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.     

Interprétation hydrogéologique de l'aquifère des bassins sud-rifains (Maroc) : apport de la sismique réflexion

The aquifer of the Rharb Basin is constituted by heterogeneous material. The seismic reflexion interpretation carried out in this area, highlighted a permeable device compartmentalized in raised and subsided blocks. Depressions identified in the northern and southernmost zones are characterized by Plio-Quaternary fillings that are favourable to the hydrogeological exploitation. Two mechanisms contribute to structure the Plio-Quaternary aquifer: the Hercynian reactivation in the southernmost part, and the gravitational mechanism of the Pre-Rifean nappe. The groundwater flow and the aquifer thickening are controlled by this reactivation.     

Paleolimnological evidence for increased landslide activity due to forest clearing and land-use since 3600 cal BP in the western Swiss Alps

Schwarzsee is located in the western Swiss Alps, in a region that has been affected by numerous landslides during the Holocene, as evidenced by geological surveys. Lacustrine sediments were cored to a depth of 13 m. The vegetation history of the lake's catchment was reconstructed and investigated to identify possible impacts on slope stability. The pollen analyses record development of forest cover during the middle and late Holocene, and provide strong evidence for regional anthropogenic influence such as forest clearing and agricultural activity. Vegetation change is characterized by continuous landscape denudation that begins at ca. 4300 cal. yrs BP, with five distinct pulses of increased deforestation, at 3650, 2700, 1500, 900, and 450 cal. yrs BP. Each pulse can be attributed to increased human impact, recorded by the appearance or increase of specific anthropogenic indicator plant taxa. These periods of intensified deforestation also appear to be correlated with increased landslide activity in the lake's catchment and increased turbidite frequency in the sediment record. Therefore, this study gives new evidence for a strong influence of vegetation changes on slope stability during the middle and late Holocene in the western Swiss Alps, and may be used as a case study for anthropogenically induced landslide activity.     

A Novel Surrogate-Assisted Multi-objective Optimization Method for Well Control Parameters Based on Tri-Training

Natural Resources Research - Multi-objective well control optimization, which considers simultaneous optimization of more than one objective, has become an essential tool for efficient intelligent...     

Recent Fluvial, Volcanic, and Tectonic Activity on the Cerberus Plains of Mars

Athabasca and Marte Valles lie on the Cerberus plains, between the young, lava-covered plains of Elysium Planitia and Amazonis Planitia. To test pre-MGS (Mars Global Surveyor) suggestions of extremely young volcanic and fluvial activity, we present the first crater counts from MGS imagery, at resolutions (∼2-20 m/pixel) much higher than previously available. The most striking result, based on morphologic relations as well as crater counts from different stratigraphic units, is to confirm quantitatively that these channel systems are much younger than most other major outflow channels. The general region has an average model age for lava and fluvial surfaces of ≤200 Myr, and has possibly seen localized water releases, interspersed with lava flows, within the past 20 Myr. The youngest lavas may be no more than a few megayears old. Access of lava and liquid brines to the surface may be favored by openings of the Cerberus Fossae fracture system, but, as shown in the new images, the fractures appear to have continued developing more recently than the most recent lavas or fluvial activity. The Cerberus Fossae system may be an analog to an early stage of Valles Marineris, and its youthful activity raises questions about regional tectonic history. Large-volume water delivery to the surface of young lava flows in recent martian history puts significant boundary conditions on the storage and history of water on Mars.     

Inundation,sea-level rise and transition from Neolithic to Bronze Age cultures,Yangtze Delta,China

Petrological, faunal and floral information derived from a new drill core taken in the Yangtze delta, coupled with data from borings recovered earlier, record a marked transition to warmer, wetter conditions which resulted in widespread inundation of the delta about 4000 years ago. Also identified for that time on the delta plain is a major discontinuity between the Neolithic Liangzhu and Bronze age Maqiao cultures. The cultural discontinuity is indicated by: (1) absence of in situ material between the two at ∼4000 yr B.P.; (2) missing Maqiao material in strata above many Liangzhu sites; (3) less sophisticated Maqiao material than in the older Neolithic phase; and (4) notably fewer Maqiao sites in more restricted areas of the delta plain. It is of note that the change from the Liangzhu to the younger Maqiao does not show an increasingly complex cultural advancement of the type generally associated with the foundation of Chinese civilization. We propose that this cultural discontinuity was caused by the interplay of increased environmental stress and new population migrations into the delta. © 1999 John Wiley & Sons, Inc.     

Spatial error correction and cointegration in nonstationary panel data: regional house prices in Israel

We “spatialize” residual-based panel cointegration tests for nonstationary spatial panel data in terms of a spatial error correction model (SpECM). Local panel cointegration arises when the data are cointegrated within spatial units but not between them. Spatial panel cointegration arises when the data are cointegrated through spatial lags between spatial units but not within them. Global panel cointegration arises when the data are cointegrated both within and between spatial units. Spatial error correction arises when error correction occurs within and between spatial units. We use nonstationary spatial panel data on the housing market in Israel to illustrate the methodology. We show that regional house prices in Israel are globally cointegrated in the long run and there is evidence of spatial error correction in the short run.     

Financial market actors as urban policy-makers: the case of real estate investment trusts in Brazil

Focusing on the growth of Real Estate Investment Trusts in Brazil, the paper explores how financializing policy instruments intertwine financial markets and the urban built environment. It studies the career of REITs and questions the role of financial market capital and actors in urban dynamics. The paper uncovers three processes usually considered separately: i) how a network of public and private financial market actors coaxes state bodies into using their regulatory powers and financial resources to transform real estate into an asset class; ii) how the government-run financial market authority and banks lure urban households into liquid real estate through marketing and education campaigns; and iii) how asset managers are “applied economic geographers” insofar as they channel households’ capital into a selected cities and properties. The active role played by financial actors in the design, enhancement and implementation of such a policy instrument leads us to conclude on their role as urban policy-makers.