Análise de risco ambiental da irrigação pública do Estado do Ceará: o caso do perímetro irrigado de Morada Nova

Abstract

This dissertation analyzes the environmental risk of public irrigation in Ceará: the Case of the irrigated perimeter of Morada Nova. The study consisted in analyzing the environmental impacts of the Project, considering the following components: vegetal cover, uncultivated, primitive and natural areas, rivers and river systems, productivity, water quality, soil quality und soil salinity. The triangular probability distribution was used for the quantitative dimensions, substituting the deterministic conventional methods, without abandoning, however, the indispensable descriptive-narrative valuation with a subjective and essentially qualitative character. The results showed that the vegetal cover suffered a major negative impact as a consequence of the indiscriminate deforestation during the establishment of the project, harming the biological processes of many species. On the other hand, the productivity presented the only positive impact, by the fact that 80% of the area is occupied by rice, requiring great quantities of water, which carries the salts to deeper layers not interfering in the yield of the culture. Thus it was concluded that the irrigation affected the environment of the project Morada Nova within the analyzed components, since just one of the seven studied categories presented positive impact, one didn't manifest and five presented negative impacts. Hence it is suggested to establish the principles of the environmental planning of irrigated agriculture in a more detailed way, defining norms for the establishment of the activity and proceedings to control the negative impacts of the irrigation project.