Advantages of longer–term tracing -- three case studies from Slovenia

A variety of human activities can negatively impact on sensitive karst environments, especially on karst water. To protect such water adequately it is necessary to obtain as much information as possible on the extent of the recharge zones and characteristics of the groundwater flow. The authors experience has shown tracer tests to be a very useful tool in acquiring such information. Three examples from Slovenia are presented in this paper. In the first, an estimate was made of the danger of water contamination resulting from a petrochemical storage depot. In the second, the possible impacts of an area used for military training were studied. In the third, the effects of the construction of a railway line on regionally important water resources were assessed. Besides basic information about the direction and velocity of groundwater flow, some methodological principles were also identified by the studies. In all three test areas sampling was carried out for a lengthy period and continued after the detection of the peak concentrations. The results show that only the use of such lengthy tracer tests enable the definition of those flow paths, which are activated in extreme hydrological conditions.     

Assessing the influence of environmental parameters on the hydrological cycle

Human activity is exerting an increasing influence on the hydrological cycle. In order to avoid adverse impacts and to establish optimum conditions for the water balance, it is necessary to understand the role of environmental parameters in influencing the hydrological cycle. Work is currently in progress in China to study the relationships between environmental parameters and the hydrological cycle to provide a basis for planning future development.     

Temporal variations of sandstorms in Minqin oasis during 1954–2000

The purpose of this present study is to investigate in detail the frequency and variation of sandstorms in the Minqin oasis. Using daily observational data from sandstorms and other meteorologic data from 1954 to 2000, the relationship between a sandstorm and meteorological parameters and human activities, which can be used for daily weather forecasting, have been illuminated. The results of the analysis show that sandstorms have a clear daily and monthly variation. Monthly mean and annual mean duration of sandstorms in the Minqin oasis coincide well with the frequencies of sandstorm occurrence.     

Women as individuals and members of minority groups: how to reconcile human rights and the values of cultural pluralism

The paper represents an attempt to understand how, in a democratic and pluralistic state, it is possible to reconcile the values of individual freedom with those granted to minority groups. In this perspective, the paper argues that, without questioning the importance of differentiated cultural rights that allow cultural minorities to be on an equal footing with the mainstream society, women’s rights cannot be ignored. Instead, rights for women are not exclusive of any particular culture or society, being indeed one of the human rights common to all groups of people, those rights which attest to the existence of a bond among individuals as members of the human community.     

The creation and conduct of the Guatemalan Commission for Historical Clarification

As in other Latin American nations, Guatemala established a truth commission as a part of a negotiated transition from war to peace. The establishment of a particular truth commission arises out of the unique circumstances of that nation’s conflict and its negotiated resolution. As with other examples of truth commissions, the Guatemalan experience demonstrates the dilemmas of answering the demands for accountability, within the precarious context of a negotiated transition. Once established, a truth commission is subjected to the struggles within sectors of society striving to control the truth commission, and make it respond to certain interests. These struggles influence the practices, powers, and potential of the truth commissions.This article analyses the context in which the Guatemalan Commission for Historical Clarification emerged, the conditions in which it operated, and the potential consequences of the truth-seeking process. I argue that the Guatemalan truth commission became a site of struggle in which battles concerning impunity versus accountability occurred. This article first traces the phenomenon of truth commissions in Latin America, and locates the Guatemalan case within this regional context. Next, the negotiations that led to the formation of the truth commission are examined, in order to highlight the particular powers and interests at stake. Finally, I describe the operations of the Guatemalan truth commission in practice (1997-1999), and discuss the ways in which the commission developed a life of its own, despite the politics of its birth.     

Geography’s changing lexicon: measuring disciplinary change in Anglophone human geography through journal content analysis

Much writing on changing trends in geographical practices is based on subjective interpretations of the discipline’s scholarly output. This paper introduces a data source which provides quantitative information on the discipline’s lexicon through full-text searching of the contents of five of the discipline’s major Anglophone journals. Analysis of the large data set identifies two main trends in geography’s language and practices during the period 1950-1998: one group of terms associated with quantitative work became prominent in the 1970s but declined in relative importance thereafter - though by no means disappearing from the lexicon; the other, comprising a range of terms generally associated with cultural and social geography, increased in prominence from the 1980s on.     

River mouth bar formation, riverbed aggradation and channel migration in the modern Huanghe (Yellow) River delta, China

This paper addresses the recent (1970s–1990s) processes of river mouth bar formation, riverbed aggradation and distributary migration in the Huanghe River mouth area, in the light of station-based monitoring, field measurements and remote sensing interpretation. The results show that the morphological changes of the river mouth bar have been closely associated with the largely reduced fluvial discharge and sediment load. Landform development such as bar progradation occurred in two phases, i.e. before and after 1989, which correspond to faster and lower bar growth rates, respectively. Fast riverbed aggradation in the mouth channel was strongly related to river mouth bar progradation. During 1976–1996, about 2.8% of the total sediment loads were deposited in the river channel on the upper to middle delta. Therefore, the river water level rose by a few meters from 1984 to 1996. The frequent distributary channel migration, which switched the radial channel pattern into the SE-directed pattern in the mid-1980s, was linked with mouth bar formation. Marine conditions also constrain seaward bar progradation. Furthermore, the history of river mouth bar formation reflects human impacts, such as dredging and dyking in order to stabilize the coastal area.     

Human impact on land–ocean sediment transfer by the world's rivers

Land–ocean transfer of sediment by rivers is a key pathway for material transfer on Earth. Contemporary data on the sediment loads of rivers provide clear evidence of significant recent changes in the sediment fluxes of several rivers in response to human impact. The key drivers of increased sediment loads include land clearance for agriculture and other facets of land surface disturbance, including logging activity and mining. Although, programmes for soil conservation and sediment control can result in reduced sediment loads, the trapping of sediment by dams represents the dominant cause of reduced loads. This influence is currently assuming increasing importance at the global scale. Any attempt to link these drivers to changes in the global land–ocean sediment flux must take account of the aggregation and buffering effects that operate in larger basins, which can cause damping and even removal of signals of increasing flux within the upstream basin, and complicate the link between upstream and downstream response to human impact. Further work is required to provide a precise quantitative assessment of the human impact on global land–ocean sediment fluxes and the net effect of increasing and decreasing fluxes. Particular attention must be paid to the temporal perspective and the variation of impact trajectories in different areas of the globe and for river basins of different sizes.     

Upcoming International Events

Metals in lacustrine sediment have both anthropogenic and natural sources. Because of intensified human activities, the anthropogenic input of metal elements has exceeded the natural variability. How to distinguish the anthropogenic sources in lake sediments is one of the tasks in environmental management. The authors present a case study, which combined the geochemical and statistical methods to distinguish the anthropogenic sources from the natural background. A 56 cm core (core DJ-5) was collected from Dongjiu Lake, Taihu Lake catchment, China. The concentration distributions of Al, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Sr, Ti, V and Zn in core DJ-5 indicated that Dongjiu Lake had serious Cd pollution, and the concentrations of Cr, Cu, Pb, Mn and Zn had also exceeded the Chinese State Standards of Soil Environmental Quality in the upper layer of the core. Using Al as a reference element, the other metals were normalized and compared with their baselines to calculate the enrichment factors (EFs). The principal component analysis (PCA) of metal concentrations was performed using ViSta6.4. The results of EFs and PCA indicated that the concentration variations of Cd, Cu, Pb, Mn and Zn were mainly caused by the anthropogenic sources, and the concentration variations of Cr and Ni were influenced by both the anthropogenic and natural factors, while the other metals were mainly derived from the natural sources. Intensified human activities within the lake catchment area resulted in the increase of heavy metal inputs directly and the acceleration of erosion which caused other metal elements to deposit in the aquatic environment. The results of this work will be useful in probing changes forced by humans in the lake environment and in adjusting human activity in restoring the lake environment.

Sources of human insecurity in the face of hydro-climatic change

Policy agendas increasingly respond to the perceived security threats of climate change, not least via its effects on water. Yet, solid links between climate, water, conflict and security have seldom been substantiated empirically. Drawing from the conceptual framework and empirical results of the EC-funded research project CLICO (‘Climate Change, Hydro-Conflict and Human Security’) which is presented in this Special Issue, this opening article looks at the conditions that shape conflict and insecurity, with a focus on the role of adaptation policies. We find three main sources of human insecurity: first, democratic deficits, which are more influential than hydro-climatic stresses; second, mal-adaptations, i.e. adaptations that have adverse effects for the security of some groups; and third, structural violence, often related to economic and state development. There is a systemic contradiction insofar as the pursuit of adaptation through state-led economic growth projects ends up producing new insecurities for parts of the population. Adaptation to hydro-climatic change, therefore, is likely to be a contested and painful process. Research on security and climate change must move beyond narrow investigations of conflict and study the links between structural violence and human insecurity, in particular the conditions and processes that reduce the options available to deal with potential insecurities.