Morphology and structure of a landslide complex in an active margin setting: The Waitawhiti complex, North Island, New Zealand   总被引：1，自引：0，他引：1  

Aurlien Lacoste  Lies Loncke  Frank Chanier  Julien Bailleul  Bruno C. Vendeville  Geoffroy Mahieux 《Geomorphology》2009,109(3-4):184-196

Multi-scale gravitational instabilities are widespread in the Coastal Ranges of the North Island of New Zealand. We document here a detailed analysis of the Waitawhiti landslide complex, located in the core of the Tawhero syncline, and investigate the potential landslides triggering factors in the area. Four contiguous large slides form the Waitawhiti complex. These slides involve fine-grained Miocene sandstones and massive fractured siltstones. Sliding occurs mostly along nearly horizontal strata. All slides are bounded laterally and/or distally by deep-incised valleys. Three gas seeps evidencing thermogenic gas release have been discovered in the vicinity of the slides. We propose that river incision, continuously removing distal buttresses, is the main destabilizing factor in the area. However, additional factors, such as tectonic activity and intense rainfall, cannot be excluded. We also propose that fluid overpressure, reducing the effective shear strength at the base of low-permeability layers, may have influenced the triggering of landslides in the Waitawhiti area.  相似文献   

The influence of tidal streams on the pre-spawning movements of atlantic herring, Clupea harengus L., in the St Lawrence estuary     

Lacoste  Karine N.; Munro  Jean; Castonguay  Martin; Saucier  Francois J.; Gagne  Jacques A. 《ICES Journal of Marine Science》2001,58(6):1286-1298

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Model‐based evaluation of impact of soil redistribution on soil organic carbon stocks in a temperate hedgerow landscape          下载免费PDF全文

Marine Lacoste  Valérie Viaud  Didier Michot  Christian Walter 《地球表面变化过程与地形》2016,41(11):1536-1549

Agroforestry systems are promoted for providing a number of ecosystem services and environmental benefits, including soil protection and carbon sequestration. This study proposes a modelling approach to quantify the impact of soil redistribution on soil organic carbon (SOC) storage in a temperate hedgerow landscape. Evolution of SOC stocks at the landscape scale was examined by simulating vertical and horizontal SOC transfers in the 0–105 cm soil layer due to soil redistribution by tillage and water processes. A spatially explicit SOC dynamics model (adapted from RothC‐26.3) was used, coupled with a soil‐redistribution model (LandSoil). SOC dynamics were simulated over 90 years in an agricultural hedgerow landscape dedicated to dairy farming, with a mix of cropping and grasslands. Climate and land use were simulated considering business‐as‐usual scenarios derived from existing information on the study area. A net decrease in SOC stocks was predicted at the end of the simulation period. Soil redistribution induced a net SOC loss equivalent to 2 kg C ha^?1 yr^?1 because of soil exportation out of the study site and an increase in SOC mineralization. Hedgerows and woods were the only land use in which soil redistribution induced net SOC storage. Soil tillage was the main process that induced soil redistribution within cultivated fields. Soil exportation out of the study area was due to erosion by water, but remained low because of the protective role of the hedgerow network. These soil transfers redistributed SOC stocks in the landscape, mostly within cultivated fields. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

Nutrient fluxes between water column and sediments: Potential influence of the pearl oyster culture   总被引：1，自引：0，他引：1  

Gaertner-Mazouni N  Lacoste E  Bodoy A  Peacock L  Rodier M  Langlade MJ  Orempuller J  Charpy L 《Marine pollution bulletin》2012,65(10-12):500-505

This study quantifies benthic nutrient fluxes and sedimentation rates in the Ahe Atoll lagoon (French Polynesia), in two stations located under pearl oyster frames, and two control stations away from the pearl culture facility. Dissolved inorganic nitrogen fluxes ranged between 2 and 35μmolNm(-2)h(-1) and Soluble Reactive Phosphorus varied between -3 and 8.2μmolPm(-2)h(-1). Particulate sedimentation rates beneath the oysters were approximately five times higher than in the control zone and the percentage of small particles (?63μm) were about the twice. In contrast, sediment composition was similar under and outside the direct influence of oyster frames. In this ecosystem, where primary production is dependent on the available nitrogen, our study revealed that, while highly variable, benthic fluxes could sometimes contribute up to 28% of the nitrogen demand for primary production.  相似文献