Conference paperFree to read
Spatial modeling of contaminant transport in groundwater systems using GIS
- Department of Preschool and Primary Education, Termez University of Economics and Service, Termez, Uzbekistan
- Department of Physical Geography, National University of Uzbekistan, Tashkent, Uzbekistan
- Department of Hematology and Clinical Laboratory Diagnostics, Bukhara State Medical Institute named after Abu Ali ibn Sino, Bukhara, Uzbekistan
- Department of Theory and Practice of German Language, Andijan State Institute of Foreign Languages, Andijan, Uzbekistan
- Navoi State University of Mining and Technologies, Navoi, Uzbekistan
- Department of Languages, Samarkand State Medical University, Samarkand, Uzbekistan
- Department of General Technical Disciplines, National University of Science and Technology MISIS, Almalyk branch, Almalyk, Uzbekistan
- Al-Nisour University, Baghdad, Iraq
Highlights
- 150 monitoring wells, 20–150 m deep, sampled every quarter for 18 months.
- Nitrate: mean 33.0 mg/L; Fergana Valley 42.3, Zarafshan 31.7, Bukhara–Khiva 25.1 mg/L.
- Arsenic: 14.8 µg/L at 20–50 m, 8.5 µg/L at 50–100 m, 4.2 µg/L at 100–150 m.
- Porosity 0.2–0.35 (cores); hydraulic conductivity from 450 pumping tests.
- Modelled nitrate plumes: 26.1 km² now, 136.9 km² in 50 years.
Keywords
- contaminant transport
- GIS modeling
- groundwater contamination
- Uzbekistan aquifers
Summary
The study covers three groundwater basins: the Fergana Valley, the Zarafshan River basin and the Bukhara–Khiva region. For 18 months, 150 monitoring wells screened at 20–150 m were sampled every quarter for nitrate, pesticide residues and heavy metals. Maps of hydraulic conductivity were interpolated from 450 pumping tests, porosity of 0.2–0.35 came from core samples, and a MODFLOW-USG transport model with 100 m cells and 10 layers was set up and calibrated in GIS (R² = 0.93).
Nitrate averaged 33.0 mg/L, with 17.6% of wells above 50 mg/L: 42.3 mg/L in the Fergana Valley (28.4% above 50 mg/L), 31.7 mg/L in the Zarafshan basin and 25.1 mg/L in the Bukhara–Khiva region. Arsenic averaged 9.2 µg/L in 120 samples, with 22.1% above 10 µg/L, and fell with depth: 14.8 µg/L at 20–50 m, 8.5 µg/L at 50–100 m and 4.2 µg/L at 100–150 m. Arsenic clustered around legacy mining sites in the Zarafshan basin.
The model projects nitrate plumes growing from 26.1 km² today to 136.9 km² in 50 years, with 31.5% of wells at high risk within 5 km of sources; a 20% fall in recharge enlarges the affected areas by 42%.
How to cite
D. Badalov, M. Avezov, S. Egamova, N. Gulbaxor, H. Mirzayeva, G. Sharopova, U. Kozibaev and A. N. Nema (2026). Spatial modeling of contaminant transport in groundwater systems using GIS. Procedia Environmental Science, Engineering and Management, vol. 13, no. 1, pp. 207–214. https://www.procedia-esem.eu/2026_vol13_no1.htm