THE EXTERNAL IMPACT OF AGRICULTURE ON INLAND WETLANDS: A CASE STUDY FROM ARGENTINA

Abstract

We develop a simple model to identify the link between indirect impact of agriculture - soil erosion and the level of damage of inland wetlands by sedimentation. The economic impact of wetland degradation service, specifically flood control, is then estimated. The study area covers 1.4 million ha, located in the south of Córdoba, Argentina. The change in wetlands and croplands between 1975 and 2001 was estimated by multiperiod analysis of satellite images. The value loss of cropland is estimated by using real prices 2000, and data from two surveys 1886 and 1999. The results show the loss of wetland services accounted for more than 58,000ha of degraded cropland, with an estimate of land value loss of $133 million at a 6% of discount rate between 1975 and 2001. If the trend of agricultural modernization and degradation continues the degraded cropland would reach around 120,000 ha and the aggregate value of wetland services loss $210 million for planning period of 30 years (or $128 ha-1 year-1). Although agricultural modernization hided the damage of inland wetlands, the environmental units located in the intermediate watershed are critically affected. These finding support the needs to integrate policy of promoting agricultural modernization along with soil conservation and wetlands protection.