Ocorrência de veranicos no município de Macapá-AP

Abstract

The municipality of Macapá, located around the equator, is characterized by having large seasonal variations in the precipitation regime, due to the annual migration of the Intertropical Convergence Zone (ITZC), which consists of a band of convective cloudiness that goes around the globe, associated with the confluence of trade winds, low atmospheric pressure at the surface in the equator, areas of maximum sea surface temperature and maximum convergence of moisture at low levels of the atmosphere (MELO; CAVALCANTI; SOUZA, 2009). According to Oliveira (2010), rainfall, even today, is a defining element of the conditions offered by the environment, determining the physical qualities of the environment for the development of agriculture and livestock in the various production systems. Thus, the volume of rainfall occurring throughout the year, as well as its form of temporal distribution in space, gives the environment characteristics that facilitate or hinder the establishment of certain agricultural production processes. For Carvalho et. al. (2000) the total rainfall in the rainy season is sufficient for the development of agriculture in the intertropical zone, but it is affected by dry spells, a phenomenon that is characterized by periods of interruption of rainfall during the rainy season. Summers can be classified based on the degree of intensity, frequency and duration. The greater the intensity, frequency of occurrence and longevity of consecutive days in which this phenomenon occurs during a rainy season, the greater the negative impacts on human activities (CUPOLILLO, 2008). For Carvalho et al., (1999) the prediction of the occurrence of Indian summers is quite significant for agriculture, as it provides additional information to agricultural planning, both rainfed and irrigated, as it can help to maximize the efficient use of water in cultivated areas. And even if the producer has an empirical view of the place where he plants, mainly related to proper soil management, it is not entirely enough, as understanding the climate is extremely important for the success of agricultural crops practiced by him (ROLDÃO, 2015) And when it comes to agricultural production in the state of Amapá, the Metropolitan region of Macapá becomes the most important, as the largest number of rural producers is concentrated, especially in terms of horticulture, fruit and manioc. The main 6 Cultivated vegetables are hardwoods (lettuce, cabbage, cabbage, coriander, chives and parsley) and some tubers (manda and sweet potatoes). To a lesser extent, watermelon, pumpkin, okra and gherkin are also cultivated. Cultivation is carried out throughout the year, with producers using improvised irrigation systems in the dry period (EMBRAPA, 2005). Therefore, knowledge about rainfall and its variations throughout the year in each location is of fundamental importance for carrying out agricultural planning, as it is based on these data that the farmer can better define his agricultural activity calendar, such as preparation of soil, planting, harvest time, among others. In addition, the rural producer will be able to interact better in the management of his irrigation in rainy periods, with the occurrence of dry spells, because, as is known, the water supply through a more efficient and effective irrigation during the phenological stages of the plant, especially in the which refers to the development and reproductive stages, corroborate a lot for the increase of production and productivity of the planting. Given the above, this study aimed to identify the occurrence of the summer phenomenon and its frequency in the city of Macapá-AP in a period of 21 years.