Hi, in my opinion to make an accurate landslides inventory you need of some informations about the landslide body. This in order to keep the possibility to explore your database for several statistical analysis dealing with surface/volume of moved masses.

Dear Chiara,

Thank you for your opinion.

Hi, in my opinion it is dependent on the method which you want use in the landslide susceptibility mapping. However scarp is the most important, because you need information where the landslide initiated and not a location of the accumulation. Thus in the most of the cases it would be necessary to split landslide polygon to two parts - scarp (source zone) and landslide accumulation.

Dear Michal Brezny,

Thank you for your opinion, and i think it depends on your data resolution which you are using also. For 30 m resolution datasets it is impossible to use polygon based inventory.

What do you think about this issue?

Dear Mukhiddin Julie

To prepare the landslide inventory it is very important to mark both scarp and body because the initiation point (Scarp) and deposition point (Body) both are important for susceptibility studies. normally the initiation point may be some cliff or steep slope where vulnerability is very low or no vulnerability but the foot hills where the load is sitting may highly vulnerable. So the detail information is important for susceptibility assessment.

Hi, Mukhiddin Juliev. You can read the below paper. The three landslide sampling strategies were used for landslide susceptibility modelling including (1) the landslide scarp centroid, (2) points populating the scarp on a 50-m grid, and (3) the entire scarp polygon. The model results were discussed and analyzed in detailed based on three landslide sampling strategies.

Hussin H Y, Zumpano V, Reichenbach P, et al. Different landslide sampling strategies in a grid-based bi-variate statistical susceptibility model[J]. Geomorphology, 2016, 253: 508-523.

Dear Qigen Lin,

Thank you for the suggestion and a paper. I will definitely go through the paper.

All the best.

Dear Juliev

1- Your question, if I am not mistaken, is: "how to represent landslide body spatially" or as feature class for modeling purposes.

2- Purpose of modeling: Landslide body has centre of shape gravity (scarp), top and bottom. If the purpose is preparing landslide susceptibility Map using statistical methods, then your proposed polygon might give misleading impression (fall into two or more different classes of one conditioning factor).

3- The point or centre of slope strain trigger might be misleading as well, therefore.

4- Most common representation is to use natural Slope Unite representation, rather than grid based.

All the best

Althuwaynee

Dear Omar,

Thank you for your nice expalanation.

Yes i want to use the accurate landslide inventory for the landslide susceptibility mapping.

I think on scale of 50,000 or even smaller scale, landslide point data will be OK. On scale 25, 000 or larger scale, poly-gone data (including 1. zone of depletion, 2. zone of transportation/translation and 3. zone of accumulation/deposition) of landslide is required to perform a model-based study.

regards

ijaz

I prepared an inventory of the landslides in the Province of Salta, Argentina by stereostudy of airphotos, scale 1/50,000, then field examination of as many as possible in the time I had available. Field study also let me add a few that that occurred after the photos had been taken and to check their geology.

Dear William John Wayne,

Thank you for the answer. I will use your suggestions also.

Thank you Marco Emanuele for the suggestions.

• One of the important aspect of landslide inventory data is the point of initiation(crown) and the toe of the failure zone. Usually, collection of data close to the crown is most difficult task and at the same time the toe is usually covered with landslide debries. In order to do a more accurate interpretation and the verification of landslide susceptibility mapping is only required coordinates at least closer to the point of initiation (or the crown) of old landslides. Data which are similar to the landslide body or the derbies deposition zones will indicates landslide risk scenario/s mapping approach and not the susceptibility.

Dear A.A Virajh Dias ,

Thank you for the explanation.

Landslide Inventory data is obviously a very important basic data set/ information of landslide incidences that have taken place in a hilly terrain - may it be a hilly area or a hill road section or may be a hill town environment etc.

I feel, the LI data is important not only from recording the landslide incidences, but it can also be helpful to understand the type/ processes of landslide/ slope failure incidences that have taken place in afore-stated kind of geo-environment. Further, LI data is also helpful for Landslide Susceptibility Mapping/ Zonation etc, as like select other mandatory/ relevant thematic parameters e.g. Structure, Lithology, LU/ LC, Geo-hydrological conditions etc., it also affects various ratings.

With a view to make an accurate LI data, the relevant information pertaining to Landslide Incidences in a hilly area is to be enumerated properly. This may include, Geographic information (viz. Coordinates, Locality, Topographic Sheet No., Date of Recording etc.), Geological Information (Basic information about Geology of the area, Lithology, Site Geology etc.), Basic Rock Mass/ Soil/ Debris characters etc., Process of Slide/ Slope failure, Geo-scientific causes, Brief Summary PLUS Good field photographs etc. As you are planning for a good LI dataset, better to give Code Nos. to LS incidences which are being recorded in such dataset.

Best regards

A. Kohli.

I think it depends on your purpose. As for LSM, I suggest using a scarp polygon to represent the landslide inventory because scapr is much unstable compared with the body. we also use test it. Scarp for LSM has better results.

Landslide inventory generation from satellite data requires the complete single polygon including scarp and the body.

However, in case of of long distance travelled debris flow, scarp and the body are normally mapped in a multiple polygons including the pathway too.

Dear Javed Iqbal,

Thank you for your answer.