scholarly journals L’Alpe d’Huez: A Benchmark for Topographic Map Generalisation

2022 ◽  
Vol 4 ◽  
pp. 1-2
Author(s):  
Guillaume Touya
Keyword(s):  

2019 ◽  
Vol 2 (1) ◽  
pp. 071-084
Author(s):  
Silwanus M. Talakua ◽  
Rafael M. Osok

The study was conducted in Wai Sari sub-watershed, Western Seram Regency Maluku to develop an accurate land degradation assessment model for tropical small islands. The Stocking’s field land degradation measurement and RUSLE methods were applied to estimate soil loss by erosion and the results of both methods were statistically tested in order to obtain a correction factor. Field indicators and prediction data were measured on 95 slope units derived from the topographic map. The rates of soil loss were calculated according to both methods, and the results were used to classify the degree of land degradation. The results show that the degree of land degradation based on the field assessment ranges from none-slight (4.04 - 17.565 t/ha/yr) to very high (235.44 - 404.00 t/ha/yr), while the RUSLE method ranges from none-slight (0.04-4.59 t/ha/yr) to very high 203.90 - 518.13 t/ha/yr.  However, the RUSLE method shows much higher in average soil loss (133.4 t/ha/yr) than the field assessment (33.9 t/ha/yr). The best regression equation of  logD/RP = - 0.594 + 1.0 logK + 1.0 logLS + 1.0 logC or D = 0.2547xRxKxLSx CxP was found to be a more suitable land degradation assessment  model for a small-scale catchment area in the tropical small islands.


2002 ◽  
pp. 32-43
Author(s):  
V. I. Vlasenko ◽  
M. G. Erunova ◽  
I. S. Scerbinina

The reserve “Stolby” is characteristic key plot of the mountain-taiga and subtaiga-forest steppe altitudinal belts in the East Sayan Mountains, where anthropogenic influence is the least pronounced. It was founded in 1925, in 15 km southward of Krasnoyarsk city, on north-west spurs of the Western Sayan Mountains which adjoin closely to right bank of the Yenisei River bordering upon the Middle Siberian Plateau. Reserve's physiography is characterized by low mountain and middle mountain erosion-accumulation relief with absolute heights of 200-800 m. Low mountain part (200-500 m) is composed of loose sedimentary rocks. In the middle mountain part of the reserve (500-800 m) there are outcrops of sienite rocks of various stages of destruction. Vegetation and soils of the reserve change in agreement with absolute heights and climate. In low mountains spread the subtaiga and forest-steppe leaved-light needle forests on mountain grey forest soils (8.1 % of reserve territory); the middle mountain part is occupied by the light needle and dark needle taiga forests on mountain podzol soils (91.9 % of the area). As the basement for vegetation map we took the map of forest environments of reserve by T. N. Butorina compiled according to materials of land forest management of 1977 year. As the result of forest management near 2000 biogeocoenoses were distinguished. The type of biogeocoenosis, according to V. N. Sukachev, is selected as mapping unit. Biogeocoenoses were united into 70 groups of forest types, representing 21 series of associations which are reflected in the map legend (Fig. 1). The main goal of map is to show the territorial distribution of groups and series of types of biogeocoenoses in the main structural units - altitudinal be't complexes (ВПК) which are equivalents of altitudinal vegetation belts. For designation of forest tree species various kinds of hatches were used. Formations of Siberian pine, larch, pine, fir, spruce, birch and aspen forests are shown on the map. Within the ВПК arabic numerals show the groups of types of biogeocoenoses (forest types), united into series according to similarity of dominants in ground layer. The mountain-taiga ВПК includes the following series and groups of types of biogeocoenoses: dwarf-shrub-moss (1-4); sedge-moss (5-9); bilberry-low herb-moss (10-14); tall herb-sedge (15-19); tall herb-wood sour-moss (20-26); tall herb-small reed (27-32). The subtaiga-forest steppe ВГ1К embraces: shrub steppificated (33-34); shrub-forb steppificated (35-38): sedge- bilberry (39-40); sedge-forb (41-43); bracken (44); small reed-forb (45); bilberrv-forb- sedge (46, 47); forb-tall herb (48-51); tall herb (52-55); wet tall herb-small reed (56-59); fern-tall herb (60). Intrazonal phytocoenoses: brook tall herb (61-63); brook shrub (64-68); lichen-moss (69); cowberry (70). In 1999-2000 on the base of topographic map in a scale 1 : 25 000, map of forest environments, transformed by us into vegetation map of the reserve, M. J . Erunova and I. S. Scerbinina worked out an electronic variant. For this project the instrumental facilities of GIS, GeoDraw and GeoGraph (CGI IG RAS, Moscow) and programs of Geophyt were used.


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