Background

Over the last decade, various tools based on Remote Sensing (RS) techniques from satellites to assist water managers have been developed. In the early days of RS, images were mainly used qualitative, but the increase in accuracy of sensors and especially a better understanding of processes, have evolved in the development of quantitative algorithms to convert raw data into useful information. One of the key aspects in this is the development of methodologies to estimate actual evapotranspiration from land surfaces using a combination of sensors of different temporal and spatial scales. However, one of the characteristics of RS is that, despite the excellent opportunities for monitoring, it offers fewer opportunities in itself to perform the so much required tool for long-term strategic planning of water resources.

From the RS tools available to water managers developed over the last years are the ones related to estimation of actual evapotranspiration the most relevant ones. A typical example is the Surface Energy Balance Algorithm of Land (SEBAL; Bastiaanssen et al., 1998). SEBAL has evolved into the world leading algorithm for estimating actual evapotranspiration by Remote Sensing and has been applied worldwide. However, its application is much more as a monitoring tool rather than a long-term planning tool.

The linkage between the previous mentioned RS techniques and strategic decision support systems (S-DSS) is that simulation models provide also spatial information on evapotranspiration. This opens the unique opportunity to calibrate models using the observed evapotranspiration from RS. The importance of this should not be underestimated. The application of an S-DSS in data scarce areas was so-far nearly impossible as proper calibration could not be performed. Without such an S-DSS water managers were not able to systematically quantify the impact of proposed changes in water management.

The overall objective of this project therefore is:

Embedding a methodology to support water managers in making sound and long term strategic decisions regarding water resources management by using Remotely Sensed based evapotranspiration estimates for calibration of Strategic Decision Support Systems.

Bastiaanssen W.G.M., Feddes R. A., Holtslag A.A.M., Menenti M. 1998. A Remote Sensing suface energy balance algorithm for land (SEBAL) 1. Formulation. Journal of of Hydrology, 212/213:198-212.

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Khadakwasla dam

Irrigation

Sugarcane harvest