**2. Study areas**

(hyperspectral), leaf pigment indices, stress indices and water stress indices. They reported that VI can be simply divided according to the wavelength characteristics used in their formula (broadband and narrowband indices). Using airborne remotely sensed imagery, Pickerill and Malthus (1998) analyzed two known water leaks and found that different vegetation indices and single bands were required in order to identify each leak. The spectral profile of one leak responded best to a ratio of NIR to red reflectance, while in the other, NIR to red reflectance

Huang et al. (2009) used airborne multispectral remote sensing imagery with high-resolution imaging sensors in the visible, NIR and thermal infrared wavelengths and found that airborne multispectral imaging is a useful tool in the detection of irrigation canal leakage in distribution networks. They concluded that the analysis of the processed image data from red, NIR and thermal bands is highly consistent with the observations from field investigation. Images from individual bands, particularly from the thermal band, can help detect leakage from irrigation canals. The NDVI image, which combines the data from the red and the NIR bands, can help

On-site observation, which consists of data collection, periodical observations, and multivari‐ ate risk assessment analysis, is the most common technique of monitoring the water pipe network in Cyprus. However, this is difficult to accomplish with traditional methods since it is time consuming, expensive and monitoring is localized. Furthermore, part of the water network tends to be located in inaccessible areas, away from the main road network and urban areas. A complete geoinformation system providing the exact location, characteristics and relevant data for the water mains does not exist, making the leakage monitoring procedures

This paper presents the results from a project which combines different remote sensing technologies for the detection and monitoring of water leakages for water utility systems located in open fields in Cyprus. Two case studies areas were evaluated using freely distrib‐ uted Landsat 7 ETM+ satellite images and ground spectroradiometric data. In addition, a low

Finally, different remote sensing techniques have been used evaluated as in the detection of leakage from a major water pipe in Cyprus ("*Southern Conveyor Project*"). Although significant efforts have been made to detect possible water leakages, as shown above, the detection of the water pipe itself it still problematic . This is because such water pipes networks are commonly mapped in a digital form (e.g. GIS environment). However, in most cases the digital location of the water pipe does not fully correspond with the real world, since many obstacles during the construction can be arise and therefore the route of the proposed pipe can change.

In order to explore further the capabilities of remote sensing –beyond the detection of water leakages- the authors have applied several algorithms for the detection of buried water pipes. The detection of buried features is well established procedure in archaeological research since buried anthropogenic remains can be found using remote sensing techniques (Agapiou *et al*., 2010, 2012b; Sarris *et al*., 2013). Indeed, soil marks or crop marks related with water pipes can

altitude system was deployed to observe these pipelines from different heights.

be used, in a similar approach, for mapping the real footprint of a pipe network.

ratio was not useful in differentiating it from its surroundings.

156 Remote Sensing of Environment: Integrated Approaches

detect and correct errors observed on the thermal imagery.

even more challenging.

In this section, three different case studies are presented. In the first case study, a part of the *"Southern Conveyor Project"* is described; following, two case studies for the "*Lakatameia* " and the "*Choirokoitia -Frenaros*" water pipes are presented. In the first case study, the authors have focused to the detection of the actual footprint of the pipe while in the next two case studies, remote sensing techniques have been evaluated for the detection of water leakages. The "*Lakatameia*"is a pipeline which is currently not in use while the "*Choirokoitia -Frenaros*" is a major pipeline of Cyprus where three major leakages have been recorded between 2007 to 2010.
