Soil quality indicator of oxisols grown with sugarcane and native forest in northeastern São Paulo state,Brazil     

Ludmila de Freitas  Marcílio Vieira Martins Filho  José Carlos Casagrande  Ivanildo Amorim de Oliveira  Luiz Gabriel da Silva 《Environmental Earth Sciences》2018,77(18):642

The evaluation of soil quality is an important tool for degradation monitoring and sustainable management implementation. The objective of this study was to measure physical and chemical soil properties to set soil quality and validate a model of soil quality indicator in latosols (oxisols) under sugarcane cropping and native forest. The study was carried out in the cities of Araras, Santa Ernestina, and Guariba in São Paulo State, Brazil. We collected 24 samples of disturbed and undisturbed soil at 0.0–0.10 m layer from three areas grown with sugarcane and neighboring locations under native woodland. We assessed the following soil properties: (a) chemical—pH in CaCl₂, organic matter (OM), phosphorus (P), potassium (K⁺), calcium (Ca²⁺), magnesium (Mg²⁺), potential acidity (H?+?Al), aluminum (Al³⁺), and sulfur (S); (b) physical—macro- and microporosity, soil bulk density (Ds), aggregate stability, mean weight diameter (MWD), rill (K_r) and interrill (K_i) global erodibility, shear stress (τc), and magnetic susceptibility (MS). Data underwent multivariate statistics to identify the properties that denote soil quality and to set their weights within the functions of soil quality indicator (SQI). This study showed that the multivariate analysis was efficient in determining which physical and chemical properties were most sensitive, of which we can mention total sand, MS, clay, microporosity, Mg, Ca, pH, and OM. We can therefore conclude that the quality indicators of soils grown with sugarcane were lower than those under forest were, showing the need for adoption of conservation management practices.  相似文献   

Ra and Rn isotopes as natural tracers of submarine groundwater discharge in the patagonian coastal zone (Argentina): an initial assessment     

Américo I. Torres  Carlos F. Andrade  Willard S. Moore  Mauricio Faleschini  José L. Esteves  Luis F. H. Niencheski  Pedro J. Depetris 《Environmental Earth Sciences》2018,77(4):145

Submarine groundwater discharge (SGD) is herein recognized as a significant pathway of material transport from land to the coastal SW Atlantic Ocean and thus, it can be a relevant factor affecting the marine biogeochemical cycles in the region. This paper focuses on the initial measurements of ²²⁶Ra, ²²⁸Ra and ²²²Rn made in Patagonia’s coastal zone of Chubut and Santa Cruz provinces (42°S–48°S, Argentina). ²²⁶Ra activity ranged from 2.9 to 73.5 dpm 100 L^?1, and ²²⁸Ra activity ranged from 11.9 to 311.0 dpm 100 L^?1 in groundwater wells. The radium activities found in Patagonia’s marine coastal regions and adjacent shelf indicate significant enrichment throughout the coastal waters. Groundwater samples presented the largest ²²²Rn activity and ranged from 2.66 to 1083 dpm L^?1. Conversely, in the coastal marine environment, the ²²²Rn activity ranged from 1.03 to 6.23 dpm L^?1. The Patagonian coastal aquifer showed a larger enrichment in ²²⁸Ra than in ²²⁶Ra, which is a typical feature for sites where SGD is dominant, probably playing a significant role in the biogeochemistry of these coastal waters.  相似文献   

Identification of hydrogeochemical processes in a volcano-sedimentary aquifer of Ciénega de Chapala in Michoacán,Mexico     

José Alfredo Ramos-Leal  Janete Morán-Ramírez  José Teodoro Silva-García  Rosa María Fuentes-Rivas  Gustavo Cruz-Cárdenas  Salvador Ochoa-Estrada  Francisco Estrada-Godoy 《Arabian Journal of Geosciences》2018,11(15):422

The present study characterized the hydrogeochemical processes of the aquifer of Ciénega de Chapala in Michoacán, Mexico. The dominant water families contained bicarbonate magnesium and sodium. In the region, water infiltrates into a fractured volcanic environment exposed in the surrounding mountains and is transmitted to the volcano-sedimentary units of the ciénega, where silicate alteration and ion exchange processes occur in the clays of the subsoil. The Gibb diagrams confirm that the main evolutionary processes in the aquifer are rock-water interactions in the local flow and evaporation in the intermediate and regional flows. The molar ratios of HCO₃/Na and Ca/Na are congruent with the type of volcano-sedimentary environment present in the area. Ternary mixing processes associated with three end members were also identified and were related to the flow systems in the area. The local flow contributes 77% of water to the system, and the intermediate and regional flows contribute 16% and 7%, respectively.  相似文献   

Diagnosis of Free and Convectively Coupled Equatorial Waves     

Carlos A. F. Marques  José M. Castanheira 《Mathematical Geosciences》2018,50(5):585-606

A methodology for diagnosis of free and convectively coupled equatorial waves (CCEWs) is reviewed and illustrated for Kelvin and mixed Rossby–gravity (MRG) waves. The method is based on prefiltering of the geopotential and horizontal wind, using three-dimensional normal mode functions of the adiabatic linearized equations of a resting atmosphere, followed by space–time power and cross-spectral analysis applied to the normal-mode-filtered fields and the outgoing long-wave radiation (OLR) to identify spectral regions of coherence. The methodology is applied to geopotential and horizontal wind fields produced by European Centre for Medium-Range Weather Forecasts interim reanalysis and OLR data produced by the National Oceanic and Atmospheric Administration. The same type of data simulated by two climate models that participated in the fifth phase of the climate model intercomparison project are also used. Overall, simulation of free and CCEWs was achieved by the models with moderate success. Kelvin and MRG waves were identified in the space–time spectral domains, using both observationally based and climate model datasets. Other nonequatorial waves, classified as tropical depression and extratropical storm track activity, along with the Madden–Julian oscillation were also observed. However, significant deviations were also evident in the models, which may help identification of deficiencies in the models’ simulation schemes for some physical processes. Therefore, this diagnosis method should be a useful procedure for climate model validation and model benchmarking.  相似文献   

Recommendation system to determine suitable and viable hiking routes: a prototype application in Sierra de las Nieves Nature Reserve (southern Spain)     

Jesús Vías  José Rolland  María Luisa Gómez  Carmen Ocaña  Ana Luque 《Journal of Geographical Systems》2018,20(3):275-294

This paper describes a system for recommending hiking routes to help manage hiking activities in a protected area. The system proposes various routes, based on five criteria that maximize some aspects of hikers’ requirements (by analyzing the viability and difficulty of the trails) and also those of protected areas managers (by proposals to relieve congestion in areas already used for hiking and to promote awareness of new ones, as a contribution to environmental education). The recommendation system uses network analysis, multi-criteria decision analysis and geographic information system by free software tools: PgRouting, PostgreSQL and PostGIS. This system has been tested in Sierra de las Nieves Nature Reserve (Andalusia, Spain). Of the 182 routes obtained by the system, 62 (34%) are considered viable for hikers in Sierra de las Nieves, taking into account the type of user most likely to visit this protected area. Most routes have a high difficulty level, which is coherent with the mountainous character of the protected area.  相似文献   

Characterization of a landslide-triggered debris flow at a rainforest-covered mountain region in Brazil     

Cabral  Victor Carvalho  Reis  Fábio Augusto Gomes Vieira  D’Affonseca  Fernando Mazo  Lucía  Ana  dos Santos Corrêa  Claudia Vanessa  Veloso  Vinicius  Gramani  Marcelo Fischer  Ogura  Agostinho Tadashi  Lazaretti  Andrea Fregolente  Vemado  Felipe  Pereira Filho  Augusto José  dos Santos  Claudia Cristina  Lopes  Eymar Silva Sampaio  Rabaco  Lis Maria Reoni  do Carmo Giordano  Lucilia  Zarfl  Christiane 《Natural Hazards》2021,108(3):3021-3043

Natural Hazards - Debris flows represent great hazard to humans due to their high destructive power. Understanding their hydrogeomorphic dynamics is fundamental in hazard assessment studies,...  相似文献   

A combined structural and seasonal approach to assess wildfire susceptibility and hazard in summertime     

Bergonse  Rafaello  Oliveira  Sandra  Gonçalves  Ana  Nunes  Sílvia  da Câmara  Carlos  Zêzere  José Luis 《Natural Hazards》2021,106(3):2545-2573

Natural Hazards - Wildfire susceptibility and hazard models based on drivers that change only on a multiyear timescale are considered of a structural nature. They ignore specific short-term...  相似文献   

Rapid characterisation of the extremely large landslide threatening the Rules Reservoir (Southern Spain)     

Reyes-Carmona  Cristina  Galve  Jorge Pedro  Moreno-Sánchez  Marcos  Riquelme  Adrián  Ruano  Patricia  Millares  Agustín  Teixidó  Teresa  Sarro  Roberto  Pérez-Peña  José Vicente  Barra  Anna  Ezquerro  Pablo  López-Vinielles  Juan  Béjar-Pizarro  Marta  Azañón  José Miguel  Monserrat  Oriol  Mateos  Rosa María 《Landslides》2021,18(12):3781-3798

Landslides - When an active landslide is first identified in an artificial reservoir, a comprehensive study has to be quickly conducted to analyse the possible hazard that it may represent to such...  相似文献   

Variability of particulate (SS,POC) and dissolved (DOC,NO3) matter during storm events in the Alegria agricultural watershed          下载免费PDF全文

Itsasne Cerro  José Miguel Sanchez‐Perez  Estilita Ruiz‐Romera  Iñaki Antigüedad 《水文研究》2014,28(5):2855-2867

The temporal variability of suspended sediment, nitrates (NO₃) and dissolved (DOC) and particulate organic carbon concentrations was analysed in the Alegria agricultural watershed over a 2‐year period. Nine storm events were studied, including an exhaustive analysis of hydrometeorological conditions, quantification of fluxes, and concentration‐discharge hysteresis loop characterization. The overall aim was to study the variability in these components during storm events and determine the mechanisms (flow paths) affecting the trajectories, from the source to the stream. The forms, rotational patterns and trends of hysteretic loops were investigated, and relationships between hysteresis features and hydrological parameters were studied. The results revealed clear differences between particulate (suspended sediment, particulate organic carbon) and dissolved (DOC, NO₃) matter transport responses. Movement of the particulate matter was attributed to surface water, as reflected in clockwise hysteresis loops, whereas dissolved matter showed, in general, counterclockwise hysteresis loops, indicating a time delay in the arrival of solutes to the stream. This could be related to subsurface flow paths for DOC and a groundwater source for NO₃. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

Rights to carbon and payments for services rendered under REDD+: Options for the case of Mexico     

Margaret Skutsch  Cecilia Simon  Alejandro Velazquez  José Carlos Fernández 《Global Environmental Change》2013,23(4):813-825

Mexico is relatively advanced in its preparation for international policy on Reduced Emissions from Deforestation and forest Degradation (REDD+) and has many of the pre-conditions needed to support a community approach in the implementation of a national REDD+ programme, particularly as regards tenure of forests and experience with community forest management and PES schemes, although these conditions do not pertain everywhere. One critical issue that is yet to be resolved concerns rights to carbon credits and distribution of the financial benefits flowing from REDD+. We demonstrate that attribution of carbon credits from reduced deforestation and degradation at the community level is virtually impossible from a technical viewpoint, since these credits are counterfactual. Payments based on assessment of performance of each community in terms of such reductions would moreover be inequitable and inefficient. Flat rate payments in return for agreed improvements in management are likely to be more motivating and much easier to administer. However, increases in carbon stock (forest enhancement) can be physically measured on site, and could be more easily attributed to each individual community. We therefore propose a system in which reduced deforestation and degradation are considered environmental services, with credits accruing to national government. The financial value of the credits may be used to finance flat rate payments to communities who agree to implement improved management. On the other hand, credits for forest enhancement, which reflect measurable increases in carbon in the communities’ trees, would be considered environmental goods. These should be considered the direct property of the owners of the forest (in the same sense as wood or poles) and it would be possible for communities to sell these credits themselves. We acknowledge however that many other problems face implementation of REDD+ in Mexico, and provide a number of important examples.  相似文献