laredac – Page 9 – la croix de gattigues

May 3, 2017August 1, 2017

Altitude measurements

I used a Garmin GPS 64 to record altitudes during a recent hike along the the Vidourle river-mill circuit and compared the recordings to the theoretical altitudes obtained by generating the GPX with an online tool using the IGN basemaps. Here below is a comparison chart.

First, notice there is a growing lag between the peaks on the theoretical profile (green line) and the recording (red line) with the peaks on the recording occuring later then the peaks on the theoretical profile. This is normal, because we did not stick exactly to the theoretical track. At Montredon, we wandered around the site which added some distance to the recording that does not appear in the theoretical profile. (Note: We also climbed a bit higher than planned.)

However, there is still something strange going on. The recorded Garmin altitude, starting from around 3 km in, starts tracking progressively lower than the theoretical altitude. The Garmin data stabilises between 10 and 20 m altitude while in reality, no point on this circuit is below 20-25 m so the Garmin data is incorrect. Is this because the differences are within a margin of error for altitude measurements with a handheld device ? Maybe but if so, why is the tracking much closer for the first 3 km ?

May 2, 2017October 31, 2021

Rivermills on the Vidourle

Hiking distance : 12.3 km ; Hiking time : 04:00

In these parts, almost everyone has heard of the river Vidourle. It’s famous for flash floods and devastation. But the river is a lot more interesting than just the flood damage it causes. For starters, it rises in a steep valley on the south face of the Cévennes mountain range where it collects water from many streams and occasionally from violent thunderstorm downpours. Flowing out of the valley at St-Hippolyte-du-Fort, it enters a karstic plain and promptly disappears underground. There is an “above ground” river bed which runs the 10 odd km between St-Hippolyte and Sauve and is often dry. In the small town of Sauve a substantial stream emerges from the base of the Coutach hills – this is the so-called “fountain” of Sauve – and flows straight into the Vidourle riverbed. This fountain presumably restitutes the lost Vidourle waters, and a lot more, to the main above ground riverbed. Then the Vidourle meanders on to Quissac and Sommieres. Later on, closer to the sea, the river flows into the Camargue marshes and has many possible courses. But that’s another story. This hike concerns the Vidourle river from the Runel river-mill north of Salinelles to Sommières. We start in Sommières and visit a number of interesting spots. Continue reading “Rivermills on the Vidourle”

February 27, 2017April 11, 2018

A bad day for measurements

Here are the results of another try at comparing GPS track logs – in particular the elevation profiles – between different devices and applications.

The weather was fine, if a bit cold with gusty winds. The hike was mostly in open terrain or on wide forest tracks. Less than an estimated 20 % of the track was under forest cover. The devices and apps are : Continue reading “A bad day for measurements”

February 24, 2017October 31, 2021

The Eschino d’Azé and the Cham des Bondons

Hiking distance : 16 km ; Hiking time : 05:00

On the western end of Mount Lozère a limestone plateau known as the “Cham des Bondons” bridges the space between Mont Lozère and the Sauveterre Causse. The Cham is interesting for a number of reasons.

- The plateau is sprinkled with an estimated 150 prehistoric monolithic standing stones. Over time, many have been knocked over but many are also still standing or have been replaced upright in modern times. The meaning or purpose of the stones is unknown. Religious significance, waymarkers for travellers, burial markers… ? Christian prelates, however, considered these monoliths to be a symbol of paganism and so some were voluntarily knocked down to signify the dominance of the Christian faith. These monoliths are all granite and have therefore been quarried elsewhere – presumably on Mount Lozère – and transported to the Cham to be erected. The Cham has the largest accumulation of these monoliths in southern France. No one knows why prehistoric peoples would have gone to all the trouble so the monoliths represent a cultural heritage yet to be explained. To the best of my knowledge, however, there are no upright monoliths along this particular route.

Continue reading “The Eschino d’Azé and the Cham des Bondons”

Hiking in south central France

This site is about walking, mostly in south central France, specifically the Cévennes “mountain” range, the Grands Causses area with it’s plateaus and canyons, the departments of Gard with the garrigue landscapes, the Vaucluse, the Herault, sometimes the Ardèche, the Avéyron and the Drôme. There are descriptions of interesting walks, but sometimes also the non-interesting ones. There are occasional articles about the hardware and software you might use while hiking and in particular handheld GPS devices and smartphones. There are also references to cartography both in the field and on the computer screen back home. The progress in the area of web mapping in the past several years, with the arrival of services like Google Maps, Nokia Here (now “Here we go”) and the OSM Open source map service, has been spectacular.

However, hiking in this region is more than just walking with eyes focused forward or concentration on the GPS screen. It’s also about observing and understanding the landscapes, villages, farms, ancient ruins and various geological curiosities. Often the subject of interest is not the “what”, but the “why”. Why did people settle here hundreds of years ago? Why did the ancient trade routes pass this spot?

In this region, traces of human activity are everywhere – in the still occupied villages and farms, but also in the undergrowth, on the riverbanks and and on the abandoned hillsides. This site aims to explore these subjects, traveling on foot, at about 3.5 km per hour.

This site is also for people who like maps. There are maps in nearly every article, often with interactive features. Try them out.

For every walk mentioned in an article, the site provides a downloadable gpx file suitable for use on a handheld gps device. The site provides additional access to a database of some 700 circuits also complete with downloadable gpx. It is worth noting however, that a gpx track is a perishable commodity. Over time waymakings change, land owners block walking routes, obstacles appear. For this reason, when available, dates of the most recent passage on the circuits are also provided. Use with care.

Everywhere you go on these hiking routes you are likely to see a field cross. They can be in iron, stone, or wood and can be simple or ornate. These field crosses are supposed to have protected travellers from bandits – as supposedly no bandit would dare attack near a symbol of the all powerful religion.

So the french word “croix” translates to cross and holds the connotation of the cross as a religious symbol. However, in the context of this site, cross means crossroad or intersection. “La Croix de Gattigues” refers to a crossroad in a hamlet in the Gard department at which, no surprise, there is also a fine an iron cross.