Subsidence due to groundwater withdrawal is a complex hydrogeological process affecting numerous cities settled on top of fluviolacustrine deposits. The discrete spatial variation in the thickness of these deposits, i...Subsidence due to groundwater withdrawal is a complex hydrogeological process affecting numerous cities settled on top of fluviolacustrine deposits. The discrete spatial variation in the thickness of these deposits, in combination with subsidence due to groundwater withdrawal, generates differential settlements and aseismic ground failure (AGF) characterized by a welldefined scarp. In cities, such AGF causes severe damages to urban infrastructure and considerable economic impact. With the goal of arriving to a general criterion for evaluating the economic losses derived from AGF, in the present work we propose the following equation: ELi = PVi*DFi. Where PVi is the value of a property “i”, and DFi is a depreciation factor caused by structural damages of a property “i” due to AGF. The DFi is calculated empirically through: . This last equation is based on the spatial relations of coexistence and proximity of property polygons and the AGF axis. The coexistence is valued as the quotient of the affectation area divided by the total area of the involved property;and the proximity to the AGF axis is expressed as the inverse of the perpendicular distance from the centroid of the property polygon to the AGF axis. The sum of these terms is divided by two to determine the percentage that affects the property value (PVi). These equations are relevant because it is the first indicator designed for the discrete assessment of the economic impacts due to AGF, and can be applied to real estate infrastructure from either urban or rural areas.展开更多
Large-scale water pumping has caused significant decline in groundwater level in the Upper Arkansas corridor region, which in turn has triggered a chain of hydrological and ecological impacts. A newly developed concep...Large-scale water pumping has caused significant decline in groundwater level in the Upper Arkansas corridor region, which in turn has triggered a chain of hydrological and ecological impacts. A newly developed conceptualization groundwater data model was used to organize various datasets on the Upper Arkansas corridor groundwater system and to develop a MODFLOW model to simulate groundwater flow in the region from 1959 to 2005. The simulation results have shown a sig- nificant decline in groundwater level and the conversion of Arkansas River from a gaining river to a losing river in the western two-thirds of the study area. Correlation analysis between percentage of salt cedar and the hydrogeological conditions indicates that these hydrogeological changes at least partially account for invasion of salt cedar that is more drought tolerant. The analysis also illustrates the com- plexity of the interaction mechanisms between hydrological conditions and salt cedar distribution, and suggests the need for better data on salt cedar distribution with higher spatial resolution and across larger hydrological gradients.展开更多
基金support from CONACYT for the Basic Science Project 134575Scientific Research Coordination of the Universidad Michoacana de San Nicolás de Hidalgo,Project 1.37-2013.
文摘Subsidence due to groundwater withdrawal is a complex hydrogeological process affecting numerous cities settled on top of fluviolacustrine deposits. The discrete spatial variation in the thickness of these deposits, in combination with subsidence due to groundwater withdrawal, generates differential settlements and aseismic ground failure (AGF) characterized by a welldefined scarp. In cities, such AGF causes severe damages to urban infrastructure and considerable economic impact. With the goal of arriving to a general criterion for evaluating the economic losses derived from AGF, in the present work we propose the following equation: ELi = PVi*DFi. Where PVi is the value of a property “i”, and DFi is a depreciation factor caused by structural damages of a property “i” due to AGF. The DFi is calculated empirically through: . This last equation is based on the spatial relations of coexistence and proximity of property polygons and the AGF axis. The coexistence is valued as the quotient of the affectation area divided by the total area of the involved property;and the proximity to the AGF axis is expressed as the inverse of the perpendicular distance from the centroid of the property polygon to the AGF axis. The sum of these terms is divided by two to determine the percentage that affects the property value (PVi). These equations are relevant because it is the first indicator designed for the discrete assessment of the economic impacts due to AGF, and can be applied to real estate infrastructure from either urban or rural areas.
基金supported by the Provost Office’s Targeted Excellence Program at Kansas State University,the U.S. National Science Foundation (No. EPS0553722)the United States Department of Agriculture/Agricultural Research Service (Co-operative Agreement 58-6209-3-018)
文摘Large-scale water pumping has caused significant decline in groundwater level in the Upper Arkansas corridor region, which in turn has triggered a chain of hydrological and ecological impacts. A newly developed conceptualization groundwater data model was used to organize various datasets on the Upper Arkansas corridor groundwater system and to develop a MODFLOW model to simulate groundwater flow in the region from 1959 to 2005. The simulation results have shown a sig- nificant decline in groundwater level and the conversion of Arkansas River from a gaining river to a losing river in the western two-thirds of the study area. Correlation analysis between percentage of salt cedar and the hydrogeological conditions indicates that these hydrogeological changes at least partially account for invasion of salt cedar that is more drought tolerant. The analysis also illustrates the com- plexity of the interaction mechanisms between hydrological conditions and salt cedar distribution, and suggests the need for better data on salt cedar distribution with higher spatial resolution and across larger hydrological gradients.
