For the Lake Michigan Basin, data from five strandplains were combined to produce a hydrograph of lake-level change over the past 4,700 years (Baedke and Thompson, 2000). This graph (fig. 8) illustrates the upper limit of lakelevel through time and suggests that several periodic lake-level fluctuations were active in the past and are probably still active in the lake basin today. The chart shows that lakelevel was roughly 13 ft higher 4,500 years ago. This high phase is called the Nipissing II phase of ancestral Lake Michigan, and it is represented around the lakes by high, dune-capped ridges, mainland- attached beaches, barrier beaches, and spits. This shoreline commonly was instrumental in isolating small lakes from the larger lake basins. The Nipissing II phase was followed by more than 500 years of lake-level decline during which lake levels dropped to eleva- tions similar to historical averages. Three high phases from 2,300 to 3,300, 1,100 to 2,000, and 0 to 800 years ago followed this rapid decline. Pervasive in the hydrograph is a quasi-periodic rise-and-fall pattern of about 160 ± 40 years in duration. This fluctuation can be extended into the historical record, and it appears that the entire histori- cal dataset (mid-1800s to present) may be one such 160-year quasi-periodic fluctuation. Superimposed on this 160-year fluctuation is a short-term fluctuation of 32 ± 6 years in duration (fig. 8). This lake-level rise-and-fall pattern produced the individual beach ridges in most embayments and is also expressed in the historical data, most easily seen in the low levels in the 1930s and 1960s and again starting in the late 1990s.
Regional migration and growth are increasingly associated with high-quality in situ natural amenities. However, most of the previous U.S. research has focused on the natural amenities of the Mountain West or the South. The GreatLakes, with their abundant fresh water and natural amenities, would also appear well-positioned to provide the foundation for this type of economic growth. Yet, while some parts of the western GreatLakes region are prime examples of amenity-led growth, other areas in the eastern GreatLakes may not have capitalized on their natural amenities, perhaps because of their strong industrial legacy. Using a unique county-level dataset for the GreatLakes region (including Indiana, Illinois, Michigan, Minnesota, New York, Ohio, Pennsylvania, and Wisconsin), we test whether growth in the region is associated with proximity to lake amenities and whether there are offsetting industrial legacy or pollution effects. We also examine whether amenities have additional attraction value for those with high levels of human capital. Consistent with theory that suggests that natural amenities are normal or superior goods, we find that coastal areas in the region are positively associated with increases in shares of college graduates. However, we find little evidence that lake amenities contribute to broader household
A number of constraints exist in the Waikaremoana Scheme which means that effective water management must be applied. These constraints include in particular, the location of the scheme in the conservation land of the Urewera National Park. Also the small storage capacity of Lakes Kaitawa and Whakamarino requires the three stations to be run in tandem. Another constraint derives from leakage of the natural dam which holds back Lake Waikaremoana. This leakage water was originally used to supply the Tuai and Piripaua power stations prior to the commission of the Kaitawa power station. This substantial leakage through the dam has the ability to quickly fill Lake Kaitawa, thus the scheme must constantly be run at a minimum of 12 MW (Genesis Energy, 2006). The daily operational efficiency of the Waikaremoana scheme requires estimation of lakewateravailability for hydro power generation on a per day basis. At the time of this study, net daily wateravailability of Lake Waikaremoana is estimated using a mathematical model of net storage change obtained from lakewaterlevel changes. This model uses daily lakewaterlevel differencing after correcting for the volume extracted for power generation and known lake losses to estimate net daily lake inflows. The model is used as opposed to direct measurement of river inflows due to the impracticality of gauging the large number of small tributaries and direct groundwater inflows which supply the lake. The wateravailability estimate is sometimes subject to error when changes in lakelevel are small, giving rise to negative estimates which may indicate errors in level differencing or inaccurate estimation of leakage. Under low flow conditions the unknown portion of lake losses may be not insignificant relative to inflows, thus in these instances the model approximates storage change.
DOI: 10.4236/jwarp.2018.1011065 1110 Journal of Water Resource and Protection the capacity and reliability of crop production. The extreme weather events will also increase erosion and the loss of nutrients from fields, and increase the run-off of toxic chemical pesticides and fertilizers. For the GreatLakes overall, climate models predict a warmer and wetter climate with more variability. In specific, temperatures in the GreatLakes are expected to increase 3˚C - 7˚C in the next 60 - 70 years . Precipitation models vary greatly and predict a range of change from a decrease in precipitation by 9% to an increase in precipitation by 21% , this wide variability coupled with the inconclusiveness of predictions make it difficult for planning and policy to address climate change in the agri- cultural sector. In addition to temperatures and precipitation, the amount of evaporation affects the efficiency of water use in the agricultural sector as well as the lake levels, and evaporation is expected to increase significantly, 19% - 36% in the GreatLakes , due to increases in temperature from climate change. The growing season is expanding and the global demand for food crops is increasing, which will present an opportunity to increase agricultural production, if the ex- treme weather variability and sporadic droughts and crop damage can be ad- dressed. The growing season has already increased by four weeks in the GreatLakes region and it is expected to increase up to nine weeks in the upcoming decades . An increased growing season will also will put more pressure on the land and water resources of the GreatLakes, as well as increase the chemical pes- ticides and fertilizers used, and there are no policies in place to manage this po- tential climate variability and possible agricultural growth.
CHAPTER 1: Introduction
Snowfall forecasting is challenging, especially due to the cumulative error associated with three variables: snow duration, precipitation amounts, and snow density. Small changes in any of these three variables can drastically change the societal impacts, such as the effects of snow cover on agriculture or transportation. While the forecasted amount of precipitation and density of snow are critical for interests in water resources and avalanches, respectively, the primary concern for the general public is snowfall. Since snow removal practices are reliant on accurate snowfall amounts, improved short- term forecasts of snowfall could greatly improve road transportation during an event. The end result could be a reduction in traffic incidents and economic losses from missed work, especially for events that are not as severe as forecast. After a snowfall event, taking a measurement of the fresh snowfall is fraught with difficulty, and the subjectivity associated with these observations could cause observed snowfall and its characteristics to be misinterpreted. Areas that receive snowfall from locally enhanced synoptic weather systems, such as in mountainous terrain and near large lakes, have an increased level of challenge. In this paper, we will focus on snowfalls occurring in the GreatLakes region of the United States, with particular interest in lake-effect snow, defined as snow being generated purely by the thermodynamic mechanism of having cold dry air flow across a warm lake.
The article is focused on the assessment of changes in the average annual wa- ter levels of large lakes of the planet in the changing climate conditions cha- racteristic of the recent decades. Eight large lakes, i.e. Baikal, Balkhash, Supe- rior, Issyk-Kul, Ladoga, Onega, Ontario, and Erie, located on the territory of Eurasia and North America, were chosen as the research objects. They were selected because of the availability of a long-term observations series of the waterlevel. As is known, long-term changes in the lakeswaterlevel result from variation in the water volume. The latter depends on the ratios between the water balance components of the lake that have developed during a given year, which, in turn, reflect the climatic conditions of the respective years. The features of the water balance structure of the above-mentioned lakes and the intra-annual course of the waterlevel are considered. The available long-term records of observational data on all selected lakes and their stations were divided into two periods: from 1960 to 1979 (the period of stationary climatic situation) and from 1980 to 2008 (the period of non-stationary climatic situation). The homogeneity and significance of trends in the long-term waterlevel series of records have been estimated. It has been established that over the second period the nature and magnitude of the lakeswater levels variations differ significantly. For lakes Balkhash, Is- syk-Kul, Ladoga, Superior, and Erie, there is a general tendency for a decrease in water levels. For the remaining three lakes (Baikal, Onega, and Ontario), the opposite tendency has been noted: the levels of these lakes increased. Quantitatively, the range of changes in water levels on the lakes in question over the period of 1980-2008 ranged from −4 cm to +26 cm.
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Once the Laurentian Ice Sheet was removed the ground could decompress in a process known as isostatic rebound or adjustment. The rates of rebound in relation to Port Huron outlet are depicted in figure 2. Rates of isostatic rebound are not uniform; generally, rates of rebound around Lakes Superior and Ontario are greater than those around Lakes Michigan-Huron and Erie (Neff and Nicholas, 2005). This is due to the thickest glacial ice having been located north of the GreatLakes Basin, pictured in figure 3. Lack of uniformity causes segments of coastline rebounding more rapidly than the lake’s outlet to experience a long-term lake-level fall, whereas coastlines rebounding more slowly than the outlet experience a long-term lake-level rise (Wilcox et al. 2007). Isostatic adjustment accounts for long term adjustment of the Lake levels that have been happening since the final glacial retreat, but to assess fluctuations on a smaller time frame, balances of inflow and outflow must be analyzed.
The climate in the GreatLakes Basin is changing. Average air and surface water temperatures are rising, precipitation and evaporation are both increasing, and average annual ice cover is decreasing 19 20 21 22 23 24 . For the Lake Michigan-Huron Basin, the increases in evaporation are being mostly balanced by increases in local precipitation over the last 60 years. 25 26 But, in the Lake Superior Basin, increased precipitation has not compensated for increased evaporation, explaining a trend towards declining water supplies in Lake Superior over the last 60 years. 27 28 29 While the trends may be weak with respect to the inter-annual climate variability and magnitude of uncertainty in the hydrologic components of the lakewater balance, there has likely been a modest trend of declines in total GreatLakes supplies in recent decades, although recent (2013 and 2014) high runoff and precipitation levels have resulted in significant rebounds in Lakes Superior and Michigan Huron.
The strength of the positive relationship between high producing grassland and in–lake TN and TP concentrations is particularly significant given the scale of the study. Goldstein et al. (2007) found that the relationship between land use and physical stream habitat condition characteristics became weaker with increasing spatial scale from regional to national level. By distinguishing between low and high producing grassland, it has been shown that the intensity of pastoral land use has a significant bearing on the magnitude of nutrient losses to lakes. The major pastoral–related nutrient sources are urine and N fertiliser in the case of N, and faeces and superphosphate fertiliser in the case of P (Monaghan et al. 2007). The magnitude of nutrient loss is broadly related to stocking rate (ibid.) and therefore increasing intensity results in greater nutrient loss. Whilst research into management options to mitigate nutrient losses from pasture has been an active field (see Cherry et al. 2008), it is clear that a significant change in practices is required if productivity is to be decoupled from nutrient loss. The contrast in nutrient losses between low and high productivity grassland is further emphasised by the fact that even though low intensity pasture and mean catchment soil P content were positively correlated (see Figure 3.4 and Table 3.5), both correlated negatively with in–lake P due to the opposing influence of high producing grassland. Although estimates of mean acid–soluble P content for catchment soils are derived from relatively broad categories, a positive relationship between soil P and in–lake TP concentrations was expected, especially given the range in the soil P values (4.0 – 47.1 mg (100 g) -1 ) and the fact that unusually high concentrations of P in igneous rocks in New Zealand have been shown to be associated with elevated P concentrations in freshwaters at a regional scale (Timperley 1983) and a local scale (Quinn and Stroud 2002). The fact that results are contrary to this expectation indicates that, at the national scale, anthropogenic sources of P exert a greater influence on in–lake TP concentrations than naturally occurring edaphic sources.
But the federal government must also encourage states and localities to stop retrofitting aging infrastructure and technology and invest infrastructure design that is more efficient and actually returns useful resources (energy, reusable water, nutrients) to users. Current funding projections for such changes are insufficient, however. For example, American Rivers found that demand for “green” infrastructure projects from the clean water and drinking water State Revolving Funds this past year exceeded availability by an average of 1.5 and 1.2, respectively. 17 The GreatLakes Restoration Initiative (GLRI) is providing a good start to restoring the GreatLakes by focusing on reducing the number of “Areas of Concern,” expanding waste minimization and pollution prevention projects, reducing new invasive species, enhancing habitat restoration, and improving lake-wide monitoring and management. The GLRI, however, does not provide funding for water and wastewater infrastructure, nor does it support innovative water-related technologies, or other critical research.
loss of macrophyte species and abundance as their physi- ological capabilities are surpassed. An extreme example is from Lake Sevan in Armenia, where a multiannual drop of the waterlevel by 19.5 m resulted in the loss of most of the macrophyte vegetation, followed by a shift in primary producer dominance to planktonic algae (Parparov 1990). Wilcox and Meeker (1992) reported that both larger (2.7 m) and smaller (1.1 m) than natural (~1.6 m) WLF in northern Minnesota lakes resulted in lower species diversity of macrophytes, with implications to the rest of the biota. The reduced structural diversity led to diminished habitats for invertebrates, reduced availability of invertebrates as food for fish and water birds, reduced winter food supplies for muskrats, and reduced feeding efficiency for adult northern pike, yellow perch, and muskellunge. In Lake Constance, 24% of reed beds were lost in an exceptional flood in 1999 with waterlevel rising about 1 m higher than the normal annual maximum (Dienst et al. 2004). In Lake Biwa, 70% of the reed beds were lost with artificial lowering of the waterlevel by only 0.3 m (Yamamoto et al. 2006). Waterlevel fluctuations alone explained 88% of the variation in the occurrence of the native macrophyte Typha in Lake Ontario marshes (Wei and Chow-Fraser 2006). Hill et al. (1998) found that regulated lakes were less diverse, contained more exotic species, and were usually devoid of rare species when compared to unregulated water bodies. Smith et al. (1987) recorded that reservoirs used for hydropower that experienced regular, large fluctuations were devoid of littoral macrophytes.
The Ohio Nowcast, a cooperative project between the USGS and local agencies, has been providing near-real-time beach advisories to the public on the basis of predictive mod- els since 2006 (http://www.ohionowcast.info). The probability of exceeding the bathing-water standard is posted on the Ohio Nowcast Web site by 9:30 a.m. during the recreational season. Local agencies that collect daily data and run the nowcast include the Cuyahoga County Board of Health, Northeast Ohio Regional Sewer District, and the University of Toledo, with postings for Huntington, Edgewater, Maumee Bay State Park, and Villa Angela beaches. Predictive models have included such variables as turbidity, wave height, antecedent rainfall, change in lakelevel in the past 24 hours, and day of the year. At Huntington—in Bay Village, Ohio, a suburb of Cleveland—nowcasts were provided to the public for 581 days during the recreational seasons of 2006–11. A hindsight examination of the Huntington nowcast results in which the same-day cultured E. coli concentration in beach-water samples was used as the criterion for correct response indi- cated that the nowcast yielded a correct response 84.2 percent of the time. By comparison, use of the previous day’s E. coli concentration (the persistence model) resulted in a correct response 76.1 percent of the time. The predictive model exhib- ited greater sensitivity and specificity (54.9 and 89.6 percent) than the persistence model (22.4 and 85.9 percent). Nowcasts for other Ohio beaches yielded similar results, showing that they can better estimate current water-quality conditions than can the persistence model used by most beach managers, espe- cially in regard to sensitivity (http://www.ohionowcast.info).
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curriculum as the foundation for two new IVC classes. These classes feature the work of three GreatLakes scientists and engineers from within the coastal zone, E.J. Isaac, Great Portage Band of Lake Superior Chippewa; Jessica Olson, Barr Engineering; and Jason Butcher, U.S. Forest Service. As noted above in outcome 2, the classes increased the diversity of grade levels reached by the IVC program and will have a longer shelf life. The two IVC classes developed, Food Web in Motion and Culvert Design and Engineering complement on-line videos of the original scientific presentations and the accompanying kit based learning curriculum available to teachers for free at GreatLakes Aquarium. As of the end of the grant period these two Science Institute based IVC lessons had reached 163 students and 14 educators. An additional 30 educators were scheduled to engage with the class and content as part of the Science Institute in November 2013. Unfortunately, the Science Institute planned for November had to be rescheduled to January 2014, placing it outside of the established grant period that ended December 31, 2013. In January/February 2014, an additional 30 educators were engaged with the Culvert Design and Engineering IVC program as part of the Science Institute for Educators. These additional educators live and teach within the Lake Superior watershed.
As regards to abstractions at FBP, the 4.9 applied is a gross measure. Mpusia (2006) showed net consumption is 3.5 . The difference between gross and net abstractions is assumed to become surface runoff and to end up in Lake Naivasha through the Karati River. Since the Karati is not included in the model as a river due to its ostensibly insignificant contribution, the residual is accounted for by adding it to the lake. This amount, which equals 1 , may however, in whole or in part return to the groundwater or evaporate from the greenhouses. In this case the model overestimates lake inflow. Considering calibration, the uncertainty attributed to many (if not all) model parameters qualifies other parameters besides hydraulic conductivity for calibration too. Few data exists on river bed leakance, stressors to the lake are variable and, as mentioned above, recharge is ambiguous. The fact that this study tried to generate two non-unique calibration sets for the same schematization, while only altering bed leakance, underscores this issue. However, even within the current calibration sets, the extents of the 26 predefined hydraulic conductivity zones are debatable as to their necessity or appropriateness. In retrospect, the subterfuge of reducing the number of zones by fixating certain polygons might have been anticipated: the ratio observations over calibration parameters is rather low. Still, a further simplification of the model by reducing the number of zones would likely fail to turn out the desired spatial resolution. In the present schematization, the flipside of the more detailed zoning of the aquifer came to light in automated calibration through UCODE. The low number of observations in combination with the large number of degrees of freedom allowed UCODE a vast range of possible, physically valid outputs. After all, plausible values for hydraulic conductivity envelop many orders of magnitude. The effect of starting values could thus be detected, especially in the observation-scarce mountainous polygons. Caution is prompted when considering these fringe areas.
Stephen Ternullo investigates and prepares detailed reports for a wide variety of property casualty damage issues including; structural failures and defects, water intrusions, roof distresses, origin and cause of fires, mechanical failures, electrical failures, and evaluating trip and fall conditions. He has over fifteen years of active experience as a forensic engineer having personally investigated or supervised over 3,000 investigations, often being requested to determine a cause of distresses to structures and to develop repair plans.