IB ESS · 2021 to 2026

4.1 Water systems

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SL archive · 2022 to 2025

4.1 Water systems

Latest exam session: May 2025

questions
15
questions
papers
10
papers
exam sessions
6
exam sessions
micro-topics
4

Micro-topics in 4.1 Water systems

In syllabus order. The ring is the share of papers each appears in.

  • 16

    4.1.1

    The hydrological cycle

    5 questions · in 16% of papersAppears in 5 of the 31 ESS papers analysed (16%), at least once each.

    Regular

    last May 25 P1 TZ3

  • 16

    4.1.2

    Water stores and flows

    6 questions · in 16% of papersAppears in 5 of the 31 ESS papers analysed (16%), at least once each.

    Regular

    last May 25 P2 TZ3

  • 3

    4.1.3

    Drainage basins

    1 question · in 3% of papersAppears in 1 of the 31 ESS papers analysed (3%), at least once each.

    Less common

    last May 23 P2 TZ1

  • 10

    4.1.4

    Water and climate regulation

    3 questions · in 10% of papersAppears in 3 of the 31 ESS papers analysed (10%), at least once each.

    Occasional

    last Nov 24 P2 TZ2

Exam pattern

How often each micro-topic has been examined, year by year. Each label is explained under the grid.

Does it repeat?

Questions per year for each micro-topic.

fewermore

Micro-topic202120222023202420252026
4.1.2Water stores and flowsRegular
·Water stores and flows, 2021: 0 questions2Water stores and flows, 2022: 2 questions2Water stores and flows, 2023: 2 questions1Water stores and flows, 2024: 1 question1Water stores and flows, 2025: 1 question·Water stores and flows, 2026: 0 questions
4.1.1The hydrological cycleRegular
·The hydrological cycle, 2021: 0 questions2The hydrological cycle, 2022: 2 questions2The hydrological cycle, 2023: 2 questions·The hydrological cycle, 2024: 0 questions1The hydrological cycle, 2025: 1 question·The hydrological cycle, 2026: 0 questions
4.1.4Water and climate regulationOccasional
·Water and climate regulation, 2021: 0 questions·Water and climate regulation, 2022: 0 questions·Water and climate regulation, 2023: 0 questions3Water and climate regulation, 2024: 3 questions·Water and climate regulation, 2025: 0 questions·Water and climate regulation, 2026: 0 questions
4.1.3Drainage basinsLess common
·Drainage basins, 2021: 0 questions·Drainage basins, 2022: 0 questions1Drainage basins, 2023: 1 question·Drainage basins, 2024: 0 questions·Drainage basins, 2025: 0 questions·Drainage basins, 2026: 0 questions
  • Regularin roughly one paper in six or more
  • Occasionalin about one paper in ten
  • Less commonin fewer than one paper in fifteen

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Questions on 4.1 Water systems, by exam session

Which papers asked about 4.1 Water systems, and which question numbers. Open a paper to see them highlighted.

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Frequently asked questions

Short answers about this page.

Which ESS exam sessions are covered for 4.1 Water systems?

10 exam sessions from 2022 to 2025, the latest May 2025. Every Paper 1 and 2 in every timezone is read and classified in full, which gives 10 papers in this archive.

Which 4.1 Water systems topic comes up most?

Water stores and flows (4.1.2): in 16% of papers, last seen May 25 P2 TZ3. Usually "outline", worth about 1.8 marks in a paper that includes it.

Can I see the original question and mark scheme?

No. The wording belongs to the IB. You get the citation, the marks, the command term and the skill tested, plus our own matched practice questions with worked answers and AI marking.

What do "banker", "due" and "rising" mean?

Banker: examined in at least one sitting in four and still appearing. Due: regular before, but absent for the last two exam sessions. Rising: clearly more common in the last two years. Our classification of real papers, not an IB statistic.

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