Identification

Title

Extreme-value analysis for the characterization of extremes in water resources: A generalized workflow and case study on New Mexico monsoon precipitation

Abstract

Water managers need non-stationary tools to better characterize precipitation extremes. Statistical approaches based on extreme value theory (EVT) are increasingly being used, but few end-to-end generalized workflows are available. In this paper, a step-by-step framework is demonstrated for developing an EVT model that considers the influence of dominant weather patterns on precipitation extremes in a watershed. Specifically, the Point Process (PP) model is utilized, which is a unified statistical framework for modeling the frequency and magnitude of extremes above a threshold. Because threshold selection can be subjective, a demonstration of how to go about selecting a threshold is provided; in particular, by examining a range of thresholds. The workflow is applied to daily precipitation from the Rio Grande watershed in New Mexico. In this arid watershed, extreme precipitation events substantially contribute to total runoff. An improved understanding of the drivers and extent of changes in extreme precipitation is essential for water resource and risk management. In addition to a stationary PP model without covariates, several covariates are examined for inclusion in the location and scale parameters. The significance of including the covariates is assessed, as well as several additional criteria, including if the covariate (s) make intuitive sense and if it is a good candidate for statistical downscaling (i.e., methods that relate largescale variables to the local scale). A final PP model is selected that includes the wet weather types in the location and scale parameters. This model is applied in a downscaling context using a large ensemble of climate projections, which shows that the frequency of exceeding a high threshold increases after 2050, but the conditional likelihood of exceeding the maximum observed precipitation stays relatively constant.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d7s46w88

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Geographic location

West bounding longitude

East bounding longitude

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2020-09-01T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

Data format

name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact