Urban sprawl analysis of Akhmim city (Egypt) and its risk to buried heritage sites: insights from geochemistry and geospatial analysis

Heritage Science

Table 4 Chemical analysis and saturation indices of groundwater in the urban area and the wilderness area around the Open-Air Museum (mg/L)

Sample	1	2	3	4	5
Latitude	26°33′57.83ʺN	26°33′27.82ʺN	26°34′3.71ʺN	26°34′17.63ʺN	26°33′29.713ʺN
longitude	31°44′46.16ʺE	31°44′34.53ʺE	31°44′37.17ʺE	31°45′35.26ʺE	31°43′25.385ʺE
Class	Urban area	Urban area	Urban area	Wilderness area	Wilderness area
TDS	993	889	959	408	438
HCO₃	384	444	383	251	278
NH₃	14	0.01	0.01	22.5	14.51
Ca	77.15	59.83	72.45	52.29	57.06
K	4	8	6	7	3
Mg	31	17.7	19.07	21	22
Na	188	200	183	42	50
Cl	134.0	113.32	122.52	27.48	34
NO₃	18.23	7.72	125.8	0.21	1.14
So₄	166	119.8	94.61	39	42
PO₄	< 0.2	< 0.2	< 0.2	3.4	0.22
Saturation index (SI)^*
Dolomite	− 8.07	− 9.18	− 8.48	− 10.30	− 9.84
Calcite	1.24	0.96	1.15	0.83	0.90
Aragonite	1.19	0.92	1.11	0.80	0.87
Gypsum	− 0.61	− 0.68	− 0.55	− 0.90	− 0.84
Anhydrite	− 0.76	− 0.85	− 0.71	− 1.11	− 1.04
Halite	4.06	4.75	4.29	5.76	5.47

^*A positive value indicates supersaturation, meaning the mineral is more likely to precipitate, while a negative value indicates undersaturation, meaning the mineral is more likely to dissolve