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Historical trends in Florida temperature and precipitation 总被引：1，自引：0，他引：1
Michelle M. Irizarry‐Ortiz Jayantha Obeysekera Joseph Park Paul Trimble Jenifer Barnes Winifred Park‐Said Erik Gadzinski 《水文研究》2013,27(16):2225-2246
Because of its low topographic relief, unique hydrology, and the large interannual variability of precipitation, Florida is especially vulnerable to climate change. In this paper, we investigate a comprehensive collection of climate metrics to study historical trends in both averages and extremes of precipitation and temperature in the state. The data investigated consist of long‐term records (1892–2008) of precipitation and raw (unadjusted) temperature at 32 stations distributed throughout the state. To evaluate trends in climate metrics, we use an iterative pre‐whitening method, which aims to separate positive autocorrelation from trend present in time series. Results show a general decrease in wet season precipitation, most evident for the month of May and possibly tied to a delayed onset of the wet season. In contrast, there seems to be an increase in the number of wet days during the dry season, especially during November through January. We found that the number of dog days (above 26.7 °C) during the year and during the wet season has increased at many locations. For the post‐1950 period, a widespread decrease in the daily temperature range (DTR) is observed mainly because of increased daily minimum temperature (Tmin). Although we did not attempt to formally attribute these trends to natural versus anthropogenic causes, we find that the urban heat island effect is at least partially responsible for the increase in Tmin and its corresponding decrease in DTR at urbanized stations compared with nearby rural stations. In the future, a formal trend attribution study should be conducted for the region. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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A Wetland Simulation Module for the MODFLOW Ground Water Model 总被引：8，自引：0，他引：8
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Simulation of daily rainfall scenarios with interannual and multidecadal climate cycles for South Florida 总被引：4，自引：3，他引：1
Hyun-Han Kwon Upmanu Lall Jayantha Obeysekera 《Stochastic Environmental Research and Risk Assessment (SERRA)》2009,23(7):879-896
Concerns about the potential effects of anthropogenic climate change have led to a closer examination of how climate varies
in the long run, and how such variations may impact rainfall variations at daily to seasonal time scales. For South Florida
in particular, the influences of the low-frequency climate phenomena, such as the El Nino Southern Oscillation (ENSO) and
the Atlantic Multi-decadal Oscillation (AMO), have been identified with aggregate annual or seasonal rainfall variations.
Since the combined effect of these variations is manifest as persistent multi-year variations in rainfall, the question of
modeling these variations at the time and space scales relevant for use with the daily time step-driven hydrologic models
in use by the South Florida Water Management District (SFWMD) has arisen. To address this problem, a general methodology for
the hierarchical modeling of low- and high-frequency phenomenon at multiple rain gauge locations is developed and illustrated.
The essential strategy is to use long-term proxies for regional climate to first develop stochastic scenarios for regional
climate that include the low-frequency variations driving the regional rainfall process, and then to use these indicators
to condition the concurrent simulation of daily rainfall at all rain gauges under consideration. A newly developed methodology,
called Wavelet Autoregressive Modeling (WARM), is used in the first step after suitable climate proxies for regional rainfall
are identified. These proxies typically have data available for a century to four centuries so that long-term quasi-periodic
climate modes of interest can be identified more reliably. Correlation analyses with seasonal rainfall in the region are used
to identify the specific proxies considered as candidates for subsequent conditioning of daily rainfall attributes using a
Non-homogeneous hidden Markov model (NHMM). The combined strategy is illustrated for the May–June–July (MJJ) season. The details
of the modeling methods and results for the MJJ season are presented in this study. 相似文献
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Jayantha Obeysekera Michelle Irizarry Joseph Park Jenifer Barnes Tibebe Dessalegne 《Stochastic Environmental Research and Risk Assessment (SERRA)》2011,25(4):495-516
Recent climate change projections suggest that negative impacts on flood control and water supply functions and on existing
and future ecosystem restoration projects in south Florida are possible. An analysis of historical rainfall and temperature
data of the Florida peninsula indicates that there were no discernible trends in both the long-term record and during the
more recent period (1950–2007). A comparison of General Circulation Model (GCM) results for the 20th century with the historical
data shows that many of the GCMs do not capture the statistical characteristics of regional rainfall and temperature regimes
in south Florida. Investigation of historical sea level data at Key West finds evidence for an increase in the occurrence
and variance of maximum sea level events for the period 1961–2008 in relation to 1913–1960, along with a shift of energy from
shorter to longer timescales. In order to understand the vulnerability of the water management system in south Florida in
response to changing precipitation and evapotranspiration forcing, a sensitivity analysis using a regional-scale hydrologic
and water management model is conducted. Model results suggest that projected climate change has potential to reduce the effectiveness
of water supply and flood control operations for all water sectors. These findings emphasize that questions on the potential
impacts of climate change need to be investigated with particular attention paid to the uncertainties of such projections. 相似文献
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Joseph Park Jayantha Obeysekera Michelle Irizarry Jenifer Barnes Paul Trimble Winifred Park-Said 《Climatic change》2011,107(1-2):109-128
Water resource management in South Florida faces nearly intractable problems, in part due to weather and climate variability. Rising sea level and coastal storm surge are two phenomena with significant impacts on natural systems, fresh water supplies and flood drainage capability. However, decision support information regarding management of water resources in response to storm surge is not well developed. In an effort to address this need we analyze long term tidal records from Key West, Pensacola and Mayport Florida to extract surge distributions, to which we apply a nonlinear eustatic sea level rise model to project storm surge return levels and periods. Examination of climate connections reveals a statistically significant dependence between surge distributions and the Atlantic Multidecadal Oscillation (AMO). Based on a recent probabilistic model for AMO phase changes, we develop AMO-dependent surge distributions. These AMO-dependent surge projections are used to examine the flood control response of a coastal water management structure as an example of how climate dependent water resource forcings can be used in the formulation of decision support tools. 相似文献
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Rogers Martina Sukop Michael C. Obeysekera Jayantha George Florence 《Hydrogeology Journal》2023,31(4):1031-1049
The Biscayne Aquifer (Florida, USA) is a coastal, shallow, unconfined, and heterogeneous aquifer with high water tables, composed of less-permeable sand to highly permeable karstic limestone. These properties make the Biscayne Aquifer one of the world’s most productive groundwater resources. The aquifer’s high yield and non-Darcian flow cause challenges for estimating aquifer parameters, which are essential for understanding groundwater processes and managing and protecting the groundwater resources. Water-table fluctuations in the Biscayne Aquifer are associated with astronomical tidal forces and gate operations on canal water-control structures. Analysis of observed groundwater level fluctuations can provide an understanding of the connectivity between the aquifer, Biscayne Bay, and the water level in the canals. Further, groundwater level fluctuations can be used for aquifer parameter estimation. In this research, observed ocean water levels measured at tidal stations and groundwater levels are fitted to Jacob’s analytical solution, where the amplitude of the groundwater head fluctuation decreases exponentially, and the time lag increases with distance from the shore. Observed groundwater levels were obtained from monitoring wells along the Miami-Dade shore and the barrier island of Miami Beach. Results indicate that Jacob’s solution is effective for aquifer parameter estimation in Miami Beach, where monitoring wells are closer to the shore. Estimated hydraulic conductivity appears to increase by four orders of magnitude to approximately 1 m s–1 as the distance from shore increases. Constructing monitoring wells closer to the shore in Miami-Dade County and elsewhere would permit improved aquifer parameter estimation and support enhanced groundwater modeling efforts.
相似文献8.
Statistical and physically-based methods have been used for designing and assessing water infrastructure such as spillways and stormwater drainage systems. Traditional approaches assume that hydrological processes evolve in an environment where the hydrological cycle is stationary over time. However, in recent years, it has become increasingly evident that in many areas of the world the foregoing assumption may no longer apply, due to the effect of anthropogenic and climatic induced stressors that cause nonstationary conditions. This has attracted the attention of national and international agencies, research institutions, academia, and practicing water specialists, which has led to developing new techniques that may be useful in those cases where there is good evidence and attribution of nonstationarity. We review the various techniques proposed in the field and point out some of the challenges ahead in future developments and applications. Our review emphasizes hydrological design to protect against extreme events such as floods and low flows. 相似文献
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Declining trends in pan and lake evaporation have been reported. It is important to study this trend in every region to evaluate the validity of the trend and water management implications. Data from nine pan evaporation sites in South Florida were evaluated to see if there is a trend and if the quality of the data is sufficient for such analysis. The conclusion is that pan evaporation measurements are prone to too many sources of errors to be used for trend analysis. This condition is demonstrated in South Florida and in other regions by differences in magnitude and direction between spatially related pan stations and unexplainable observations. Also, potential evapotranspiration (ETp) was estimated with the Simple (Abtew equation) and the Penman–Monteith method. Both cases indicated no decline in evapotranspiration for the period of analysis. Based on the decline in humidity and the increasing trend in vapor pressure deficit for the short period of analysis, 1992–2009, it appears that South Florida is experiencing increase in evaporation and evapotranspiration at this time assuming no systematic error in the weather stations' observations. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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