https://www.linkedin.com/pulse/r-statistical-tools-engineering-student-ramesh-dhungel?articleId=6109043332409741312#comments-6109043332409741312&trk=prof-post

1. 2/26/2016 “R”­ Statistical Tool for Engineering/Environment/Hydrology Students | Ramesh Dhungel | LinkedIn
https://www.linkedin.com/pulse/r­statistical­tools­engineering­student­ramesh­dhungel?trk=pulse_spock­articles 1/31
Be a Bigcommerce Partner ­ Build ecommerce solutions on our powerful platform & launch websites faster
“R”­ Statistical Tool for
Engineering/Environment/Hydrology Students
Feb 26, 2016 79 views 3 Likes 1 Comment   
As a student of engineering, when I started using “R”, it used to be a kind of black
box. R is mostly used by a statistician, a general saying. I will write a very short
story of the journey about how R become a good friend. My first attempt was to a
make a scatter plot and fit a regression line, but it can be easily done in excel,
right? Then, why I have to write these complicated codes to just to show these
scatter plots. I am not very much convinced, but I did it.
a) Basic plot (Water management and consumption)
Ramesh Dhungel
Water Resources, Remote Sensing and Land
Surface Modeler (LSM) (Ph.D. Civil Engineering)
Edit post View stats

2. 2/26/2016 “R”­ Statistical Tool for Engineering/Environment/Hydrology Students | Ramesh Dhungel | LinkedIn
https://www.linkedin.com/pulse/r­statistical­tools­engineering­student­ramesh­dhungel?trk=pulse_spock­articles 2/31
Figure 1. Linear regression of daily evaporation from (a) the original FAO­56
model compared against lysimeter measurements for a bare silt loam soil near
Kimberly, Idaho with daily data during August and September, 1977
Let’s make a similar plot like above, but multiple lines and axis as well
as secondary axis. It took me a long time and a little hard work to make this
happen. Still, I was not very much convinced, why I have to learn R as you can do
this easily in excel.

3. 2/26/2016 “R”­ Statistical Tool for Engineering/Environment/Hydrology Students | Ramesh Dhungel | LinkedIn
https://www.linkedin.com/pulse/r­statistical­tools­engineering­student­ramesh­dhungel?trk=pulse_spock­articles 3/31
Figure 2. Daily average K based on the grass reference from the original FAO­56
model and the FAO­56 (skin) and from the Hydrus­1D for silt loam using h = ­3
m compared against lysimeter measurements near Kimberly, Idaho during
August and September, 1977
b) Analyzing and plotting (Water consumption, economic and policy
analysis)
Now, I have to plot multiple crops in multiple counties with irrigated crop areas
with a massive data set in multiple formats. I was already known to R, so I
started looking how it can be done, because this kind of work can be complicated
on excel too. Exploring multiple packages in R, I was able to analyze, write a code
and compile the results. I started thinking, R seems helpful as well as powerful.
My earlier hard work to learn R had paid a little bit.
# Code example
library(MASS)
library(calibrate)
p ­ ggplot( data = DAU_monthly, aes(x=County, y=ICA)) +
geom_boxplot(aes(fill=Crop),outlier.size=6,outlier.colour="green",notch=FALSE)
p + facet_wrap( ~ County, scales="free") +
xlab ("County") +
ylab ("ICA (1000 acres)")+
guides(fill=guide_legend(title="Crop", size=10)) +
theme(axis.text=element_text(size=20),
axis.title=element_text(size=20,face="bold"))

4. 2/26/2016 “R”­ Statistical Tool for Engineering/Environment/Hydrology Students | Ramesh Dhungel | LinkedIn
https://www.linkedin.com/pulse/r­statistical­tools­engineering­student­ramesh­dhungel?trk=pulse_spock­articles 4/31
Figure 3. Irrigated Crop area (ICA in 1000 acres) for DAUs within California
counties, USA of 20 proxy crops (2005)
c) 3d Plot (Ground water and surface management, interactions and
policy analysis)
Now, I am thinking, I want to show something interesting in 3D, a more
interesting result, right. Yes, I think, I did it.
# Code example
Plot1=cloud(as.matrix(Plot_data1), panel.3d.cloud = panel.3dbars,
#trellis.par.set("axis.line",list(col="transparent")),
xbase =0.4, ybase = 0.4,
zlim = c(0, max(Plot_data1),cex=1),
scales = list(arrows = FALSE, just = "right",
x=list(cex=1, at =
c(1:40),lab=c("",212.00,213.00,214.00,215.00,233.00,234.00,240.00,242.00,243.00,256.0
y=list(cex=1),z=list(cex=1) ),
xlab = list("DAU",cex=1),
ylab = NULL,
zlab=NULL,
main = list(" a) % GW Contribution (2012)", cex = 1.5,inset = c(50,.81)),
col.facet = level.colors(as.matrix(Plot_data1), at =
do.breaks(range(Plot_data1), 10),

5. 2/26/2016 “R”­ Statistical Tool for Engineering/Environment/Hydrology Students | Ramesh Dhungel | LinkedIn
https://www.linkedin.com/pulse/r­statistical­tools­engineering­student­ramesh­dhungel?trk=pulse_spock­articles 5/31
col.regions = terrain.colors,
colors = TRUE),
aspect = c(0.8, 0.4),check.overlap = TRUE, par.settings =
list(layout.heights=list(xlab.key.padding=1)), colorkey = list(col =
terrain.colors, width = 1.8, height = 0.6,at = do.breaks(range(Plot_data1), 20),
space = 'right',labels=list(cex=2),draw=TRUE), screen = list(z = 50, x =­60 ))
Plot1
Figure 4. Ground water contribution to certain DAUs of Central Valley,
California, USA
d) Complicated 2d plots (Environmental management, ecosystem
services and water quality)
Finally, I want to do something different. I want to plot a water temperature
profile of each layer in different hypothetical pools for an entire season of the San
Joaquin River, California, USA.
# Code example
levelplot_DNB_1­levelplot(as.matrix(z_DNB),col.regions=rgb.palette,
scales=list(x=list(at=seq(1,36009, by = 1800),labels=seq(100, 300,

6. 2/26/2016 “R”­ Statistical Tool for Engineering/Environment/Hydrology Students | Ramesh Dhungel | LinkedIn
https://www.linkedin.com/pulse/r­statistical­tools­engineering­student­ramesh­dhungel?trk=pulse_spock­articles 6/31
by=10),cex=1.5),
y=list(at=seq(1,23, by = 2),
labels=round(seq(0.28, 7.02, by=0.61272),2), cex=1.5)),
par.settings = list(layout.heights=list(xlab.key.padding=1)),
xlab=list(label="Julian Day",cex=1),
ylab=list(label="Depth (23 levels of 6m pool)",cex=1.2),
main=list(label="Simulated Temperature for DNB (oC)", cex=2.5),
aspect="fill",colorkey=list(space="bottom"))
Figure 5. Water temperature profile of hypothetical pool in San Joaquin River,
California
e) Dynamic modeling (statistical tools for water resources
management and policy analysis)
One day, I have to plot the vector auto regression model results with literally
1000s of coefficients. I need to write a fine dynamic code to accompanying these
coefficients. Without thinking too much, I realized that R can be powerful. I
worked long hours to develop this code where I virtually developed a dynamic
daily discharge forecasting model for the San Joaquin River with various
exogenous and endogenous gauging stations. A big relief. Now I am thinking, how
can be this achieved without R. Woo, yes, it can be a very good friend to
engineering students too.
# Code example (Very long and complicated ­ Not shown)
to that first job
Valerie Jarrett
Pulse Publish a post
Home Profile My Network Jobs Interests Business Services Try Premium for free
 Advanced 
1
 Search for people, jobs, companies, and more...

7. 2/26/2016 “R”­ Statistical Tool for Engineering/Environment/Hydrology Students | Ramesh Dhungel | LinkedIn
https://www.linkedin.com/pulse/r­statistical­tools­engineering­student­ramesh­dhungel?trk=pulse_spock­articles 7/31
Figure 6. Observed vs. simulated discharges in San Joaquin River, California
gauging stations below Millerton Lake in daily time­steps for 2012 based on
Vector Auto Regression
References:
Dhungel, R., Allen, R.G. and Trezza. R., 2015. Comparisons of soil water
evaporation calculated with the FAO­56 and Hydrus­1D models (Under review).
Hydrological Sciences Journal (HSJ­2015­0160).
H41G­1424: Assessment of Ecosystem Services in a Semi­arid Agriculture­
dominant Area: Framework and Case Study
(https://agu.confex.com/agu/fm15/meetingapp.cgi/Paper/71034?mini=true)
http://adsabs.harvard.edu/abs/2014AGUFM.H31H0739S
Valerie Jarrett
“If you stop learning, you stop
living” – Why Alexia Tsotsis Left
TechCrunch for Stanford…
BSchoolHunter Walk
Mizzou professor who pushed
reporter away from protesters is
fired
www.washingtonpost.com
Apple pushes back on iPhone
order, says FBI is seeking
‘dangerous power'
www.theverge.com
FBI's Comey Calls Apple Battle
'Hardest Question I've Seen In
Government'
fortune.com
It's not your father's
globalization anymore
James Manyika
What Google Learned From Its
Quest to Build the Perfect
Team
www.nytimes.com
Six Years Later: What I've
Learned From Co­Founding
Warby Parker and Harry's
Jeffrey Raider
What I learned from living with
a Navy SEAL
Jesse Itzler
Is Oscar a Bulletproof Brand?
Lynne Everatt
Sundar Pichai’s big European
adventure

8. 2/26/2016 “R”­ Statistical Tool for Engineering/Environment/Hydrology Students | Ramesh Dhungel | LinkedIn
https://www.linkedin.com/pulse/r­statistical­tools­engineering­student­ramesh­dhungel?trk=pulse_spock­articles 8/31
Written by
Ramesh Dhungel
   1 comment
TIME INTEGRATION OF EVAPOTRANSPIRATION
USING A TWO SOURCE SURFACE ENERGY BALANCE
MODEL USING NARR REANALYSIS WEATHER DATA
AND SATELLITE BASED METRIC DATA :: Electronic
Theses and Dissertations
http://digital.lib.uidaho.edu
Like Comment 3 likes
Janesh Devkota
Environmental / Water Resources Engineer at Dynamic Solutions
International, LLC
Yes, R is very versatile to people of all fields. I work in the field of hydrology
/ water resources myself and use it all the time.
Like Reply 19 minutes ago
2nd
Add your comment