Mainly according to the distribution of aquifers and buried features, water richness, water level depth, water quality, combined with the technical and economic rationality of the basin of the plain area of groundwater according to the conditions of mining is divided into four types of areas.
I, suitable for mining area
(A) a single diving mining area
Changma flood fan front edge of the town of Yumen - four beach area, diving single wells with a water influx greater than 5000m3 / d; Dunhuang Basin, the town of seven miles west of the flood fan front edge of the diving, a single well with a water influx of 3000 ~ 5000m3 / d; the above sections of the water table depth are Less than 50m, diving TDS less than 1.00g / L, is the most suitable for mining section, can be used as a large water source for centralized mining. Dunhuang city, south of the town of seven miles - Wudun, Tashihui farm, the central flower sea basin, flower sea township - Sanjiu company farms south of the section, diving single wells gushing 1000 ~ 3000m3 / d, TDS less than 1.50g / L, local 1.50 ~ 2.00g / L, the depth of the water table is 10 ~ 50m, suitable for decentralized or continuous mining.
(B) diving - pressurized water mining area
Changma flood fan front edge of Huanghua - seven ditch - rabbit gourd - Qiaotzu area, pressurized water aquifer depth of 6 ~ 41m, head depth of less than 2m, a single well gushing more than 1,000m3 / d; diving water-rich less than 1,000m3 / d, the water table depth is generally less than 2m, Drinking Horse Farm 28m; groundwater TDS Generally less than 1.00g/L, local diving TDS is greater than 1.00g/L.
Anxi Basin, climbed the waist of the tree - four workers - Anxi County line south to the Shuangta Reservoir, diving and pressurized water (aquifer depth 21 ~ 136m) water-rich are 1000 ~ 3000m3 / d; water level (head) depth less than 15m; diving and pressurized water TDS is not obvious. There is no obvious difference between submerged water and pressurized water, generally less than 1.00g/L in the east of the county, and 1.00-3.00g/L in the west and north of the county. Beilu Wells - Wukeshu Wells and the periphery, the depth of the pressurized water aquifer is 34.2-156.9m, and the water-enrichment is 1,000-3,000m3/d, and the depth of the head is less than 1m, and the TDS is less than 2.00g/L. The water-enrichment in the submerged water is less than 1,000m3/d, and the maximum TDS is more than 6.00g/L. reaches more than 6.00g/L.
Dunhuang Basin Danghexi flood fan front, Luchaojingzi - Mengjiaqiao area, pressurized water richness of 1000 ~ 3000m3 / d, diving water-rich less than 1000m3 / d, TDS is generally less than 1.00g / L, the local dive up to 2.70g / L, the water table (head) depth is less than 22m.
Flowering Sea Basin pimple wells east and west a line, pressurized water rich water 1000 ~ 3000m3 / d, head higher than the ground, diving water-rich less than 1000m3 / d, water level depth less than 20m, TDS are less than 1.00g / L.
The above lots can be mined according to the need for layered or mixed mining, but the Anxi Basin, local shallow dive TDS is high, should be strictly stop the water, to mine the lower part of the Pressurized water is appropriate.
(C) pressurized water mining area
Changma flood fan front edge of the three ditch - waist station sub south - Qiaotong area, pressurized water aquifer depth of 10.60 ~ 50.60m, a single well water influx greater than 3,000m3 / d, the maximum of 6,000m3 / d or more, TDS0.50g / L or so. The pressurized water richness of the ancient river channel south of Lugaojingzi in Dunhuang Basin is more than 3000m3/d, with a head burial depth of 14.70m and a TDS of about 1.10g/L. The above section is the best area for pressurized water mining in the region.
Second, more suitable mining area
Changma flood fan, Danghe flood fan, Yulin flood fan in the middle and lower part of the south of the Huahai Basin, the submerged aquifer in the mountainous Gobi Belt, the thickness of more than 50m, the water influx of a single well of more than 3,000m3/d, the TDS is less than 1.00g/L, but the water table depth of 50-100m. 200m south of Nanliang, the following deep bearing pressure water, TDS2.00~100m. TDS2.00～3.00g/L. Pressurized water in the northern part of Tashil Basin is less than 1000m3/d, TDS1.00～3.00g/L. Groundwater exploitation conditions, water quantity and quality in the above areas are relatively suitable for exploitation, and can be reasonably exploited according to the needs of agricultural irrigation.
Three, mining difficulties
This refers to the water table depth greater than 100m Changma flood fan, Yulin flood fan and the top of the Danghe flood fan. The thickness of diving aquifer in this area is large, and the water richness and quality of water are good, but under the current economic and technical conditions, there are certain difficulties in mining.
Four, should not be mined
Huahai Basin, the northern edge of the diving TDS is greater than 4.00g / L; Anxi Basin, the western part of the western to Liudun highway to the east, the shallow pressurized water TDS2.90 ~ 4.20g / L, diving TDS in the central part of the two wells to the west of the 4.00 ~ 7.00g / L, the south of the hollow dun 10.00g / L, the north of the West Lake, the Mawan Temple 19.50～24.40g/L; Nanliang-Dafangpan line in the north of Dunhuang Basin, diving TDS13.60～131.50g/L, medium and shallow pressurized water TDS5.00～10.00g/L; western end of Dunhuang Basin near Kumtag Desert, diving TDS7.30～23.00g/L. The above areas are diving-pressurized water zones, and there is little difference between diving and pressurized water enrichment. The above areas are all submerged-pressurized water areas, with little difference between submerged and pressurized water richness, all less than 1000m3/d. Due to the small depth of submerged and pressurized water aquifers, there are good mining conditions, but due to the high TDS and poor water quality, it is not suitable for mining.
In addition, Dunhuang Basin, Yumen Pass and the western part of the Shule River south of the ancient river channel, pressurized water richness of 1000-3000m3/d, TDS less than 1.50g/L; diving water richness of less than 1000m3/d, TDS 1.50-4.00g/L, the water table depth of less than 23m, but due to the inconvenience of the area, belonging to the natural ecological environment protection zone, there is no development planning, so it is included in the inappropriate mining area.