With the development of the economy and society, Meizhou city water supply and demand conflicts are also intensifying, water resources protection and water conservation do not pay enough attention, has become a major constraint on the development of the main factors. Meizhou urban water conservation problems are mainly manifested in the following aspects.
18.2.1 Soil and water erosion still exists
In the previous 14 chapters have been more detailed discussion of soil and water erosion, focusing here on the 1983 and 1997 two time periods for comparison (Table 18.1).
Table 18.1 Comparison of soil erosion area in Meizhou City (1983/1997) Unit: km2
From the above table, it can be seen that after 14 years of management, soil erosion has been well improved. Performance: ① the total amount of erosion has decreased from 2556.04km2 in 1983 to 1725.43km2; ② surface erosion, gully erosion has been well controlled, in addition to surface erosion in Meixian and Pingyuan, and gully erosion in Xingning rose slightly, the surface erosion and gully erosion in other counties have declined compared with 1983. However, the area of avalanches has risen. Among them, the area of avalanches in Wuhua, Xingning and Fengshun all rose substantially, and only the area of avalanches in Tai Po, Jiaoling and Meijiang districts decreased.
18.2.2 Water pollution is not optimistic
Water pollution discharged from human activities is divided into: point pollution sources (collected by pipelines and then centrally eliminated) and surface pollution sources (unorganized, for example, farmland surface runoff or rainwater runoff). Point pollution usually comes from domestic sewage and industrial wastewater. Surface pollution comes mainly from rural areas. Meizhou is a mountainous area with a large proportion of agriculture, so surface pollution sources are common.
According to the Meizhou Environmental Monitoring Center and the counties (cities, districts) environmental monitoring station on the Meijiang River cleaning nine cross-county (cities, districts) cross-section of the water quality monitoring results show that in 1998 the Meijiang River and its main tributaries of the water quality of the annual average of the five sections of suspended solids, dissolved oxygen, petroleum-based indicators, respectively, there are 1 or 2 slightly exceeded the standard, and the rest of the sections of the water quality in line with the national environmental quality of surface water 搈 Class standard water quality is good
See / mjbj (2005-03-14).
. The main pollutants in the Meijiang River Basin are COD, BOD, petroleum, volatile phenols, manganese and so on. Total coliform pollution and organic pollution of the Meijiang River are caused by a large amount of untreated urban sewage, domestic garbage, medical wastewater, and agricultural irrigation drainage. Pollution in the Meijiang River Basin is dominated by organic pollution. Individual sections of the river are affected by certain heavy metal pollution, resulting in heavy metal exceedance (e.g. manganese exceedance downstream of Jiaoling Manganese Chemical Plant). Years of monitoring results show that the water quality indicators of the Meijiang River Basin can basically meet the standard of Class II for surface water, while the downstream river sections of certain towns are affected by organic pollution or certain heavy metal pollution, which cannot meet the standard of Class II, but still can basically meet the standard of Class III. Water quality of the three reservoirs to Heshui Reservoir water quality is relatively poor, often exceeding the Ⅱ (Ⅲ) standard items DO, total phosphorus, petroleum; Yitang Reservoir and Changtan Reservoir water quality is relatively good, basically meet the surface water Ⅱ standard, but also occasionally DO, petroleum and total phosphorus exceed Ⅱ standard.The development of industrial and agricultural production and urban residents living in the increasing level of water consumption will inevitably lead to a gradual increase in industrial and mining towns and living emissions of waste. Due to the current urban management and industrial wastewater treatment in Meizhou City is still unable to keep up with the requirements of the development of the situation, most of the urban sewage and industrial wastewater without purification and treatment directly into the river, resulting in the city's surface water bodies suffered varying degrees of pollution. Discharged into the Meijiang River, the main sources of wastewater industrial pollution are Meixian paper mills, Pingyuan paper mills, Jiaoling paper mills, Meixian phosphorus fertilizer plant, Meixian power plant, Xiyang nitrogen fertilizer plant, etc. 1998 annual environmental statistics show that the cumulative industrial wastewater of these six enterprises, such as the pollution load of the city's wastewater accounted for 89.7% of the annual wastewater discharges of 97 × 104t, 590t, 480t, 50t, respectively, 1390t and 3240t
Data provided by Meizhou Municipal Bureau of Statistics.
. Meizhou township enterprises are in the stage of development, and it is common for industrial wastewater from township enterprises to be discharged directly into the river without treatment; the excreta of livestock kept in the countryside causes rural water bodies to deteriorate rapidly; in addition, the massive use of chemical fertilizers and pesticides, and the direct discharge of the tail water from farmland accelerate the pollution of the water bodies. Especially in the dry season, surface runoff decreases and the degree of pollution increases; and in the sections of the river where factories are concentrated on both sides of the river and the volume of water is not large (Pingyuan Batou River, Xingning Ningjiang River), organic pollution is particularly prominent.18.2.3 Lack of Groundwater Resource Management
In terms of the current status of water resource management in Meizhou City, although the management system has been basically rationalized, the responsibilities and powers are still not in place. Performance in the majority of farmers on the development of groundwater is still irrational, ultimately due to the water administration and management of groundwater supervision and management is not strong enough. The utilization of groundwater in urban areas of Meizhou is not extensive, but the existing problems cannot be ignored.In 2003, the total amount of groundwater resources in urban areas of Meizhou amounted to 86 million m3.Among them, the car washing industry is one of the major users of groundwater. Generally, the car washing industry adopts the method of drilling wells directly in the place of abundant groundwater resources to get water in order to save the cost. And the government has not made strict restrictions on the drilling of wells for the car wash industry. In addition, the issue of unified management of groundwater and surface water is still controversial, and the exploitation of underground hot water in some rural areas also lacks orderly management (Figure 18.2).
Figure 18.2 Current situation of underground hot water extraction in a rural village in Meizhou