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241.
We investigate eruptive activity by analysis of thermal-alert data from the MODIS (moderate resolution imaging spectrometer) thermal infrared satellite instrument, detected by the MODVOLC (MODIS Volcano alert) algorithm. These data are openly available on the Internet, and easy to use. We show how such data can plug major gaps in the conventional monitoring record of volcanoes in an otherwise generally poorly documented region (Melanesia), including: characterising the mechanism of lava effusion at Pago; demonstrating an earlier-than-realised onset of lava effusion at Lopevi; extending the known period of lava lake activity at Ambrym; and confirming ongoing activity at Bagana, Langila and Tinakula. We also add to the record of activity even at some generally better-monitored volcanoes in Indonesia, but point out that care must be taken to recognise and exclude fires.Editorial responsibility: J Stix 相似文献
242.
A climate trend analysis of Ethiopia: examining subseasonal climate impacts on crops and pasture conditions 总被引:3,自引:0,他引:3
Molly E. Brown Chris Funk Diego Pedreros Diriba Korecha Melesse Lemma James Rowland Emily Williams James Verdin 《Climatic change》2017,142(1-2):169-182
Ethiopia experiences significant climate-induced drought and stress on crop and livestock productivity, contributing to widespread food insecurity. Here, we present subseasonal crop water stress analyses that indicate degrading, growing conditions along Ethiopia’s eastern highlands, including productive and populated highland regions. These seasonally shifting areas of increasing water stress stretch from the north to south across eastern Ethiopia, intersecting regions of acute food insecurity and/or high population. Crop model simulations indicate that between 1982 and 2014, parts of eastern Amhara and eastern Oromia experienced increasing water deficits during the critical sowing, flowering, and ripening periods of crop growth. These trends occurred while population in these regions increased by 143% between 2000 and 2015. These areas of enhanced crop water stress in south-central Ethiopia coincide with regions of high population growth and ongoing crop extensification. Conversely, large regions of relatively unpopulated western Ethiopia are becoming wetter. These areas may therefore be good targets for agricultural development. 相似文献
243.
Long‐term spatial dynamics in vegetated seascapes: fragmentation and habitat loss in a human‐impacted subtropical lagoon 下载免费PDF全文
Vegetated coastal seascapes exhibit dynamic spatial patterning, some of which is directly linked to human coastal activities. Human activities (e.g. coastal development) have modified freshwater flow to marine environments, resulting in significant changes to submerged aquatic vegetation (SAV) communities. Yet, very little is known about the spatially complex process of SAV habitat loss and fragmentation that affects ecosystem function. Using habitat mapping from aerial photography spanning 71 years (1938–2009) for Biscayne Bay (Florida, USA), we quantify both SAV habitat loss and fragmentation using a novel fragmentation index. To understand the influence of water management practices on SAV seascapes, habitat loss and fragmentation were compared between nearshore and offshore locations, as well as locations adjacent to and distant from canals that transport freshwater into the marine environment. Habitat loss and fragmentation were significantly higher along the shoreline compared with offshore seascapes. Nearshore habitats experienced a net loss of 3.31% of the total SAV mapped (2.57 km2) over the time series. While areas adjacent to canals had significantly higher SAV cover, they still experienced wide fluctuations in cover and fragmentation over time. All sites exhibited higher fragmentation in 2009 compared with 1938, with four sites exhibiting high fragmentation levels between the 1990s and 2000s. We demonstrate that freshwater inputs into coastal bays modify the amount of SAV and the fragmentation dynamics of SAV habitats. Spatial changes are greater close to shore and canals, indicating that these coastal developments have transformative impacts on vegetated habitats, with undetermined consequences for the provisioning of ecosystem goods and services. 相似文献
244.
245.
We present near-infrared monitoring taken with the 1.5 m Carlos Sánchez Telescope in Tenerife and CCD photometry taken with the Jacobus Kapteyn Telescope in La Palma of the 1988 outburst of 3C 279. This is combined with archival data to examine the behaviour of the light curve fromB toK.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain. 相似文献
246.
Lucia Fanning Robin Mahon Patrick McConney Jorge Angulo Felicity Burrows Bisessar Chakalall Diego Gil Milton Haughton Sherry Heileman Sergio Martínez L’ouverture Ostine Adrian Oviedo Scott Parsons Terrence Phillips Claudia Santizo Arroya Bertha Simmons Cesar Toro 《Marine Policy》2007
A large marine ecosystem (LME) governance framework, developed from a need to effectively address the sustainable management of the shared living marine resources of the Caribbean, is proposed. The framework is based on four propositions and focuses on a linked examination of two well-known components of LME-level governance: the policy cycle process by which decisions are made and the multi-level nature of LMEs. It accommodates the diversity of policy cycles at multiple levels and the linkages among them required for effective governance of LMEs. The framework takes into account of factors such as context, purpose, jurisdictional scale, capacity and complexity and provides a means to identify critical areas for intervention. 相似文献
247.
Juan Pablo de Rosas Alexander Dario Esquivel Diego Martinez Heimann Agustin E. Negri Flavia Lohaiza Diego Leonardo Valladares Alejandro I. Zavala Hugo Huck Jimena Juri Ayub 《Environmental Earth Sciences》2018,77(16):587
This work presents the results of a soil erosion study using the 7Be technique. This technique estimates the water erosion/deposition from the comparison between 7Be soil content of a reference site and an eroded or sedimented site. The soil samples were collected from an agricultural area of the semiarid region of Argentina near San Luis City, which has a marked rainfall season. The area has been used for crop cultivation, being subjected to plowing practices. The 7Be in the Reference Site was in the first centimeter of soil, showing the typical exponential decreasing of 7Be soil content with depth, with the 7Be inventories value being 340?±?50 Bq m?2 for the dry season and 571?±?48 Bq m?2 for the rainy season. The 7Be technique was applied to a potential eroded site subjected to traditional tillage practices (plowing). A net soil erosion value of 13.5 t ha?1 (1.35 kg m?2) was obtained. From the assumptions of the applied technique, we can draw the inference that this erosion was caused by rains produced in the month prior to the date of soil sampling. 相似文献
248.
Tayyebi Saeid M. Pastor Manuel Stickle Miguel M. Yage ngel Manzanal Diego Molinos Miguel Navas Pedro 《Landslides》2022,19(2):421-435
Landslides - Rapid flow-like landslides, particularly debris flows and debris avalanches, cause significant economic damage and many victims worldwide every year. They are usually extremely fast... 相似文献
249.
D’Altri Antonio Maria Cannizzaro Francesco Petracca Massimo Talledo Diego Alejandro 《Bulletin of Earthquake Engineering》2022,20(4):1999-2043
Bulletin of Earthquake Engineering - In this paper, a simple and practitioners-friendly calibration strategy to consistently link target panel-scale mechanical properties (that can be found in... 相似文献
250.
随着工矿业、农业的发展,许多国家和地区都已发现重金属污染问题,掌握土壤重金属的来源情况对于维护生态安全十分必要。本文对三里岗镇八种重金属元素进行了含量分析和半变异函数分析,并通过正定矩阵因子分解法结合源贡献率空间分布特征探究了土壤中8种重金属元素的来源。结果表明:As、Cd、Cr、Cu、Ni和Zn的土壤含量均超出全国背景值,内梅罗综合污染指数均值为073,说明研究区整体处于尚清洁水平。半变异函数分析显示8种重金属元素更多受到结构性因素的影响。PMF源解析所得到的4个来源分别解释为震旦系和白垩系地层母岩的影响、元古界地层与乡村道路交通排放的混合源、震旦系和寒武系地层母岩的影响以及奥陶系到志留系地层母岩的影响,说明自然源是研究区重金属的主要来源。此外,本文研究结果表明PMF模型在重金属源解析工作中可以发挥十分重要的作用。 相似文献