Desempenho de índices quantitativos de seca na estimativa da produtividade de arroz de terras altas

O objetivo deste trabalho foi caracterizar a intensidade e a ocorrência de seca pelo uso de índices quantitativos, e avaliar a relação entre esses índices e os dados da série histórica da produtividade ajustada do arroz de terras altas da microrregião de Goiânia, GO. O ajuste da série histórica foi realizado para minimizar os efeitos da variabilidade climática da região e dos avanços tecnológicos sobre a produtividade. Foram avaliados os seguintes índices: severidade de seca de Palmer (PDSI); Z de Palmer (Z-index); o de anomalia de chuva (RAI); e o padronizado de precipitação (SPI). Os índices de seca foram analisados com uso da correlação de Pearson, número e frequência de ocorrência da seca e percentual de acerto dos índices em relação à produtividade ajustada. O RAI quantificou o maior número de eventos extremos de seca, enquanto o PDSI não estimou nenhum caso. O Z-index apresentou o maior percentual de acerto, em relação às variações ocorridas na produtividade ajustada. Em períodos com variações da produtividade ajustada maior que 300 kg ha-1, Z-index, RAI e SPI apresentaram 78, 78 e 67% de percentuais de acerto, respectivamente. O Z-index teve o melhor desempenho na estimação da produtividade ajustada de arroz de terras altas

Study Abroad Field Trip Improves Test Performance through Engagement and New Social Networks

Although study abroad trips provide an opportunity for affective and cognitive learning, it is largely assumed that they improve learning outcomes. The purpose of this study is to determine whether a study abroad field trip improved cognitive learning by comparing test performance between the study abroad participants (n = 20) and their peers who did not participate (n = 365). Test performance was statistically identical between these groups before and immediately after the study abroad program. On the final exam, the study abroad participants scored significantly higher. Qualitative methods were used to identify increased engagement with the course material and the creation of new social networks as likely explanations. © 2011 Copyright Taylor and Francis Group, LLC

Soil moisture: A central and unifying theme in physical geography

Soil moisture is a critical component of the earth system and plays an integrative role among the various subfields of physical geography. This paper highlights not just how soil moisture affects atmospheric, geomorphic, hydrologic, and biologic processes but that it lies at the intersection of these areas of scientific inquiry. Soil moisture impacts earth surface processes in such a way that it creates an obvious synergistic relationship among the various subfields of physical geography. The dispersive and cohesive properties of soil moisture also make it an important variable in regional and microclimatic analyses, landscape denudation and change through weathering, runoff generation and partitioning, mass wasting, and sediment transport. Thus, this paper serves as a call to use research in soil moisture as an integrative and unifying theme in physical geography. © The Author(s) 2010

An evolving Anthropocene for science and society

Anthropocene has come a long way since its inception. In 2011, two editors and a publisher affiliated with the Elsevier journal Earth-Science Reviews met over coffee at the annual meeting of the Geological Society of America in Minneapolis (USA). Inspired by the theme of the conference, “Archean to Anthropocene,” along with lively discussions surrounding the topic, the idea emerged to create a new journal titled Anthropocene. Recognizing the significance of human interactions with Earth systems throughout history and into the future, the Journal would serve to facilitate interdisciplinary exchange of knowledge and ideas in addressing broadly the question of how the interacting Earth’s surface and societies will evolve in the “Anthropocene,”—one of the grand challenges of our time ( NRC, 2010)

The Vulnerability Assessment Method for Beijing Agricultural Drought

International audienceDrought is a major disaster which Beijing agricultural systems faced with, build drought warning mechanism we need in-depth analysis the causes and mechanism of the drought to provide a basis for scientific disaster reduction and prevention. VAM vulnerability assessment method, selected 15 factors represent drought exposure, sensitivity and adaptive capacity, based on improved analytic hierarchy process to determine the weight of each factors, use K-means clustering algorithm to generate the drought vulnerability index system of research district. Draw vulnerability zoning map based on ArcGIS