Geoscience Reference
In-Depth Information
added data on quantity and quality of urban storm water from the city of Ashdod
(Asaf et al.
2004
) and Rishone Letzion (un published data), characterized by similar
topography and land uses for compressing.
5.2.2 Sampling Sites
A number of sampling points were located based on characterize land use and
on the urban drainage network structure. The stations were installed at the outlet of
the municipal drainage systems. Emphasis was placed on locating the stations at
specific land uses known from the literature as having the diverse influence on
the quality of urban runoff (e.g. residential, industrial, and main roads). Within the
framework of the research, water quality sampling stations were built to enable
automatic sampling during rainstorms. During the years of the study, 2006-2008,
seven measuring points were defined and established: five measuring points in the
Herzliya area and two in the Ra'anana area (Fig.
5.1
).
5.2.3 Land Use Classifications by Remote-Sensing and GIS
This study used remote-sensing methods with three different spectral and spatial
imaging resolutions:
1. Digital aerial photographs (RGB) of high spatial resolution (less than 1 m
2
),
covering the entire area.
2. Multispectral satellite imagery of intermediate spatial resolution (ATER)—
multispectral imaging with nine spectral bands and a low spatial resolution
averaging 15 m, covering the entire area.
3. Hyperspectral satellite imagery (AISA) of high spatial resolution (1.6 m) and
spectral resolution (198 bands), covering selected spots in the study area.
The processing methodologies were developed in different ways, according to the
information content of each source, and they are therefore described separately.
5.2.4 Classification of the Aerial Orthophotograph
Initial processing was done on the color orthophotograph of Herzliya and Ra'anana
using photo processing techniques: unguided automatic classification and guided
classification with the Mahalanobis Distance Method, using ENVI 4.4. The road
layer of the GIS was integrated into the results of the classification of all the digital
orthophotographs using Arcgis 9.3. The initial classification included 12 classes
departments, of which 4 final classes were defined, composed of built-up areas,
plant cover, open areas and roads (Fig.
5.2
).
