KDP categories · Top KDP authors
Hydrology (Earth Sciences, Books): Amazon KDP category data
Amazon Books Best Sellers data for Hydrology (Earth Sciences, Books), updated Nov 2, 2026: median price $21.78, median 16 reviews, average rating 4.5 and a KDPTop opportunity score of 35/100 (highly competitive).
| Price range (middle 50%) | $16.01 – $30.83 |
|---|---|
| Average rating | 4.5 |
| New releases (90 days) | 12% |
| Books on the list | 100 |
| Store | Books |
What stands out
- Its median reviews are 1% of the parent category Earth Sciences (1,495), one of the easier corners under it.
- Its review barrier is lower than in 76% of Books categories: the median best seller has only 16 reviews, so new books can chart with few.
Top 10 Hydrology best sellers
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The Prepper's Water Survival Handbook: Easy to Follow Steps to Find, Filter, Purify and Store Water for Long Term Readiness, Self Reliance and Emergency Preparedness (Self Reliance Essentials)
- List rank#1
- Price$17.97
- Rating4.8
- Reviews194
-
Prepper’s Water Purification Survival Bible: How to Find, Harvest, Filter, Purify, and Store Water Off the Grid
by Johnathan Nash
- List rank#2
- Price$12.99
- Rating4.6
- Reviews358
-
Spooky Lakes 2027 Wall Calendar
- List rank#3
- Price$16.99
- Rating4.4
- Reviews12
-
The Prepper’s Survival Collection: A Beginner's Guide to Find, Filter and Purify Water + How to Grow, Preserve and Store Food for Emergency Preparedness in Uncertain Times (Self Reliance Essentials)
- List rank#4
- Price$24.99
- Rating4.8
- Reviews55
-
Scientific American September 2026
- List rank#5
- Price$6.99
- Rating4.8
- Reviews13
-
Scientific American October 2026
- List rank#6
- Price$6.99
- Rating4.2
- Reviews7
-
Scientific American June 2026
- List rank#7
- Price$6.99
- Rating4.4
- Reviews42
-
The Water Freedom System: A Practical Guide to Atmospheric Water Generation
by Vijay Vijay
- List rank#8
- Price$9.99
- Rating1.0
- Reviews1
-
Scientific American November 2026
- List rank#9
- Price$6.99
- Reviews-
-
The Fourth Phase of Water : Beyond Solid, Liquid, and Vapor
by Gerald Pollack
- List rank#10
- Price$23.74
- Rating4.8
- Reviews824
FAQ
Is Hydrology a good niche for Amazon KDP?
Its KDPTop opportunity score is 35/100, which makes it highly competitive. The median best seller has 16 reviews and sells for $21.78.
How many reviews do you need to rank in Hydrology?
The median best seller has 16 reviews, and 78% of them have fewer than 100.
What do Hydrology best sellers cost?
The median price is $21.78; half of the best sellers are priced between $16.01 and $30.83.
Can new books break into Hydrology?
12% of the current best sellers were released in the last 90 days.
About this data
Data comes from KDPTop's daily crawl of Amazon's public Best Sellers pages; medians use the latest list. The opportunity score (0–100, higher is easier to enter) combines the review barrier, the share of low-review books, list turnover, new-release share and price.