| Southern XinJiang, located in South Tianshan, with low average precipitation, dry climate, is extremely fragile ecological environment. Especially wind sand hazard in the southern region has a great influence on the southern people’s production life and economic development, political stability. Agricultural production is the main economic support structure of the southern region. The construction of farmland ecosystem has become a priority among priorities. Frequently harassed the southern ecological environmental damage in the wind, sand, farmland shelterbelt construction is not only related to the production value of the local farmland ecosystem, but also on the local ecological environment improvement has a crucial significance that can’t be ignored.Previous research on forest are concerned about in the forest belt protective benefits, including structure of shelterbelt planting style, species collocation, row spacing, plant spacing, the forest belt direction, tree height, under branch height, crown, but in farmland ecosystem, crop protection benefit and protection forest system in the overall efficiency is often overlooked. In addition, in the current promotion of precision agriculture, how to quantitatively analyze the production value of farmland, optimize the unit of land productivity has become an urgent requirement in agricultural production.In view of the existence of the above problems, this study based on wind speed is investigated in the field of farmland and forest, combined with indoor wind tunnel test, flow field characteristics by viscous flow analysis method of protection forest system, and on this basis through multiple regression to find the best backbone forest, Belt in farmland of the configuration mode; introduction of hydrology and water resources protection ensures that the concept of the rate of, through modeling analysis, find the distance of the best unit of land productivity of forest. The main conclusions of the study are as follows:1)By the study of five typical forest protection benefit calculation, it is found scattered through the forest of 0.34 in protective benefit with maximum protection benefit, and can make the maximum wind speed reduction. Forest belt research from the point of view, protective effect of best not to let the wind to see 100%, but forest there a best porosity, can make the highest efficiency of the protective benefits. Studies show that porosity is 0.34 forest is the optimal porosity belt, with the best protection benefit and the best wind speed reduction.2)This study showed that the windbreak effect of Chinese jujub shelterbelt in 20 H distance remains above 85%, consider further optimize the allocation of protection forest, forest wider spacing settings, reducing Shaolin zone covers an area of, increase crop area and economic benefit. To the spacing of the research area of shelterbelt forest for 10 h, every 500 m agricultural field with 3 2 forest belt line and the line spacing is 1.8m, consider distance of belt for 20 h can reduce 3 forest belt and Chinese jujub shelterbelt wind speed is 2m/s, far below the jujube by typhoon damage threshold wind speed 6.9m/s, is can increase the jujube cultivation area of 0.54%(2700m2), with per mu to 200 million yuan economic effect, southern 700 million acres of jujube every year can increase the economic benefit of the 756 million yuan. Therefore, to fully consider the influence of jujube crop of wind protection effect, rational allocation of protection forest, reduce the protection forest area, increase crop planting area and increase economic effect.3)The results of the analysis to flow visualization of wind tunnel test shows that the protective forest system(with the role of collaborative Doreen) compared with single forest protection benefits to provide greater protection scope; numerical analysis according to the survey and actual production needs founds that when the wind speed at 9.8m/s, set to the backbone of 14 lines 6, field forest, forest belt distance is 20 H and 10H; when the wind speed smaller 8.6m/s, set the backbone to 14 lines, 6 lines in field forest, forest belt distance is 13 H and 13 H.4) determine the farmland protection forest belt distance according to the biological characteristics of the protection object. Use protection guarantee rate method, in the analysis of farmland protection forest region of typhoon characteristics based, tradeoff analysis of farmland protective forest benefits and unit farmland value. Results show that exist an optimal protection guarantee rate, the shelterbelt spacing and best economic value, in southern Xinjiang jujube research area(224 regiment), with farmland productivity as the goal, shelter forest protection guarantee rate in 95%, the distance protection is 132.1m and economic value to the optimal. |
