A remote sensing technique detecting and identifying water activity sites along irrigation canals.

One of the consequences of climatic change is that many western states in the United States are experiencing severe drought conditions. Numerous irrigation districts are losing significant amounts of water from their canal systems due to leakage. Every year, on the average 2 million acres of prime cropland in the US is lost to soil erosion, waterlogging and salinity. Lining of canals could save enormous amount of water for irrigating crops but due to soaring costs of construction and environmental mitigation, adopting such programs on a large scale would be excessively expensive. Conventional techniques of seepage detection are expensive, time consuming and labor intensive, and in addition are generally not very accurate. Technological advancements have made it possible to investigate irrigation canals for seepage site identification using remote sensing. In this research, band-9 in the NIR region and band-45 in the TIR region of airborne MASTER data has been utilized to highlight anomalies along irrigation canals in Phoenix, Arizona. A high resolution (1 to 4 meter pixels) satellite image provided by private companies, which has been made available to the public by the Google Earth, was then successfully used to separate those anomalies into water activity sites, natural vegetation, and man-made structures. We show that regions for which such high resolution satellite images are available on Google Earth can be successfully utilized for verification of anomalies along irrigation canals using airborne multispectral data. This innovative technique is much faster and cost effective compared to conventional and past airborne remote sensing techniques for verification of anomalies along irrigation canals. This technique also solves the long standing problem of discriminating true water related activities from false impressions of seepage sites due to dense natural vegetation, terrain relief and low depressions of natural drainages.