Countermeasures for prevention and control of soil erosion in Meizhou city

14.3. 1 Continue to implement comprehensive management of small watersheds.

Meizhou has a small area of cultivated land, but is rich in mountain resources. There are 257,300 hectares of mountainous areas below 25 in the city, with 6,543,800 hectares developed and 6,543,800 hectares undeveloped (see (2002-0 1-02)).

. The "three highs" (high quality, high yield and high efficiency) agriculture in Meizhou City is mostly manor agriculture developed mainly by developing sloping land and planting fruit and tea. In practice, we have gradually explored a set of experiences in soil and water conservation and the development of "three highs" agriculture. For example, open orchards on sloping fields, transform sloping fields into terraces, and plant grass on terraces to stabilize the soil and prevent erosion. Planting leguminous forage in orchard, processing forage into grass powder to raise pigs, and developing biogas with pig manure as raw material. The manure discharged from the biogas digester becomes a high-quality organic fertilizer for fruit trees and pastures, which makes fruit trees (Shatian pomelo, etc.). ) and pasture can obtain high quality and high yield, thus establishing soil protection and biological (chain) on eroded land. The development of sloping land (especially in the early stage) often leads to new soil erosion. Therefore, we must continue to carry out soil and water conservation work in the future to ensure the sustainable development of "three high" agriculture. Implementing comprehensive control of soil erosion in small watershed is the fundamental way to realize the sustainable development of agriculture with "three highs". It is a successful experience to comprehensively control soil erosion with small watershed as a unit. Its basic contents include slope management and river valley reconstruction. Only by organically combining the two can we achieve sustainable development.

Slope land management must first restore vegetation [3]. Herbs first, combine grass with shrubs and trees. After the vegetation is restored, the ecological forest (artificial stable community) is developed on the upper part of the slope, and it is encapsulated to play the role of soil and water conservation and environmental protection; In the middle and downhill slope, feed (herbaceous and woody) and fruit are mainly developed, and staggered planting and edge effect are expanded to obtain greater benefits. For slopes with gully erosion and hillock collapse, engineering measures should be combined with biological measures, such as building a valley workshop at the gully mouth, densely planting fast-growing grass and bamboo on the valley workshop to form a biological dam; Cut the steep wall and steep slope of the collapsed hillock into steps, and then plant grass and shrubs to protect the slope; The collapsed pile is also covered with grass to prevent the sand from being carried away again.

In the reconstruction of the valley, firstly, gullies, sand bars, gullies and irrigation channels around the valley are built to prevent flood and sediment from entering the farmland in rainy season, remove harmful substances in spring water (groundwater) at the foot of the mountain and reduce the groundwater level. Then leguminous forage grass and leguminous crops can be planted in the valley sandy land to increase the nutrients in the sandy land and develop the production of cash crops, fruits and vegetables and animal husbandry; You can also transform the waterlogged depression in the valley into a foundation pond, plant grass in the pond, build a chicken house and a pig house, raise ducks on the surface of the pond and fish in the water, and establish an optimized foundation pond ecosystem to achieve efficient economic benefits.

After the implementation of slope management and valley slope transformation measures, the middle and lower reaches of small watersheds can become "three high" agricultural bases, thus realizing the scientific transformation of ecological environment and the sustainable development of "three high" agriculture with small watersheds as units. In the future, we should further link small watershed management with regional agricultural economic development, formulate watershed soil and water conservation planning and regional agricultural sustainable development planning based on the principle of sustainable development, and combine them organically and put them into practice.

14.3.2 organically combine soil erosion prevention with poverty alleviation in mountainous areas.

14.3.2. 1 Agricultural production under the influence of soil erosion

According to the survey data, Summary of Soil and Water Conservation Survey in Guangdong Province (Department of Agriculture and Water Resources, Department of Geography, Sun Yat-sen University, 1994), pp. 70 ~ 7 1.

During the period of Meizhou 1980 ~ 1984, there were 23 floods in all counties of the city, with a disaster-stricken area of130,200 hm2, five droughts and a drought-affected area of 94200 hm2. The fertile land was transformed into a sand dam with an area of 4000 hm2, and the accumulated losses, including collapsed houses, water conservancy facilities and bridges, amounted to 654.38 billion yuan. 1985, the cultivated land damaged by soil erosion in the city reached 36,800 hm2, accounting for 1/4 of the total cultivated land area in the city, including 9850 hm2 of yellow mud land, 0/867 hm2 of dry land and 4950 hm2 of waterlogged paddy field.

Due to the coarse soil particle composition, more coarse sand and gravel, and less clay particles in the soil erosion area of Meizhou City, most of the sediment and gravel washed down by uneven surface runoff form the accumulated bed load nearby, and a small part of it is input into the river with the runoff in the form of suspended load; Loss of hillsides at the top of the mountain and accumulation at the foot of the mountain; The emergence of diluvial fans at pithead and gully mouth has turned fertile fields into sand bars, which has seriously affected the development of mountain economy, especially agricultural economy in Meizhou City. 1985, the agricultural output value of Meizhou was only 756 million yuan, the total grain output was 1 140600 t, and the yield per mu was 314kg; . Fruit planting area10.05 million hm2, total output10.4 million t, tea 403,000 hm2, total output 0.10.4 million t; The per capita net income of farmers is 40 1 yuan. According to the investigation of Mianyang River and Xinqiao River in Wuhua, Shima River and Daping River in Xingning, Diaohe River in Tai Po, He Sui River and Song Yuan River in Meixian and Tianxing River in the plain, the average grain yield per mu in 1985 was 30 1kg, and the per capita income of farmers was 248 yuan. 1985 There were 329,900 poor households with per capita income below 200 yuan, and poor households 1.73 million, accounting for 486.5438+0% and 50% of the total rural households and population respectively. Eight counties (cities, districts) in the city are all poverty-stricken counties at the provincial level, among which three counties, namely, Tai Po, Wuhua and Fengshun, are national key poverty-stricken counties. The data comes from Meizhou Municipal Bureau of Statistics.

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14.3.2.2 soil and water conservation promotes the development of "three highs" agriculture.

Prevention and control of soil erosion is also called soil and water conservation, and its purpose is to maintain the normal function of the ecosystem, thus linking with economic development. In Meizhou mountain area, it should be organically combined with poverty alleviation. At present, there are three counties (Wuhua, Tai Po and Fengshun) in the city as national poverty-stricken counties, with a poverty population of 279,300 at the end of 2005. Therefore, the task of getting rid of poverty and becoming rich in Meizhou is still very arduous. First of all, we should take targeted measures to increase support for soil and water conservation in poor mountainous areas, give strong support to the start of new control and development projects, ensure and increase funds for soil and water conservation, and combine investment with regional development strategies. Secondly, soil and water conservation should be incorporated into regional agricultural development, and various plans should be carefully formulated and implemented. Thirdly, 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 staggered communities to realize comprehensive management; Use the relationship of food chain to develop farming and so on. In this way, we can not only achieve the purpose of soil and water conservation, but also achieve good economic benefits [4].

1985 The Guangdong Provincial People's Congress passed the proposal on the regulation, development and utilization of areas with serious soil erosion in the upper reaches of the Hanjiang River. Based on this, Meizhou has formulated a comprehensive management plan of 10 year with towns as the unit and small watersheds as the unit, which gradually extends from key management to comprehensive management. After 10 years of treatment, the 233 river basins included in the proposal in the city have completely completed the treatment task, and soil erosion has been effectively controlled. According to the calculation of relevant departments, by the end of 1994, the amount of soil and water conservation and sediment interception in the whole city's governance area reached1400,000 m3, which greatly reduced the sediment deposition in rivers and reservoirs (the riverbed elevation in the whole city's governance area generally decreased by 0.3 ~ 1.3m), regulated the flood and dry flow of rivers, and reduced the threat of floods and droughts. According to the investigation of small watersheds that have been completed and accepted, the vegetation coverage rate increased from 35.3% to 74.6% on average in 1985, and some of them reached 90%, which effectively regulated the microclimate, improved the soil hydrothermal conditions, improved the soil fertility, and protected and improved a large number of farmland (the whole city protected and improved 65300 hm2 of farmland and restored 0.173,000). According to statistics, by 1.994, Meizhou has developed nearly 66,700 hectares of mountainous areas below 25, developed 65,670 hectares of fruits and high-quality tea, and the total fruit output reached 340,000 tons (including Shatian pomelo 1.3 million tons). Form a "three highs" (high quality, high yield and high efficiency) agricultural pattern with fruit tea as the main body and combining planting, breeding and processing. 1994, the city's agricultural output value is 5.739 billion yuan, the grain yield per mu reaches 364kg, and the per capita income of farmers is 1980 yuan. According to the investigation of eight small watersheds such as Mianyang River in Wuhua, after 10 years' treatment, the grain yield per mu reached 375kg, 74kg higher than 1985, and the per capita income of farmers was 1686 yuan, 6.8 times that of 1985.

In recent years, based on the reality of mountainous areas, Meizhou has conscientiously implemented the strategy of "four Meizhou" (opening Meizhou, industrial Meizhou, ecological Meizhou and cultural Meizhou) on the basis of consolidating the achievements of soil and water conservation management, which has made the rural economy of the city grow steadily. In 2004, the city's total grain output was 654.38+296,000 tons; The total fruit output is 740,600 t; The total output of tea is 9360t, and the per capita income of rural residents is 4 109 yuan. Meizhou Daily (March 2005-19).

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14.3.3 Focus on solving several problems in soil and water conservation.

(1) Establish a strategic concept, consolidate and improve soil and water conservation projects and facilities, and stop new soil erosion. According to the aerial survey of 1983, there were 5 157 1 collapses and losses in the whole city, covering an area of 246km2, which had been initially controlled by the end of 1994. However, of the 48,529 collapses investigated in 1995, only 39.2% were stable and 28. 1% were active. 52.2% of the grain depots and sandbars have been completely silted and 5.4% have been washed away. If these projects are not repaired and perfected in time, they will inevitably cause new hazards. At the same time, the original water conservancy facilities in the treatment area 13 156 have collapsed in 2055 places; The original Shenzhen Road was 2.95 million m, and it collapsed by 340,000 m.. The original revetment 1.43 million m collapsed by 260,000 m; There were 3625 original bridges, and 75 1 bridge collapsed. In recent years, although these damaged projects and facilities have been repaired, reinforced and repaired in a planned way, the number of them has not been completed so far [5]. In addition, the new soil erosion caused by opening new roads, digging house foundations and mining quarries (mines, coal and rare earths) can not be ignored (Figure14.2); Failure to pay attention to closing hillsides to facilitate afforestation and forest protection and fire prevention in the control area may also lead to new large-scale soil erosion. According to statistics, during the treatment period of 1983 ~ 1995 and 10 years, the soil erosion increased by 6 10km2. Therefore, in addition to continuing to maintain and consolidate the original soil and water conservation projects and facilities, effective measures must be taken to stop new soil erosion, and the countermeasures of "whoever causes new soil erosion will be treated, whoever develops and uses it will be maintained" will be adhered to. Restrict projects that are unreasonable in development and utilization and easy to cause new losses, and implement the responsibility of soil and water conservation for approved development projects [5]. It is necessary to vigorously strengthen the supervision and law enforcement of soil and water conservation, establish an examination and approval system for soil and water conservation plan reports, and formulate a unified collection standard for soil and water conservation compensation fees. All units and individuals that destroy soil and water conservation facilities due to their own construction activities and reduce or weaken the original soil and water conservation functions must pay compensation fees for soil and water conservation according to law. At the same time, it is necessary to investigate and deal with illegal cases according to law and enter the track of supervision, management and comprehensive management.

Figure 14.2 Road excavation is likely to cause new soil erosion.

(2) Intensify soil and water conservation and strengthen the awareness of soil and water conservation. Soil and water conservation is a basic national policy of China. However, due to the influence of the idea of "quick success and instant benefit" in the current tide of socialist market economy construction, local decision makers often attach importance to industrial and commercial construction projects while ignoring the basic work of developing agriculture, such as maintaining water and soil resources and maintaining ecological balance. The general public (even some local decision makers) have insufficient understanding of the importance of soil and water conservation, insufficient support and cooperation for the work of soil and water conservation departments and scientific research personnel, and do not consciously maintain soil and water conservation projects and facilities, and do not consciously pay the relevant fees for soil and water conservation. Therefore, soil and water conservation departments at all levels should take active actions, organize cadres and the masses or hold workshops on soil and water conservation laws, or use various meetings to publicize soil and water conservation laws and regulations. Use the "Water Conservation Law Publicity Month" in July every year to widely print or post publicity materials or slogans of water conservation law, and carry out various forms of prize-winning competitions. Strengthen the education of soil and water conservation and sustainable development in schools at all levels, and make it a conscious action of the broad masses of the people to abide by the soil and water conservation law and participate in soil and water conservation.

(3) Improve soil and water conservation institutions and improve the quality of soil and water conservation personnel. At present, cities, counties (cities, districts) have offices of soil and water conservation committees, which are permanent institutions for soil and water conservation, but the soil and water conservation institutions at the township level are still not perfect; Five counties with serious soil erosion in the city have established soil and water conservation stations in key erosion areas, but there are not many soil and water conservation stations at the township level, and the existing soil and water conservation staff (especially at the township level) are not many professionals, and they are frequently mobilized, and some of them are even temporary workers, which often cannot meet the needs of effectively implementing the Regulations on Soil and Water Conservation, preventing soil erosion and carrying out scientific research and experiments on soil and water conservation. Therefore, we should make great efforts to improve the management institutions of soil and water conservation at the township level, equip them with cadres with good ideological quality and strong sense of responsibility, and constantly improve their professional level by holding training courses, academic conferences, going out to visit or subscribing to professional books and periodicals.