428 APPENDIX 



Administrative Situation. Entirely in the Largentiere district, it includes a 

 total area of 100,633 acres with a population of 16,791 inhabitants scattered through 

 twenty-eight communes. 



Destruction of the Soil. The Chassezac was established by the law of July 18, 

 1906. It includes 4,774 acres, of which, 1,315 actually belongs to the State. 



Work. There is only one working group, that of Laubresse, exappropriated in 1886. 

 Others are now being acquired. This working group, situated on the mica schists at 

 an altitude varying from 3,280 to 4,167 feet, forms (on the Laubresse plateau) several 

 isolated cantons covered with superb stands of pine from 18 to 20 years old. In the 

 purchases in the working circles of Borned, Saint Laurent les Bains, Mont Selgues, 

 there is also at the same altitude on the same plateau and on the same kind of ground 

 a very complete thrifty stand of pine from 24 to 28 years old. The total area actually 

 reforested is 1,594 acres. 



Pyrenees Region (Department of Haute-Pyrenees, Gave de Pau Forestation Areas). 

 The Gave de Pau is the most important water course in the Hautes-Pyrenees. 

 When it flows into the Adour at Peyrehorade, after a length of 109 miles, its volume 

 has increased fourfold. . . . The highest altitudes vary from 7,487 to 10,673 feet. 



Geologic Conditions. The high basin of the Gave de Pau only includes stable 

 ground, with the exception of the watershed of Gararie, formed of white limestone, 

 and the Blanc and Gavieton, which are formed of gravel, marls, and limy marl. The 

 granite occupies the higher basin of the Gave de Cauterets. . . . The glacial 

 deposits and detritus are frequently mixed with the original soil on the slopes. 



Climate. The climate of the valley of the Gave de Pau is similar to the general 

 Pyrenees climate, that is to say it is temperate and humid. In the high areas there 

 are considerable changes in temperature. The northwest winds, which always bring 

 rain, give rise to erosion on the slopes. The aspect is without influence on the forma- 

 tion of avalanches, since they are produced on both north and south slopes of the Cau- 

 terets valley. Fogs and mists are frequent. The snow and the rain are very abundant, 

 but the river is chiefly dangerous in spring when the winter snow is not yet melted, or 

 sometimes in autumn after the first snowfall. Hail storms are quite frequent but their 

 effect is very localized. 



Production. The basin of the Gave de Pau was formerly more heavily forested 

 than it is to-day. . . . The forests have been cut so as to give place to pasturage, 

 which is often mediocre in character. Outside the forests and the grazing ground the 

 cultivated fields are very limited and only occupy the bottom of the valleys and the 

 foot of the slopes. They consist of meadows for fattening beef, or are in grain and po- 

 tatoes used by the agricultural or pastoral population of the region. 



Administrative Situation. The upper basin of the Gave de Pau is situated in the 

 District of the Argeles. Its area is 244,633 acres and its population about 31,000. 



State of Soil Erosion. The causes of erosion are : The steepness of the slopes, the 

 abundance of erodable deposits, the climate, and the occupation. Too often the forests 

 are destroyed and the sod broken. Occasionally, in the more inaccessible areas, the 

 forest cover has been perfectly maintained and there are no avalanches. Overgrazing 

 results in landslides or erosion. 



Composition and Area. The area includes five working groups, comprising 2,832 

 acres, of which 917 belong to the State. 



Work. This area included the Peguere slide and the torrent of Lizey. The fixation 

 of the Peguere slide is worth a special visit. The Lizey torrent, which used to be an 

 apparently inoffensive brook, quickly changed its character in 1895. From the 22d 

 to the 27th of April a flood cut the national highway for a distance of 1,970 feet and to 

 an average depth of 5 feet. . . . The volume of the material deposited has been 

 estimated at 40,000 cubic yards. All this debris came from slopes covered with glacial 



