Where does the rain go?

1 · Three paths for rain

Rain splits three ways: some returns to the air (evaporation and plant transpiration), some runs off into streams and dams, and some infiltrates: it first wets the soil, then percolates down to the aquifer. The infiltrating share is called recharge. Shares vary with climate, soil, vegetation and rain intensity; the site publishes no fixed proportions. Per basin, the official annual recharge (DSİ statistics, Table 1.3) is compared with the basin's normal annual rain volume on the Turkish page. Turkish page (Turkish)

2 · Dams fill in days, groundwater in months

Dams collect surface runoff, so their storage changes within days of a large rain (the site's dam series is daily). Groundwater is fed by infiltration: shallow aquifers respond within months, confined and deep aquifers within years. This is why the figure describes the coming period's renewal, not today's well level. Aquifer type is published only for 29 of 472 groundwater units in Türkiye's river basin management plans.

3 · Türkiye last water year

117% October 2025 – September 2026: rain over Türkiye as a share of the 1991–2020 normal — usual; cold season (October–April) 119%. Data through September 2026.

4 · Your province

Choose a province to open its page (Turkish) with the water-year ratio computed on the official provincial boundary, the class, the cold-season row and context rows.

5 · Does rain increase the reserve?

Rain affects the water that is renewed each year, not the total stock underground. DSİ publishes the renewed water as recharge (groundwater potential) and its usable share as the operating reserve (Table 1.3); both are shown per basin on basin pages. Where abstraction exceeds the operating reserve for many years, one wet year does not close the gap. Two topics discussed alongside groundwater over-abstraction in the Turkish literature are the Karapınar sinkholes in Konya (the study separates natural and induced sinkholes) and seawater intrusion in the Karaburun coastal aquifer (a modelling study). This page names the topics only; it draws no causal claim and does not summarise findings. In Türkiye the official record is the set of Official Gazette operating-area and closure notices, listed on the restriction query page (Turkish). restriction query page (Turkish)

• Natural and induced sinkholes of the Obruk Plateau and Karapınar-Hotamış Plain, Turkey (2010) — doi:10.1016/j.jseaes.2010.09.014 (opens in a new tab)
• Modeling of seawater intrusion in a coastal aquifer of Karaburun Peninsula, western Turkey (2017) — doi:10.1007/s12665-017-7124-5 (opens in a new tab)

6 · Snow and soil moisture

Snow cover (Türkiye, NOAA IMS)

normale yakın — kar mevsiminde (Kasım 2025–Nisan 2026, 6 ay) kar örtülü alan payı %26, normal %27 (2006-2025 kaydı); NOAA IMS 24 km analiz ürünü, veri Kasım 2026

Snow depth (model)

normale yakın — kar mevsimi ortalama kar derinliği 9,8 cm, normal 9,9 cm (1991-2020); NASA POWER model ürünü (yer ölçümü değil), veri Ekim 2026

Soil moisture (model)

normale yakın — su yılı kök bölgesi toprak nemi 0,60, normal 0,57 (1991-2020; doygunluk payı 0–1); NASA POWER model ürünü (yer ölçümü değil), veri Ekim 2026; uydu ölçümünde (ESA CCI) 2015-2024 yıllık ortalama eğilimi: artış (yılda +0,7 %), veri Aralık 2024

Rows are in Turkish (same text as the Turkish page). Snow depth and soil moisture are NASA POWER model products, not ground measurements; snow cover is the NOAA IMS 24 km product; the satellite trend is ESA CCI Soil Moisture.

7 · What these numbers say, and what they don't

This figure is context at province and basin scale; it says nothing about the amount of water at any parcel or well. Drilling and licensing decisions require an on-site ground and groundwater survey.

• Says: the ratio of the latest measured water year's rain to the 1991–2020 mean for a province or basin; the cold-season share; the last ten water years.
• Does not say: whether a parcel has water, at what depth a well would yield, or what a well level will be this year.
• Measurement limits: CHIRPS blends satellite and station data; errors grow in mountains with few stations. Cells are 0.05° (about 5 km); very small provinces still include some neighbouring area. Basin boundaries come from a non-official source; provincial boundaries are official. Satellite water storage (NASA GRACE) is a change signal at about 300 km, last data month March 2026.

8 · Sources and method

Rule: water year (1 October–30 September) rain ÷ the 1991–2020 mean of the same months (CHIRPS v3.0, UCSB Climate Hazards Center, CC BY 4.0; normal computed by this site, no MGM data). Below 80% low, 80–120% usual, above 120% high. If the water year is incomplete, only complete months are compared with the normal of the same months. Context rows never change the class. No forecast model, no scoring, no AI commentary.

Computation: CHIRPS v3.0 0.05° monthly cells; area-weighted mean (cell∩polygon area × cos latitude) for provinces (official boundaries) and basins; Türkiye = union of the 81 provinces. Data through October 2026 (preliminary: 2026-10). source and licence table (Turkish)

Source: CHIRPS v3.0 (UCSB, CC BY 4.0), DSİ, NASA GRACE, NOAA IMS, NASA POWER, ESA CCI · Data as of: October 2026