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排序方式: 共有1057条查询结果,搜索用时 15 毫秒
1.
Song Jun Young Sim Youngjong Jang Jaewon Hong Won-Taek Yun Tae Sup 《Acta Geotechnica》2020,15(7):1967-1980
Acta Geotechnica - To resolve the environmental and sustainability issues from fugitive dust emission and conventional mitigation methods, multiple experiments were conducted to evaluate the... 相似文献
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A simple relation between pore pressure change and one-dimensional surface deformation is presented. The relation is for pore pressure change in a confined aquifer that causes surface deformation. It can be applied to groundwater models of any discretization and is computationally efficient. The estimated surface deformation from model results can be compared to observed surface deformation through geodetic techniques such as Differential Interferometric Synthetic Aperture Radar. Model parameters then are constrained using the observed surface deformation. The validity of this relation is shown through constraint of model parameters for surface uplift due to pore pressure increase caused by wastewater disposal injection. 相似文献
4.
Gama Andre B. Perondi Daniel Dewdney Megan M. Fraisse Clyde W. Small Ian M. Peres Natalia A. 《Theoretical and Applied Climatology》2022,149(1-2):83-99
Theoretical and Applied Climatology - Disease alert systems (DAS) of the AgroClimate platform are intended to facilitate grower decision-making when planning fungicide applications. These DAS... 相似文献
5.
Arif Mohaimin Sadri Satish V. Ukkusuri Seungyoon Lee Rosalee Clawson Daniel Aldrich Megan Sapp Nelson Justin Seipel Daniel Kelly 《Natural Hazards》2018,90(3):1377-1406
The factors that explain the speed of recovery after disaster remain contested. While many have argued that physical infrastructure, social capital, and disaster damage influence the arc of recovery, empirical studies that test these various factors within a unified modeling framework are few. We conducted a mail survey to collect data on household recovery in four small towns in southern Indiana that were hit by deadly tornadoes in March 2012. The recovery effort is ongoing; while many of the homes, businesses, and community facilities were rebuilt in 2013, some are still under construction. We investigate how households in these communities are recovering from damage that they experienced and the role of social capital, personal networks, and assistance from emergency responders on the overall recovery experience. We used an ordered probit modeling framework to test the combined as well as relative effects of (a) damage to physical infrastructures (houses, vehicles, etc.); (b) recovery assistance from emergency responders (FEMA) as well as friends and neighbors; (c) personal network characteristics (size, network density, proximity, length of relationship); (d) social capital (civic engagement, contact with neighbors, trust); and (e) household characteristics. Results show that while households with higher levels of damage experienced slower recovery, those with recovery assistance from neighbors, stronger personal networks, and higher levels of social capital experienced faster recovery. The insights gained in this study will enable emergency managers and disaster response personnel to implement targeted strategies in facilitating post-disaster recovery and community resilience. 相似文献
6.
Periodical algal blooms result in deposition and release of phosphorus (P) from the sediment into the water. Therefore, during seasonal changes when algal particles begin to settle to the bottom, understanding the behavior and distribution characteristics of the P in sediment is the most important key to manage the water quality of the Saemangeum Reservoir. In this study, the variation of water quality and sediment composition including chlorophyll-a (Chl-a) and P was investigated to determine the interaction between water and sediment. The study focused primarily on algal particle sedimentation that affects the P release and mineralization of sediment. The Chl-a concentration in water showed a sharp decline in October when the algae began to die in the fall, and afterward the concentration of chemical oxygen demand (COD) and total P (TP) in the sediment increased due to the sedimentation of decaying algal particles in November. During the same period of time, the readily bio-available P (RAP) in the sediment showed a drastic increase in the upper region where the Chl-a concentration of water was high. In sequence, the high RAP zone shifted from the upper region to the lower region in the early winter. The RAP shift was considered to be derived from the physical flow of the overlying water from which the decomposing algae settled on the surface of the sediment. The Saemangeum Reservoir was constructed recently; therefore, all the types of inorganic P fractions except soluble reactive phosphorus (SRP) that exist on the bottom surface of the lake and the marsh's sediment layer were not sufficient to significantly influence the overlying water. On the other hand, the released P from the algae was distinct and sensitive to the seasonal change. In conclusion, the algal particle sedimentation was important to control eutrophication rather than P release from the mineralized inorganic P of the sediment surface layer in the Seamangeum Reservoir. 相似文献
7.
Quantifying sedimentation patterns of small landslide-dammed lakes in the central Oregon Coast Range
Logan R. Wetherell Lisa L. Ely Joshua J. Roering Megan K. Walsh Molly J. Burchfield Keifer E. Nace Meaghan M. Wetherell William T. Struble 《地球表面变化过程与地形》2021,46(7):1375-1392
Understanding sedimentation patterns in small coastal watersheds due to landscape perturbations is critical for connecting hillslope and fluvial processes, in addition to managing aquatic habitats for anadromous fish and other aquatic species in the Oregon Coast Range (OCR). Changes in sedimentation patterns spanning the last 250 years are preserved in two landslide-dammed lakes in small watersheds (< 10 km2) underlain by the Tyee Formation in the central OCR. Dendrochronology of drowned Douglas-fir stumps in both lakes provided precise timing of the damming and formation of the lakes, with Klickitat Lake forming in winter ad 1751/52 and Wasson Lake in winter ad 1819/20. Perturbations from wildfires, logging and road development, and previously underappreciated snow events affect sedimentation rates in the lakes to different degrees, and are identified in the sediment record using cesium-137 (137Cs), high-resolution charcoal stratigraphy, local fire records, and aerial photography. Each lake has variable sedimentation accumulation rates (0.05–4.4 cm yr−1) and mass accumulation rates (0.02–1.42 g cm−2 yr−1). Sedimentation rates remained low from the landslide-damming events until the mid-19th century, when they increased following stand-replacing wildfires. Aside from a sediment remobilization triggered by human modification of the landslide dam at Klickitat Lake around 1960, the largest peaks in mass accumulation rates in the mid-20th century at both lakes in the early 1950s precede major road construction and logging activity in the watersheds. Subsequent sedimentation rates are lower, but variable, and possible effects of logging and road development might be exacerbated by abnormal precipitation and heavy snow events. A comparison of previous studies of landslide-dammed lakes in larger watershed of the OCR are consistent with our findings of increased sedimentation in the mid-20th century, as well as higher sedimentation rates in the debris-flow dominated southern Tyee Formation than in the lower-relief northern Tyee Formation. 相似文献
8.
J. Christopher Rutherford Roger G. Young John M. Quinn Robert J. Wilcock 《新西兰海洋与淡水研究杂志》2020,54(3):410-430
ABSTRACT Instream processes alter the concentration and bioavailability of nutrients as they are transported downstream. By relating primary production and periphyton composition to changes in nutrient concentration in a gravel-bed river this study made inferences about recycling and attenuation. Where dissolved inorganic nitrogen (DIN) was abundant, concentrations decreased linearly with distance but by less than required to meet the nitrogen demand of primary production. Where DIN was barely measurable photosynthesis was reduced but only by 50%. We infer that recycling sustained primary production even when DIN concentrations were negligibly small. One implication is that DIN removal underestimates attenuation. Further experimental research on recycling and improved modelling is required to better quantify the length of streams adversely affected by nutrients. 相似文献
9.
Pesticide use by farmers on Santa Cruz Island, Galapagos—a perceived adaptation to changing ecological and economic dynamics—has the potential to lead to environmental degradation in an area that is known and valued worldwide for its biodiversity. We survey Santa Cruz farmers to understand motivations for and concerns about pesticide use on the island. Results from farmer surveys are supplemented with interview data to develop the case study of pesticide use on Santa Cruz Island. We then apply a “complex trade-off” framework to explore and navigate the tensions between conservation and livelihoods. We conclude by elaborating the implementation of a participatory certification system, the Participatory Guarantee System, as a possible path for reconciling trade-offs in Santa Cruz, Galapagos. 相似文献
10.
Kenneth R. Young 《Geographical review》2019,109(2):258-264