I am new to Grass and need your help. I am doing a course and I will be grateful if you can advise me on the following question and where to start. Thanks for your time. _________________________ As the GIS engineer at a consulting firm, you are to find and assess the hazard risk of a debris flows in a watershed in the NC database. The minimum variables to be used for hazard assessment, alone and in combination, are: i. valley slope (longitudinal upstream of the area to protect, which you can extract using the appropriate GIS function you have used in lab; use 100 m and 1000 m upstream) ii. geology of the valley (measure of vulnerability to sudden slope failure/erosion events e.g. silt soil is more erodible, as are sedimentary rocks; you may use a buffer distance of approx. 500 m from the river axis outwards to the left/right banks, and uplsope areas). You need to detail very clearly your specific: catchment, crossing, source maps, and criteria of hazard valuation. For credit, your answer should guide the reader on all logical steps you take sequentially using GRASS. Note: Include a mention of all the material that you would use to support your answer; e.g., maps, layers, queries, tables, etc. SOLN A (less than 50%) steps (only general delineation, used 1 page description): 1. Select the basin correctly but didn't make sure your base map has reasonable elevation resolution. 2. Didn't select correct cell coordinates [X,Y] to extract basin 3. Determine slope but didn't make sure DTM had enough resolution – e.g. 6m). 4. Didn't compute stream power P=pQS or similar measure for flow hazard 5. Didn't check rock type in the buffer zone, only in the general catchment.
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