Measures and experiences in combating desertification?

Technology and Mode of Desertification Control in China

Five technologies can effectively curb desertification.

1. Plant sand fixation

This is the most fundamental and economical and effective measure to control quicksand. Sand-fixing plants can provide fuel and feed for people and animals in sand areas, and at the same time, they can restore and improve the ecological environment. Its contents mainly include: establishing artificial vegetation or restoring natural vegetation; Create a large forest belt to prevent sandstorms from invading oases, traffic lines and urban residential areas; Establish a shelterbelt network to control wind erosion of cultivated land and pasture degradation; Protect closed natural vegetation and prevent desertification hazards in fixed and semi-fixed dunes and sandy land.

2. Engineering sand control

When controlling quicksand, use firewood, clay, pebbles, mesh boards and other materials to set obstacles or spread pressure to cover them, so as to stop sand fixation; Use the terrain to set up barriers, change the direction of strong winds, transport and guide the directional blowing of sediment; Take certain engineering measures to mechanically control the interference, so as to fix and guide the quicksand, directionally shape the aeolian landform, change the sand condition, and turn harm into benefit.

3. Chemical sand fixation

Spraying chemical cementing materials on quicksand can form a protective shell with certain strength on the sand surface, isolate the direct effect of airflow on the sand surface, improve the wind erosion resistance of the sand surface, and achieve the purpose of fixing quicksand.

4. Dry land water saving

The lack of water resources is the main problem that restricts the comprehensive improvement and development of land in desertification areas. Therefore, it is very important to introduce and develop water-saving technology and develop irrigated agriculture. Generally, technologies such as canal seepage control, low-pressure pipeline water delivery, sprinkler irrigation and micro-irrigation, and field water saving are adopted.

5. Degraded land development

While preventing and controlling desertification, China has carried out moderate development and utilization, and formed and improved many agricultural and animal husbandry development technologies. In agriculture, there are mainly techniques such as water diversion and sand making, farmland transformation in old oasis, sand-lined rice planting, saline-alkali land improvement, solar greenhouse planting and breeding, plastic film mulching cultivation, soilless culture and so on. In animal husbandry, there are mainly reasonable rotational grazing, livestock determination by grass, grassland improvement and greenhouse breeding techniques; The comprehensive technology of agriculture and animal husbandry mainly includes the construction of "small biological economic circle" and the comprehensive management technology of small watershed.

Four domestic models are worth popularizing.

1. Chifeng mode

Chifeng City is located in the eastern part of Inner Mongolia Autonomous Region, which is a grassland with abundant water plants in history. Due to unreasonable land use, the desertified land is 70,000 square kilometers, accounting for 77% of the total land area, and the degraded grassland is 25 1 10,000 hectares. 70% of the city's population and 148 towns and villages in 12 flags (counties) are endangered by desertification. After that, the techniques of sand fixation, afforestation and grass planting, rice cultivation with film mulching in sand and regulation technology of "small biological economic circle" were adopted to control it. The forest coverage rate of the whole city increased from less than 5% in the early days of the founding of New China to 2 1.2%, and the regional ecological environment was obviously improved. Chifeng model is suitable to be popularized in semi-humid desert areas.

2. Yulin model

Yulin area is located in the southern edge of Mu Us sandy land, with a desertification area of 24,400 square kilometers. Six counties fell into severe desert, and 4 12 villages were buried by sandstorms. During 100, 140 thousand hectares of farmland and pasture were swallowed up. In view of the sandy desertification land dominated by wind, people have established a sand control system combining "belt, sheet and net", which has reduced the number of annual sandstorm days from more than 70 days in the 1950s to more than 20 days now, showing the scene of people retreating into the sand forest and flourishing crops. Yulin model is suitable for desertification control in semi-arid areas.

3. Lin Ze model

Linze County is located on both sides of Heihe River in the middle of Hexi Corridor in Gansu Province. Due to excessive firewood cutting and grazing, vegetation destruction and serious desertification, the original oasis retreated nearly 500 meters to the south. Later, the protection system of "blocking, fixing and sealing" was adopted with oasis as the center, which reduced the area of quicksand from 54.6% to 9.4%. Lin Ze model is suitable to be popularized in oasis areas where desertification is serious in arid areas.

4. Hotan model

Hotan is located on the southwest edge of Taklimakan Desert in Xinjiang. Taking oasis as the center, establishing protection system, building water conservancy, carrying out water-saving irrigation and adopting the method of fixed mobile sand dunes have obvious sand control effects. It was awarded the title of "Top 500 Global Environment" by the United Nations Development Programme. Hotan model is suitable for desertification control in extremely arid areas.