I'm having a problem where islands (uploaded as part of a kml file) don't match up to the location of the island on the map when I upload them to a particular site (iNaturalist). It is part of a personal project to filter among the organisms on the site for certain ecoregions. I've been looking for a couple days to solve it and I wonder if you could help me.

This is what the error looks like:

https://preview.redd.it/ce2rn4jkzzvc1.png?width=612&format=png&auto=webp&s=39e7ba304f94f5fdcceca636cc11056517dca5e1

Notice that the shape of the island is also slightly different.

The problem is larger for this very southerly island, but also exist for some mid-latitude islands:

Isla Ángel (center) is part of a region I uploaded and has this problem, while the island on the right is a standard place already incorporated into the site and doesn't (but standard places do include the surrounding waters). The Baja peninsula (left mainland) is completely unaffected.

And in Jamaica it is very subtle; some mis-registration shows up where the overlay (my boundary) is shifted south, but it's so small I guess it could be the error in the file/data itself, although given the others I think it's not:

Jamaica South

Jamaica North

The data is coming from this shapefile (click About tab), the RESOLVE Ecoregions 2017 data, after being uploaded to Google Earth and the island exported as kml.

I also notice that in the Northern regions (Alaska ecoregions), the shapes from Eco-2017 are distorted compared to those of the equivalent regions which were already on the iNaturalist website. Same region, just as if projected differently.

This makes me think that it's a projection problem.

However, iNaturalsit only takes data a kml files, and I've recently discovered that they are all supposed to have the same encoding. So I figure it must be able to interpret my data, unless when I downloaded it as kml it had already not be exported properly.

I opened the .prj file of my data and this is the content:

GEOGCS["WGS 84",DATUM["WGS_1984",SPHEROID["WGS 84",6378137,298.257223563,AUTHORITY["EPSG","7030"]],AUTHORITY["EPSG","6326"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.01745329251994328,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4326"]]

Which makes me think this is in WGS 84, although there may be different sub-kinds. I read that Google Earth Pro uses WGS 84, and that iNat uses a version of it to store places, though it may use something else to display them. Later, I uploaded the shapefile to QGIS, I exported as geopackage to be able to select just this island, re-imported the geopacage, set via 'Properties' the coordinate system to WGS 84, set the default CRS as same, exported the island as kml, and re-imported to iNaturalist, but I still get the same error.

Someone else had the same problem, here, but no solution, they think it's due to old data (which they were told by a professional GIS friend).

Do you think it's an 'old map data' problem? I mean, it only affecting islands lends some support to this, but it's not as if the islands change shape (of this magnitude) over time.

If it is a projection problem, how do I diagnose and how do I fix it?

If this is not the right sub, please point me to it.

I am a complete newbie to GIS (only for this project am I using it or have I ever used it), so explanation is helpful.

Thank you

I created a layer of buffer polygons, 1/4 mile radius around point location. I want to see where this polygon intersects with block groups, and then average the attributes. I set the merge action to "mean".

However, if the buffer polygon lies completely within one block group, then it would just get those corresponding attributes.

I tried joining one-to-one with the match option as 'intersect'. The target feature was my location polygons, and the join features were my block group polygons.

I'm running into some issue and I'm not sure if I'm doing this correctly.

Hello, I'm currently working on my master's thesis on the evolution of the rocky coast... however I'm having some problems regarding the calculation of susceptibility to slope movements, using the multivariate logistic regression method. To carry out this work I am using terrain units, however I am having difficulties in obtaining the susceptibility values ​​for each unit, and when I do the regression calculations I cannot have a correct representation in the arcmap and all the units have the same value. I don't know what could be wrong but if anyone can help me I'll be grateful...

I gave a very brief explanation of the work I'm doing, if you need any more information to help me, don't hesitate to ask. thanks! <3

Hello one and all, a question here about analyzing some point data. I'm working within ArcGIS Pro with a professional license, so most of Esri's tools are available for me to use.

I have a dataset containing (i) the names of certain businesses, (ii) the coordinate locations of those businesses, and (iii) a label for what kind of business it is (e.g., Food, Retail, etc.). The dataset is not one I've created, and my job isn't to change/reassign the label for the business. There are 10 possible labels.

In the original dataset, some businesses contain more than one label. E.g., Business A might be both Food and Retail.

My tasks are to:

(1) Identify whether businesses of the same label are clustered, dispersed, or randomly distributed across the study area (state of Wisconsin). In my situation, ideally they will be dispersed, allowing for greater accessibility across the study area.

(2) Identify whether businesses of different labels are clustered, dispersed, or randomly distributed across the study area. In my situation, ideally businesses of different labels are clustered, allowing for greater variety where lots of business are present (such as in a city, where clusters of businesses are more likely).

To prepare the data, I have:

(A) Parsed out the field of labels into several fields, since original values contained lists. Now, there is one field for each label, where businesses assigned that label have a value of 1 and businesses not assigned that label have a value of 0.

E.g., original data (in Excel):

Business Label

A Food

B Food

C Food, Retail

D Retail

E.g., parsed data (now in ArcGIS):

Business Food Retail ...

A 1 0 ...

B 1 0 ...

C 1 1 ...

D 0 1 ...

My thinking is:

(1) Spatial Autocorrelation (Moran's I) is used to evaluate clustering, dispersion, and randomness when feature locations and feature values matter. Is there a way I can merely evaluate the data based on location? Is using Average Nearest Neighbor more in the right direction?

(2) I am really struggling to conceptualize the appropriate way to do this, as far as a way I can make the labels matter. There is hypothetically a way to evaluate categorical data like this, no? Could I assign a number to each label, and let's say run Spatial Autocorrelation--in that case, I can account for the value, but how do I account for the fact that some businesses have multiple labels?

Any suggestions are well-appreciated, thanks.

Hello, I used to download free data from a Japenese website, but since I lost access to my cloud, I cannot find the website. If anyone knows it, please share it in here. Many thanks 😊

Hi all! I need help finding a polygon map of Willapa Bay, WA, USA. I found one here but it seems to be only lines and not a polygon. I'm interested in a bathymetry map but honestly would take even a boundary-level map. If you know any good resources for finding this information, I would be super grateful. I figured it would be easier, between all the available NOAA and state stuff.

A little background: I am a shark researcher and PhD student, and I'm trying to make a map to plot my tagged shark data on. I have absolutely no GIS experience but am working in R...the current code I'm trying to adapt uses .shp files and I'm trying to find a set of files that I could use!

Hi buddies,

What tool should I use if I want to extract the exact location point data set from excel. Like I extract temperature data from satellite image after pre processing and applying suitable equation in raster calculator. now I want to exact point temperature value. I did not find any suitable video in youtube.

Looking to understand if the graduate Mapping with Small Unmanned Aerial Systems certicate offered at the University of Florida is worth it as a supplement to a Master's and Bachelor's degree in Geomatics. Why not just get the Part 107 licensure instead? Not sure what job to get when I graduate, therefore, I'm not sure if this will help me stand out on my resume.

Hello there!

I am working on a project where I am taking resulting MOD35_L2 HDF files to create historical cloud coverage/fraction raster with a 5km resolution. The file spec for these files can be found here:
[https://atmosphere-imager.gsfc.nasa.gov/sites/default/files/ModAtmo/MYD35_L2.C6.CDL.fs]

My current thinking for a naive approach (without quality checking) is that I need to read the first 3 bit fields in byte 1 which represent the cloud mask flag, then checking bits 1 and 2 for cloudiness "levels". Take this information in the 1km swaths and do some math to calculate the fraction over 5km.

Figure 1. Screenshot of MOD35_L2 Byte 1

I plan to write this using Python, but for now I'm using HDFView to understand the file structure, the problem is I'm not sure what I'm looking at when I open these files. My current thinking is that the information I want should be inside the Cloud_Mask subset, however I could use some assistance to understand what the data represents.

Figure 2. HDF Subsets

Figure 3. Opening Cloud_Mask

So, would love to hear any thoughts and guidance on understanding how data is stored in an HDF4-EOS, specifically how to get the cloud mask bits, and whether I'm making any mistakes in my thinking for this problem.

Thank you so much!

How long would it take to learn update & eork with an MSSQL-database in a GIS-context?

Hello all!

I am building proto.

A map content platform that allows users to create maps, monetise map content and share it widely.

1. We’re still in early days. And have a beta version for PoI’s (an App).
2. We’re also doing map-a-thons in a few places in India.
3. And we’ve started Co-mapping sessions online, where we sit on a call and build maps together for fun.

Note: Everything is free to use. We’re trying to build this line youtube with a creator-platform split of 55-45. Revenue comes from businesses that use the maps or ai models built on them.

We’re not associated in any way with osm, overture or any of the other big mapping platforms. We’re independent.

Looking for subs where this will find an audience. Hence sharing at a few places.

If you are interested , I’d love to share more.

Won’t share links or anything that might be construed as spam. If enough people find the idea interesting/upvote/comment.

Will add relevant info in the comments / make another post. Whatever folks prefer.
(Sharing this in a few GIS subs, so you might see it else where as well.

I have a project where I have 5 polygon shapefiles (flood risk areas) and then a point shapefile (assets in a specific area.)

What I want to achieve is to add an attribute column to the point file that records how many of the 5 polygon layers a point intersects with (so a number between 0 and 5). Thank you in advance!

I then also want to assign a score (for the sales of symbology) in a separate column where each polygon layer has its own score based on a multiplier/percentage chance of that layer happening. So if the multipliers are: Layer Chance 1 3.3% 2 1% 3 0.1% 4 1% 5 0.1%

A point that sits within layer 2 and 3 and 4 would have a chance of 1%, 0.1%, and 1% so how would be a good way of approaching this? I was initially thinking of adding them together and having a default score of 10, and then multipyling the 10 by my total multiplier (so in the above example (2.1(%) X 10 = 21.

Let me know if there is a better more efficient way to do this in ArcMap 10.8 thank you!!

I am attempting to run a network analysis in qgis to determine the service areas within a 15 minute walk from the rail stations in my city. The issue is the results are paths that are far too short, which is verified by checking the directions from an endpoint in a service line to a railstation in Google maps. what is being output is only at most a 7 minute walk away.

all layers in my map have been reprojected to the local CRS.

I am using the service area from layer processing tool in qgis, with the following inputs:

Vector Layer representing network: City centerlines shapefile

Path Type: fastest

Travel Cost: 0.25

Default Speed: 4.82 km/h (~3mph)

Where am I going wrong here? I was considering downloading the paths from OSM to use as my network, but my city is very large and this might take a while.

​

Let me know if you need any additional information, and thanks in advance for any insights you might have.

Hello!

I want to make a map of a specific neighborhood so that images of the structure appear when the user clicks on the property. A good example would be the Vieux Carre's Virtual Library: https://vieuxcarre.nola.gov. Would using ArcGIS be suitable for this project?

If so, what should my first steps be? I'm entirely new to this software.

I recently graduated with a Masters in Urban Planning and a Grad Cert in GIS. One thing that turns me off about working in the private sector in planning is billable hours. Almost 100% of planning jobs in the private sector fall in this category. I love GIS, however, and have been considering working in a more GIS focused position. Is this also the case in private sector GIS positions?

Hi all. I was interested in learning how to use python to make maps. Are there any resources or tutorials that I might find helpful? Thank you.

I'm trying to upload a desktop map to ArcGIS Online and when I analyze the map I get the following error:

"24138: Layers pop-up definition includes one or more measurement fields that is not supported online"

The fields it is referring to are those within the routes layer of a closest facility analysis and the lines layer within a service area analysis.

The link below suggests hiding the field or creating a new field that has the same values as the original shape length column and then calculating the original shape length field based on the second. It states that this should be done for the following attributes:

Measure Minimum Measure Maximum Measure Measure Values Parts Unknown Measures

None of these attributes exist as columns so I'm unsure of what to do.

https://pro.arcgis.com/en/pro-app/latest/help/sharing/analyzer-warning-messages/24138-layers-pop-up-definition-includes-one-or-more-measurement-field-that-is-not-supported-online.htm

Any help on this would be appreciated!

Just got a new job (whoo!) that will require me to make maps for masterplans and redevelopment plans.

Its been almost 3 years since I've had to make a map and Im quite rusty. What are some good projects to work on to refresh my skills?

I am trying out anything GIS-related for the first time and I wanted to do an ESG Data Science project which involves mapping flood risk. So my question was, how do I extract the data from the following map? It would be useful for me to have the data for the 1-10 Flood Risk ranking.

https://www.arcgis.com/home/webmap/viewer.html?layers=5372c70e9d0b4d278ba8c572bbc2eac7

I am wondering how many organizations are using a dev enterprise gdb that pushes to a production enterprise gdb for their organization.

Secondly, if you are, how are you maintaining them? I have been using replication, but find it tedious to maintain as our organization grows, and new requested layers are added.

Lastly, if you are, do you have an internal definition query that restricts what gets replicated?

I would love to hear your thoughts!

I am relatively new to GIS software and I am currently working on an assignment. I am trying to get a dataset from Geoscience Australia into ArcGIS. I have played around trying to figure it out myself but it never brings over data other than the polygons.

This is the data:

https://portal.ga.gov.au/metadata/geology/alkaline-and-related-igneous-rocks/cenozoic-alkaline-and-related-igneous-rocks-of-australia-02-geological-unit-polygons/2bcdb186-163a-4534-abb1-368429baa417

Would someone be able to assist me with getting it over into ArcGIS web browser version. I have desktop, but less familiar with it currently.

[ArcGIS Pro] I've got over 2000 viewshed rasters that I need to run through raster calculator individually. Is there something like Iterate Feature Selection in model builder where it can iterate the rasters from within a folder in my map pane? I don't know how to use workspaces, which is what Iterate Raster wants.

I'm fairly new at arcmap, so please bare with me.

I have this shapefile (polyline) of water mains throughout a city. One attribute of these assets is the diameter of the pipes. All the pipes of every diameter are currently lumped into one layer.

How would I go about separating these pipes into multiple layers based on query values (layer 1 = all pipes where 400mm < diameter < 600 mm, layer 2 = all pipes where 600mm < diameter < 1000 mm, etc). This would allow me to filter by pipe diameter, or even change the look of each layer to see what pipe sizes are in which areas of town.

Thank you in advance!