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Hydrology (PHD) 
Program Description

The department offers a program leading to the Doctor of Philosophy (Ph.D.) degree with a major in hydrology. The faculty offers competence in hydrogeology, hydrogeochemistry, hydrometeorology, hydroclimatology, environmental hydrology, ground-water hydrology, surface-water hydrology, vadose zone hydrology, mathematical and statistical methods in hydrology (including stochastic and numerical modeling), water resources systems, and water resources policy. More informationa about faculty research areas of expertise may be found at the department website, Research Focus Areas.

The program is designed for students with interests in the physical, chemical, and biological aspects of the hydrologic cycle, as well as water resources systems, environmental studies, or water policy and the social sciences related to water resources. Students may concentrate in one or a combination of these fields but should acquire some proficiency in all aspects of hydrology and water resources. Research-based Ph.D. study programs are individually planned to meet the student's special interests and professional objectives.

Ph.D. applicants should have completed a Master of Science degree with a major in hydrology, water resources, environmental sciences, environmental engineering, or a related field. (Holders of a Bachelor’s degree cannot enter the Ph.D. program directly.)

All Ph.D. students are expected to acquire basic computer programming skills and complete a field methods-field synthesis course sequence. To meet the professional development requirement, Ph.D. students are required to attend departmental seminars and colloquia at the beginning of academic residency and to make two formal seminar presentations (minimum one oral presentation) of their own dissertation research at two professional conferences at or near the end of their academic residency. A presentation at the department's annual student research symposium, El Dia del Agua y la Atmosfera, satisfies one of these requirements.

Ph.D. students may, or may not, be required to complete fundamental, or core, courses in hydrology and water resources depending on each student’s prior educational background. Where gaps exist in background knowledge of relevant subject matter, the student may be required to take additional course work prior to the Oral Qualifying Examination. The Doctoral Oral Qualifying Examination must be passed by the end of the second semester in residence. Comprehensive Examinations (Written/Oral) must be passed by the end of the third year in residence. For Ph.D. students, a Doctoral Dissertation is required; the Doctoral Dissertation Publication option is also available. A Doctoral Final Oral Examination, or defense of the dissertation, is required. More information is available at the department's website, Doctor of Philosophy in HWRS.

Department/Academic Unit(s)

Hydrology and Atmospheric Sciences

College of Science  
Campus where offered
Main Campus - Tucson  
Admissions Contact
Guadalupe V Romero
Graduate Program Coordinator
Guadalupe V Romero
Director of Graduate Studies
Martha P L Whitaker
Graduate College Degree Counselor
Kristi R Davenport
Tuition and Fees
Please refer to the UA Bursar's Office Tuition and Fees Calculator for up-to-date information about tuition and fees. 
Please refer to the UA Registrar's's Office Special Course Fees for up-to-date information about special course fees. 

Admissions Information

Admissions Requirements

Applications for the Fall Semester must be completed by January 15.

Applications for the Spring Semester must be completed by August 1 (for a student requiring a visa) and by October 1 (for a student not requiring a visa).

If your GRE scores are close to the minimum requirement, we recommend you apply. Other factors in your application may help mitigate this requirement.

Required: Applicants should upload required documents to the Graduate College application, including a Statement of Research Interests; a Resume or Curriculum Vitae; Three Letters of Recommendation (instructions provided); copy of Transcripts for all colleges and universities attended; Diploma Certificates (international applicants). All of these documents may be uploaded and attached to the Graduate College online application.

At the Graduate College website, click on Apply-Now to begin your application.

Undergraduate course prerequisites in science and mathematics include:

Physical Geology: 1 semester
College Chemistry: 2-semester sequence, Inorganic/Analytical
College Physics: 2-semester sequence, 1 course in Mechanics; 1 course in Electricity/Magnetism or Optics/Thermodynamics
Fluid mechanics: 1 semester
Mathematics: Calculus 1, Calculus 2, Vector Calculus, Introduction to Ordinary Differential Equations
Engineering Statistics or Probability Theory: 1 semester

Standardized Tests

Required test(s): GRE
Required GRE Subject tests: None
Recommended tests:
Recommended GRE Subject tests:
Minimum GRE Verbal:
Minimum GRE Quantitative: 155
Minumum GRE Written: 4.5
Minimum GMAT:
Minimum MAT:
Minimum TOEFL: 550
Minimum IELTS: 7

Financial Aid

Graduate Assistantships in Research
Graduate Assistantships in Teaching
Tuition Scholarships

Admissions Deadlines

Domestic Applicants:

  • Fall: January 15
  • Spring: October 1

International Applicants:

  • Fall: January 15
  • Spring: August 1
International Conditional Admission
International applicants may be considered for conditional admission to this program at the department's discretion.
Other Information
The GRE Institution Code for The University of Arizona is 4832
ETS Major Field Code(s) for this program: 1699
NRC Taxon(a) for this program: Earth Sciences, Civil and Environmental Engineering, Chemical Engineering

Completion Requirements

Degree Requirements

Minumum credits: 54
Core coursework: Minimum Credit Hours for the Major include 36 credit hours of course work for Major and 18 units of Dissertation (total of 54). Of the 36 credit hours for the major, 21 units of course work and 3 units of field methods/synthesis course work with HWRS Primary Faculty instructors is required. The remaining units 12 units may include approved transfer course work, approved non-primary instructor HWRS course work (courses cross-listed with HWRS where another department is considered the "home" department), and UA courses outside the HWRS department.

No specific Core Courses are required for PHD students, although Master's level Core Courses may be used in preparation for the Doctoral Oral Qualifying Examination to be taken in the first year of residence. Prior academic course work and experience will help determine which Core Courses might be beneficial for a student's exam preparation. Master's Core Courses include:

HWRS 517A Fundamentals of Water Quality
HWRS 518 Fundamentals in Subsurface Hydrology
HWRS 519 Fundamentals in Surface Hydrology
HWRS 528 Fundamentals: Systems Approach to Hydrologic Modeling

Language requirements: None

Other requirements: 1) Advanced Elective Requirement:

Advanced elective course work must be approved by the department. The Doctoral Plan of Study must include a minimum of 21 credit hours of course work with primary HWRS faculty members. (Independent study, professional development enrollment, and field methods are not included in this category.)

2) Field Methods Requirement (3 units total)

HWRS 513A Field Methods (Spring) and HWRS 513B Field Synthesis (Summer Presession) are required.

3) Professional Development Requirements:

(a) Enrollment in HWRS 595A Section 001 (one unit) for at least one semester. These units are not included in the Doctoral Plan of Study.

(b) Two presentations of Doctoral Dissertation research (minimum one oral presentation) at approved regional or national conferences. No academic credit is awarded for paper or poster presentations. Presentations may be made at a local conference, such as the department's annual student research symposium, El Dia del Agua y la Atmosfera, or the Arizona Hydrological Society Annual Conference. Other conference venues include AGU, AMS, and GSA.

4) Doctoral Minor Requirement:

A doctoral minor area of study (outside the department) that complements and supports the dissertation research is required. Minimum credit hours vary by department, ranging from 9-15 (the average is 12 credit hours). Typical minors for HWR students include Applied Mathematics, Atmospheric Sciences, Chemical Engineering, Civil Engineering, Computer Science, Environmental Science (Soil-Water-Environmental Science), Geological Engineering, Geosciences, Global Change, Remote Sensing and Spatial Analysis, Renewable Natural Resource Studies, and Systems Engineering. Other minor areas of study may also be possible.

5) Examination Requirements:

Year 1: Doctoral Qualifying Examination in the Major
Year 1: Doctoral Qualifying Examination in the Minor (may be optional; consult Minor Department)
Year 2.5-3: Doctoral Written and Oral Comprehensive Examinations in Major and Minor
Year 4: Doctoral Final Oral Examination

6) Dissertation Archival

Electronic submission of the Doctoral Dissertation to the Graduate College and archival with ProQuest UMI is required. The department does not maintain a separate archive, although members of the student's faculty committee may request a copy of the manuscript.

Minor Requirements

Contact the graduate academic advisor ( or 520-621-3131) for information regarding the Doctoral Minor in Hydrology and Water Resources.

Student Handbook  

Program StatisticsInformation about these numbers

Program-level Information
Application Acceptance Rate 52%
Med. Time-to-degree (years) 4.75
Department-level Information
Enrollment Percent Male 52%
Enrollment Percent Female 48%
Enrollment Percent International 36%
Enrollment Percent URM 14%

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Last revised 03 Sep 2019