Prevention and Control Countermeasures of Soil and Water Erosion in Meizhou City

14.3.1 Continue to implement comprehensive management based on small watersheds

Meizhou City has a small area of ??cultivated land, but rich mountain resources. There are 257,300 hm2 of developable mountainous land with a slope below 25° in the city, 124,000 hm2 of which have been developed and utilized, and 133,300 hm2 of which have not been developed and utilized.

See (2002-01-02). . Most of Meizhou City’s “Three Highs” (high quality, high yield, high efficiency) agriculture is manor-style agriculture developed mainly on developing hillside land and growing fruit tea. In practice, a set of soil and water conservation and development methods for sloping farmland have been gradually explored. The experience of “three highs” agriculture. For example, when opening an orchard on a sloping land, the slope is renovated into terraces, and pasture is planted on the terraces to stabilize the soil and prevent erosion. Leguminous pasture is planted in the orchard, and the pasture is processed into grass powder to feed pigs. The pig manure is used as raw material to develop biogas, and the biogas pool produces The aerated manure residue becomes high-quality organic fertilizer for fruit trees and pastures, allowing fruit trees (Shatian pomelo, etc.) and pastures to obtain high-quality and high-yields, thereby establishing erosion prevention and soil conservation and biological (chain) circulation cultivation on the eroded land. The "three highs" agriculture of fertilizer to soil and the ecological-economic system of sustainable development. The development of sloping land (especially in the early stages) is often prone to new water and soil erosion. Therefore, soil and water conservation must continue to be done in the future to ensure the sustainable development of "three high" agriculture. Implementing comprehensive management of water and soil erosion based on small watersheds is the fundamental way to achieve the sustainable development of "three highs" agriculture. Taking small watersheds as units to comprehensively control soil erosion has proven to be a successful experience. Its basic content includes the management of slope land and the transformation of valleys. Only the organic combination of the two can achieve sustainable development.

Slope land management should first restore vegetation [3]. Use herbs first and combine grass, shrubs and trees. After the vegetation is restored, ecological forests (artificial stable communities) will be developed on the upper slopes and encapsulated to maintain water and soil and protect the environment; the middle and lower slopes will mainly develop fodder (herbaceous and woody) and forest fruits, with staggered planting, Expand the edge effect and obtain greater benefits. For slopes with gully erosion and collapsing hills, a combination of engineering measures and biological measures should be adopted, such as building a valley at the mouth of the ravine and densely planting fast-growing grass and bamboo on the valley to form a biological dam; Cut it into steps, and then plant grass and shrubs to protect the slope; the collapsed piles are also covered with grass to prevent sand and soil from being transported again.

The valley reconstruction first adopts the construction of surrounding ravines, sand dams, surrounding valley gullies and drainage and irrigation canals to prevent flood sediments from entering the farmland during the rainy season, eliminate harmful substances in the spring water (groundwater) at the foothills, and reduce water table. Then, leguminous pastures and leguminous crops can be planted in the sandy land in the valley to increase the nutrients in the sandy land and develop the production of cash crops, fruits, vegetables and livestock; the waterlogged depressions in the valley can also be transformed into foundation ponds and ponds. Grass is planted as base, chicken sheds and pig houses are built, ducks are raised on the water surface of the pond, and fish are raised in the water, thereby establishing an optimized base pond ecosystem and achieving efficient economic benefits.

After the measures for slope land management and valley slope transformation are implemented, the middle and lower reaches of the small watershed can become the "three high" agricultural base, thereby realizing the scientific transformation of the ecological environment and the "three high" agriculture based on the small watershed as a unit. sustainable development. In the future, we should further link small watershed management with regional agricultural economic development, formulate watershed soil and water conservation plans and regional agricultural sustainable development plans based on the principle of sustainable development, and organically combine the two and put them into practice.

14.3.2 Organically combine the prevention and control of water and soil erosion with poverty alleviation and prosperity in mountainous areas

14.3.2.1 Agricultural production under the influence of water and soil erosion

According to survey data

Survey Summary of Soil and Water Conservation Work in Guangdong Province (Agricultural and Water Resources Department of Guangdong Provincial Department of Hydropower, Department of Geography, Sun Yat-sen University, 1994), P. 70～71. In Meizhou City, from 1980 to 1984, there were a total of 23 floods in all counties in the city, with a flooded area of ??130,200 hm2, and 5 droughts, with a drought-affected area of ??94,200 hm2; fertile farmland turned into sand dams of 4,000 hm2, plus collapse The cumulative losses to houses, washed-out water conservancy facilities and bridges amounted to more than 100 million yuan.

In 1985, the city's farmland affected by water and soil erosion reached 36,800 hm2, accounting for 1/4 of the city's cultivated land area. Among them, 9,850 hm2 were affected by yellow mud, 18,670 hm2 were dry fields, and 4,950 hm2 were flooded paddy fields.

Since the particle composition of the soil in the soil and water loss area of ??Meizhou City is relatively coarse, with more coarse sand and gravel and less clay particles, most of the sediment and gravel washed down by the runoff from the uneven surface is accumulated nearby. A small part of the sediment is transported into the river in the form of suspended sediment with the runoff; it is lost on the mountain tops and slopes and accumulated at the foot of the mountains; alluvial fans appear at the entrances of pits and ditches, turning fertile fields into sand bars, which seriously affects the economy of the mountainous areas of Meizhou City, especially development of agricultural economy. In 1985, the agricultural output value of Meizhou City was only 756 million yuan, the total grain output was 1.1406 million tons, and the yield per mu was 314kg; the fruit planting area was 10,050 hm2, the total output was 1,400 tons, and the tea was 4,030 hm2, and the total output was 1,400 tons; the per capita net income of farmers 401 yuan. According to a survey of eight small watersheds including Wuhua Mianyang River and Xinqiao River, Xingning Shima River and Daping River, Dabu Diaohe River, Meixian Hesi River and Songyuan River, and Pingyuan Tianxing River, the average grain yield per mu in 1985 was 301kg. Farmers The per capita income is 248 yuan. In 1985, there were 329,900 poor households and 1.73 million poor households in the city with a per capita income of less than 200 yuan, accounting for 48.1 and 50 of the total rural households and total population respectively. All eight counties (cities, districts) in the city are designated as poverty-stricken counties by the province, and three of them, Dabu, Wuhua, and Fengshun, are national key poverty alleviation counties.

The data comes from the Meizhou Municipal Bureau of Statistics. .

14.3.2.2 Soil and water conservation promotes the development of "three high" agriculture

Preventing and controlling water and soil erosion is also called soil and water conservation. Its purpose is to maintain the normal functions of the ecosystem and thereby contribute to economic development. The hook should be organically combined with poverty alleviation and wealth creation in the mountainous areas of Meizhou. Currently, three counties in the city (Wuhua, Dabu, and Fengshun) are designated as national poverty-stricken counties. At the end of 2005, the city's poor population was 279,300. Therefore, the task of getting rid of poverty and becoming rich in Meizhou is still very arduous. First of all, we must take targeted measures to increase support for water conservation in impoverished mountainous areas, provide strong support at the start-up of new management and development projects, ensure and increase funds for soil and water conservation, and integrate capital investment with regional development strategies. stand up. Secondly, soil and water conservation should be integrated into the development process of regional large-scale agriculture, and various plans should be effectively planned and implemented carefully. Thirdly, it is necessary to make full use of ecological principles to combine soil and water conservation with "three highs" agriculture, such as using the relationship between early evolution and stable evolution of biological communities to restore and develop green plants; using the edge effect of interlaced communities to achieve comprehensive management; Use the relationship between the food chain to develop farming, etc. In this way, the purpose of water and soil conservation can be achieved and good economic benefits can be achieved [4].

In 1985, the Guangdong Provincial People’s Congress passed a bill on “Remediation, Development and Utilization of Severe Soil and Water Loss Areas in the Upper Reaches of Hanjiang River”. Based on this, Meizhou City has formulated a 10-year comprehensive management plan based on towns and small watersheds, gradually extending from key management to comprehensive management. After 10 years of management, the city's 233 watersheds included in the proposal have fully completed their management tasks and effectively controlled water and soil erosion. According to calculations by relevant departments, by the end of 1994, the amount of soil and water conservation sedimentation in the city's control areas reached more than 140 million m3, thus greatly reducing sedimentation in rivers and reservoirs (the elevation of riverbeds in the city's control areas generally dropped by 0.3 to 1.3m). Adjustment Reduce river flow and reduce the threat of floods and droughts. According to the survey of small watersheds that have been completed and accepted, the vegetation coverage has increased from an average of 35.3 in 1985 to 74.6, with some reaching 90, thus effectively regulating the microclimate, improving the water and heat conditions of the soil, improving soil fertility, protecting and improving A large amount of farmland has been acquired (the city has protected and improved farmland of 65,300 hm2 and restored cultivated land of 0.173 million hm2.

) According to data from the statistics department, by 1994, Meizhou City had developed nearly 66,700 hm2 of mountainous land with a slope below 25°, developed 168,000 small estates, planted 65,670 hm2 of fruits and high-quality tea, and had a total fruit output of 340,000 tons. (including 130,000 tons of Shatian pomelo); forming a three-dimensional agricultural pattern of "three highs" (high quality, high yield, and high efficiency) that focuses on fruit tea and combines planting, breeding, and processing. In 1994, the city's agricultural output value was 5.739 billion yuan, the grain yield per mu reached 364kg, and the per capita income of farmers was 1,980 yuan. According to a survey of the aforementioned eight small watersheds including the Wuhua Mianyang River, after 10 years of treatment, the grain yield per mu reached 375 kg, an increase of 74 kg from 1985, and the per capita income of farmers was 1,686 yuan, 6.8 times that of 1985.

In recent years, Meizhou City has conscientiously implemented the "Four Meizhou" strategy (open Meizhou, industrial Meizhou, ecological Meizhou, and cultural Meizhou) based on the actual conditions of mountainous areas and on the basis of consolidating the results of water and soil conservation management, making the city The rural economy has grown steadily. In 2004, the city's total grain output was 1.296 million tons; the total fruit output was 740,600 tons; the total tea output was 9,360 tons, and the per capita income of rural residents was 4,109 yuan

"Meizhou Daily" (2005-03-19). .

14.3.3 Focus on solving several problems in water conservation work

(1) Establish strategic concepts, consolidate and improve water conservation projects and facilities, and prevent new water and soil erosion. According to the 1983 aerial photo census, there were 51,571 hill collapses and losses in the city, covering an area of ??246km2. By the end of 1994, all had been initially managed. However, according to a 1995 survey of 48,529 collapsed hills, only 39.2 were stable and 28.1 were active; among the built valleys and sand dams, 52.2 were completely filled and 5.4 were washed away. If these projects are not repaired and improved in time, they will inevitably cause new hazards. At the same time, there were 13,156 original water conservancy facilities (dams) in the treatment area, 2,055 of which collapsed; the original 2.95 million m of Zhen Road, 340,000 m of which collapsed; the original 1.43 million m of bank protection, of which 260,000 m collapsed ; Of the 3,625 original bridges, 751 collapsed. In recent years, although plans have been made to repair, consolidate and restore these damaged projects and facilities, only a small amount has been completed so far [5]. In addition, new water and soil erosion caused by newly opened roads, digging house foundations, and quarrying (mine, coal, rare earth) fields, etc. cannot be ignored (Figure 14.2); failure to pay attention to mountain closures for afforestation and forest protection and fire prevention in the management area may also lead to new Extensive soil erosion. According to statistics, during the 10-year treatment period from 1983 to 1995, new water and soil loss reached 610km2. Therefore, in addition to continuing to maintain and consolidate the original water conservation projects and facilities, we must take effective measures to stop new water and soil erosion. We must adhere to the principle of "whoever causes new water and soil erosion will control it, and whoever develops and utilizes it will maintain it." Countermeasures: Restrict projects whose development and utilization are unreasonable and can easily cause new losses, and implement water and soil conservation responsibilities for approved development projects [5]. It is necessary to vigorously strengthen the supervision and law enforcement of water and soil conservation, establish a reporting and approval system for soil and water conservation plans, and formulate unified standards for collecting compensation fees for soil and water conservation. All units and individuals that damage water conservation facilities and reduce or weaken the original water conservation functions due to their own construction activities , all must pay soil and water conservation compensation fees in accordance with the law. At the same time, it is necessary to investigate and deal with illegal cases and enter the track of supervision, management, protection and comprehensive management in accordance with the law.

Figure 14.2 Road excavation will easily cause new water and soil loss

(2) Increase efforts in soil and water conservation and strengthen awareness of soil and water conservation. Soil and water conservation is one of my country's basic national policies. However, due to the influence of the "rush for quick success" mentality in the current wave of socialist market economy construction, local decision-makers often focus on industrial and commercial construction projects when formulating regional economic development strategies, while neglecting the development of maintaining water and land resources and maintaining ecological balance. Basic work in agriculture. The general public (even including some local decision-makers) have insufficient understanding of the importance of soil and water conservation work, insufficient support and cooperation for the work of soil and water conservation departments and soil and water conservation researchers, and do not consciously maintain soil and water conservation projects and facilities, and do not consciously pay for soil and water conservation. related expenses, etc.

Therefore, water conservation departments at all levels should take active action to organize cadres and the masses to hold workshops on the Soil and Water Conservation Law, or use various meetings to publicize laws or regulations on water conservation. Make use of the "Water Conservation Law Publicity Month" in July every year to widely print or post publicity materials or slogans about the "Water Conservation Law" and carry out various forms of prize-winning competitions. Strengthen education on soil and water conservation and sustainable development in schools at all levels and make it a conscious action for the general public to abide by the Soil and Water Conservation Law and participate in soil and water conservation.

(3) Improve water conservation institutions and improve the quality of water conservation personnel. At present, the city and counties (cities, districts) all have permanent institutions for soil and water conservation work - the Soil and Water Conservation Committee Office, but the water and soil conservation institutions at the township level are still not sound; the five counties in the city with serious soil and water loss have set up offices in key loss areas. Soil and water conservation stations have been established, but there are not many at the township level. There are not many professionals in the existing water conservation staff (especially at the township level), and they are mobilized frequently. Some are even temporary workers, who often cannot work very quickly. It can well meet the needs of effectively implementing the "Regulations on Soil and Water Conservation", preventing and controlling water and soil erosion, and carrying out scientific research and experiments on water and soil conservation. Therefore, it is necessary to make great efforts to improve the water conservation management institutions at the township level, and to equip water conservation cadres with good ideological quality and strong sense of responsibility to continuously improve their business through holding training courses, academic conferences, outings, or subscribing to professional books and periodicals. level.