ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (33)
  • Mexico  (17)
  • groundwater  (15)
  • Animals
  • Chemical Engineering
  • Electronic structure and strongly correlated systems
  • temperature
  • Springer  (33)
  • Geography  (33)
  • 1
    Electronic Resource
    Electronic Resource
    Determination of hydraulic diffusivity of aquifers by spectral analysis (1999)
    Springer
    Stochastic environmental research and risk assessment 13 (1999), S. 85-99 
    Details
    ISSN: 1436-3259
    Keywords: Key words: Hydraulic diffusivity ; groundwater ; spectral analysis ; stochastic boundaries.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract: This study uses the cyclical frequency to develop the mathematical relationship between hydraulic diffusivity and spectral density functions calculated from groundwater level variation. Such relationship can be applied to (1) unsteady state, one-dimensional confined aquifer with time-dependent water level on both end boundaries, and (2) linearized unconfined aquifer with or without vertical recharge. The spectral density functions of groundwater fluctuations are largely affected by the spectral density functions obtained from time-dependent end boundaries and their cross-spectral density functions. Hydraulic diffusivity of an aquifer can be solved by type-curve matching technique at a specified frequency band under the conditions of (1) confined aquifer having equal time-dependent boundaries on both ends, (2) unconfined aquifer having equal time-dependent boundaries on both ends with surface recharge, and (3) unconfined aquifer subjected to surface recharge but neglecting the water table fluctuations on both end boundaries.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004770050033
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Dew and its effect on two heliophile understorey species of a tropical dry deciduous forest in Mexico (1999)
    Springer
    International journal of biometeorology 43 (1999), S. 1-7 
    Details
    ISSN: 1432-1254
    Keywords: Key words Dew ; Heliophile species ; Mexico ; Transpiration ; Tropical dry deciduous forest
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography , Physics
    Notes: Abstract  A series of horizontal and vertical measurements of dew deposition and dew duration were carried out in a tropical dry deciduous forest in western Mexico (19° 30′ N, 105° 03′ W). The effect of dew on transpiration in heliophile species was also investigated. The amount of dew was very variable with no temporal or spatial pattern. The amount of dew measured at two horizontal transects (maximum and minimum) (at heights of 0.20 m and 1.30 m above ground level) was from 0.014 to 0.203 mm and from 0.013 to 0.061 mm in the middle and at the end of the dry season, respectively. Dew deposition at different vertical levels (0.50–12.5 m height) ranged from 0.04 to 0.36 mm. The duration of dew formation ranged between 60 and 129 min after sunrise above the canopy (a height of 11 m), and between 259 and 290 min after sunrise at a height of 2 m. Daily transpiration rates were 883 and 632 g m–2 d–1 in Coccoloba liebmannii and 538 and 864 g m–2 d–1 in Jacquinia pungens in January and April, respectively. Transpiration was restricted from sunrise to early afternoon in April, as a result of the pronounced midday closure of stomata in both species. The reduction of transpiration by dew ranged from 13.2 to 50.1 g m–2 d–1 and from 4.5 to 77.7 g m–2 d–1 for C. liebmannii and J. pungens, respectively. Dew can play an important role in enhancing the survival of heliophile species in the dry season by reducing transpiration rates during the morning.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004840050109
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Field Investigations for Sustainable Groundwater Utilization in the Konan Basin (1999)
    Springer
    Water resources management 13 (1999), S. 443-470 
    Details
    ISSN: 1573-1650
    Keywords: freshwater crisis ; groundwater ; hydrogeology ; Japan ; konan basin ; pumping-tests ; safe pumpage ; sustainable water supply
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geography
    Notes: Abstract The Konan groundwater basin of Kochi Prefecture, Japan, is experiencing freshwater shortages for the past few years, particularly during the winter season. The present study aimed at analyzing the problem and exploring increased groundwater withdrawals to meet burgeoning freshwater demands in various sectors. The trend analysis of waterconsumption indicates that the groundwater demandwould increase by 43 and 52% by the years 2010 and2025, respectively, compared to 32 100 m3 d-1 at present.The streamflow of the Monobe River reduces to a minimumin winter and it shows a decreasing trend in recentyears. The geologic investigation results indicatethat unconfined (phreatic) aquifers comprisingalluvial sand and gravel and/or diluvial silty sandand gravel are dominant, and that the northwestern andwestern portions of the basin have greater potentialfor groundwater. Groundwater flows essentially fromnorth to south into the ocean. Groundwater levelfluctuations over the basin vary appreciably in spaceand time, indicating a wide variation of naturalrecharge. Field observations confirm the hypothesisthat stream-aquifer interaction also significantlycontributes to groundwater recharge, besides therainfall infiltration. Further, the pumping testsresults demonstrate that though the aquifers arelow-yielding, enhanced groundwater withdrawals couldbe possible. The aquifer hydraulic conductivity ischaracterized as high and ranges from 65 to 804 m d-1(mean = 229 m d-1), thereby suggesting great aquiferheterogeneity. Finally, it is concluded that thelong-term sustainability of the scarce groundwaterresource of the Konan basin is doubtful, and that acomprehensive analysis of the groundwater system isessential prior to formulating plans for the futuregroundwater development and management.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008184010262
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    An Aquifer Management Case Study – The Chalk of the English South Downs (1999)
    Springer
    Water resources management 13 (1999), S. 205-218 
    Details
    ISSN: 1573-1650
    Keywords: groundwater ; management ; monitoring ; pollution prevention ; saline intrusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geography
    Notes: Abstract The Chalk aquifer of the English South Downs is very heavily utilised. The groundwater resources have enjoyed a formal programme of management which started in the 1950s, although a number of actions had been taken earlier in order to deal with saline intrusion and potential risk to groundwater quality from urbanisation. In the late 1950s the policy of ‘leakage/storage’ boreholes was first adopted, whereby the ‘leakage’ boreholes along the coast were pumped in winter to intercept fresh water discharge to the sea and to maximise the recharge potential inland, and inland ‘storage’ boreholes were used, as much as possible, in the summer months only. A comprehensive monitoring programme supported by aquifer modelling has enabled a gradual increase in overall abstraction to take place without increasing groundwater degradation due to saline intrusion. There have been various pollution prevention strategies over the years, and these have been effective in protecting the groundwater despite the high population density and widespread agricultural activity within the South Downs. The management of the aquifer has clearly been successful; there are many lessons from this experience that can be applied to other regions and other aquifers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008101727356
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Littoral benthos of the saline crater lakes of the basin of Oriental, Mexico (1998)
    Springer
    International journal of salt lake research 7 (1998), S. 87-108 
    Details
    ISSN: 1573-8590
    Keywords: benthos ; crater lakes ; littoral ; macroinvertebrates ; Mexico ; Puebla ; saline lakes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract Two saline crater lakes in the basin of Oriental, Puebla-Tlaxcala-Veracruz, were investigated for littoral benthic macroinvertebrates. Fifty taxa were identified with the oligochaetes, amphipods, chironomids and leeches the dominant organisms. These four taxa made up to 99 per cent in both number and biomass. Limnodrilus hoffmeisteri, Hyalella azteca, Tanypus (Apelopia) sp. and Stictochironomus sp. were the most abundant organisms. Unlike other saline lakes which have a littoral benthos dominated by chironomids, Alchichica and Atexcac were dominated by oligochaetes (70–73 per cent). The gastropod, Physa sp., was found up to a salinity of 8 g L-1; in other studies, it has been found in lower salinities. L. hoffmeisteri is also a typical inhabitant of freshwater lakes, particularly of deep waters. It was dominant in the shallow, saline waters of the two lakes studied. Salinity did not affect species richness. Alchichica, the most saline of the six crater lakes of Puebla (salinity, 7.4 g L-1), had 30 per cent more species than the freshwater lakes, and double the species number of Atexcac. It seems the main factor controlling species richness and the density and biomass of organisms in Alchichica and Atexcac is the presence of aquatic vegetation. It does this by increasing habitat heterogeneity and providing food and protection against predators.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009077214847
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Littoral benthos of the saline crater lakes of the basin of Oriental, Mexico (1998)
    Springer
    International journal of salt lake research 7 (1998), S. 87-108 
    Details
    ISSN: 1573-8590
    Keywords: benthos ; crater lakes ; littoral ; macroinvertebrates ; Mexico ; Puebla ; saline lakes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract Two saline crater lakes in the basin of Oriental, Puebla-Tlaxcala-Veracruz, were investigated for littoral benthic macroinvertebrates. Fifty taxa were identified with the oligochaetes, amphipods, chironomids and leeches the dominant organisms. These four taxa made up to 99 per cent in both number and biomass.Limnodrilus hoffmeisteri, Hyalella azteca, Tanypus (Apelopia) sp. andStictochironomus sp. were the most abundant organisms. Unlike other saline lakes which have a littoral benthos dominated by chironomids, Alchichica and Atexcac were dominated by oligochaetes (70–73 per cent). The gastropod,Physa sp., was found up to a salinity of 8 g L−1; in other studies, it has been found in lower salinities.L. hoffmeisteri is also a typical inhabitant of freshwater lakes, particularly of deep waters. It was dominant in the shallow, saline waters of the two lakes studied. Salinity did not affect species richness. Alchichica, the most saline of the six crater lakes of Puebla (salinity, 7.4 g L−1), had 30 per cent more species than the freshwater lakes, and double the species number of Atexcac. It seems the main factor controlling species richness and the density and biomass of organisms in Alchichica and Atexcac is the presence of aquatic vegetation. It does this by increasing habitat heterogeneity and providing food and protection against predators.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02441880
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Numerical prognosis for salinity profiles of future lakes in the opencast mine Merseburg-Ost (1998)
    Springer
    International journal of salt lake research 7 (1998), S. 235-260 
    Details
    ISSN: 1573-8590
    Keywords: groundwater ; Merseburg-Ost ; mine ; meromixis ; numerical model ; monimolimnion ; opencast ; physical limnology ; salinity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract Salt-laden groundwater inflows have formed monimolimnia in developing lakes of the abandoned opencast lignite mine Merseburg-Ost, Central Germany. Water-levels are still rising. To predict the future status of the lakes, two numerical models were developed. One was designed to predict groundwater flows, the second included limnophysical processes. The models were run in parallel and data exchange between them was performed every 1 to 10 years of model time. A trial of a 100-years prognosis was done. The results of surface salinity, mixing depth, and salinity profile are given. A sensitivity analysis yielded indications for the accuracy of the prediction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009097319823
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    An Integrated Model for the Danubian Lowland – Methodology and Applications (1998)
    Springer
    Water resources management 12 (1998), S. 433-465 
    Details
    ISSN: 1573-1650
    Keywords: Danube ; environmental impacts ; floodplain ; Gabcikovo ; groundwater ; hydropower ; integrated modelling ; river branch
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geography
    Notes: Abstract A unique integrated modelling system has been developed and applied for environmental assessment studies in connection with the Gabcikovo hydropower scheme along the Danube. The modelling system integrates model codes for describing the reservoir (2D flow, eutrophication, sediment transport), the river and river branches (1D flow including effects of hydraulic control structures, water quality, sediment transport), the ground water (3D flow, solute transport, geochemistry), agricultural aspects (crop yield, irrigation, nitrogen leaching) and flood plain conditions (dynamics of inundation pattern, ground water and soil moisture conditions, and water quality). The uniqueness of the established modelling system is the integration between the individual model codes, each of which provides complex descriptions of the various processes. The validation tests have generally been carried out for the individual models, whereas only a few tests on the integrated model were possible. Based on discussion and examples, it is concluded that the results from the integrated model can be assumed less uncertain than outputs from the individual model components. In an example, the impacts of the Gabcikovo scheme on the ecologically unique wetlands created by the river branch system downstream of the new reservoir have been simulated. In this case, the impacts of alternative water management scenarios on ecologically important factors such as flood frequency and duration, depth of flooding, depth to ground water table, capillary rise, flow velocities, sedimentation and water quality in the river system have been explicitly calculated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008088901770
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Numerical prognosis for salinity profiles of future lakes in the opencast mine Merseburg-Ost (1998)
    Springer
    International journal of salt lake research 7 (1998), S. 235-260 
    Details
    ISSN: 1573-8590
    Keywords: groundwater ; Merseburg-Ost ; mine ; meromixis ; numerical model ; monimolimnion ; opencast ; physical limnology ; salinity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract Salt-laden groundwater inflows have formed monimolimnia in developing lakes of the abandoned opencast lignite mine Merseburg-Ost, Central Germany. Water-levels are still rising. To predict the future status of the lakes, two numerical models were developed. One was designed to predict groundwater flows, the second included limnophysical processes. The models were run in parallel and data exchange between them was performed every 1 to 10 years of model time. A trial of a 100-years prognosis was done. The results of surface salinity, mixing depth, and salinity profile are given. A sensitivity analysis yielded indications for the accuracy of the prediction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02441877
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Carbon stable isotopes ratios of pelagic and littoral communities in Alchichica crater-lake, Mexico (1998)
    Springer
    International journal of salt lake research 7 (1998), S. 345-355 
    Details
    ISSN: 1573-8590
    Keywords: δ13C ; crater-lake ; food webs ; Mexico ; pelagic and littoral communities ; saline-lake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract Carbon stable isotope ratios were determined in dominant biotic components of pelagic and littoral systems in Alchichica crater-lake. Results showed that carbon signatures were significantly different between both systems. The pelagic environment was more depleted (−26.15 to −15.14 per mille) than the littoral zone (−21.03 to −17.91 per mille). The potential source end-point in the simplified pelagic community was established to be diatomaceous phytoplankton; its predicted value was −21.7 per mille. There is a clear evidence that Nodularia does not sustain the pelagic food chain. In contrast, the highly diverse littoral community was sustained by epiphytes. No allochthonous sources seemed to influence this food web. 13C enrichment was observed along the components of both systems with fractionations of 0.8 to 1.4 per mille. The contribution of the seagrass Ruppia maritima is probably associated with the detritus pathway. Carbon source partitioning between both systems was not recorded. The δ13C in Alchichica crater-lake was more enriched than in other saline lakes and could be attributed to different salinity and CO2 concentrations among lakes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009052526657
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Carbon stable isotopes ratios of pelagic and littoral communities in Alchichica crater-lake, Mexico (1998)
    Springer
    International journal of salt lake research 7 (1998), S. 345-355 
    Details
    ISSN: 1573-8590
    Keywords: δ13C ; crater-lake ; food webs ; Mexico ; pelagic and littoral communities ; saline-lake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract Carbon stable isotope ratios were determined in dominant biotic components of pelagic and littoral systems in Alchichica crater-lake. Results showed that carbon signatures were significantly different between both systems. The pelagic environment was more depleted (−26.15 to −15.14 per mille) than the littoral zone (−21.03 to −17.91 per mille). The potential source end-point in the simplified pelagic community was established to be diatomaceous phytoplankton; its predicted value was −21.7 per mille. There is a clear evidence thatNodularia does not sustain the pelagic food chain. In contrast, the highly diverse littoral community was sustained by epiphytes. No allochthonous sources seemed to influence this food web.13C enrichment was observed along the components of both systems with fractionations of 0.8 to 1.4 per mille. The contribution of the seagrassRuppia maritima is probably associated with the detritus pathway. Carbon source partitioning between both systems was not recorded. The δ13C in Alchichica crater-lake was more enriched than in other saline lakes and could be attributed to different salinity and CO2 concentrations among lakes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02442143
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Carbon Dioxide Emission Reduction Scenarios in Mexico for Year 2005: Industrial Cogeneration and Efficient Lighting (1998)
    Springer
    Mitigation and adaptation strategies for global change 2 (1998), S. 359-372 
    Details
    ISSN: 1573-1596
    Keywords: CO2emissions ; CO2mitigation costs ; cogeneration ; efficient lighting ; Mexico
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Geography
    Notes: Abstract An analysis of the impacts on Mexican energy demand and associated carbon dioxide (CO2) emissions in the year 2005 due to efficient lighting in the commercial and residential sectors and cogeneration in the industrial sector is presented. Estimation of CO2 abatement costs and an incremental cost curve for CO2 mitigation options are considered. These technologies are cost effective opportunities, and together are projected to reduce CO2 emissions in 2005 by nearly 13 percent. Implementation of efficient lighting is already part of the demand side management (DSM) programs of the Mexican state-owned utility. However, there are important barriers that may hinder the implementation of large scale cogeneration plants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/B:MITI.0000004665.58546.4b
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Terrestrial Carbon Dynamics: Case Studies in the Former Soviet Union, the Conterminous United States, Mexico and Brazil (1997)
    Springer
    Mitigation and adaptation strategies for global change 1 (1997), S. 363-383 
    Details
    ISSN: 1573-1596
    Keywords: carbon flux ; land use ; former Soviet Union ; United States ; Mexico ; Brazil ; forests
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Geography
    Notes: Abstract This research assessed land-use impacts on C flux at a national level in four countries: former Soviet Union, United States, Mexico and Brazil, including biotic processes in terrestrial ecosystems (closed forests, woodlands, and croplands), harvest of trees for wood and paper products, and direct C emission from fires. The terrestrial ecosystems of the four countries contain approximately 40% of the world's terrestrial biosphere C pool, with the FSU alone having 27% of the global total. Average phytomass C densities decreased from south to north while average soil C densities in all three vegetation types generally increased from south to north. The C flux from land cover conversion was divided into a biotic component and a land-use component. We estimate that the total net biotic flux (Tg/yr) was positive (= uptake) in the FSU (631) and the U.S. (332), but negative in Mexico (−37) and Brazil (−16). In contrast, total flux from land use was negative (= emissions) in all four countries (TgC/yr): FSU −343; U.S. −243; Mexico −35; and Brazil −235. The total net effect of the biotic and land-use factors was a C sink in the FSU and the U.S. and a C source in both Brazil and Mexico.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/B:MITI.0000027388.65532.60
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Carbon dioxide emission reduction scenarios in Mexico for year 2005: Industrial cogeneration and efficient lighting (1997)
    Springer
    Mitigation and adaptation strategies for global change 2 (1997), S. 359-372 
    Details
    ISSN: 1573-1596
    Keywords: CO2emissions ; CO2mitigation costs ; cogeneration ; efficient lighting ; Mexico
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Geography
    Notes: Abstract An analysis of the impacts on Mexican energy demand and associated carbon dioxide (CO2) emissions in the year 2005 due to efficient lighting in the commercial and residential sectors and cogeneration in the industrial sector is presented. Estimation of CO2 abatement costs and an incremental cost curve for CO2 mitigation options are considered. These technologies are cost effective opportunities, and together are projected to reduce CO2 emissions in 2005 by nearly 13 percent. Implementation of efficient lighting is already part of the demand side management (DSM) programs of the Mexican state-owned utility. However, there are important barriers that may hinder the implementation of large scale cogeneration plants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02437051
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Terrestrial carbon dynamics: Case studies in the former Soviet Union, the conterminous United States, Mexico and Brazil (1997)
    Springer
    Mitigation and adaptation strategies for global change 1 (1997), S. 363-383 
    Details
    ISSN: 1573-1596
    Keywords: carbon flux ; land use ; former Soviet Union ; United States ; Mexico ; Brazil ; forests
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Geography
    Notes: Abstract This research assessed land-use impacts on C flux at a national level in four countries: former Soviet Union, United States, Mexico and Brazil, including biotic processes in terrestrial ecosystems (closed forests, woodlands, and croplands), harvest of trees for wood and paper products, and direct C emission from fires. The terrestrial ecosystems of the four countries contain approximately 40% of the world's terrestrial biosphere C pool, with the FSU alone having 27% of the global total. Average phytomass C densities decreased from south to north while average soil C densities in all three vegetation types generally increased from south to north. The C flux from land cover conversion was divided into a biotic component and a land-use component. We estimate that the total net biotic flux (Tg/yr) was positive (=uptake) in the FSU (631) and the U.S. (332), but negative in Mexico (-37) and Brazil (-16). In contrast, total flux from land use was negative (=emissions) in all four countries (TgC/yr): FSU -342; U.S. -243; Mexico -35; and Brazil -235. The total net effect of the biotic and land-use factors was a C sink in the FSU and the U.S. and a C source in both Brazil and Mexico.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00464888
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    A Finite Element Model for the Unsteady Groundwater Flow over Sloping Beds (1997)
    Springer
    Water resources management 11 (1997), S. 69-81 
    Details
    ISSN: 1573-1650
    Keywords: groundwater ; sloping bed ; finite element method ; free surface
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geography
    Notes: Abstract A numerical solution of the nonlinear two-dimensional unsteady groundwater flow over sloping beds, using the Galerkin finite element method, is presented. The applied differential equation is based on the assumption that the streamlines are parallel to the sloping bed while the conventional differential equation is based on the Dupuit–Forchheimer assumption of horizontal flow. Furthermore, the gradient of the piezometric head is evaluated as a function of the unknown slope of the groundwater free surface and not simply as the absolute slope of the water table. Water table profiles and seepage rates obtained from the model are compared with those obtained by analytical solutions and experimental results for steady one-dimensional flow and for different values of bed slope. Results of the present model compares reasonably well with experimental results and with the results of Childs' analytical solution. The unsteady-state solution for different values of bed slope are compared to the results of a model based on the assumption that the water table slope is equal to the bed slope. The differences in the predicted water table by these two models are insignificant for small slopes but increase with increasing slope.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007926507718
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Metropolitan growth and labor markets in Mexico (1997)
    Springer
    GeoJournal 43 (1997), S. 371-383 
    Details
    ISSN: 1572-9893
    Keywords: metropolitan labor markets ; Mexico ; social polarization ; precarization of labor force
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography
    Notes: Abstract The objective of this paper is to examine the main changes in the metropolitan labor markets associated with economic restructuring in Mexico during the late 1980s and beginning of the 1990s. The analysis refers particularly to the four largest metropoles of the country, Mexico City, Guadalajara, Monterrey and Puebla, looking for common characteristics in their emergent employment structures now strongly differentiated in terms of rewards, stability in employment relations and conditions of access to jobs. The analysis reveals that largest metropolitan areas have been the most profoundly affected by the economic restructuring resulting from globalization, through a rapid de-industrialization and the expansion of the tertiary sector. Metropolitan labor markets in Mexico, at the time that show signs of social polarization in the formal sector, put in evidence a general process of precarization – less labor stability, replacement of permanent by part-time jobs, and increasing subcontracting –, segmentation of the labor force, and an increasing informal conditions of economic activities with small businesses and unskilled, temporarly and poorly paid jobs. The labor force segmentation and its more precarious and casual conditions are mostly explained by the impact of recent neoliberal policies, and recurrent economic crisis during the 1980s and 1990s which highly contributes to social inequality.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006895907459
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Water-table variation in a sloping aquifer due to random recharge (1996)
    Springer
    Water resources management 10 (1996), S. 241-250 
    Details
    ISSN: 1573-1650
    Keywords: groundwater ; aquifer ; water table ; drainage ; random recharge
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geography
    Notes: Abstract Variation in the level of the water table is closely linked with recharge. Therefore, any uncertainty associated with the recharge rate is bound to affect the nature of the water-table fluctuation. In this note, a ditch-drainage problem of a sloping aquifer is considered to investigate the effect of uncertainty in the recharge rate on water-table fluctuation. The rate of recharge is taken as an exponentially decaying function with its decay constant as a Gaussian random variable. Expressions for the first two moments of the water-table height, i.e. mean and standard deviation, are presented. By using these expressions, the effect of uncertainty in the recharge rate on the water-table fluctuation has been analyzed with the help of a numerical example.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00424205
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Historical and recent changes in Lake Texcoco, a saline lake in Mexico (1996)
    Springer
    International journal of salt lake research 5 (1996), S. 45-61 
    Details
    ISSN: 1573-8590
    Keywords: conservation ; human impacts ; Lake Texcoco ; Mexico ; saline lake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract Historical and recent changes in the nature of Lake Texcoco, a saline lake in Mexico, are described. These changes are particularly important since they significantly affect water supply, drainage and other urban issues in Mexico City, Mexico's largest city and capital located within the general boundaries of the lake basin and gradually sinking (mean annual sinking rate is 30 cm). After brief reviews of the present status of the lake and background geological, palaeolimnological and climatic features, human activities during historical and recent times are considered. Of particular note have been drainage basin activities, diversion of inflows, pollution and over-exploitation of groundwater and biological resources (especially fish and waterfowl). The major effects of these activities are water shortages, soil erosion, salinization, dust storms, sinking ground, poor water quality and decreased biological resources. Conservation measures are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01996035
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    The macrobenthic fauna of a former perennial and now episodically filled mexican saline lake (1996)
    Springer
    International journal of salt lake research 5 (1996), S. 261-274 
    Details
    ISSN: 1573-8590
    Keywords: episodic playa lakes ; macroinvertebrates ; Mexico ; salt lakes ; temporary waters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract Totolcingo (El Carmen), a large and now episodically filled playa lake in the east-ernmost portion of the Mexican Plateau, filled with water in 1993. Water persisted for just one month (May). Alkaline (pH ≈ 10), saline (K25 up to 30,000μS/cm) waters, dominated by NaHCO3 and Na2CO3, characterized the lake. The fauna was depauperate. The components of the fauna wereEphydra (Hydropyrus)hians Say (ephydrid),Limnodrilus hoffmeisteri Claparède (tubificid), andBerosus sp. (Coleoptera). The species in the lake were widely dispersed and typical inhabitants of saline lakes. Possible reasons for the depauperate fauna include (a) overall physical and chemical conditions, (b) unpredictable hydrology, and (c) the short (one month) inundation period prevented colonization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01997141
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    Use of Geographic Information Systems (GIS) in water resources: A review (1996)
    Springer
    Water resources management 10 (1996), S. 251-277 
    Details
    ISSN: 1573-1650
    Keywords: Geographic information systems (GIS) ; modeling ; hydrology ; surface water ; groundwater ; water supply ; sewer design ; agricultural pollution ; nonpoint source pollution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geography
    Notes: Abstract Increasing public awareness, stricter measures and promulgation of new laws in the area of water resources have made the use of advanced technologies indispensable. Geographic Information Systems (GIS) are an effective tool for storing, managing, and displaying spatial data often encountered in water resources management. The application of GIS in water resources is constantly on the rise. In order to stress the importance of GIS in water resources management, applications related to this area are addressed and evaluated for efficient future research and development. Fundamentals of GIS are summarized and the history of the GIS evolution in water resources is discussed. Current GIS applications are presented including surface hydrologic and groundwater modeling, water supply and sewer system modeling, stormwater and nonpoint source pollution modeling for urban and agricultural areas, and other related applications. Future research and development needs are presented, based on these reviews.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00508896
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Application of remote sensing technology for groundwater potential evaluation (1995)
    Springer
    Water resources management 9 (1995), S. 161-173 
    Details
    ISSN: 1573-1650
    Keywords: Toposheet ; lineaments ; georesistivity ; geomorphology ; drainage ; groundwater
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geography
    Notes: Abstract With the help of the information drawn from a survey of India toposheet and by visual interpretation of satellite imagery of bands 2, 3 and 4, different thematic maps such as geomorphology and lineaments, drainage and land use, and land cover were prepared. These thematic maps have been superimposed and finally a groundwater potential zone map delineated on a survey of India toposheet. The whole block has been demarcated into 5 zones. Zones 1 and 2 are considered ideal groundwater potential areas, zone 3 is moderately ideal, and zones 4 and 5 are unfavourable for groundwater exploration. The validity of demarcation of the study area into different zones, as decided by remote sensing technology, has been justified by analysing the georesistivity sounding data of a number of places in this area. The net potential of the study area is estimated by GEC norm. It is observed that only 11.8% of annual utilisable groundwater is now used and there is vast scope of further exploitation of this resource.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00872127
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    Variations in some physico-chemical parameters in a hypersaline coastal lagoon of Baja California, Mexico (1995)
    Springer
    International journal of salt lake research 4 (1995), S. 265-280 
    Details
    ISSN: 1573-8590
    Keywords: hypersaline coastal lagoon ; physico-chemical seasonal variations ; winds ; Artemia ; cysts ; Baja California ; Mexico
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geography
    Notes: Abstract San Jose lagoon is a hypersaline body of water located in Mexico in the Baja California Peninsula. The lagoon belongs to a system that lies between the fault ridge known as San Jose Creek. Because of its marine origin, it can be considered as thalassohaline, but its isolation from the ocean has brought about changes in its salt composition. It has an area of 13,500 m2, a mean depth of 80 cm and a total volume of 10,000 m3. It does not desiccate and can be considered as a permanent lagoon. Seasonal variations are small. TheArtemia population in San Jose produces cysts all year. To determine the physico-chemical conditions inducing permanent production of cysts, temperature, salinity, dissolved oxygen, and pH of the lagoon were monitored, as well as relative humidity and wind conditions in the region in different seasons of the year. From spring to summer, differences of 1 mg L−1 of O2, 1°C in water temperature, and 8 g L−1 in salinity were observed, and from summer to winter differences of 3.3 mg L−1, 6.5°C, and 14 g L−1, respectively. Despite small seasonal variations, the lagoon exhibits strong spatial and daily changes that are important for cyst production.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02001495
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Evaluation of climatic change through harmonic analysis (1994)
    Springer
    Natural hazards 9 (1994), S. 5-16 
    Details
    ISSN: 1573-0840
    Keywords: Fourier transform ; maximum entropy spectral analysis ; precipitation ; temperature ; climatic change
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract In the present work, a precipitation and temperature series from Barcelona (Spain) are analysed in order to detect the possible existence of climatic changes or cycles. The analysis is carried out both from the temporal and spectral standpoints. The techniques used range from the classical periodogram and Blackman-Tukey method through to the Maximum Entropy method. The results do not show the existence of climatic cycles, though they do show a clear tendency toward increased precipitation and decreased temperature, since the last years of series.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00662588
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Future groundwater conditions under long-term water stresses in an arid urban area (1994)
    Springer
    Water resources management 8 (1994), S. 245-264 
    Details
    ISSN: 1573-1650
    Keywords: groundwater ; hydrogeochemical investigation ; simulation ; urban area ; arid climate groundwater management ; conservation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geography
    Notes: Abstract The urban area of Greater Dhahran has an extremely arid climate where the average annual rainfail is less than 71 mm. The Umm Er Radhuma (UER) aquifer in that area is the main source of domestic and landscape irrigation demands. Groudwater use has increased drastically during the last 15 years due to extensive developments in the area. Numerical simulation techiques and hydrogeochemical investigations were carried out to assess the effects of increasing pumping rates on the piezometric surface in the UER aquifer and to predict the future levels and quality of water under different pumping scenarios. A groundwater flow model was developed and calibrated for the area. The increase in the water extraction rate between 1967 and 1990 has resulted in a decline in the piezometric surface by about 4 m in the Dhahran area. The results of simulation investigations indicated that if the present trend of the groundwater withdrawal rate continues, the water level is expected to drop by an additional 2 and by the end of the year 2000, by an additional 6 m by the end of 2010. If the present increasing rate in groundwater withdrawal is reduced by 50%, the additional drawdown will also be reduced to about 1 and 2.5 m by the end of years 2000 and 2010, respectively. The average total dissolved solids (TDS) has increased from 2750 to 3545 mg/l between 1967 and 1990 and will continue to rise to 3922 and 4361 by the end of years 2000 and 2010, respectively. These original findings are important because they postulates the negative impacts of increasing groundwater pumping from an aquifer in an arid urban area on future groundwater levels and quality. Therefore, effective groundwater management and conservation schemes should be adopted to maintain the long-term productivity and quality of aquifers in the area.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00872400
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Volcanic hazards in the surroundings of Pico de Orizaba, eastern Mexico (1994)
    Springer
    Natural hazards 10 (1994), S. 197-219 
    Details
    ISSN: 1573-0840
    Keywords: Mexico ; Citlaltepetl ; volcanic lava ; pyroclastic ; epiclastic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract Volcanic hazards from Pico de Orizaba volcano are presented here tor the first time. Some 1.3 million people live within the hazard zone, which in the most severe case would encompass the Mexican Gulf coast, east of the volcano. Three major cities located in the eastern part of the hazard zone account for 800 000 of this population and about 200 000 people live within a 20 km radius of the volcano. Probability calculations are presented as an attempt to quantify the hazards in the surroundings of the volcano. Such quantification can be of use in planning for future land use within the hazard zones. A zone of about 10 km radius centred on the top crater is a high hazard zone for gravity-driven flows and fallout ejecta. For large volume eruptions, the radius could be extended to 120 km to the east and 60 km to the west. The asymmetrical distribution is related to the topography of the volcano. Hazards from Pyroclastic-fall deposits are principally to the west of the volcano, since easterly winds are dominant in the area lava-flow hazards are greatest within a 10 km radius from the summit crater. Pyroclastic flow hazards are high up to 20 km from the volcano summit. In the case of reactivation of the volcano, melting of a glacier covering the summit of Pico de Orizaba having a volume equivalent to some 45 × 109 litres of water, would produce lahars which would descend the flanks of the volcano.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00596142
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Mathematical models for saltwater intrusion in coastal aquifers (1993)
    Springer
    Water resources management 7 (1993), S. 3-37 
    Details
    ISSN: 1573-1650
    Keywords: Coastal aquifers ; saltwater intrusion ; groundwater ; mathematical models ; analytical and numerical models
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geography
    Notes: Abstract Flow of freshwater and saltwater intrusion in coastal aquifers has drawn the attention of many investigators. Several laboratory, as well as mathematical models have been developed to study the pattern of flow of groundwater in coastal aquifers. Mathematical models have wider range of application and are the concern of this paper. Due to the complex nature of the problem, each of these mathematical models are based on certain simplifying assumptions and approximations. This paper presents a critical review of various methods of solution which have been proposed. The validity of the results abtained and the limitations of these models are also discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00872240
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    Albedo model for a tropical dry deciduous forest in western Mexico (1992)
    Springer
    International journal of biometeorology 36 (1992), S. 113-117 
    Details
    ISSN: 1432-1254
    Keywords: Albedo ; Deciduous vegetation ; Energy regime ; Mexico ; Tropical deciduous forests
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography , Physics
    Notes: Abstract A simple albedo model is presented for a tropical dry deciduous forest. The model is based on point observations of the solar radiation, leaf cover of the vegetation, precipitation and air temperature from 1981 to 1988 in western Mexico. Four main periods were noted: leafing, leafed, leaf-fall and leafless. During the leafed period the albedo was almost constant (0.16) but increased slowly in the leaf-fall period, at a rate of 0.0008/day, until its maximal values in the leafless period (0.24). During the leafing and leafed periods, the albedo decrease was a hyperbolic function of precipitation at a rate of 7.9 albedo percentage/mm. Albedo showed a linear regression on leaf cover and decreased at a rate of 0.119 albedo percentage per leaf cover percentage.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01208922
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Appraisal and optimization of agricultural water use in large irrigation schemes: II. Applications (1992)
    Springer
    Water resources management 6 (1992), S. 201-221 
    Details
    ISSN: 1573-1650
    Keywords: Argentina ; groundwater ; irrigation ; simulation model ; surface water ; water use
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geography
    Notes: Abstract In this paper, the theoretical approach presented in Part I is demonstrated by means of case studies on the irrigation schemes of Rio Mendoza and Rio Tunuyán in the Province of Mendoza, Argentina. The object of the case studies was the determination of optimal allocation of surface water to reduce the use of groundwater. Current and optimal conjunctive allocation of ground and surface water is studied by means of the developed simulation and optimization models. The second case study was designed on the basis of the experience gathered during the first one: each step of the case studies is compared. The comparison between the two case studies illustrates how to apply the proposed approach when the amount and quality of available data are different. For the more detailed Rio Tunuyán study, we determined the following physical characteristics of all terminal nodes: on-farm rotational intervals, mean water application depth, actual soil water storage capacity, crop water requirements, depth of groundwater table, aquifer transmissivity, and efficiency of groundwater use. The performance of the entire system is sensitive to changes in the water application depth, as it was shown by a simulation study. The application of our optimization approach to the conjunctive use of ground- and surface water showed that the total water requirements over a year can be met by a reassignment of water that reduces the total costs of a great amount.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00872356
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    The tsunami threat on the Mexican west coast: A historical analysis and recommendations for hazard mitigation (1991)
    Springer
    Natural hazards 4 (1991), S. 301-316 
    Details
    ISSN: 1573-0840
    Keywords: Tsunami catalog ; precursors ; warning system ; public education ; risk assessment ; Mexico ; Mesoamerican subduction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract From an inspection of all tide gauge records for the western coast of Mexico over the last 37 years, a data base of all recorded tsunamis was made. Information on relevant historical events dating back two centuries, using newspaper archives, previous catalogs, and local witness interviews, was added to produce a catalog of tsunamis for the western coast of Mexico. A description of the 1932 Cuyutlán tsunami is given. This is considered to be the most destructive local tsunami which has ever occurred in the region for which historical accounts are available. It was preceded by two precursor events, a not uncommon occurrence in that zone. A summary of the generation and coastal effects from the 1985 Michoacán tsunamis is also given. These Michoacán tsunamis are the most recent local events in that zone. This information, and knowledge of local undersea faulting characteristics along the Mexican Pacific coast, leads to a clear differentiation of two zones of potential tsunami hazard: locally generated tsunamis south of the Rivera fracture, in the Cocos plate subsidence region, and remotely generated tsunamis north of this zone. Based on this zonation, two types of tsunami warning systems are proposed: real-time for the southern zone, and delayed-time for the northern. A description is provided of the Baja California Regional Tsunami Warning System that is presently operational in the northern zone. Several major industrial ports and tourist resort areas are located in the southern zone, and are therefore most vulnerable to local destructive tsunamis. Some of these sites represent important socioeconomic resources for Mexico, and have therefore been chosen for a vulnerability assessment and microzonation risk analysis. Land use patterns are identified, risks defined, and recommendations to minimize future tsunami impact are given. One case is illustrated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00162795
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    The artificial recharge of groundwater: A solution by successive variations of steady states (1989)
    Springer
    Water resources management 3 (1989), S. 231-239 
    Details
    ISSN: 1573-1650
    Keywords: Artificial recharge ; well ; successive variation of steady state ; groundwater ; action radius ; finite elements ; dimensionless graphs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geography
    Notes: Abstract The artificial recharge of groundwater aims at the modification of water quality, an increase of groundwater resources, and the optimization of the exploitation and recovery of contaminated aquifers. The purpose of this work is to develop a new mathematical model for the problem of an artificial recharge well, using the method of successive variations of steady states. Applying this method, one arrives at an expression of time as a double integral. This integral contains the time-dependent radius of the recharge boundary and the piezometric head of the well, calculated with the finite-element method. The new model is simple and useful, and can be applied to many practical problems, using the designed dimensionless graphs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00872344
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Source mechanism of the tsunamis of 19 and 21 September 1985, in Mexico (1988)
    Springer
    Natural hazards 1 (1988), S. 285-294 
    Details
    ISSN: 1573-0840
    Keywords: Source-mechanism ; tsunami ; Mexico
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract The major earthquake measuring 8.1 on the Richter scale which struck the west coast of Mexico on Thursday 19 September 1985, generated a small tsunami. A major aftershock on 21 September, with a magnitude of 7.5 also produced a small tsunami. Both tsunamis propagated across the Pacific and were recorded by several tide stations in Central America, Colombia, Ecuador, French Polynesia, Samoa, and Hawaii. No reports of damage were received from any of the stations, and only minor damage due to the first tsunami was reported from the source region. A survey was made by the International Tsunami Information Center (ITIC) of the coastal area affected, from Manzanillo to Zihuatanejo. Tsunami runup measurements were taken and interviews with local residents in the coastal areas were conducted. A source mechanism study of the tsunamis was undertaken using seismic and geologic data and empirical relationships. Earthquake and tsunami energies were estimated and the tsunami genertion areas defined. The earthquake energies were estimated to be 5.61 × 1024 erg for the 19 September event and 9.9 × 1023 erg for the 21 September event. Tsunami energies were estimated to be 0.7 × 1020 erg for the first event and 0.56 × 1020 erg for the second event. The source area of the first tsunami was determined to be approximately one-half of the earthquake source area, or approximately 7500 km2, while the source area of the second tsunami was estimated to be equal to the earthquake area. The relatively small tsunamis generated by these large earthquakes are attributed to the shallow angle of subduction of the Cocos plate underneath the North American plate for this particular region, and to the small vertical component of crustal displacements. However, the angle of subduction increases further south and local earthquakes from that area have the potential of producing large tsunamis on the west coast of Mexico.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00137233
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    Micro-scale modelling in the study of plume evolution in heterogeneous media (1987)
    Springer
    Stochastic environmental research and risk assessment 1 (1987), S. 263-279 
    Details
    ISSN: 1436-3259
    Keywords: Porous media ; heterogeneity ; groundwater ; dispersion ; stochastic theory ; plume evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract The migration of contaminants in heterogeneous aquifers involves dispersive processes that act at different scales. The interaction of these processes as a plume evolves can be studied by micro-scale modelling whereby two scales, a local- or micro-scale and an aquifer- or macro-scale, are covered simultaneously. Local-scale dispersive processes are represented through the local dispersion coefficient in the transport equation, while large-scale dispersion due to heterogeneities is represented through the resolution of the flow field and the diffusive exchange between streamtubes. The micro-scale model provides both the high degree of resolution compatible with local-scale processes, and the extent required for the approach to asymptotic conditions, using grids of up to a million nodal points. The model is based on the dual potential-streamfunction formulation for flow, and the transport problem is formulated in a natural coordinate system provided by the flownet. Simulations can be used to verify stochastic theories of dispersion, without the restrictive assumptions inherent in the theory. For the two-dimensional case, results indicate convergence of the effective dispersivity to the theoretical macrodispersivity value. Convergence takes place within a travel distance of about 50 correlation lengths of the hydraulic conductivity field. However, the approach taken to asymptotic conditions, as well as the macrodispersivity value, may differ for different realizations of the same medium. The influence of early-time events such as plume splitting on the asymptotic convergence remains to be investigated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01543098
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...