[GIS] Creating NDVI time series from single polygon of shapefile using Google Earth Engine

google-earth-enginemodisndvipolygontime series

I am new in Google Earth Engine, I am trying to plot ndvi timeseries from a single polygon of shapefile, but when I run the code I get "Error generating chart: Collection query aborted after accumulating over 5000 elements".

var broad_leaved= ee.FeatureCollection('users/spatola/MCD45A1_broad_leaved_311/MCD45A1_2004_clc311');
var modis = ee.ImageCollection('MODIS/006/MOD13Q1');
var modisNDVI = modis.filterBounds(broad_leaved)
                    .filterDate('2002-01-01', '2009-12-31')
                    .select('NDVI');
                    print(modisNDVI);
var timeseries = ui.Chart.image.seriesByRegion(
  modisNDVI, broad_leaved , ee.Reducer.mean(), 'NDVI', 250)
  .setOptions({
    title : 'vegetation series',
    xAxis : {title : 'YEAR'},
    yAxis : {title : 'NDVI'}
    });
  print(timeseries);

Best Answer

I believe the issue is in your feature collection. I can't access it as you don't have it shared, so can't investigate what is going on there.

But I have tested the script with a random geometry placed on the map, and had no issues.NDVI of somewhere Central USA

Check that your feature collection doesn't have too many features to it.

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EDIT

Thanks for including the link. The problem lies with the fact that you have 1918 features in your collection, and 184 images in that collection.

Multiply those 2 numbers together, and you get more than 5000 elements.

In any case I'm not sure how much information you would extract from a graph that had 1918 NDVI series on it.

Here is the modified code so you can see the print in the console.

var table = ee.FeatureCollection("users/spatola/MCD45A1_broad_leaved_311/MCD45A1_2004_clc311");

print("Original",table);

var subset = table.limit(2);
print("Subset",subset);

var broad_leaved= subset //ee.FeatureCollection('users/spatola/MCD45A1_broad_leaved_311/MCD45A1_2004_clc311');
var modis = ee.ImageCollection('MODIS/006/MOD13Q1');
var modisNDVI = modis.filterBounds(broad_leaved)
                    .filterDate('2002-01-01', '2009-12-31')
                    .select('NDVI');
                    print(modisNDVI);
var timeseries = ui.Chart.image.seriesByRegion(
  modisNDVI, broad_leaved , ee.Reducer.mean(), 'NDVI', 250)
  .setOptions({
    title : 'vegetation series',
    xAxis : {title : 'YEAR'},
    yAxis : {title : 'NDVI'}
    });
  print(timeseries);

This code gives the following image. enter image description here

Perhaps what you meant to do is have a chart for each polygon? That would give you 1918 charts, and I'm unsure how to build it so that you could print it to the console.

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