The Guarani Aquifer is one of the world’s largest underground fresh water reservoirs, 70% of it is located in Brazilian territory (840 thousand km2). With an estimated capacity of 45 thousand km3 of underground water, it is an important source of fresh water and for the development of economic activities. The Alter do Chão Aquifer, located under the world’s largest hydrographic basin (river Amazonas), extends under Brazilian ground with an estimate potential volume of 86 thousand km3. The Northern region makes up more than half of the national territory and its main features, among others, are its low population density and the length of its frontier. The Northeast is the third most densely populated geographical region, largely concentrated along the coastline, where main urban centers are located. The Midwest, the second largest region, also presents low population density. It has a border line of nearly 2 thousand kilometers long. The Southeast is the most densely populated, urbanized and developed region of the country and includes the largest population centers. The South region is the smallest in land area. It shares borders with nations of the River Plate. It also has a high level of urbanization and demographic density. The Amazon is one of the areas of highest interest to the Ministry of Defense. The PanAmazon, which is constituted by the entire Amazon forest in South America, consists of approximately 40% of the South American continental area and holds 20% of the world’s fresh water reserves. The largest area of the Pan-Amazon belongs to Brazil — around 70%. Brazil defends its unconditional sovereignty over the Brazilian Amazon, which comprises over 4 million square kilometers, shelters all kind of mineral reserves and the planet’s largest biodiversity. Brazil’s cooperation with other countries holding territory in the Pan-Amazon is essential for the preservation of this natural treasure. The “borderland”4 concept was adopted by Brazil, through the 1988 Federal Constitution and by law. Although this concept was initially linked to the area of National Defense, the concern with the consolidation and the gradual Brazilian presence in this borderland reflects the priority given by the state to sustainable development, national integration and cooperation with bordering countries in matters related to security and the fight against transnational contraband. Federal Constitution Art. 20 § 2: “The strip up to one hundred and fifty kilometers width, alongside the terrestrial boundaries, designated as boundary zone, considered essential to the defense of the national territory and its occupation and utilization, shall be regulated by law.” 4 DEFENSE WHITE PAPER 19 CHAPTER 1 — THE BRAZILIAN STATE AND NATIONAL DEFENSE Aquifers Guarani and Alter do Chão (Amazon)