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Water Injection Dredging (WID) has been successfully applied for removing sediment deposits in reservoirs, which results in an increase of their storage capacity. This dredging method is based on the fluidization of the top sediment layer by pressurized injection of water by a dredging vessel. The fluidized sediment can be transported towards the dead storage of the reservoir or sluiced out of the reservoir through the bottom outlets of a dam. This flow can either occur by gravity induced flow or especially directed by the dredging strategy of the WID vessel. This dredging technique can increase the water storage capacity of the reservoir and prevent the erosion of the river downstream, hence the sediment blockage. Recent developments in modelling and measuring tools have enabled stakeholders to design, optimize and monitor WID in reservoirs. In this paper, we will demonstrate how modelling and measuring tools can be used to evaluate alternative dredging strategies for reservoir maintenance. In particular, we show how a mid-field and far-field modelling can be applied for designing WID actions and predicting sediment plume dynamics in a given reservoir. Additionally, we will present recently-developed in-situ measuring tools, that are currently used for monitoring turbidity in a water column and sediment properties during and after WID actions. Finally, potential benefit of applying WID in Shihmen Reservoir (Taiwan) is discussed.

We present a new technique for laparoscopic splenectomy which allows manual control of endoscopic dissection. After induction of pneumoperitoneum and insertion of an endoscope to check the absence of any contraindications, an incision is made for insertion of the hand and forearm. An airtight system allowing insertion of the hand while maintaining the pneumoperitoneum is fixed around the incision. A second port is inserted in the left flank. The procedure is then performed with laparoscopic instruments while the left hand allows for spleen mobilisation and easier exposure of the structures to be dissected and divided. Eight patients with a mean age of 51.3 years have been operated on for Idiopathic Thrombocytopenia. The average duration of the procedure was 90 min (80-130 min). No postoperative complication occurred. The mean duration of stay was 3.8 days (3-7 days). These results of this technique are encouraging. The procedure is quicker and safer than an exclusive laparoscopic approach. The incision allows removal of the intact spleen. Other applications of this system can be envisaged.