Evaluation On Windbreak Efficiency Of Farmland Shelterbelt With Remote Sensing Monitoring

In recent years,with the change of climate and environment,various kinds of agricultural disasters are occurring more and more frequently.Because of the huge loss of agricultural disasters every year,it has a serious impact on agricultural production,food security,natural ecological environment and economic development in China.As a large agricultural country,agriculture is the guarantee of national production and life and economic development.Food security plays a very important role in the steady development and rapid rise of China in the future.Heilongjiang province is a major agricultural province in China,and is also an important commodity grain base in the country.It provides food products for the whole country and in all regions of the world.However,Heilongjiang province is also a region of frequent occurrence of agricultural disasters.In recent years,Heilongjiang province's agricultural disaster frequency increased resulting in many areas of the province's food production or even never produced,have a significant impact on agricultural production and harvest.Therefore,the typhoon monitoring methods scientific,reasonable and effective,the correct analysis of crop lodging caused by typhoon,the relationship between scientific validation of crop lodging and farmland shelterbelts.It is not only conducive to the smooth progress of disaster warning,disaster relief and disaster assessment,but also to the guiding significance of agricultural production and sustainable development.The wind protection efficiency of shelterbelt is mainly analyzed by data such as porosity,spacing of forest belts,ratio of tree height to forest width and so on.Lack of windbreak efficiency is quantified by quantitative analysis of dependent variables.And are using remote sensing means,through the analysis of forest shelterbelt density,width and area index to evaluate the windbreak efficiency.Although much research has been done on crop lodging and RS extraction from shelterbelt,a lot of work has been done.However,there is less quantitative research on windbreak effectiveness in terms of temporal and spatial pattern of crop lodging and forest belt.Using high resolution remote sensing image to extract crop lodging and forest belt information,it can be used as a reference medium and evaluation index to achieve quantitative evaluation of windbreak effectiveness of farmland shelterbelt.In this study,through field survey,through the investigation and arrangement of samples,selection of sample needed,Rapideye GF-1 and PMS two different foods of high spatial resolution remote sensing satellite image based on starting from the protection efficiency results from the perspective of crop lodging and shelterbelt respectively on the regional scale of remote sensing.Including the use of visual interpretation and the maximum likelihood method to obtain the wind crop lodging area,shelterbelt extraction using NDVI threshold method,through the analysis between the protection forest and crop lodging area,in the evaluation of windbreak efficiency of shelter forest quantitative results caused by the typhoon will crop lodging and shelterbelt extraction results were constructed index.Including:Crop lodging area the windbreak efficiency of quantitative indicators is the main dependent variable;with forest density,forest area,forest belt width index as independent variables,the two indicators are combined to construct windbreak efficiency evaluation model,the results show that:forest density and forest area(East and North),the width of the belt(on the eastern side)and the comprehensive index showed a nonlinear relationship with lodging area.Among them,the most important effect of forest density on windbreak efficiency,followed by the forest area(East and North)and the width(East).Suitable for forest planting index,forest density:0.04~0.07,forest area(East and North):2000~3500m~2,the width of the belt(East):35~55m,the effective protection distance of the main belt spacing:150~225m.Based on field observation,research and lots of experimental research,the relationship between farmland shelterbelt and crop lodging is obtained,and the main protective forest belt indicators,including forest belt density,forest belt width and forest area,are clearly defined.Through the analysis of the relationship between the index and the lodging area of the shelterbelt,we get the relationship between each index,and put forward the suitable layout index of shelterbelt,and prove the hypothesis of relative research on the windbreak effectiveness of shelter forest.In order to achieve the quantitative evaluation of windbreak effect of shelterbelts,provide scientific and accurate methods of quantitative and objective evaluation for the windbreak efficiency of farmland shelterbelt,provide technical guidance of scientific and reasonable ideas for future research of farmland protection forest reasonable layout,and for the farmland shelterbelt construction design and layout optimization to provide a scientific basis for.