Elaboração de um sistema de classificação da capacidade de suporte em ambiente semi-árido Elaboration of a classification system of support capacity in the semi-arid environment

Esta pesquisa foi realizada com o objetivo de identificar a relação de colonos assentados em projetos de reforma agrária no Rio Grande do Norte, com os recursos naturais das suas respectivas áreas e, posteriormente, elaborar um sistema de classificação de suporte do meio físico. Para isto, foram selecionados dez projetos de assentamento na região oeste do estado, caracterizada por regime de semi-aridez, abrangendo uma área de cerca de 30.000 ha, em que se buscou identificar parâmetros qualitativos e quantitativos dos recursos edáficos, florestais e hídricos de cada área, sempre os relacionando com o seu tipo de uso. Verificou-se que todos os assentamentos apresentaram número de colonos superior ao limite que o ambiente poderia suportar, demonstrando a necessidade de se reavaliar o tamanho do módulo agrícola adotado para essas áreas, como também a necessidade da oferta satisfatória de água, que propicia melhor exploração do potencial agrícola dos solos da região, diminuindo a pressão sobre os recursos florestais.<br>This work aimed as general objective, to identify the farmers of the Settlement Projects of Agricultural Reform in the State of Rio Grande do Norte, with the natural resources of their respective areas and later to elaborate a system of classification of support capacity of the ambient. For the purpose, ten Settlement Projects were selected in the western part of the state, characterized by semi-arid regime in an area of 30.000 ha where qualitative and quantitative parameters of the soil where edalfo, forest and water resources were identified. It was verified that all Settlement Projects presented number of settlers more than the ambient could support, demonstrating the need to reevaluate the size of the agricultural module adopted in these areas, as well as the satisfactory offer of water which allows better exploration of the agricultural potential of the soils of the area, thereby decreasing the pressure on the forest resources

The circulation of the lower Capibaribe Estuary (Brazil) and its implications for the transport of scalars

Abstract The Capibaribe Estuary is a water body that crosses the Recife Metropolitan Area (RMA), one of the largest population centers in Brazil, and causes large pollutant loads and poor water quality. The fresh water inflow of wastewater from the RMA can account for three times the volume of the river discharge during the low discharge period. This article assesses the hydrodynamics and potential transport of particulate and dissolved scalars in this estuary. A field experiment was conducted to record the water level, current velocity, salinity, temperature and suspended particulate matter (SPM) contents during a full semi-diurnal tidal cycle. This experiment was performed during low river discharge and spring tide conditions. The estuary showed a partially mixed circulation pattern. The residual transport of water and salt were up estuary, while the SPM residual transport was down estuary. The former were understood as the effect of the residual circulation around the islands, while the latter was interpreted as a morphological factor inducing greater resuspension during the ebb, despite the symmetrical ebb and flood currents. This mechanism may transport SPM to the inner shelf, even under tide-dominated conditions when the opposite would be expected