I. Results of karst aquifer protection area zoning
Irrational exploitation of karst water resources often induces the generation of karst subsidence geologic disasters, and the open karst fissures and karst subsidence pits, etc. that have been generated for the infiltration of surface sewage channels, and has become an important pathway for the pollution of the karst water system in the Shiliquan area. Especially, the water source of this area is mainly distributed in the systematic karst water discharge area, with strong karst development, large aquifer thickness, and thin covering soil layer, and the karst water mining area has become a serious occurrence area of karst subsidence. Carrying out water resource protection in the karst collapse area centered on the water source (discharge area) is the core of water quantity protection in this system.
Based on the results of the karst collapse risk evaluation of the karst water system in the Shiliquan domain of Zaozhuang in the previous section, the karst aquifer is divided into three levels of protection areas (Figure 9-4).
Figure 9-4 Shiliquan karst water system based on the karst collapse of the aquifer water volume protection area zoning map
1.Ⅰ level collapse protection area
Mainly in the Shiliquan water source, Dingzhuang - Dongwangzhuang water source and thirsty mouth water source of the centralized mining area, covering an area of 17.56km2. the area of karst collapse risk is high, and the groundwater activity is strong. Shiliquan water source is located in the downstream of Qicun tributary of Dasha River in Yicheng, which gathers all the domestic sewage and industrial wastewater from the western part of the municipal quarters and Shiliquan industrial area, while the thin layer of the fourth system soil in the area of Shiliquan, the open-type fissure karst and the karst subsidence that has been produced have created the conditions for the infiltration of the surface sewage. The long-term large-scale over-exploitation of groundwater in the area has caused the groundwater level to drop significantly, accelerating the infiltration of surface sewage and aggravating the degree of pollution of karst water.
With the rapid development of cities and industries, Dingzhuang-Dongwangzhuang water source and Thirsty Mouth water source are exploiting groundwater resources to an increasingly high degree. Over-exploitation of groundwater has caused the groundwater level to drop significantly, accelerated the recharge of surface sewage to groundwater, and aggravated the degree of pollution. Under the influence of human economic activities, the quality of groundwater has gradually deteriorated, with a rise in the bacterial index, an increase in the ion content, and a continuous rise in total dissolved solids and total hardness.
2. Class II Collapse Protection Zone
Mainly distributed in the peripheral part of the centralized mining area of Shiliquan water source and Dingzhuang-Dongwangzhuang water source, with an area of 32.94km2.
Shiliquan, Dingzhuang-Dongwangzhuang water source boundary range, there have been small-scale karst collapses in the history, and by the effect of the over-exploitation of groundwater, the karst groundwater is also polluted to a certain extent, which needs to be strengthened to protect. A certain degree of pollution, need to strengthen the protection and prevention.
3. Class III Collapse Protection Zone
The other areas of the karst water system in Shiliquan area, with a total area of 591.31km2, as a part of the typical karst area, the special conditions of karst development and the water environment determine that the protection of its water resources should be emphasized.
Two, karst water protection countermeasures
Zaozhuang Shiliquan karst water resources protection should adhere to the "flow, open source, and protection of water sources," the approach, focusing on the following work:
1) make full use of the existing water sources, the rational development of new water sources, and the appropriate citation of guest water resources. Development of surface water-based, moderate exploitation of groundwater. According to the actual supply capacity of water resources, guidance and regulation of water resources demand, the construction of water-saving city. Insist on putting the safety of urban water supply in the first place. Consider all measures of water resources protection and development in an integrated manner, rationally allocate water resources, improve water use efficiency, and form a water cycle system that optimizes the use of water and makes multiple use of water.
2) pay attention to the protection of groundwater sources. Strictly control the water quality of water sources, do a good job in Shiliquan, Dingzhuang, thirsty mouth and other drinking water source protection. Groundwater wells and water plants around, according to the requirements of the relevant state regulations to delineate the groundwater source protection zone, the implementation of appropriate protective measures. Strictly control the over-exploitation of groundwater, multi-way groundwater conservation, and planned groundwater recharge. Strengthen the protection of non-potable surface water environment functional zones for agricultural irrigation water, landscape water, industrial water, etc., and ensure that non-potable surface water environment functional zones can meet the water quality requirements of the corresponding functions. With regard to the ecological status quo in the water source protection area, carry out ecological restoration and ecological engineering construction, so as to strengthen ecological protection, enhance the natural purification capacity of the protection area, promote the benign cycle of the ecosystem, and improve and protect the quality of drinking water sources. Strengthen the ability to prevent the risk of environmental accidents, to avoid or prevent the pollution of drinking water sources, to ensure the safety of water for residential life.
3) Accelerate the construction pace of key pollution control projects and fully implement the comprehensive treatment of water pollution in the watershed. Completion of the Yicheng Shahe and other major rivers in the interception of sewage diversion project. In accordance with the newly promulgated south-to-north sewage discharge standards in Shandong Province, in accordance with the law on the implementation of excessive sewage discharge enterprises to ensure that the full discharge of pollutants in industrial enterprises to meet the standards. Accelerate the construction of urban sewage treatment facilities, and effectively do a good job of supervision of normal operation of sewage treatment facilities. In the existing sewage treatment plant operation and management at the same time, the construction of new sewage treatment plants. Highlight the basin pollution management, to ensure the safety of the water environment. Completion of the outbound river interception, storage, conduction, with the comprehensive management of the watershed project, the basic realization of all river water bodies become clear, to ensure that the outbound river control cross-section of the water quality to stabilize the Ⅲ standard.
4) strengthen groundwater environmental monitoring. Under the premise of verifying the distribution of existing monitoring points, thoroughly check the location of existing monitoring points, observation purposes, observation quality, etc., analyze and study the distribution of monitoring points and monitoring purposes and other rationality. Existing monitoring wells distribution, monitoring quality, control area, distribution density, etc. to check, focusing on analyzing and studying the relevance of monitoring work and its problems. Combined with the local hydrogeological conditions, for major water sources and new large and medium-sized water sources, spring areas and geothermal areas, and groundwater-related environmental geological problems in prominent areas, based on the "Technical Specification for Groundwater Environmental Monitoring", should be tailored to the local conditions to develop the optimization and adjustment of the monitoring points and restoration and construction programs.
5) Implementing shallow well decentralized mining and increasing source mining. The fourth series of pore water-rich areas, groundwater distribution is more uniform, the water table is shallow, and the surface water system is developed. In the exploitation of groundwater should be shallow well decentralized mining, well depth should not be greater than 60m, well distance greater than 500m is appropriate. It is recommended to construct ground works such as check dams to increase the infiltration and recharge of surface water to groundwater and increase the amount of groundwater that can be extracted. Adopting the measure of increasing the source from whole to zero by changing concentration to decentralization can increase the groundwater resources greatly, and also improve the ecological environment of the area and promote the economic benefits. It is suggested to plant trees and grasses in the low mountainous and hilly areas upstream of the water source to strengthen soil and water conservation; to implement water storage projects and comprehensive management of small watersheds; and to conserve water sources and increase groundwater recharge. Downstream of the intermountain plains covered pooling area, take specialized hydrogeological measures, increase mining, expand underground reservoir capacity, increase the recharge of abundant water, give full play to the regulatory capacity of the storage capacity, construction of dams, blocking surface water, and increase the recharge of seepage of karst water.
6) the implementation of the new water law, to do according to the law of water management and water management. Urban construction should be in accordance with the requirements of the construction of water-saving city to adjust the industrial structure and strengthen water conservation measures. Under the premise of adhering to the equal importance of open-source and flow-saving, and giving priority to water-saving, adopt advanced irrigation technology and farming methods, and develop water-saving agriculture and eco-agriculture; vigorously develop water-saving industries, increase industrial structure adjustment, and strictly prohibit new high water-consuming and highly polluting industrial projects; close and stop wasteful and ineffective industrial enterprises, and build internal water recycling systems to improve the reuse rate of industrial water; vigorously promote water-saving appliances and equipments, and improve water-saving measures. Water-saving appliances and equipment to improve the efficiency of water use; accelerate the construction of water reuse projects to improve the rate of sewage resources; vigorously carry out publicity work on water conservation, to enhance the city residents' awareness of water and water law, and advocate water, water conservation, water conservation, water protection, a good social climate.