Graduate Abstract

Majed A. Khater
Winter 2005

Assessing the relationships between the spatial variation in land-use spatial patterns and surface water quality

by

Majed A. Khater

B.S. In Architectural Engineering
Yarmouk University, Jordan
1986

Master of Public Urban Planning and Policy
The University of Illinois at Chicago
1993

A Thesis submitted in partial fulfillment
of the requirement for the degree of

Doctor of Philosophy Degree
Department of Environmental Studies
Greenspun College of Urban Affairs

Winter 2005

Thesis Adviser: Dr. Krystyna A. Stave
Examination Committee Chair
Associate Professor of Environmental Studies
University of Nevada, Las Vegas

ABSTRACT

The purpose of this dissertation was to examine the association between the spatial patterns of urban land uses and surface water quality parameters at the watershed outlet. The aim of the study was to understand the strength and nature of this relationship, and examine new methods of classifying and quantifying contributing urban land-uses and their spatial patterns. The hypothesis of this research was: in an urban watershed, the variation in the spatial patterns of contributing land uses will have significant impact on the surface water quality parameters at the watershed outlet.

Their relationship between urbanization and water quality is important terms of understanding and managing urban growth to preserve water resources, especially in dry arid regions. The outcome of this study will establish and define relationships between patterns of urban land uses and surface water quality parameters at the watershed outlet. The urban area of the Las Vegas valley watershed was used as a case study to test the research hypothesis. Existing water quality monitoring stations on the four major tributaries to the Las Vegas wash were used to define four independent watersheds. Geographic Information Systems (GIS) was used to geo-reference water quality monitoring stations and to delineate contributing watersheds at each sampling point. Rainfall events leading to water quality sampling were used to derive contributing land uses within each watershed. The association between the total amount, types, patterns of contributing land uses, and surface water quality parameters at the watershed outlet were tested using Pearson correlation.

Correlation results showed very clearly that total amount and types of the contributing land uses cannot fully explain by themselves the variations in the surface water quality parameters at the watershed outlet. Further analysis of the association between the spatial patterns of the contributing land uses and the water quality parameters showed some of the measured water quality parameters to be more sensitive to changes in the spatial patterns of the overall contributing land uses.

Two different patterns of contributing land uses were identified: 1. Fragmented pattern, and 2. Clustered pattern. We found that some of the water quality parameters to be positively correlated with landscape metrics describing fragmentation. The trend for the same parameters was opposite when compared to metrics describing clustered patterns. The results indicated that there is a significant association between water quality parameters at the watershed outlet and the spatial patterns of the contributing land uses. This study also illustrates that using people oriented land-use classification method, which is based on the actual use of the land is more appropriate for highly urbanized areas compared to the resource oriented method, which is based on remotely-sensed data and often used for land use and land cover classification.