Posts

Posts from the group about interesting results, planning, interesting insights and much more!

After two months in Ziguinchor, this project about hypersalinity in the Casamance is almost finished. Yesterday was the presentation in French and tomorrow we will depart for a short trip through the east of Senegal.

The second part of our time in the Casamance region consists mostly of contact moments with important stakeholders such as the Genie Rurale. With them we made an excursion trough the city of Ziguinchor, to see how severe urban erosion is. We spent a lot of time behind our laptops to finish the report. Unfortunately, the final report isn't completely finished yet, so the last pieces have to be finished when we are back in Holland. Maybe this is because of another badly timed electricity breakdown. This happened just the day before the presentation.

In the last weeks, we also visited Oussouye, Diembering and Abéné. The last two villages are situated besides the sea, and are therefore good places to relax. A view on the beach taught us that parts of the Atlantic coast suffers from erosion. In Kafountine we saw a lot of fishermen, even fishermen from Bissau and The Gambia. From this town a lot of fish is transported to Dakar and other regions.

The last week was a short one, because of the celebration of the end of the Ramadan. This week was filled with the writing of the report and the preparing of the French presentation in Ziguinchor. This presentation turned out to be quite well, although the language problems. Most conclusions were showed in pictures, and their explanation caused much discussion. The first important discussions was the fact that the hypersalinity in the Casamance estuary can only become normal again by means of a year with the double of normal yearly rainfall. This was the outcome of a scenario of our salt intrusion model. The second conclusion considered the locations of the anti salt dams in the bolons. In several cases they are located at several kilometres from the mouth of these bolons, while this causes a lot of mortality of mangrove, sedimentation and an increase of salinity nearby the dams.

Now it's time a few days off in the east. The final report will be finished in the Netherlands. Then we will also give the last update.

Roel

After the moment we handed in the progress report, it's time for an English update for the website. Since our arrival in Ziguinchor a lot has happened.

The first week was mainly used for exploring the city, not in the last place by gathering information at several institutes in Ziguinchor. Of course everything took a bit more time because of the communication problems (everybody speaks only French). It also took much time to be referred to other institutes on and on. In Senegal there is also bureaucracy. At the same time we started to validate the old salt intrusion model of professor Savenije. Although our cartographic material is a bit ancient, the most recent hydrographic map is from 1960, we started to renew this information in the salt model.

At the end of the first week, the first set of measurements was done at the bridge of Ziguinchor. Maybe nice to mention that this bridge is the only one over the Casamance River, besides that of Kolda which is 150 km further upstream. We measured the tidal range, water velocity, High Water Slack and Low Water Slack. We were exhausted after a long day under the hot African sun. However, it gave some interesting results. The tidal range, the difference of the water level between high and low water, was quite less that the predictions of Total Tidetm.

These results gave new input for the salt model. The modeling went on steadily in the second week; there was only a bit trouble with Fortran, the computer program language in which the model is made. However, the complete river is now modeled, but not yet with recent data. Especially the rainfall and runoff of the last years have to be processed in the next weeks.

The next set of measurements was made of the same tidal wave at three locations along the Casamance River. At Sedhiou, Goudomp and Ziguinchor the water level, HWS and LWS are measured together with a couple of samples to determine the salinity of the water. With these measurements, we got insight in the propagation of the tidal wave and salt intrusion through the estuary.

The third week was filled with getting the last data from the institutes and the writing of the progress report. Besides, Île de Karabane was visited to see the estuary mouth and to see the surroundings of Ziguinchor.

The last four weeks in Senegal will be spend on further validation and calibration of the salt intrusion model with recent data, together with an integral water management analysis of the Casamance region. To be continued…

On Thursday August 31st we leave the airport of Schiphol and head to Dakar. We arrive perfect in time on the airport of Dakar, although we had little delay in Casablanca. The first two nights we stay in the 'Via Via guesthouse' in the small city of Yoff. Here we can acclimate and find how the Senegalese culture is. As real tourists we make small visits to the beach, to Dakar and the most western point of Africa.
After the two nights in Yoff we move to downtown Dakar where we'd found a cheaper room. Here we meet Mohammed, he will be our personal guide for 2 days. With him we visit the soccer match Senegal - Mozambique. A real cracker, as it is for qualification of the world championship in 2010 and the Africa Cup in 2008. Star player is Diouf, but unfortunately he is not able to score. Fortunately Senegal won, with 2-0, so everybody is happy. The next day we visit the island of Iles de la Madeleine, a bird island. It's a pleasant day of walking around and discovering the island. Also some bird watching is done, especially by Arthur, who is extremely happy when he sees the Red-billed Tropicbird.
In the evening we hear about troubles in Casamance. 4000 refugees went to the Gambia, because of the Senegalese army is fighting against the Casamance rebels. Anyway, after we have visited the Dutch ambassy, we decide to go to Ziguinchor the next day. We are going to do that by car, as the boat is will not leave town for a week and a plane is too expensive.

Traveling to Ziguinchor

We leave Dakar as early as 4.30 AM. The driver is reasonably good and at 10 AM we have already crossed the Gambia River. The Gambian roads, or at least the trans-Gambian route, are much worse than their Senegales equivalents. Fortunately this is only a small part of the whole route.
En route we have a collision with a dog, but fortunately he survives. At 1.30 PM we arrive at the office of Idee Casamance. The first night we stay in the house of Iba, next day we will move to another apartment, where we will stay for the coming 7 weeks.

Next Thursday we will fly to Dakar. After a couple of days there, we will travel to Ziguinchor for the start of our project. Now we are very busy with the last preparations for our departure, yesterday was the last meeting with our supervisors. Also the laptops we get from Van Oord are being prepared for Senegal. The plan of work is finished and right now we are working on a more detailed planning.

Maarten fixed a guestbook on the site, so that you can all leave your comments here. When we are in Senegal, we'll try to update this site every week.

Sponsoring has had a good start with allready 4 four companies donating money for our project! Four more to go! Van Oord, a big dutch dredging company, is our main sponsor and has her profile posted on this site. We would like to thank all sponsors for their generous donations.

However, we still need more sponsors to finance our project. If you are interested please look at our sponsoring page. Thanks for your interest!

The first pictures of the Casamance regio can be found at the "pictures" tab. Soon our own pictures will be available here as well!