3 research outputs found
New 2012 Precipitation Frequency Estimation Analysis for Alaska: Musings on Data Used and the Final Product
INE/AUTC 13.1
Using Snow Fences to Augment Fresh Water Supplies in Shallow Arctic Lakes
This project was funded by the U.S. Department of Energy, National Energy Technology Laboratory (NETL) to address
environmental research questions specifically related to Alaskaâs oil and gas natural resources development. The focus
of this project was on the environmental issues associated with allocation of water resources for construction of ice
roads and ice pads. Earlier NETL projects showed that oil and gas exploration activities in the U.S. Arctic require large
amounts of water for ice road and ice pad construction. Traditionally, lakes have been the source of freshwater for this
purpose. The distinctive hydrological regime of northern lakes, caused by the presence of ice cover and permafrost,
exerts influence on lake water availability in winter. Lakes are covered with ice from October to June, and there is often
no water recharge of lakes until snowmelt in early June. After snowmelt, water volumes in the lakes decrease
throughout the summer, when water loss due to evaporation is considerably greater than water gained from rainfall.
This balance switches in August, when air temperature drops, evaporation decreases, and rain (or snow) is more likely
to occur. Some of the summer surface storage deficit in the active layer and surface water bodies (lakes, ponds,
wetlands) is recharged during this time. However, if the surface storage deficit is not replenished (for example,
precipitation in the fall is low and nearâsurface soils are dry), lake recharge is directly affected, and water availability for
the following winter is reduced.
In this study, we used snow fences to augment fresh water supplies in shallow arctic lakes despite unfavorable natural
conditions. We implemented snowâcontrol practices to enhance snowdrift accumulation (greater snow water
equivalent), which led to increased meltwater production and an extended melting season that resulted in lake
recharge despite low precipitation during the years of the experiment. For three years (2009, 2010, and 2011), we
selected and monitored two lakes with similar hydrological regimes. Both lakes are located 30 miles south of Prudhoe
Bay, Alaska, near Franklin Bluffs. One is an experimental lake, where we installed a snow fence; the other is a control
lake, where the natural regime was preserved. The general approach was to compare the hydrologic response of the
lake to the snowdrift during the summers of 2010 and 2011 against the âbaselineâ conditions in 2009. Highlights of the
project included new data on snow transport rates on the Alaska North Slope, an evaluation of the experimental lakeâs
hydrological response to snowdrift melt, and cost assessment of snowdriftâgenerated water. High snow transport rates
(0.49 kg/s/m) ensured that the snowdrift reached its equilibrium profile by winter's end. Generally, natural snowpack
disappeared by the beginning of June in this area. In contrast, snow in the drift lasted through early July, supplying the
experimental lake with snowmelt when water in other tundra lakes was decreasing. The experimental lake retained
elevated water levels during the entire openâwater season. Comparison of lake water volumes during the experiment
against the baseline year showed that, by the end of summer, the drift generated by the snow fence had increased lake
water volume by at least 21â29%. We estimated water cost at 1.9 cents per gallon during the first year and 0.8 cents
per gallon during the second year. This estimate depends on the cost of snow fence construction in remote arctic
locations, which we assumed to be at $7.66 per square foot of snow fence frontal area. The snow fence technique was
effective in augmenting the supply of lake water during summers 2010 and 2011 despite low rainfall during both
summers. Snow fences are a simple, yet an effective, way to replenish tundra lakes with freshwater and increase water
availability in winter.
This research project was synergetic with the NETL project, âNorth Slope Decision Support System (NSDSS) for Water
Resources Planning and Management.â The results of these projects were implemented in the NSDSS model and added
to the annual water budget. This implementation allows one to account for snowdrift contributions during ice road
planning with the NSDSS and assists with mitigating those risks associated with potentially unfavorable climate and
hydrological conditions (that is, surface storage deficit and/or low precipitation).Disclaimer 3
Acknowledgments 4
Abstract 5
Executive Summary 6
Report Details 9
Experimental methods 10
Location of the experimental site 10
Land use permits 11
Hydrological and meteorological data collection 11
Snow fence design and location 12
Results and discussion 16
Snow transport and drift growth 16
Snowdrift melt 18
Precipitation and evaporation 20
Hydrological response of the lake 23
Water cost 27
North Slope Decision Support System 27
Conclusions 28
Graphical Material List 29
References 30
List of Acronyms and Abbreviations 3