CHG Objectives

The main objective of CHG is to manage water resources of the demarcation. Activity and economic development of this territory are sensible to the fluctuations of these resources as they have a strong presence in the irrigable agriculture. During the summer season temperatures and evaporation/transpiration are very high whereas rains are scarce. It is just in this season when water needs grow as the demand for human use also grows. This unbalanced situation is even worse in drought times when the organization has been forced to reduce the supply of irrigation water. The growing demand of a limited resource like water makes a must of a very strict control of its consumption.

In order to get a regulation of the water resources in the demarcation there must be consistent, reliable and fast methods that allow obtaining results in a relatively short period of time at an adequate spatial and temporal scale for its management. Among means currently available, spatial remote sensing is one of the most promising techniques for this aim as it gives quite a detailed spatial and temporal coverage.

If we integrate the data source offered by remote sensing in the organization’s Geography Information System, we will obtain a greater knowledge about the information. One of the most immediate objectives is the combining of these images with administrative and meteorological data, for a more exhaustive water control.

For this purpose at CHG they are carrying-out various remote sensing tasks that will allow getting a total vision of the environmental status of the demarcation, by analysing images taken by MODIS, TM, ETM+ and AWiFS sensors:

• With the use of low spatial resolution sensors like MODIS we obtain global information about the basin vegetation and hydrology. The frequency of data obtaining (daily) allows a practically “real time” control. Among other things, these data allow to evaluate the beginning, the end and the impact of draughts with greater accuracy.
• Satellites with medium spatial resolution, like Landsat, have as counterpart a lesser temporal resolution usually of two images per month. The greater detail of these images allows the execution of studies at plot level what makes them specially suited for the follow-up of the basin irrigations. It is important to note that this is the main water use in the basin with almost 3.400 hm³ per year, 85 % of the total consumption.