scholarly journals A Spatially Distributed Groundwater Metric for Describing Hydrologic Changes in a Regional Population of Wetlands North of Tampa Bay, Florida, from 1990 to 2015

Wetlands ◽  
2021 ◽  
Vol 41 (8) ◽  
Author(s):  
Geoffrey Fouad ◽  
Terrie M. Lee
2021 ◽  
Author(s):  
Geoffrey Fouad ◽  
Terrie M. Lee

Abstract A groundwater condition metric is presented and used to evaluate hydrologic changes in a regional population of wetlands in and around municipal well fields with large groundwater withdrawals. The approach compares a 26-year, monthly time series of groundwater potentiometric surfaces to light detection and ranging (LiDAR) land-surface elevations at 10,516 wetlands in a 1505-square-kilometer area. Elevation differences between the potentiometric surface and wetland land surface provide a flow direction (upward or downward) and a proxy for vertical hydraulic head difference in Darcy’s groundwater flow equation. The resulting metric quantifies the groundwater condition at a wetland through time as the potential for groundwater to discharge upward into a wetland or for water in a wetland to leak downward to recharge the underlying aquifer. The potential for wetland leakage across the regional wetland population decreased by 33% in the 13 years after cutbacks in groundwater withdrawals (2003-2015) compared to years before cutbacks (1990-2002). Inside well field properties, wetland leakage potential decreased by 24%. In the wet season month of September, wetlands with the potential to receive groundwater discharge increased to 21.6% of the regional population after cutbacks compared to 13.3% before cutbacks. When mapped across regional drainage basins, discharging wetlands formed spatial connections suggesting they play a critical role in generating streamflow.


2020 ◽  
pp. 133-158
Author(s):  
K. A. Kholodilin ◽  
Y. I. Yanzhimaeva

A relative uniformity of population distribution on the territory of the country is of importance from socio-economic and strategic perspectives. It is especially important in the case of Russia with its densely populated West and underpopulated East. This paper considers changes in population density in Russian regions, which occurred between 1897 and 2017. It explores whether there was convergence in population density and what factors influenced it. For this purpose, it uses the data both at county and regional levels, which are brought to common borders for comparability purposes. Further, the models of unconditional and conditional β-convergence are estimated, taking into account the spatial dependence. The paper concludes that the population density equalization took place in 1897-2017 at the county level and in 1926—1970 at the regional level. In addition, the population density increase is shown to be influenced not only by spatial effects, but also by political and geographical factors such as climate, number of GULAG camps, and the distance from the capital city.


Author(s):  
N. V. Yefi mova ◽  
I. V. Myl’nikova ◽  
M. V. Kuz’mina ◽  
L. G. Lisetskaya ◽  
Ye. Ye. Loznevaya

Irkutsk region is among territories of intense industrial development. Considerable part of the regional population is long exposed to chemical pollutants of environmental objects. Th e authors evaluated carcinogenic risk for the population of industrial centers and rural area. Findings are that maximal carcinogenic risk is carried by the urban population. Aggregated carcinogenic risk parameters evaluation proved inhalation to be a priority route of exposure. Irkutsk region appeared to have territories with high carcinogenic risk for public health. Among a list of chemicals in the ambient air are priority carcinogens: six-valent chromium and lead. The evidences necessitate measures on the risks minimization. Due to absent data on carcinogens content of drinkable water in some rural area, the necessity is to evaluate risk for the rural population by studies of drinkable water quality that does not match hygienic regulations, because oral one is a main route of carcinogens intake.


2001 ◽  
Author(s):  
Jimmy Johnston ◽  
Kimberly Yates ◽  
Pete Bourgeois ◽  
Diane Burdick ◽  
Jim Giattina ◽  
...  

2001 ◽  
Author(s):  
Peter W. Swarzenski ◽  
Kimberly Yates ◽  
Paul Carlson ◽  
D.L. Felder ◽  
Mario Fernandez ◽  
...  

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