Generation of intensity duration frequency curves and intensity temporal variability pattern of intense rainfall for Lages/SC

The objective of this work was to analyze the frequency distribution and intensity temporal variability of intense rainfall for Lages/SC from diary pluviograph data. Data on annual series of maximum rainfalls from rain gauges of the CAV-UDESC Weather Station in Lages/SC were used from 2000 to 2009. Gumbel statistic distribution was applied in order to obtain the rainfall height and intensity in the following return periods: 2, 5, 10, 15 and 20 years. Results showed intensity-duration-frequency curves (I-D-F) for those return periods, as well as I-D-F equations: i=2050.Tr0,20.(t+30)-0,89, where i was the intensity, Tr was the rainfall return periods and t was the rainfall duration. For the intensity of temporal variability pattern along of the rainfall duration time, the convective, or advanced pattern was the predominant, with larger precipitate rainfalls in the first half of the duration. The same pattern presented larger occurrences in the spring and summer stations.

Corn performance with late sowing in Planalto Catarinense, Brazil, simulated with CERES-maize model

This work had the objective to investigate the delay effects in the sowing date on corn establishment, cycle duration and yield through the computer simulations using CERES-Maize model, in order to help agrarian producers from the Mountainous Area of Santa Catarina, Brazil to take better decisions on it. The computer simulations showed that: 1)the risks on corn establishment increased due to the delay of sowing during the studied years; 2) in some years, its cycles were drastically affected for the lower temperatures; 3) the cycle durations were longer when confronted with the low temperatures; 4) corn income decreased when the cycles were confronted with the low temperatures, water deficiency and low solar radiation; 5) potential incomes averaged 4944 kg ha-1, and under the natural rain conditions averaged 2490 kg ha-1, during all the months analyzed from October to March; 6) besides January, the exploration of this cultivar was not viable because of the high risk of the crop frustration associated to the same ones, due to the thermal conditions (low temperatures and frost).

O trabalho teve como objetivo investigar os efeitos decorrentes do atraso da semeadura no estabelecimento, duração do ciclo e rendimento do milho, mediante simulações em computador com o uso do modelo CERES-Maize, a fim de orientar os produtores na tomada de decisão na região do Planalto Serrano Catarinense. Em função da época em que é cultivado, o milho com semeadura tardia normalmente está exposto a riscos maiores de perdas por geadas e deficiência hídrica em relação ao cultivo na época recomendada, atingindo um menor potencial de produtividade e tendência de alongamento do ciclo. As simulações permitiram concluir que: os riscos de estabelecimento do milho foram bastante variáveis ao longo dos decêndios analisados; em alguns anos os ciclos foram afetados drasticamente por temperaturas bastante baixas; as durações dos ciclos tenderam a alongar-se quando confrontados com temperaturas baixas; os rendimentos decresceram quando os ciclos se confrontaram com temperaturas baixas, menor disponibilidade hídrica e de radiação solar; os rendimentos potenciais foram em média de 4944 kg ha-1 e em condições de chuva natural de 2490 kg ha-1, considerando todo o período analisado (outubro a março); a exploração desta cultivar, além do mês de janeiro não seria viável devido ao alto risco de frustrações de safras associadas às mesmas, decorrentes das condições térmicas (temperaturas baixas e geadas).