|
|
|
|
|
Today, the team walking back from the escarpment are considering the problems of the steppe. This has been degraded by overgrazing, reducing the feed available for sheep, goats and camels--and, therefore, of meat, milk and other dairy products. Encouraging regeneration of vegetation is not easy.
One problem is the presence of calcareous soils. MRMP hydrologist Mohamed Ramsy Shaker runs his fingers over the surface of the soil. "This is a crusty surface, making rainwater infiltration difficult," he explains. "That means not much soil moisture for plants."
One answer in the past has been ripping. This involves bulldozing of the soil to create a long trench which will encourage collection of water and growth of new vegetation.
That this can work, is demonstrated by the presence of a very long trench indeed running along the front of the escarpment. In it grow trees, bushes and rangeland species that are scarce elsewhere on the steppe. The trench, however, was not dug for that purpose. It is a relic of the clash of armies at Marsa Matrouh nearly 60 years ago. It is intriguing that what once meant death and destruction now means the growth of new life along many kilometers of the escarpment, providing food for sheep and goats.
So is the answer to copy this work on the steppe, using modern machines instead of soldiers with pickaxes?
"No. Not in this case," says ICARDA range scientist Dr Gustave Gintzburger, who has been discussing the issue with MRMP rangeland researcher Mustapha Hakim and his colleagues. "The Egyptian authorities have very mixed feelings about ripping and have now forbidden it within a certain distance of the sea. The problem is that rainwater runoff from the steppe is providing the water supply for agriculture in the wadis and on the coastal strip. That's one reason why the soil on that strip is so much better; centuries of runoff have carried it down there along the wadis.
"And this water is coming from a long way inland. The very shallow slope of the steppe, and the calcareous soil which slows infiltration, mean a very deep watershed. Rip the rangeland on a large scale 10, 20, even 30 kilometers back from the escarpment and there'll be less water in the wadi. And less water means less food. You have to choose."
It is a message strongly reinforced by another member of the party--a farmer from Wadi Salloufa, a narrower wadi a few kilometres down the valley. He tells the scientists bluntly that sometimes they must choose between range development and wadi development, as the former could totally disrupt the sophisticated farming system in the wadi. Moreover there is another consideration--biodiversity in the wadi tips,
|
|
|
|
|
|
 |
|
|
|
 |
|
|
|
|
|
where Dr Gintzburger has found an unusual mixture of low- and high-rainfall species. "I wouldn't want to lose those, either," he says.
Understanding the exact depth and shape of the watershed is therefore critical. One way to obtain that information is by digital satellite images so that the topography can be analyzed using Geographic Information Systems, or GIS. ICARDA is placing increasing emphasis on this tool. MRMP is already working with GIS and a GIS expert from ICARDA, Nick Thomas, is here to see what can be done to strengthen their capacity.
"GIS is one of those things that is simple in theory, but difficult in practice," he explains. "First of all, GIS is a tool for using information. That information can be derived from a number of different types of sources--a map, an aerial photograph--we do use those--or a satellite image. Suppose you are working from satellite images, which is known as remote sensing. How good is your satellite image? The more recent the satellite, the higher the resolution. The latest ones can see an object only a meter wide. But images from satellites that good are costly. "Moreover, whatever the source, you have to know what you are seeing and represent it correctly in the GIS database. Some totally different vegetation types can become confused with each other, especially on rangeland, and then the resulting database will be wrong. However, if you want to model a wide area or watershed and come up with integrated solutions, it is a marvellous tool." MRMP staff already have skills in GIS and Mr Thomas hopes to build on these with a training course for them.
While his colleagues make sure that the wadi below has enough water, Dr Dieter Gomer is planning for those occasions when there is too much. Standing by the dry watercourse where it comes out at the foot of the escarpment, he points past a clump of palms to what look like the remains of long-ago earthworks.
|
|
|
|
|
|
 |
|
|
|
|
|
"The Romans and others built a lot of structures here," he says. "They knew the danger of flash floods, and they knew how to harvest the water in the wadi--but without stopping so much of it that, in a flash flood, the structures were carried away. So they built spillways."
Dr Gomer, who is a consultant for ICARDA, also points out the ancient cisterns, sometimes still in use, that dot the area. There is real potential for learning from the past. In the meantime, he is working with MRMP on the design and construction of structures. This must be done properly. Traveling in the area between the coastal strip and the escarpment, it is possible to see shallow wadis where earth dams have been built to control and exploit the runoff. Some have been done well, but others, dating from a past project in the area, have not. One, lacking a proper spillway, has been neatly split in the center. It's a reminder that farmers have two problems with water in the region. One is its scarcity. The other is its tendency to come all at once.
The next day, it's time to summarize what has been learned in Wadi Abou Grouf.
"If you're going to come up with integrated solutions in a watershed, you need to discuss the problems as a team," says ICARDA soil conservation researcher Dr Michael Zöbisch. He is addressing a meeting of MRMP's own researchers, accompanied by ICARDA's permanent representative on the project, socioeconomist Dr Abdul Bari Salkini. "People from every discipline should be at a meeting like this, and the farmers should be involved too," Dr Zöbisch goes on. "You could make your own individual plans, and then stitch them together--but would the result make sense?"
|
|
|
|
|
|
