WG-HYDrology news

The Working Group on Hydrological Modelling met last June 1998 for its third meeting. Fourteen members participated and some issues have been discussed, mainly concerned with the preparation of the experiment of monitoring the soil moisture content during the Special Observing Period (SOP). Since then further progress has been done.

As will be reported in the in forthcoming MAP Implementation Plan, some flights are planned by CNR-IROE with airborne microwave radiometers in the Lago Maggiore target area. The experiment intends to measure soil moisture conditions over some selected sites (indicated with the white squares in Fig. 1) where some research teams will measure ground truth data for the antenna calibration and verification.

It is planned to carry out at least 5 flights (5 missions of maximum 3 hours duration each), using an ultralight aeroplane, over the Pieve Vergonte (8.283°E, 46.017°N) to Domodossola (8.283°E, 46.093°N) area in the Toce valley floodplain and over the lateral slopes (Fig. 1).

Figure 1 The flight track of the aeroplane used for the microwave soil moisture monitoring in the Toce valley. The white squares indicate the position of the fields where the soil moisture will be measured.

One flight is planned at the end of August beginning of September, when dry soil moisture conditions are more likely to occur.

A couple of supplemental flights are needed 24-48 hours before precipitation is expected. For these flights a strict contact with the POC/MOC is needed, because the take off will be based on the rainfall warnings issued by the weather forecasters. The measurements taken during these flights are intended to provide initial soil moisture conditions prior to the expected flood events.

Other flights will be done 24-48 hours after relevant IOP rainy episodes, when the soil moisture content will be close to saturation and during the soil-drying phase.

The missions will be planned in connection with the MOC and the POC, but the small aircraft will not be based in Milano Linate.

Figure 2. Ticino-Toce watershed: the existing hydrometric stations (non real-time in white squares; real-time in grey circles).

The characteristics of the small aeroplane are the following:

Aircraft: Flash
Ceiling: 6.000-7.000ft
Endurance: 3h
Range: 215nmi at1.000ft
Payload: 140kg

For this type of experiment the aircraft needs to fly at a height lower than 300m (1.000ft).

Some research teams, linked with the MOC and the POC will implement quasi-operational flood forecasts using hydrological flood models forced by rainfall observations and NWP fields. The streamgauges where the forecasts will be issued will be selected among those existing in the Lago Maggiore target area and indicated in the Fig.   . Details on their characteristics can be asked to ranzi@bsing.ing.unibs.it.

In summary, the research teams that officially confirmed their involvement in the hydrological SOP activities are those reported in the following . Also French hydrologists have expressed their interest in participating in the SOP, although their involvement has not been officially confirmed yet.

Table 1. The research teams involved in the activities of the MAP-SOP that are of peculiar interest for hydrology.