|Abstract or Summary
- Coastal wetlands provide basic linkages between productive estuarine and freshwater ecosystems. Throughout the Mexican coast, rates of wetland loss and change are unknown. This project developed wetland inventories for 1973 and 1991, including ecological functions and values, and human activities in and around the wetlands. Data was integrated by use of a geographic information system. Identification of changes in wetlands and human activities was completed, as well as analyses of relationships between wetland change and changes in human activities. The model also identified and evaluated Mexican governmental policies affecting wetland changes. Results include descriptions, maps, and analyses of wetlands conditions and human activities, changes over an 18 year period, and interactions supported by correlation analyses Wetlands functions were summarized for the Tobari system. Human activities showed an increase in aquaculture, salt mining, agriculture, and fisheries. Changes by spatial distribution are shown in an intensity map. The federal government has promoted policies focused on development of irrigation districts, including self-sufficiency in grains and opening agricultural land. Economic incentives include subsidies, infrastructure financing, price controls, and compensation for international market fluctuations. Federal government policies did have important impacts on wetland change. The emphasis of this model was on correlation between changes in wetland functions and values, and changes in human activities. While wetland distribution, classes, and interactions are essential information, assigning value to them requires knowledge of their functions. Since values often depend upon local cultural and economic conditions, local perception of wetland values emerge from people's awareness of them. Some values are recognized by local people in the Tobari system, especially those related to their economic system. Others, such as those related to water quality and climatic regulation, are not recognized yet. Results indicate that statistical analysis resulted in moderate to high correlation between changes in wetland types and changes in land use patterns. This research contributes to understanding wetland functions and their relationships with human life styles.