PREFACE

One of the principal reasons for writing this text is a personal curiosity: Can we teach, or most

properly, transmit the passion we feel for mathematical modeling to individuals with a learned

aversion to exact sciences?

During my mother nature-forced early-age sabbatical in 2011, I enrolled myself into a course

on basic psychopedagogy recommended by my then girlfriend (now wife). There, after long

time I found myself into a lecture room full with professionals from fields others than

engineering. My fellow students were mostly professionals from health science-related fields,

and all seemed to share a common aversion to the word Mathematics. From the perspective

of the psychopedagogy, such aversion would be explained by the matter of having developed

different kinds of intelligences along their adolescent life. However, I would not stop

wondering what their future would have been if they had have found how important Math is

to predict the behavior of the elements constituting the environment that surround us. Thus, I

had the time, I had the curiosity, and I wanted to organize and rearrange all the material

reviewed during my graduate experiences. Writing this text seemed to be a pretty good idea.

The overall objective of this book is to demonstrate to the readers, regardless their

background, that mathematical models are not as complex as they might seem. I approach to

such challenge from the perspective of a civil engineer who has spent most of his professional

career working on watershed modeling. Such field of knowledge is wide, because of which I

have decided to split it into three parts. The current manuscript is aimed to demonstrate that

Calculus is not a useless and tedious subject. The forthcoming second part will be aimed at

showing the basics of watershed modeling. The third part will be aimed to cover the issue of

the predictive uncertainty.

This book is aimed at undergraduate students pursuing a career in the fields of life sciences

and principally engineering, who may need or feel curious for understanding what is behind

mathematical models (watershed models). This book can also be used by graduate students of

engineering as an introductory text. However, I shall emphasize that the contents is unlikely to

cover the expectations of graduate students pursuing a career in the field of physics and

sciences involved in the study of the climate system.

Living, studying and working in a different environment is an exciting and rewarding

experience. My six-year experience at the graduate school in Asia (Japan) gave a substantial

turn to my life. Living in a rich environment, cultural and environmental wise, and working in a

world-class university (Tohoku University) made me feel alive. The experience of living far from

my family, wife (girlfriend then) and friends, made me understand what my priorities in life

were. But definitely what has defined the path I am truly committed to, is the awakening I am

experiencing now that I have returned to my home country. Awakening? Yes, because

returning to a place that has changed a lot, it is comparable to the experience of someone who

has been kept frozen for a while. What does this has to do with this text? A lot, because the

experience of having stayed away for a while, provided the time to analyze some deficiencies

in the establishment of the curricula of basic subjects taught in the faculties of civil engineering

in several institutions of Latin America, which are likely to be seen also in several institutions of

the developing and the developed world. I shall restate that I am not an expert in the field of

psychopedagogy; however, I expect that the following pages will at least awake the curiosity of

those students with a learned aversion to Math, and particularly to Calculus. The challenge is

been set, and with the support of my family, I expect to accomplish it within the next three

years.

Several authors (some of whom are not aware of my existence) have inspired this work,

among which I shall mention to Keith Beven, Andrea Saltelli, Greg St. George, and particularly

Priyantha Ranjan and Thorsten Wagener. From my perspective, their works shall always be on

the bookshelf of any student curious in the exciting world of the watershed models.

Freddy Soria Cespedes*

La Paz, Bolivia

*Back cover

Freddy Soria Cespedes is a civil engineer graduated from the Universidad Mayor de San Andrés

in La Paz-Bolivia. He pursued his graduate education in Japan (M Eng, PhD), majoring at surface

hydrology and watershed modeling in the Graduate School of Engineering at Tohoku University

(Sendai-Japan), sponsored by a scholarship awarded by the Government of Japan, He returned

to his home country after a short postdoctoral experience in the latter mentioned institution,

and after having published several articles in recognized international, national journals and

international conferences. Convinced that education is the key to development, he founded

the Water Science Group, a NGO that gathers young professionals committed to develop

projects in the area of water, sanitation and environmental education in the developing world.

This book is the first of a series of manuscripts aimed to share all of his overseas experiences. It

is principally aimed at senior-year students of life sciences, senior-year students of the

engineering fields, and young engineering professionals interested in the exciting and

rewarding topic of watershed modeling.