Groundwater and surface water connectivity within the recharge area of Guarani aquifer system during El Niño 2014–2016          下载免费PDF全文

Ludmila Vianna Batista  Didier Gastmans  Ricardo Sánchez‐Murillo  Bárbara Saeta Farinha  Sarah Maria Rodrigues dos Santos  Chang Hung Kiang 《水文研究》2018,32(16):2483-2495

Recharge areas of the Guarani Aquifer System (GAS) are particularly sensitive and vulnerable to climate variability; therefore, the understanding of infiltration mechanisms for aquifer recharge and surface run‐off generation represent a relevant issue for water resources management in the southeastern portion of the Brazilian territory, particularly in the Jacaré‐Pepira River watershed. The main purpose of this study is to understand the interactions between precipitation, surface water, and groundwater using stable isotopes during the strong 2014–2016 El Niño Southern Oscillation event. The large variation in the isotopic composition of precipitation (from ?9.26‰ to +0.02‰ for δ¹⁸O and from ?63.3‰ to +17.6‰ for δ²H), mainly associated with regional climatic features, was not reflected in the isotopic composition of surface water (from ?7.84‰ to ?5.83‰ for δ¹⁸O and from ?49.7‰ to +33.6‰ for δ²H), mainly due to the monthly sampling frequency, and groundwater (from ?7.04‰ to ?7.76‰ for δ¹⁸O and from ?49.5‰ to ?44.7‰ for δ²H), which exhibited less variation throughout the year. However, variations in deuterium excess (d‐excess) in groundwater and surface water suggest the occurrence of strong secondary evaporation during the infiltration process, corresponding with groundwater level recovery. Similar isotopic composition in groundwater and surface water, as well as the same temporal variations in d‐excess and line‐conditioned excess denote the strong connectivity between these two reservoirs during baseflow recession periods. Isotopic mass balance modelling and hydrograph separation estimate that the groundwater contribution varied between 70% and 80%, however, during peak flows, the isotopic mass balance tends to overestimate the groundwater contribution when compared with the other hydrograph separation methods. Our findings indicate that the application of isotopic mass balance methods for ungauged rivers draining large groundwater reservoirs, such as the GAS outcrop, could provide a powerful tool for hydrological studies in the future, helping in the identification of flow contributions to river discharge draining these areas.  相似文献   

Using a shifted Grünwald-Letnikov scheme for the Caputo derivative to study anomalous solute transport in porous medium     

Pedro Victor Serra Mascarenhas  Ricardo Mendonça de Moraes  André Luís Brasil Cavalcante 《国际地质力学数值与分析法杂志》2019,43(11):1956-1977

We propose an extension of the shifted Grünwald-Letnikov method to solve fractional partial differential equations in the Caputo sense with arbitrary fractional order derivative α and with an advective term. The method uses the relation between Caputo and Riemann-Liouville definitions, the shifted Grünwald-Letnikov, and the traditional backward and forward finite difference method. The stability of the method is investigated for the implicit and explicit scheme with homogeneous boundary conditions, and a stability criterion is found for the advective-dispersive equation. An application of the method is used to solve contaminant diffusion and advective-dispersive problems. The numerical solution for the fractional diffusion and fractional advection-dispersion is compared with their respective analytical solutions for different time and space grid refinements. The diffusion simulation exhibited a good fit between the analytical and numerical solutions, with the explicit scheme going from stable to unstable as the time and space refinement changes. The fractional advection-dispersion application produced small deviations from the analytical solution. These deviations, however, are analogous to the numerical dispersions encountered in conventional finite difference solutions of the advection-dispersion equation. The new method is also compared with the traditional L2 method. Notably, an example that involves asymmetrical fractional conditions, a fractional diffusivity that depends on time, and a source term show how the methods compare. Overall, this study assesses the quality and easiness of use of the numerical method.  相似文献   

Headwaters drive streamflow and lowland tracer export in a large-scale humid tropical catchment     

Christian Birkel  Alicia Correa-Barahona  Marco Martinez-Martinez  Sebastian Granados-Bolaños  Nelson Venegas-Cordero  Kenneth Gutiérrez-García  Sara Blanco-Ramírez  Rafael Quesada-Mora  Vanessa Solano-Rivera  Jasson Mussio-Mora  Andres Chavarría-Palma  Katherine Vargas-Arias  Georgianne W. Moore  Ana Maria Durán-Quesada  Javier Vasquez-Morera  Chris Soulsby  Dörthe Tetzlaff  Edgar Espinoza-Cisneros  Ricardo Sánchez-Murillo 《水文研究》2020,34(18):3824-3841

Headwaters are generally assumed to contribute the majority of water to downstream users, but how much water, of what quality and where it is generated are rarely known in the humid tropics. Here, using monthly monitoring in the data scarce (2,370 km²) San Carlos catchment in northeastern Costa Rica, we determined runoff-area relationships linked to geochemical and isotope tracers. We established 46 monitoring sites covering the full range of climatic, land use and geological gradients in the catchment. Regression and cluster analysis revealed unique spatial patterns and hydrologically functional landscape units. These units were used for seasonal and annual Bayesian tracer mixing models to assess spatial water source contributions to the outlet. Generally, the Bayesian mixing analysis showed that the chemical and isotopic imprint at the outlet is throughout the year dominated by the adjacent lowland catchments (68%) with much less tracer influence from the headwaters. However, the headwater catchments contributed the bulk of water and tracers to the outlet during the dry season (>50%) despite covering less than half of the total catchment area. Additionally, flow volumes seemed to be linearly scaled by area maintaining a link between the headwaters and the outlet particularly during high flows of the rainy season. Stable isotopes indicated mean recharge elevations above the mean catchment altitude, which further supports that headwaters were the primary source of downstream water. Our spatially detailed “snap-shot” sampling enabled a viable alternative source of large-scale hydrological process knowledge in the humid tropics with limited data availability.  相似文献   

The environment of early Mars and the missing carbonates     

David C. FERNÁNDEZ‐REMOLAR  Mónica SÁNCHEZ‐ROMÁN  Andrew C. HILL  David GÓMEZ‐ORTÍZ  Olga Prieto BALLESTEROS  Christopher S. ROMANEK  Ricardo AMILS 《Meteoritics & planetary science》2011,46(10):1447-1469

Abstract– A model is presented in which the aqueous conditions needed to generate phyllosilicate minerals in the absence of carbonates found in the ancient Noachian crust are maintained by an early CO₂‐rich atmosphere, that, together with iron (II) oxidation, would prevent carbonate formation at the surface. After cessation of the internal magnetic dynamo, a CO₂‐rich primordial atmosphere was stripped by interactions with the solar wind and surface conditions evolved from humid to arid, with ground waters partially dissolving subsurface carbonate and sulfide minerals to produce acid‐sulfate evaporitic deposits in areas with upwelling ground water. In a subsequent geochemical state (Late Noachian to Hesperian), surface and subsurface acidic solutions were neutralized in the subsurface through interaction with basaltic crust, allowing the precipitation of secondary carbonates. This model suggests that, in the early Noachian, the surface waters of Mars maintained acidity because of a drop in temperature. This would have favored increased dissolution of CO₂ and a reduction in atmospheric pressure. In this scenario, physicochemical conditions precluded the formation of surface carbonates, but induced the precipitation of carbonates in the subsurface.  相似文献   

Another Record: Ocean Warming Continues through 2021 despite La Ni?a Conditions     

Lijing CHENG  John ABRAHAM  Kevin E. TRENBERTH  John FASULLO  Tim BOYER  Michael E. MANN  Jiang ZHU  Fan WANG  Ricardo LOCARNINI  Yuanlong LI  Bin ZHANG  Zhetao TAN  Fujiang YU  Liying WAN  Xingrong CHEN  Xiangzhou SONG  Yulong LIU  Franco RESEGHETTI  Simona SIMONCELLI  Viktor GOURETSKI  Gengxin CHEN  Alexey MISHONOV  Jim REAGAN 《大气科学进展》2022,39(3):373-385

The increased concentration of greenhouse gases in the atmosphere from human activities traps heat within the climate system and increases ocean heat content (O...  相似文献   

Reproductive cycle,size at first maturation and fecundity in the golden ling,Genypterus blacodes,in Chile     

Felipe Paredes  Ricardo Bravo 《新西兰海洋与淡水研究杂志》2013,47(5):1085-1096

Reproductive aspects of the golden ling, Genypterus blacodes, from the southern Chilean fishery are presented. Gonad samples were obtained from commercially caught fish between September 1999 and October 2000. Stage of sexual maturity, gonadosomatic index (GSI), and size of females at 50% maturation determined by logistic methods and by plotting the mean GSI by total length, are presented for both years. Batch fecundity was calculated from subsampling mature ovaries containing oocytes in advanced stages of maturity. Changes in GSI and monthly diameters of oocytes showed that ling had a spawning season which extended between August and November. The sizes at first maturity in 1999 and 2000 were 86.6 and 84.8 cm total length (TL), respectively, using the logistic model, and 84 cm for both years using the mean GSI‐size plotting method. The mean batch fecundity was 333 330 oocytes per individual for fish sized 85–120 cm TL. Fecundity increased with increasing weight and total length.  相似文献   

On the landslide event in 2010 in the Monarch Butterfly Biosphere Reserve, Angangueo, Michoacán, Mexico     

Irasema Alcántara-Ayala  José López-García  Ricardo J. Garnica 《Landslides》2012,9(2):263-273

In February 2010, 19 fatalities and economic damage were caused by a regional landslide episode in the state of Michoacán, México. The municipalities of Angangueo, Ocampo, Tiquicheo de Nicolás Romero, Tuxpan, and Tuzantla were severely damaged, with Angangueo being the most affected. The event involved a series of debris flows, of which four were the most significant; these four caused 16 deaths in addition to considerable damage to roads, electricity, and the water supply system, with indirect consequences in crop production, cattle farming, and tourism. The area affected by these four flows was calculated as 282?km², with an estimated 697,346?m³ of mobilized material. General observations indicated that the initiation sources of the debris flows were on deforested zones. The present research is concentrated on the Angangueo basin, an area situated within the Monarch Butterfly Biosphere Reserve. Given the lack of rain gauges in the area of interest, records from neighboring points were used to build a comprehensive overview of the extreme precipitation event that triggered the devastating debris flows. The nearest rain gauge, Laguna del Fresno, situated 21?km to the south, recorded 204?mm of rainfall from 1 to 5 February, equivalent to 30% of the mean annual rainfall. Moreover, during a 24-h period the El Bosque rain gauge recorded 144.5?mm of precipitation, the equivalent of 2,270% of the mean rainfall for the same month (6.36?mm). The occurrence of a hailstorm preceding the rainfall event is notable; conditions in the superficial soil layer would have included an increased pore water pressure. Presumably, before the 2,000-year return period extreme rainfall event, thawing of hail and consequent moisture and/or pore-pressure increase result in decreased frictional strength. This paper presents a spatial analysis of the distribution of these landslides, mainly debris flows, as well as general observations on the triggering mechanism, the strength properties of the materials involved, and the societal impact.  相似文献   

Spatial and temporal variations of atmospheric aerosol optical thickness in northwestern Mexico     

Ricardo M. Llamas  Roberto Bonifaz  Mauro Valdés  David Riveros-Rosas  Amando LeyvaContreras 《Geofísica Internacional》2013,52(4):321-341

The purpose of this paper was to study aerosol particles in the Northwestern region of Mexico (NWM) through Aerosol Optical Thickness (AOT) parameter in the atmosphere. This parameter represents one of the extinction coefficients of solar radiation and the rate of suspended particles in the atmosphere. For determination of AOT, we considered the use of remote sensors outside of the atmosphere. In particular, Moderate Resolution Imaging Spectroradiometer (MODIS) which can measure the atmospheric AOT thickness. Data from the MODIS sensor must be validated before they are considered reliable. For this task, we required surface measurements to obtain a correlation with the data acquired with the remote radiometer. The paper describes the validation process performed for data obtained with MODIS through measurements provided by an AErosol RObotic NETwork (AERONET) photometer located in the city of Hermosillo, Sonora, NWM. Additionally, we carried out a temporal analysis based on the behavior of the AOT graphics and spatial analysis supported in maps with sufficient information.  相似文献   

A local spatial decision support system for developing countries based on MCA,fuzzy sets and OWA – case study of a municipality in Cuba     

Ricardo DELGADO TELLEZ  Ershun ZHONG  Yang ZUHU  Arisleydis PEÑA DE LA CRUZ 《地球空间信息科学学报》2013,16(2):120-129

This paper presents a Spatial Decision Support System for local governments of developing countries. It allows municipality government, enterprises, scientific community and civil society to address decision problems using GIS. The framework is supported by four modules of information technologies: Environmental Decision Support Database, Data Manipulation, Decision Support, and Mapping. A case study is presented covering the implementation of this framework in one municipality of Cuba. An example of land suitability planning for coconut crops is used to evaluate the system performance and usability. Results show local municipalities are able to use this framework to solve local decision problems using state of the art decision making even with low infrastructure development.  相似文献   

Chirripó hydrological research site: Advancing stable isotope hydrology in the Central American Páramo     

Germain Esquivel-Hernández  Ricardo Sánchez-Murillo  Enzo Vargas-Salazar 《水文研究》2021,35(5):e14181

The Chirripó hydrological research site (CHRS) is located within the Chirripó National Park, Costa Rica (between 3100 and 3820 m asl) whereby ~100 km² are covered by Páramo, a high-elevation tropical grassland ecosystem. A lake district with approximately 30 lakes of glacial origin is also protected in this area. The CHRS has been monitored since April 2015 with the aim of establishing the first water isotope baseline for the Central American Páramo. At a regional scale, the water isotope ratios (δ²H and δ¹⁸O) in precipitation and surface water at CHRS are useful for describing the governing moisture transport from the Caribbean Sea and Pacific Ocean and the complex rainfall producing systems across the N–S mountain range of Central America. These data are also providing unique information about the evaporation and water balance conditions of tropical glacial lakes and the formation of orographic and convective precipitation in high-elevation tropical ecosystems. Current data sets from CHRS include continuous lake water temperature and meteorological conditions (i.e., precipitation amount, air temperature and relative humidity), as well as water stable isotopes in precipitation, stream water, and lake water (daily to biweekly sampling frequency). Stream water is collected at several locations across the topographic gradient whereas lake water is sampled in the three main lake systems of CHRS. CHRS serves as a reference site for conducting pilot isotopic research in high-elevation ecosystems to advance the atmospheric, hydrogeological and ecohydrological studies in these understudied biomes. All data from April 2015 to November 2020 are publicly available.  相似文献