ABSTRACT The MATOPIBA, encompassing parts of the states of Maranhão, Piauí, and Bahia, as well as the entire state of Tocantins, is an expanding agricultural region characterized by water resource management challenges. The availability of water in the hydrographic basins of this region plays a fundamental role in sustaining agricultural activities and preserving local ecosystems. Remote sensing information was used to estimate the flow in 32 hydrographic basins sited in the MATOPIBA region. For this purpose, precipitation and evapotranspiration variables obtained from TerraClimate using the Google Earth Engine (GEE) platform, were considered to calculate monthly, annual, and long-term simplified water balances. To verify the performance of the remotely sensed flow data, the results were compared with those of the Agência Nacional de Águas e Saneamento Básico (ANA), using statistical performance parameters. The results showed that the estimates of long-term and annual mean flows were better than monthly ones. These findings reveal that the simplified water balance done long-term using remote sensing satisfactorily determines mean streamflow in the hydrographic basins of the study area. Maranhão Piauí Bahia Tocantins challenges ecosystems 3 purpose GEE (GEE platform longterm long term balances data ANA, ANA , (ANA) parameters ones area (ANA

ABSTRACT The disorderly soil occupation without the necessary conservationist practices leads to impacts on the local hydrology and induces the pollution of water resources. This pollution may come from more urbanized areas due to the amount of pollutants drained during the rains. Even moderate precipitations constitute one of the main factors that define pollutant runoff on the surface. These rains have recently been called light rains. Light rains have a lower precipitation height and a higher frequency compared to classic rains of drainage projects, being necessary to define them according to patterns of rain frequency for each region. This study aimed to characterize light rain in the municipality of Piracicaba to establish statistical standards for the frequency of certain precipitation heights. A database provided by the ESALQ/USP automatic weather station, which provides precipitation measurements every 15 minutes, was used in the present study. Light rain heights reached 40.3, 41.4, and 42.7 mm for 100, 90, or 80% frequencies, respectively, which implies the use of return periods of 1.00, 1.11, and 1.25 years, respectively. resources surface projects region ESALQUSP ESALQ USP station 1 minutes 403 40 3 40.3 414 41 4 41.4 427 42 7 42. 100 90 80 frequencies respectively 00 1.00 111 11 1.11 125 25 1.2 years 40. 41. 10 9 8 0 1.0 1.1 12 2 1.

Quando se buscam, em literatura, dados sobre a irrigação no Brasil, o que se encontra disponível é a área irrigada por estado e por método de irrigação. A distribuição dentro dos estados, o número de equipamentos e seu tamanho são de difícil obtenção, mesmo junto às indústrias. No entanto, essas são informações fundamentais quando se pretende estudar a disponibilidade hídrica ou o potencial de crescimento da área irrigada de uma região, por exemplo, temas esses bastante atuais com a crescente demanda por água potável em nível mundial e nacional. Com o presente trabalho objetivou-se coletar essas informações utilizando-se de imagens do satélite Landsat com base na característica intrínseca do sistema de pivô central de marcar com um círculo o local onde está instalado. Em função do referenciamento cartesiano das imagens e da sua articulação com os mapas do IBGE, foi possível desenhar os mapas estaduais com as áreas de concentração desse tipo de equipamento que, quando comparados com outras fontes, permitiram concluir-se pela validade da metodologia para obtenção dessas informações.

Irrigated areas by state and by irrigation method is the available information about irrigation in Brazil. Distribution inside the states, number or size is not easily found even through the industry. These data are very important when one intends to study water availability or growth potencial of irrigated areas for a specific site due to the increasing concern about drinking water worldwide and nationally. The present study had the objective to collect such information using satellite images from Landsat based on the intrinsic characteristic of the center pivot equipments, the circular mark on landscape easily visible. With comparison the geo-referenced images and its articulation with the official IBGE maps, it was possible to draw the state maps with the equipment density distribution, which, when compared to other available sources permitted to validate the methodology used for this purpose.