Thursday, January 13, 2022

Snoqualmie Falls at Flood Stage and Cle Elum Digs Out

I had some work in central Washington and had to alter my route due to Highway 2 being closed across Stevens Pass. I added a bit an additional detour as water levels in the Snoqualmie River were very high. 

Road closure in the Snoqualmie River valley 

The detour was a chance to see Snoqualmie Falls at flood stage.

The spray from the base of the falls obliterated any veiwing from the main view spot

Further on my journey I observed Cle Elum still digging out from the snow. Temperatures have moderated and it was just above freezing as I passed through town.


Friday, January 7, 2022

Marginal Revolution Geology Posts

Tyler Cowen at Marginal Revolution claims not care about geology:

He finished the post with "One lesson of this post is that it is possible to be interested in things one is not interested in, and vice versa." 

A comment by Dinwar on the post was then turned into a post:

Dinwar notes that "Engineers and geologists think VERY differently, in nearly incompatible ways, which is fun because we work together all the time." I would tend to agree. Engineers are problem solvers and geologists spot the problems. I try to put effort into making sure the geology of a site makes sense to the engineers, but I also try to understand the way engineers can solve a problem so I can anticipate just how bad a geology hazard is or not. 

Dinwar finishes with a bit on field work "Field geologists are even worse–we do all that, only in conditions that would make any sane person run screaming." and he also has a note about safety managers. Navigating thick brush and steep rough ground is a skill set that is probably just as valuable as understanding the glacial history of an area, and it is an activity that most people might consider insane.   

Wednesday, January 5, 2022

Mail Problems on Decatur

Decatur Island has a mail problem: Decatur Mail Challenge and sanjuanjournal: Mail issues on Decatur.

Only four of the San Juan Islands are served by Washington State Ferries: Shaw, Lopez, San Juan and Orcas. Getting to and from the other islands varies. Several including Decatur have air strips. Water "taxi" chartered boats mostly from Anacortes also routinely provide service to the non ferry islands. The charter boats pull up to docks and land on beaches to pick up and drop people off. Given their ability to 'land' at a wide range of sites, the charter service is pretty great and I have used it to get to Decatur and a few other islands.

Approaching an island beach on an Island Express Charter
The mail problem on Decatur seems to have partially evolved due to the increased amount of mail as more seasonal use of the island has morphed into more year round long term residences. With access to internet and good cell phone coverage more people have taken up living year round on the island. The demand for mail packages has increased and hence the controversy of an island without a post office. I would note as well that the charter boats also deliver groceries and other goods.  

Monday, January 3, 2022

Northwest Arkansas Appeals to Seattle

Billboard in Seattle

I have a soft spot for northwest Arkansas - Van Burien County specifically. In a different era I rode my bike through northwest Arkansas. It was pleasant change of scenery after miles of being on the plains. It is a landscape that would appeal to western Washington folks - mountains, forest and lakes. 

In a later era I wrote a draft resolution supporting an amendment to the Secure Schools Funding Act supporting an amendment that allowed for consideration of environmental values for National Forest projects under the Act. Other than Whatcom County, not one county in Washington State (including King County) supported my effort. Several Washington State Counties sent letters in opposition and the State Association of Counties called me to let me know my position was contrary to that of the State Association. 

But Van Burien County Arkansas quickly passed the resolution as written and sent a letter of thanks. They valued the environmental benefits of their National Forests more than most of the local governments in Washington State. So the appeal to Washington residents with similar values is sincere.

Thursday, November 25, 2021

Atmospheric Rivers reads and notes

Since northwest Washington State (and more so southwest British Columbia) are experiencing a series of atmospheric rivers (AR), I have been doing a bit of reading/catching up on the subject. On a professional level ARs paly a role in my work assessing geology risk so understanding ARs is important in assessing geology hazards. 

ARs have and continue to receive a lot of attention as they are the cause of much of the large flooding events of the west coastal watershed of North America and are also the source of much of the water in watersheds of the southern portions of the west coastal area. Due to the risk of large floods and the impact to reservoirs, there has and will likely be a continued interest in evaluation and understanding ARs. The most recent flooding in southwest BC and northwest Washington emphasized the importance of this issue. Further, ARs are expected to change with global warming -- there are numerous papers of modeling and climate simulations that indicate changes in ARs over past and present day.  

What follows are a few papers with my own notes and what I thought to be pertinent quotes from the papers themselves.   

Neiman and others (2011) focus on ARs impacts on 4 different western Washington watersheds, the Sauk, Green, Satsop and Queets. They identify some key attributes to ARs that produce floods. 

"ARs were responsible for all floods in these basins during the 30-yr period, even though not all ARs during that period generated flooding. Those ARs that produced flooding typically exhibited two or more of the following attributes: (i) the AR was optimally oriented for orographic precipitation enhancement in a given basin, (ii) the low-level onshore water vapor fluxes into the basin were quite strong, (iii) the AR stalled over the basin, (iv) the melting level was especially high, and/or (v) basin soils were already saturated prior to AR landfall."

The recent AR flooding in northwest Washington and southwest BC had essentially all of the above attributes. 

 A figure from Neiman and others (2011) illustrates the attributions for the basins they evaluated.

Conceptual representation of key atmospheric conditions associated with the top 10 annual peak daily flows observed in four watersheds in western Washington. (a) Offshore composite IWV analysis (cm; green shading >2.8 cm) based on the NARR for the Queets and Green Rivers. Washington State is shaded and labeled. (b) Overland composite low-level wind-flow direction (blue arrows) based on the NARR for the Green and Queets Rivers. See Fig. 3 for details on the base map. (c),(d) As in panels (a) and (b), except for the Sauk and Satsop Rivers and red arrows. (e) Composite NARR-based vertical profile information common to all four watersheds in the low-level onshore flow (bold arrow). The upper and lower horizontal dashed lines mark the observed and climatological melting levels, respectively (the climatological melting level is from Minder 2010). Gray shading represents the layer of weak moist static stability. The black curve depicts the water vapor flux profile.

Baek and Lora (2021) suggest that ARs intensity may increase sooner rather than later relative to other published papers. If their assessment holds true, changes to ARs will come sooner than most other modeling papers suggests:

"Here we use a series of coupled model experiments to show that there was little to no change in mean AR characteristics in 1920–2005 due to opposite but equal influences from industrial aerosols, which weaken ARs, and greenhouse gases (GHGs), which strengthen them. Despite little historical change, the simulations project steep intensification of ARs in the coming decades, including mean AR-driven precipitation increases of up to ~20 mm per month, as the influence of GHGs greatly outpaces that of industrial aerosols." 

Espinoza and others (2018) suggest that ARs will not be as frequent in the future, but may be much more impactful: 

"The projections indicate that while there will be ~10% fewer ARs in the future, the ARs will be ~25% longer, ~25% wider, and exhibit stronger integrated water vapor transports (IVTs) under RCP8.5.

Further works on field experiments, process studies, and model evaluation and improvement (e.g., Guan & Waliser, 2017; Hagos et al., 2015; Payne & Magnusdottir, 2015; Ralph et al., 2016; Wick et al., 2013) need to be undertaken to improve the model fidelity and reduce the uncertainty in the projections."

Gershunov and others (2017) consider the increased trend in AR to have already begun and project the increase trend will continue. They also note that the trend will not be uniform along the west coast:  

"Moreover, a long-term trend expressed broadly in stronger winter AR activity over the U.S. and Canadian west coast (weaker over Mexico) is associated with long-term warming of the western tropical Pacific; the latter SST trend has previously been identified in multiple observational data sets and explained by anthropogenic forcing [Wang et al., 2015]. Long-term precipitation changes over western North America have been very consistent with this trend. This broad increase in AR activity is corroborated by total seasonal IVT version of the analysis, where it is clearly associated with basin-scale ocean surface warming, as well as by a consistent increasing trend pattern in observed precipitation. These results suggest that the increase in IVT projected for the midlatitudes in response to global warming [Lavers et al., 2015] has been ongoing over at least the north Pacific, which calls for an investigation of the role of ARs in the projected enhancement of extreme precipitation over California and the Western U.S. [Polade et al., 2014] as well as a fresh investigation into observed changes already under way."

Rhodes and others (2020) project that the changes in total precipitation in the west of North America will be primarily the result of ARs 

"Changes in precipitation totals are due to a significant increase in AR (+260%) rather than non-AR (+7%) precipitation, largely through increases in the most intense category of AR events and a decrease in the interval between landfalling ARs."

Gershunov and others (2019) also project changes in precipitation specific the watersheds on the west coast. For the the Chehalis River:

"In fact, AR contributions increase in all precipitation bins, with the increases becoming greater at higher intensities, while non-AR precipitation contribution is projected to become more frequent in the drizzle and other low-intensity precipitation categories, and decreasing at higher intensities."

Dongyue and others (2019) did a broad overview of rain-on-snow, a possible contributor to AR flood events (see Neiman and others, 2011 above). Their assessment was not specific to ARs and covered all areas of the US subject to rain-on-snow. Cliff Mass cited this paper in a blog post suggesting that snow melt is a minor contributor to recent flooding after comments suggested snow melt was an additive factor to the recent flooding. However, despite that reference, Dongyue and others (2019) note:  

"It is also clear that a significant portion of floods that occur in basins that drain the west facing slopes of the Cascades and the Sierra Nevada are ROS related."

I do agree that for the recent AR event (November 14-15) rain was the source of the majority of the water in the floods, but even a relative minor snow melt component, say 10 percent, can push a river to a much more consequential flood event.

 Dongyue and others (2019) further note:

"Historically, the contribution of ROS to extreme runoff in the western United States has been greatest in midelevation areas (1,000 to 1,500 m); this “significant influence zone” will shift higher in the future (above 2,000 m). 

This elevation range matches many but not all Cascade watersheds.

The recent AR event in northwest Washington and southwest BC is a preview of what society should plan and prepare for as ARs become more intense with global warming.

Monday, November 15, 2021

Notes on Skagit and Nooksack Flood Levels

An atmospheric river  has been aimed at northwest Washington over the past few days and the rain continues today. A look at river level gages and predictions indicates some serious river flooding. But note too that many small streams have no flow gauges or predicted flood crests will flood as well.

The Skagit River has reached flood stage , but the current predicted flood crest at Mount Vernon will not arrive until tomorrow. The Skagit is a large river watershed and the peak flows take a while to get down to the delta area. Projections are for record flood levels at Mount Vernon.    

The much smaller Samish River also flows out onto the Skagit delta will peak faster with a record peak today. 

Both of these rivers flow out across broad low delta areas with portions of the deltas diked from tidal flooding. The Skagit has very large levees through Mount Vernon. But some over topping may take place. The Samish also has levees, but they will very likely be over topped. Once the delta floods the drainage out of the delta is restricted by the tidal levees -- all that water that spills out of the rivers then has to flow through drainage systems and tide gates.   

The Nooksack River began flooding yesterday. The Nooksack flooding is complicated. At Ferndale the projection is a moderate flood level. 

However, upstream at Cedarville the projection is potential record flood levels. 

Between Cedarville and Ferndale the river flood waters flood out of the Nooksack and into the Sumas River River (everson-sumas-overflow). Hence, the flood levels at Ferndale is somewhat diminished by water laving the Nooksack and flooding into the Sumas River. The border town of Sumas in the Sumas watershed began flooding yesterday.     

The Nooksack River has three forks that converge above Cedarville. This ads another complication to the Nooksack flooding because the timing of each forks peak discharge makes a big difference in the flooding downstream. There will be major flooding in the South Fork valley. 

Sunday, November 14, 2021

Cedar Boughs

 Evaluating a valley in the Olympics earlier this fall I noted these cropped trees. 

The limbing was not for creating views through the forest, but was a partial harvest of the tree boughs for evergreen arrangements and/or wreaths. The trees in this case are western red cedar. And this was an allowed operation by the land owner. Evergreen foliage is a big business on the Olympic Peninsula and southwest Washington, and unfortunately some of that business is illegal harvesting. It is particularly problematic in young tree stands as the removal of branches and even the tips of the trees destroys the tree plantation. The very fact that the trees above were scaled and limbed (by hand) in the manner they were indicates the value of these products.