scholarly journals ENTRE CHAPADAS E MALHADAS: TRANSFORMAÇÕES DA PAISAGEM E A EXPANSÃO AGRICOLA EM GILBUES, PIAUI

GEOgraphia ◽  
2019 ◽  
Vol 21 (45) ◽  
pp. 47
Author(s):  
Ivamauro Ailton de Sousa Silva ◽  
Dirce Maria Antunes Suertegaray ◽  
Juliana Ramalho Barros

: Em Gilbués, os cerrados caracterizam-se por extensos chapadões de topografia plana, que facilita a expansão da agricultura mecanizada. Já em outras regiões existem áreas conhecidas como malhadas e grotas, que apresentam intensos processos erosivos causados pelas características climáticas e morfopedológicas. O objetivo, nesse estudo, é analisar a dinâmica da cobertura e uso das terras, enfatizando os aspectos da paisagem, o processo de apropriação, as transformações socioambientais, os arranjos socioeconômicos e sua articulação com as terras erodidas no município de Gilbués, sudoeste do Estado do Piauí. Para o desenvolvimento deste trabalho, foram necessárias quatro etapas distintas e complementares: revisão bibliográfica, trabalhos de campo, construção e análise de gráficos, compilação de mapas temáticos construídos a partir de técnicas de sensoriamento remoto e geoprocessamento. Como resultados, o artigo, elucida a ocorrência de intensos processos erosivos na região centro-sul de Gilbués e no setor norte expansão da agricultura mecanizada em áreas de cerrado. A análise temporal realizada em 1987 e 2009, indicou mudanças na dinâmica da cobertura e uso das terras, como, por exemplo, a expansão agrícola em áreas de cerrado denso que ocasionou a subtração da cobertura vegetal na região norte, o aumento da produtividade, a ampliação de áreas de solo exposto que resultam em feições erosivas do tipo badland. A pesquisa permitiu compreender as trajetórias e dinâmicas socioeconômicas e suas influências nas transformações da paisagem, e também avaliar a importância das configurações naturais que favoreceram a implementação de atividades agrícolas.Palavras-chave: Cerrado. Chapadas. Malhadas. Expansão agrícola. Gilbués. ”BETWEEN PLATEAUS AND BADLANDS”: LANDSCAPE TRANSFORMATION AND AGRICULTURAL EXPANSION AT GILBUÉS-PIAUÍAbstract: At Gilbués, cerrados are characterized by an extensive flat topography, which facilitates the expansion of mechanized agriculture. Other regions present areas known as badlands, which undergo intense erosive processes caused by climatic and morpho-psychological characteristics. The objective herein is to analyze land cover and use dynamics, emphasizing landscape aspects, the appropriation process, social and environmental transformations and socioeconomic arrangements, as well as their articulation with eroded lands in the municipality of Gilbués, southwestern Piauí. Four distinct and complementary steps were necessary for the development of this study: a bibliographical review, field work, graph construction and analysis and the compilation of thematic maps built using remote sensing and geoprocessing techniques. As results, the study elucidates the occurrence of intense erosive processes in south-central Gilbués and the expansion of mechanized agriculture in cerrado areas in the northern sector. The temporal analysis carried out in 1987 and 2009 indicates changes in land cover and use dynamics, such as the agricultural expansion in dense cerrado areas, leading to vegetation cover removal in the northern region and increased productivity of exposed soil, resulting in erosive badland-type features. This study allowed for an understanding of socioeconomic trajectories and dynamics and their influence on landscape transformations, as well as an evaluation of the importance of the natural configurations that favored the implementation of agricultural activities.Keywords: Cerrados; Plateau. Badlands. Agricultural expansion. Gilbués. “ENTRE ALTIPLANOS Y MALHADAS”: TRANSFORMACIONES DEL PAISAJE Y LA EXPANSIÓN AGRÍCOLA EN GILBUÉS-PIAUÍResumen: En Gilbués, los cerrados se caracterizan por extensos altiplanos, lo que facilita la expansión de la agricultura mecanizada. En otras regiones, existen áreas conocidas como malhadas y cuevas, que presentan intensos procesos erosivos causados por las características climáticas y morfopedológicas. El objetivo es analizar la dinámica de la cobertura y del uso de las tierras, enfatizando los aspectos del paisaje, el proceso de apropiación, las transformaciones socioambientales, los arreglos socioeconómicos y su articulación con las tierras erosionadas en el municipio de Gilbués, suroeste del estado de Piauí. Para el desarrollo de este trabajo fueron necesarias cuatro etapas distintas y complementarias: revisión bibliográfica; trabajos de campo; construcción y análisis de gráficos; y la compilación de mapas temáticos, construidos a partir de técnicas de teledetección y geoprocesamiento. Como resultado, este artículo elucida la ocurrencia de intensos procesos erosivos en la región centro-sur de Gilbués y la expansión de la agricultura mecanizada en áreas de cerrado en su región norte. El análisis temporal realizado en 1987 y 2009 indicó cambios en la dinámica de la cobertura y en el uso de las tierras, como, por ejemplo, la expansión agrícola en áreas de cerrado denso, lo que ocasionó la sustracción de la cobertura vegetal en la región norte, el aumento de la productividad y la ampliación de áreas de suelo expuesto, resultando en formaciones erosivas del tipo badland. La investigación permitió comprender las trayectorias y las dinámicas socioeconómicas y sus influencias en las transformaciones del paisaje, así como evaluar la importancia de las configuraciones naturales que han favorecido a la implementación de actividades agrícolas.Palabras- clave: Cerrado. Altiplanos. Malhadas. Expansión Agrícola. Gilbués.

GEOGRAFIA ◽  
2018 ◽  
Vol 42 (3) ◽  
pp. 129-143
Author(s):  
Clóvis CECHIM JÚNIOR ◽  
João Francisco Gonçalves ANTUNES ◽  
Jerry Adriani JOHANN ◽  
Júlio César Dalla Mora ESQUERDO

The main land use and land cover (LULC) changes that a given area passes over the time can be evaluated by using spatial-temporal analysis of satellites images. Then, it is possible to identify the LULC changes, as well as the main causes of environmental impacts. The objective of this paper was to analyze the LULC changes of the main agricultural lands cultivated in the Alto Paraguai Basin (BAP). This paper focused on the summer crops (soybean and corn) and the analysis of agricultural expansion. The results, considering a16-year comparison, showed an increase of 40.60% in the expansion of agricultural areas. The evaluation of the accuracy showed the efficiency of the methodology of agricultural mapping, presenting a Kappa Index of 0.85 for the 2000/2001 and 0.86 for the 2015/2016 crop seasons


Politeia ◽  
2018 ◽  
Vol 37 (1) ◽  
Author(s):  
Abiba Yayah

The agency of women in most African countries is often affected by the socio-economic and political policies that are almost always disadvantageous to women, especially women who have little to no knowledge of their rights. Using the shea industry in Ghana as a case study, I chronicle the challenges as recounted by rural women involved in this home-based work in the Northern Region of Ghana and critically analyse these challenges and their implications. Focusing mainly on the results of my recent field work, I present some of the accounts relating to the lack and exclusion of recognition of and respect for the experiences of rural women who are in fact the linchpin of the shea industry in Ghana. Initiatives and strategies of non-governmental organisations and some governmental policies have attempted to address these challenges that have implications for the livelihoods of rural women. Research and policies have only offered “band-aid solutions” to the economic disempowerment of rural women in the shea industry in Ghana as they have not dealt with the causes. This article seeks to refute the claim that equity exists by indicating the lack of equity and justice in the policies in the shea industry. In an attempt to provide an understanding of the economic disempowerment of women in this industry, I consider my field work as a good source as it exposes the experiences and everyday practices as narrated by rural women in the industry. This article seeks to analyse the existing discourses especially those pertaining to the contributions and experiences of rural women in the shea industry.


1994 ◽  
Vol 30 (5) ◽  
pp. 177-186 ◽  
Author(s):  
Karin Sundblad ◽  
Andrzej Tonderski ◽  
Jacek Rulewski

Nitrogen and phosphorus concentration data representing samples collected once a month for nine months at 13 locations along the Vistula River are considered in a preliminary discussion of the sources of the nutrients transported to the Baltic Sea. Concentrations in relation to flow data indicated substantial differences between subbasins. Based on those differences, on the area-specific nutrient loss for a six-month period and on the wastewater discharge in each subbasin, four regions could be recognized in the river basin: i) the southern region with a large impact of point sources, ii) the south central region, where diffuse sources seemed to be of major importance, iii) the north central region with a combined effect of point and diffuse sources, and retention in two reservoirs, iv) the northern region where point sources seemed to be the dominating source, at least for phosphorus. Our results illustrate the importance of differences in phosphorus retention between the basins. Long-term retention along the course of the river, particularly in the two reservoirs, must be estimated to allow proper source apportionment in the Vistula basin. Concentration decreases in the Wloclawek Reservoir varied between 44 and 68% for P, and 11 to 37% for N, in the months with significant retention. In some months, however, concentrations increased, indicating a release of nutrients.


Radiocarbon ◽  
2020 ◽  
pp. 1-11
Author(s):  
R Garba ◽  
P Demján ◽  
I Svetlik ◽  
D Dreslerová

ABSTRACT Triliths are megalithic monuments scattered across the coastal plains of southern and southeastern Arabia. They consist of aligned standing stones with a parallel row of large hearths and form a space, the meaning of which is undoubtedly significant but nonetheless still unknown. This paper presents a new radiocarbon (14C) dataset acquired during the two field seasons 2018–2019 of the TSMO (Trilith Stone Monuments of Oman) project which investigated the spatial and temporal patterns of the triliths. The excavation and sampling of trilith hearths across Oman yielded a dataset of 30 new 14C dates, extending the use of trilith monuments to as early as the Iron Age III period (600–300 BC). The earlier dates are linked to two-phase trilith sites in south-central Oman. The three 14C pairs collected from the two-phase trilith sites indicated gaps between the trilith construction phases from 35 to 475 years (2 σ). The preliminary spatio-temporal analysis shows the geographical expansion of populations using trilith monuments during the 5th to 1st century BC and a later pull back in the 1st and 2nd century AD. The new 14C dataset for trilith sites will help towards a better understanding of Iron Age communities in southeastern Arabia.


Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 353
Author(s):  
Rassim Khelifa ◽  
Hayat Mahdjoub ◽  
Affef Baaloudj ◽  
Robert A. Cannings ◽  
Michael J. Samways

Agriculture can be pervasive in its effect on wild nature, affecting various types of natural habitats, including lotic ecosystems. Here, we assess the extent of agricultural expansion on lotic systems in Northern Africa (Algeria, Tunisia, and Morocco) and document its overlap with the distribution of an endemic damselfly, Platycnemis subdilatata Selys, using species distribution modeling. We found that agricultural land cover increased by 321% in the region between 1992 and 2005, and, in particular, the main watercourses experienced an increase in agricultural land cover from 21.4% in 1992 to 78.1% in 2005, together with an increase in the intensity of 226% in agricultural practices. We used capture–mark–recapture (CMR) surveys in terrestrial habitats surrounding a stream bordered by grassland and cropland in northeastern Algeria to determine demographic parameters and population size, as well as cropland occupancy. CMR modeling showed that the recapture and survival probabilities had an average of 0.14 (95%CI: 0.14–0.17) and 0.86 (0.85–0.87), respectively. We estimated a relatively large population of P. subdilatata (~1750 individuals) in terrestrial habitats. The occupancy of terrestrial habitats by adults was spatially structured by age. Our data suggest that P. subdilatata has survived agricultural expansion and intensification better than other local odonate species, mainly because it can occupy transformed landscapes, such as croplands and grasslands.


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