Technical Analysis of Groundwater Utilization and Protection Planning?

Content from user: Qian Xiaobao.

Groundwater development, utilization and protection planning in Maiji District, Tianshui City.

1. General description.

Maiji District now governs 11 towns, 6 townships and 3 offices, with a total population of 10,000 people by the end of 2005, including 10,000 urban population, 10,000 rural population, accounting for 10,000 of the total population, agricultural labor force, accounting for 167 people of the agricultural population, with an average population density of 167 km2, a population density of 226 km2 in the Weihe River Basin, and a population density of 10 people in the Yangtze River Basin. There are 10,000 acres of cultivated land, per capita cultivated land, 10,000 acres of effective irrigation area of farmland, 10,000 acres of actual irrigation area, 107485 tons of total grain output, 53,219 large livestock and 81,520 small livestock. GDP of 100 million yuan, including:

The total output value of the primary industry is 100 million yuan, the total output value of the secondary industry is 100 million yuan, the total output value of the tertiary industry is 100 million yuan, and the proportion of the primary, secondary and tertiary industries is 5,938 yuan for urban residents and 1,670 yuan for peasants.

The water resources structure of Maiji area is self-produced surface water, groundwater, and river valley diving. According to the geomorphological characteristics, groundwater in mountainous areas is divided into two categories: groundwater in mountainous areas and river valley diving, groundwater in mountainous areas mainly depends on precipitation recharge, spring water, stream water discharge, and the total amount of groundwater resources in mountainous areas is divided according to the dry year (shallow groundwater in the development and utilization of wheat accumulation area is not divided according to groundwater exploitation.

According to the "Jilin City Water Resources Comprehensive Planning Report" (January 2008), the water supply in 2010, 2020 and 2030 is 163468 million m3

166031 million m3

and 190621 million m3

Among them, the amount of groundwater available is 54.77 million m3

3% of water availability. The water supply can basically meet the water demand requirements of each Changsun Bank in the planning year, because the groundwater supply accounts for only a small share, so the groundwater in the urban area can only be used as a supplementary water source and emergency backup water source.

According to Article 8 of the Regulations on the Management of Water Resources of Jilin City, which came into force on January 1, 2008, "the development and utilization of groundwater shall be in accordance with the principle of maintaining the balance between extraction and recharge, and the groundwater shall be exploited according to the approved water intake, and shall not be over-exploited; In areas where the urban public water supply network can meet the demand for water, the extraction of groundwater is strictly restricted; In areas where groundwater is over-exploited, no new groundwater intake projects shall be approved, and existing groundwater intake projects and exploitation shall be gradually reduced, and artificial recharge shall be adopted to gradually achieve a balance of groundwater extraction and recharge." In this way, it is necessary to find out the distribution of emergency backup water sources and their recoverable resources in the study area.

Figure Hydrochemical type of groundwater in Quaternary phreatic aquifer in Jilin City.

According to the urban development plan, the groundwater exploitation level in the study area will be maintained within 2020, the urban water pipe network will cover the area, the groundwater exploitation will be restricted, and the groundwater will be limited to the development and utilization of water for special industries. Groundwater in the planning and study area is used as a backup water source for the city, and when the surface water is polluted, the groundwater is used as an emergency drinking water source.

Figure Distribution map of high-iron manganese groundwater in Quaternary phreatic aquifer in Jilin City.

1.Qingnan. The shallow groundwater in the well irrigation area in the southern part of Guangrao County is in a state of overexploitation in terms of actual exploitation, water level dynamics and saltwater intrusion, and the area should be planned and zoned as follows.

1) It is forbidden to mine the absolute zone.

In order to avoid the further development of saline water intrusion in the northern part of the shallow freshwater distribution area, the saltwater intrusion line, which is near the current boundary between brackish water and freshwater resources, is designated as a prohibited area to control the further southward intrusion of saline water. The no-mining zone is a north-west-south-east strip with a tentative width of 2,000m.

2) Restricted mining areas.

It is a strip-shaped groundwater pollution area along the Zihe River, with a width of about 3,000m, which is limited to agricultural irrigation and mining, and shall not be used for human storage and drinking, so as to ensure the health of the people on both sides of the river.

3) Reduction of mining areas.

Except for the shallow freshwater distribution area, the mining prohibition area and the restricted mining area are the mining reduction areas, and the total mining volume of each township needs to be reduced.

m3a。In dry years, the amount of groundwater recharge decreases, and the allowable exploitation amount also decreases, while the water demand and actual exploitation of the agricultural land macro cavity industry are much larger than those in the normal water year, which can be different.

The water level of m3 decreased significantly. In this way, even in a wet year, the precipitation is often low due to the small amount of precipitation, and the precipitation does not penetrate into the aquifer and is consumed in the aquifer. The large amount of mining and the large depth of water level drop in dry years are important factors for the further expansion of the overmining funnel.

Therefore, in dry years, it is necessary to pay more attention to water diversion and replenishment of sources, and reduce the exploitation of groundwater.

It is planned that in 2005, the water level will be controlled at the current level or the rate of decline will be slowed down, and the rate of saltwater intrusion will be slowed down; In 2010, the scale of water diversion and replenishment was expanded, so that the water level rebounded.

2.Qingbei. The recoverable resources of the Southern Song Dynasty - Dianzi - Wangzhuang - Shengli - Mawan Riverside Zone in Lijin County are.

m3a, the recoverable resources in the Yanwo-Beiling section are 3 106

M3a, which is higher than the current mining volume.

m3a with 2 106

m3a。The increased exploitation is mainly arranged in the area near the Yellow River, especially in the floodplains, that is, the water is drawn from the riverside. Due to the shallow burial and large changes in the interface of brackish and brackish water in various places, it is necessary to gradually increase the mining intensity, strengthen monitoring, supervision and management, control the depth and water level of wells, and prevent the deterioration of water quality caused by blind mining.

In addition, there are sporadic freshwater bodies in Hutan Township and Chenzhuang Town in Lijin County, Niujia in Longju, Shikou and Tingluo Town in Dongying District, and Xinhu in Hekou District, but the interface between brackish and brackish water is shallow (generally less than 6m), and the resources are very small, which are only suitable for the supplementary water source of residents' domestic water and a small amount of mining. The shallow freshwater quality in Qingbei is good, meeting drinking water standards, better than the water quality of local plain reservoirs, and most of them are also suitable for irrigation.

It is planned that by 2005, the annual extraction of shallow groundwater in Qingbei will reach 7,106

m3 showed no signs of saltwater intrusion; In 2010, on the basis of strengthening monitoring, we further searched for paleochannel zones and accurately exploited the amount to make the reserves reach grade C.

1.Mining areas can be enhanced.

The mining area that can be enhanced includes the western part of Li Que Town and Dawang Town in Guangrao County, where shallow water is mainly mined, and the deep groundwater is mined in a small amount, so the mining volume can be appropriately increased.

2.Control of mining areas.

Areas other than the Enhanced Mining Area are controlled mining areas. Including the Caoqiao water source of Guangrao County and the Niuzhuang water source of Dongying District, and the water source of Huatai Paper Group in Dawang Town, Guangrao Wangcao County, these water sources have the characteristics of concentrated and continuous exploitation, coupled with the difficulty of recovery of deep groundwater, once the overmining funnel is formed, it is difficult to recover, and the mining volume must be strictly controlled, and it is not suitable to continue to construct deep wells and increase mining intensity. For other towns and towns in Guangrao County, including Huaguan Township, Chenguan Township, Dingzhuang Yuanru Township, Daozhuang Township, Xiliuqiao Township, Dawharf Township, and Daying Township, there are deep wells scattered mining, and the depth of the wells is mostly about 250m, and the freshwater layer in these areas is overlying and lurking with brackish water and brackish water bodies, and excessive exploitation will inevitably lead to the deterioration of the water quality of the freshwater layer.

The deep freshwater sand layer in Lijin County is buried below a depth of 287m, and the runoff is weak, which mainly consumes elastic storage. According to the 30-year planning and design, the depth is allowed to drop by 120m, and it can be mined every year.

Only mining can be increased in m3 years.

M3 plans to build a dynamic monitoring network of deep groundwater in the city by 2005, further clarify the control of mining areas, reduce mining areas and potential areas, and evaluate the amount of deep groundwater resources and water quality in different sections; In 2010, the exploration accuracy was further improved, and the reserve level reached D level, and whether there was deep fresh water in the area north of the "deep underground freshwater tip extinguishment line" was ascertained.