 |
 |
 |
 |
 |
 |
|
The Floods
The water level difference between the dry and rainy seasons is, on average, only four meters, but due to the small declivity, the majority of "Pantanal" might be flooded. In years of high rainfall, the waters surpass the six-meter level. On these occasions, the water of rivers such as the Paraguay, Cuiabá, São Lourenço, Taquari and Miranda, as well as their tributaries, overflow and inundate enormous areas. These form a dense network of lakes, bays and flooded lowlands, interconnected by perennial - the "corixos" - or ephemeral watercourses. Only high terrains, called "cordilheiras" (mountain chains), a few islands and higher areas escape inundation. Some isolated hills of pre-Cambrian rocks, the "inselbergs", stand out in the swamps. The Morro do Azeite is one of these hills, on the banks of the Miranda river. When the waters return to normal, many bays and lakes remain, whilst
others dry. A rich herbal vegetation spreads through the lowlands,
taking advantage of the nutritious mud left by the flood. There
are also small bays of salt water. At each precipitation / evaporation
cycle the mineral salts accumulate, resulting in a certain salting
of the soils and some bays. The slow water evaporation in the lagoons
is shown by the white rings of salt deposits (sodium carbonate).
The salt concentration in these bays, in places like the Nhecolandia
region, might be near to marine concentrations. |
Environment  |
