Fieldwork and Tropicality in French Indochina: Reflections on Pierre Gourou's Les Paysans Du Delta Tonkinois, 1936

This paper examines the fieldwork undertaken by the distinguished French geographer Pierre Gourou (1900–99) in the Tonkin Delta (Red River Delta) of northern Vietnam in the 1920s and 1930s, and his wider configuration of “the tropical world” as a distinct space of knowledge and radical otherness. Gourou's fieldwork endeavours in French Indochina are interpreted in the light of recent work on “tropicality”: the idea that “the tropics” need to be understood as a western cultural construction and colonising discourse that essentialised the hot, wet regions of the world, and exalted the temperate world over its tropical counterpart. The paper focuses on Gourou's monumental 1936 study Les paysans du delta tonkinois, étude de géographie humaine. It is argued that in this study, and his later comparative work on the tropics, Gourou elaborated a distinct geographical variant of tropicality, but one that, ultimately, reinforced the essentialist logic and momentum of this discourse. Particular attention is paid to the geographical ideas, fieldwork techniques and discursive strategies that Gourou used in his 1936 study, and the French colonial context in which he worked. The article shows how Gourou appealed to western reason and science as tools of study, identified overpopulation as the key problem facing the Tonkin Delta, and suggested that colonial practices of modernisation had a limited place and ineffectual role in the rice plains of the region.     

Climate change implications for irrigation and groundwater in the Republican River Basin,USA

This study investigates the influence of climate change on groundwater availability, and thereby, irrigation across political boundaries within the US High Plains aquifer. A regression model is developed to predict changes in irrigation according to predicted changes in precipitation and temperature from a downscaled dataset of 32 general circulation models (GCMs). Precipitation recharge changes are calculated with precipitation-recharge curves developed for prognostic representations of precipitation across the Nebraska-Colorado-Kansas area and within the Republican River Basin focal landscape. Irrigation-recharge changes are scaled with changes in irrigation. The groundwater responses to climate forcings are then simulated under new pumping and recharge rates using a MODFLOW groundwater flow model. Results show that groundwater pumping and recharge both will increase and that the effects of groundwater pumping will overshadow those from natural fluctuations. Groundwater levels will decline more in areas with irrigation-driven decreasing trends in the baseline. The methodologies and predictions of this study can inform long-term water planning and the design of management strategies that help avoid and resolve water-related conflicts, enabling irrigation sustainability.     

Detecting climate change effects on forest ecosystems in Southwestern Romania using Landsat TM NDVI data

Nowadays, Southwestern Romania faces a large-scale aridization of the climate, revealed by the rise of temperatures and the decline of the amount of precipitations, with negative effects visible, among others, in the desiccation of forest vegetation. The present study means to identify the changes that occurred, quality-wise, in the past two decades （1990-2011） in forest vegetation in Southwestern Romania, and to establish the link between those changes and extant thermal stress in the region, whose particular features are high average annual and seasonal temperatures. In order to capture the evolution in time of cli- mate aridization, a first step consisted in using climate data, the temperature and precipitation parameters from three weather stations; these parameters were analyzed both individually and as aridity indexes （De Martonne and UNEP）. In order to quantify the changes in forest vegetation, NDVI indexes were used and analyzed, starting off from Landsat satellite images, acquired at three distinct moments in time, 1990, 2000 and 2011. In order to identify the link between the changes of NDVI index values and regional thermal stress, a yardstick of climate changes, statistical correlations were established between the peak values of average annual temperatures, represented in space, and negative changes in the NDVI index, as revealed by the change-detection analysis. The results obtained indicated there is an obvious （statistically significant） connection between thermal stress and the desiccation （degradation） of forest species in the analyzed area, with false acacia （Robinia Pseudoacacia） the main species to be impacted.     

Emission metrics under the 2 °C climate stabilization target

In multi-gas climate policies such as the Kyoto Protocol one has to decide how to compare the emissions of different greenhouse gases. The choice of metric could have significant implications for mitigation priorities considered under the prospective negotiations for climate mitigation agreements. Several metrics have been proposed for this task with the Global Warming Potential (GWP) being the most common. However, these metrics have not been systematically compared to each other in the context of the 2 °C climate stabilization target. Based on a single unified modeling framework, we demonstrate that metric values span a wide range, depending on the metric structure and the treatment of the time dimension. Our finding confirms the basic salient point that metrics designed to represent different aspects of the climate and socio-economic system behave differently. Our result also reflects a complex interface between science and policy surrounding metrics. Thus, it is important to select or design a metric suitable for climate stabilization based on an interaction among practitioners, policymakers, and scientists.     

Cyanobacteria and microcystin in the Nebraska (USA) Sand Hills Lakes before and after modern agriculture

Chlorophyll a, zeaxanthin, and pheophytin a were measured from sediment core samples from three lakes (Dewey, Island, and Two Mile Lakes) in the Nebraska Sand Hills. Pigments were extracted and identified by high performance liquid chromatography (HPLC) and used to estimate changes in the relative proportion of cyanobacteria to the algal community. The cyanobacterial toxins microcystin-LR and LA were extracted and measured using electrospray ionization liquid chromatography tandem mass spectrometry (LC/MS/MS). Microcystin-LR was found in core sections estimated to be as early as 1832, and was present in all three lake cores. Pigment and toxin data were used to determine if there were changes that occurred in the algal community structure with the onset of modernized agriculture in the region. No significant changes were found in the relative percent of cyanobacteria or chlorophyll a accumulation, indicating the frequency and intensity of cyanobacterial blooms has not changed over the last century. Despite this trend, there was a dramatic increase in microcystin-LR accumulation during the 1980s in Dewey Lake, which may be human induced.     

Water level control on coastal landform distribution and associated processes in a highly fluctuating shallow lake (Gallocanta Lake,NE Spain)

Shallow lakes in semi-arid environments are very sensitive to hydrological alterations associated with climate change. Their shorelines and geometry can change according to water level fluctuations. Gallocanta Lake (NE Spain) is a typical example of such lacustrine conditions because it is exposed to strong winds parallel to its elongation axis and is located in a semi-arid Mediterranean environment. In this work, a high-resolution digital elevation model (DEM) of the area is used to compare the distribution of coastal forms (beaches, barrier islands, deltas, lagoons, etc.) with the frequency at which different water levels are attained. As a result, a clear relationship is obtained between presently active forms and the water levels most frequently reached in the lake. It is deduced that, once formed, the surrounding coastal plains related to these coastal forms control the permanence of water around a given height interval, favouring the development of these morphologies, in a positive feedback mechanism only broken by subsequent climate warming and lake water lowering. The hydrodynamic conditions responsible for activating the coastal forms have been analysed by applying a mathematical model of wind-driven currents in the lake that predicts the present erosional/progradational trends associated with them. The combination of the different results obtained was used to generate a synthetic map of active coastal processes and trends along the lake shore during high water episodes, with two versions according to the two dominant wind scenarios in the region. The distribution of erosion/sedimentation trends along the lake shores has helped to propose the existence of longitudinal littoral cells, each one recording different shoreline trend (retreat, progradation, and stability), depending on the prevailing wind scenario. This synthetic scheme can be useful for predicting the eco-morphological trends of the lake shore and adapting the present management practices in this protected area accordingly.     

City on edge: immigrant businesses and the right to urban space in inner-city Johannesburg

Paradoxically, Johannesburg is a quintessentially migrant city and also ranks among the least immigrant-friendly cities in the world. Over the past 20 years, inner-city Johannesburg has been vacated and then reconstituted as a hive of informal trade networks and migration circuits that extends well beyond national borders. Research on immigrants in Johannesburg has contributed significantly to understandings of xenophobic sentiments and immigrant identities, but there remains a large gap in knowledge about immigrant entrepreneurship, economic enclaves and economic mobility. Our research is based on extensive fieldwork, discussions with immigrant organizations and in-depth interviews with immigrants and South Africans engaged in business in three prominent inner-city immigrant business enclaves: Jeppe/Delvers, Eighth Avenue and Raleigh Street. Our research shows that these immigrant business zones each operate differently and vary in the degree to which they connect to urban and national economic grids; some retain stronger ties to transnational networks that link dispersed spaces to Johannesburg, creating specific local milieus. We advocate for a more geographically sensitive and nuanced understanding of immigrant entrepreneurs and a reconsideration of their rights to the city.     

Coastal margin evolution and postulated “basin‐shipyard” area at ancient Locri‐Epizephiri,Calabria, Italy

Environmental settings on the Ionian coastal plain and inner shelf seaward of Locri‐Epizephiri in Calabria, Italy, differed markedly before, during, and following settlement by the Greeks. Sediment core analyses and geophysical surveys in this study support recent archaeological findings and the hypothesis that the margin may once have served as a harbor and/or shipyard. The subsurface Holocene stratigraphy records that (1) the shoreline advanced to a maximum landward position before Greek settlement, then regressed offshore to what is now the inner shelf before once again migrating landward. These marked coastal shifts were triggered primarily by land uplift and probable subsidence offshore along this structurally active Calabrian Arc segment. Associated with this are: (2) a sediment fining‐upward sequence in Greek–Roman time that indicates only partial protection of the coastal area, and (3) possible presence of subsurface structures seaward of the city wall in a sector now positioned ∼200 m offshore. © 2010 Wiley Periodicals, Inc.