High-resolution tropical forest mapping of the Amazon basin: a novel classification approach for the GRFM radar mosaic

Author(s):  
M. Sgrenzaroli ◽  
A. Baraldi ◽  
G.F. De Grandi ◽  
F. Achard ◽  
H. Eva
2021 ◽  
Author(s):  
Marcela Eduarda Della Libera de Godoy ◽  
Valdir F. Novello ◽  
Francisco William Cruz

<p>South American Monsoon System (SAMS) and its main feature, the South American Convergence Zone (SACZ) are responsible for the major distribution of moisture in South America. The current work presents a novel high-resolution oxygen isotope record (δ<sup>18</sup>O) based on speleothems from southwest Amazon basin (Brazil), right at SAMS' core region and SACZ onset, where there is still a gap of high resolution paleoclimate records. The novel δ<sup>18</sup>O record presents an average of 3 year-resolution, composed by 1344 stable isotope analysis performed in two speleothems with a well-resolved chronology (37 U/Th ages) with average errors <1%. This work aims to describe the rainfall variability of the core region of the South American monsoon for the last 3k years and to take a broader look at precipitation patterns over Amazon basin. The Rondônia δ18O record shows three main stages throughout this time period. The first is from -1000 to ~400 CE, where it’s in accordance with most of other paleorecords from the Amazon basin. the second segment  is from ~400 to 1200 CE, when there is a continuous increase in the δ18O record until it reaches its highest values around 850 CE during the MCA (800-1200 CE), which is in accordance with western Amazon records, whilst the record in eastern Amazon presents an opposite trend. Thus, a precipitation dipole over Amazon emerges from ~400 CE onwards, majorly triggered by anomalous climate changes such as MCA, where western (eastern) Amazon is drier (wetter). During LIA (1450-1800 CE), on the other hand, Rondônia record presents its lowest values, also agreeing with western records and with records under the influence of SACZ whilst on eastern Amazon a drier period is established. Therefore, with this novel paleoclimate record located at the core region of SAMS, it's possible to evidence the dynamics of the precipitation dipole over the Amazon region, as well as understand the SACZ intensity variations.</p>


Zootaxa ◽  
2018 ◽  
Vol 4504 (3) ◽  
pp. 401
Author(s):  
FERNANDO DA SILVA CARVALHO-FILHO ◽  
INOCÊNCIO DE SOUSA GORAYEB ◽  
JÉSSICA MARIA MENEZES SOARES ◽  
MATHEUS TAVARES DE SOUZA

The white-sand enclaves in the Amazon Basin are small areas scattered through the tropical forest, with sandy and nutrient-poor soils and an unusual vegetation type. The insect fauna of this ecosystem is poorly known, especially in the eastern Amazon. The flesh fly fauna of an area of open herbaceous white-sand vegetation known as “Campo Redondo” in the municipality of Cametá, state of Pará, was surveyed, resulting in the discovery of 43 species in 11 genera representing the subfamilies Sarcophaginae and Miltogramminae. Four new species are described: Dexosarcophaga (Dexosarcophaga) campina sp. nov., Helicobia cametaensis sp. nov., Helicobia domquixote sp. nov., and Metopia fofo sp. nov. Lepidodexia (Lepidodexia) grisea Lopes and Lepidodexia (Notochaeta) setifrons (Lopes) are newly recorded from Brazil. Dexosarcophaga (Bezzisca) ampullula (Engel), D. (Dexosarcophaga) transita Townsend and Titanogrypa (Cucullomyia) larvicida (Lopes) are newly recorded from the Brazilian Amazon. 


Author(s):  
L. Hang ◽  
G. Y. Cai

Abstract. The detection and reconstruction of building have attracted more attention in the community of remote sensing and computer vision. Light detection and ranging (LiDAR) has been proved to be a good way to extract building roofs, while we have to face the problem of data shortage for most of the time. In this paper, we tried to extract the building roofs from very high resolution (VHR) images of Chinese satellite Gaofen-2 by employing convolutional neural network (CNN). It has been proved that the CNN is of a higher capability of recognizing detailed features which may not be classified out by object-based classification approach. Several major steps are concerned in this study, such as generation of training dataset, model training, image segmentation and building roofs recognition. First, urban objects such as trees, roads, squares and buildings were classified based on random forest algorithm by an object-oriented classification approach, the building regions were separated from other classes at the aid of visually interpretation and correction; Next, different types of building roofs mainly categorized by color and size information were trained using the trained CNN. Finally, the industrial and residential building roofs have been recognized individually and the results have been validated individually. The assessment results prove effectiveness of the proposed method with approximately 91% and 88% of quality rates in detection industrial and residential building roofs, respectively. Which means that the CNN approach is prospecting in detecting buildings with a very higher accuracy.


Author(s):  
Rajesh Bahadur Thapa ◽  
Manabu Watanabe ◽  
Masanobu Shimada ◽  
Takeshi Motohka

2020 ◽  
Vol 375 (1794) ◽  
pp. 20190128 ◽  
Author(s):  
C. Soto-Navarro ◽  
C. Ravilious ◽  
A. Arnell ◽  
X. de Lamo ◽  
M. Harfoot ◽  
...  

Integrated high-resolution maps of carbon stocks and biodiversity that identify areas of potential co-benefits for climate change mitigation and biodiversity conservation can help facilitate the implementation of global climate and biodiversity commitments at local levels. However, the multi-dimensional nature of biodiversity presents a major challenge for understanding, mapping and communicating where and how biodiversity benefits coincide with climate benefits. A new integrated approach to biodiversity is therefore needed. Here, we (a) present a new high-resolution map of global above- and below-ground carbon stored in biomass and soil, (b) quantify biodiversity values using two complementary indices (BIp and BIr) representing proactive and reactive approaches to conservation, and (c) examine patterns of carbon–biodiversity overlap by identifying 'hotspots' (20% highest values for both aspects). Our indices integrate local diversity and ecosystem intactness, as well as regional ecosystem intactness across the broader area supporting a similar natural assemblage of species to the location of interest. The western Amazon Basin, Central Africa and Southeast Asia capture the last strongholds of highest local biodiversity and ecosystem intactness worldwide, while the last refuges for unique biological communities whose habitats have been greatly reduced are mostly found in the tropical Andes and central Sundaland. There is 38 and 5% overlap in carbon and biodiversity hotspots, for proactive and reactive conservation, respectively. Alarmingly, only around 12 and 21% of these proactive and reactive hotspot areas, respectively, are formally protected. This highlights that a coupled approach is urgently needed to help achieve both climate and biodiversity global targets. This would involve (1) restoring and conserving unprotected, degraded ecosystems, particularly in the Neotropics and Indomalaya, and (2) retaining the remaining strongholds of intactness. This article is part of the theme issue ‘Climate change and ecosystems: threats, opportunities and solutions’.


2012 ◽  
Vol 34 (1) ◽  
pp. 139-153 ◽  
Author(s):  
Nguyen Thanh Hoan ◽  
Ryutaro Tateishi ◽  
Bayan Alsaaideh ◽  
Thomas Ngigi ◽  
Ilham Alimuddin ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document