Paragliding flying hazards in Kijabe Rift Valley area
Due to humid air and lack of sharp terrain features, paragliding in Naivasha area is quite safe and enjoyable, but there are several dangers to be aware of:
High-voltage power lines
These run across Kijabe hill slope, between take off and landing fields near the tarmac road. A sudden sink or coming low from the mountain can make power lines as an obstacle and a factor when deciding where to land. There are plenty of landable farm fields on the slope before the power lines.
The high-voltage power lines are close to the rounded edge of a terrace, which has pronounced thermal triggers. There haven’t been accident when thermalling 50-100-200 meters over the power lines, but the whole experience is intimidating. Thermals are usually reliable and there is plenty of height for escape toward the landings along the road.
Hell’s Gate geothermal power plant is another source of power lines. This part of Rift Valley is an important transport corridor from Mombasa towards Uganda, so keep an eye on other power lines too.
Cloud suck
The surrounding Rift Valley mountains and highlands, provide good temperature gradient, which:
- increases thermal strength at higher altitudes to 4-5 m/s
- makes cumulus clouds develop fast into 5-6000 meters high congestus clouds. Thunderstorms are unlikely due to drier and stable air above.
- there is often an unnoticeable transition between thermal lift and cloud suck.
The plenty of convergences in the area provide long lasting and powerful supply of warm air, which enhances the cloud suck and makes sideways escape more difficult.
Pilots should have anti-G parachute, especially those flying with difficult to spiral competition paragliders.
And of course, prevention is the best remedy. Don’t be greedy and leave the climb well before the cloud base!
Dust devils
Dust devils usually form over the lowest parts of Rift Valley’s bottom.
Typical areas are around Naivasha lake, Gilgil and lake Elementaita, near Eburu North take off and especially between Longonot and Suswa volcanos. The last one are very spectacular, rising almost to cloud base. They are vertical and quite stationary, easy to fly around. They usually trigger from the same fields, move slowly away, disappear and start again in the same area.
The big dust devils seem safer as you can map their distribution in advance, before coming to their area.
The newborn and small one are more dangerous as they may form surprisingly during your landing approach.
Understanding dust devils, observing around and studying the wind helps a lot.
Dust devils need super adiabatic temperature gradient, which has a very tick layer in Rift Valley (that’s why they grow so high). The typical Naivasha area Convergences are a product of opposing winds, which is the main mechanism for initiating the rotation. A temporary trapping inversion over a lower terrain helps to build up momentum and stockpile heat, which can explode later. A too strong inversion wouldn’t let the dist devils to develop fully, but would cause more frequent births. The dust devil is often associated with a thermal, some say it is the tail of a thermal, triggered abruptly and squeezed through an inversion layer, sucking the leftovers of ground hot air. Between Longonot and Suswa, 1-2 km high dust devils coexist with same size thermals. At higher altitudes you can peacefully thermal few hundred meters from them, just prepare for some dust in your eyes.
The biggest risk is encountering a dust devil on landing, so observe your landing area well ahead, before committing to it. Watch for:
- previous signs of dust devil activity;
- hot sunny areas, but mind that dust devils may form in long lasting shadows, where an inversion traps hot air for a while, or hot air is brought from somewhere else;
- opposing winds;
- calm or variable in direction winds;
- a sudden surge of a wind streak , combined with sheltered by terrain zones.
The best anti-dust-devil tactic is to land in open zones with constant wind, away from rotors and gradient effects. Following a wind gust and then turning low against the wind and landing in it seem safer than landing in suspiciously calm zones with variable winds. Dust devils rarely form in strong winds.
Highland flats are safer for landing, compared to lowlands, as their instability regularly releases the energy, doesn’t allow build ups, and even if dust devils form, they dissolve quickly and their borders are milder.