Regional development problem

Let us consider a region with a developed agricultural production. The region is located in the basin of a river that runs through a lake into a sea (see the map).

The lake serves as the municipal water supply source. Moreover, the lake is an important ecological and recreational cite. The problem of the further economic development of the region is considered. If the agricultural (here grain-crops) production would increase, it may spoil the environmental situation in the region. This is related to the fact that the application of chemical fertilizers and water for irrigation may increase the grain-crops output substantially, but at the same time, it may result in negative environmental consequences:

1. a part of the chemical fertilizers may find its way into the river with the withdrawal of water,
2. a shortage of water in the lake may arise during the dry season because of the irrigation.

Two agricultural zones exist in the region. In the zone up to the lake, the irrigation and the fertilizer application may directly result in a drop of the water level in the lake and in the increment of pollution concentration in its water. The irrigation and the fertilizer application in the zone which is lower than the lake also may influence the lake, but in an indirect form: the irrigation and the fertilizers application in the lower zone may result in the need of additional water flow from the lake into the river (the release is regulated by the dam) to fulfill the requirements of pollution control.

A finite number of grain-crops production technologies may be considered. Intensive technologies are related to high level of water consumption and of fertilizers application. Several technologies are related to low water consumption and fertilizers application, but the production is low, too. Technologies that use moderate amounts of water and of fertilizers result in a moderate output. Reasonable strategies of agricultural production and of water release through the dam should be developed and negotiated.

Different economic and environmental indicators represent different interests: farmers are mainly interested in the grain-crops production while recreational business is mainly interested in the level of the lake, and the inhabitants of the city are mainly interested in the water quality. So, we consider three performance indicators (choice criteria):

• the agricultural production,
• the level of the lake,
• the pollution of the water.

Let us describe how the Interactive Decision Maps may be applied for the exploration of the problem and for the constructing of a regional development strategy.