Correlação entre índices de erosividade e características de precipitação facilmente mensuráveis da Beira e Maputo

Abstract

The cymetic energy for each occurrence of rainfall (Ei) was studied, calculated on the basis of five different equations and kinetic energy of maximum intensity for 30 minutes (Ei30), its average monthly distribution for Beira and Maputo in order to know the degree of correlation among the various equations for calculating Ei , the monthly mean temporal distribution of total kinetic energy (Ei) and EI30. Correlations are made between Ei and E130 with monthly precipitation (Primes), maximum precipitation for 24 hours (Pmax) and the modified Fournier index (pmes2/P) in an attempt to obtain a mathematical equation that estimates Ei and E130 through data of rainfall obtained with rain gauges. For this purpose, rainfall data from the observation centers of Beira (1986-1994) and Maputo (1984-1993) belonging to INAM were analyzed. all occurrences of rainfall were analyzed. It was observed that for the studied sites there is a high correlation between the five equations for calculating El; and between E1 and E130 with Pmes, Pmax and Pmes2/P. The results show that 86% of the annual El médfio erosive potential and 94% of the annual average E130 erosion potential occur between the months of September to March in Maputo. In real terms, Beira has greater erosion potential than Maputo. Through regression equations obtained, they can estimate the erosivity indices through the following equations: Beira:El=-1.972+22.853Pmes; E130=-263.681+22.853Pmax Maputo: El=-1.864+0.187Pmes; E130+-174.463+17.643Pmax where: Et(M/ha-1) E130(Mj.mm.hr-1).Pmes (mm) and Pmax(mm). or to other locations, but with climatic conditions similar to those of Beira or Maputo and that only have rainfall data obtained with rain gauges.