer forgoes a water use ratio will be compensate by the water user group by a reserved ticket (the right to use water at a high demand season).
- A farmer convert the production plot to less intensive water crop will have the right to exchange water use ticket for other farmer.
- interactions through the irrigation scheme
- Rotation in the priority use of water for group of users at the head and end of the irrigation canal.
- When a farmer along the canal takes water, another farmer further downstream may be able to take half the required water volume.
Setting up the interaction rules and coding the interaction between the stakeholders in the context of water resources management scheme of the irrigation district will be the next development of the study. It will be more informative that the interaction can be simulated in a water user groups meeting with the operator to explore the process and the outcomes. Nevertheless, as noted earlier when overlays the agent based interactions on top of the water resources allocation scheme of the irrigation district it will reveal the beauty of the method on how a cohesion or non-cooperation behavior leading to the outcome at the top level of irrigation district in term of resources used or in term of system efficiency.
At the point of view of the irrigation system operator, understanding the collective behaviors of the water users would save a lot of resources and man power. At the point of view of decision makers, understanding of how effective or how a decision would affect the water user behavior would provide valuable decision support tool. At the point of view of water users, understand how cooperation and noncooperation in their water usage pattern would help them to choose a wise solution in water use and technology upgradation. The future study in next blog will explore the interactions of stakeholders laid out in this blog with different water management schemes. The results of the ABM model will further serve as recommendation for the irrigation operators in Red river basin in future scheduling and managing irrigation water allocation.