The windbreak is an agroforestry ecological system integrating economy, ecology andsociety. It plays a key role in reducing the wind speed, improving the microclimate and soilconditions of agricultural and animal husbandry production, maintaining the health offarmland ecosystem, ensuring the stable yield of agriculture and animal husbandry, andrealizing the sustainable development of farmland ecosystem. However, farmlandwindbreaks also have negative effects on crop yield. The evaluation of the protective effectof farmland windbreak is the key to test the rational construction of the windbreak and thescientific planning and design of the future windbreak. It is the link between theconstruction and management of the windbreak. What is the comprehensive benefit of thewindbreak? Does it help to achieve the goal of planning and design? It is the urgent need toanswer the question of windbreak effect. Therefore, this study selects the oasis in theManas River Basin which is a strong representative and typical in the arid area of Xinjiangand uses the remote sensing data and statistical data to carry out the evaluation of theprotective effect of the oasis farmland windbreak in the basin. The landscape pattern offarmland windbreaks in arid oasis and its effect on the main crop yield in the study area arealso studied. The following results were obtained:(1) The analysis of the landscape pattern with the ratio of belt to patch, theconnectivity and the ring degree to the windbreak of Manas County, Shawan County andthe Regimental Farm showed that the relative error of each landscape metric was greaterthan 0.15. The prominent problems include the limited windbreak area, uneven windbreakdistribution, small number of closed grids and poor forming conditions. In order to achievethe sustainability of the farmlands, the missing windbreak needs to be developed and thedensity of windbreak should also be increased.(2) Based on the Landsat8 OLI remote sensing image as the data source and the dataof the cotton space extracted by the object-oriented method, and the light energy utilizationmodel, the CASA model, and the crop biomass-yield model was used to analyze the yield of the main crop. Cotton production was estimated using the data released by the Bureau ofStatistics of the county cotton yield data to verify. The cotton acreage of the Manas RiverBasin accounts for 61.13% of the total area of crop cultivation, and the average yield ofcotton in the basin is 2049.27kg/ha, and the estimation error is less than 4%. It can be seenthat the high yield area of cotton higher than 2400kg/ha is mainly distributed in the centralarea of the oasis in Manas County, Farm 143, Farm 121 and Farm 122. The cotton yield is1800~2400kg/ha. The middle-yielding areas of cotton are mainly distributed in ShawanCounty and Oasis East and West. The low yield area of cotton yield below 1800kg/ha ismainly distributed in Xinhu Farm, Farm 136 West, Farm 135 and other southern edge aswell as near desert areas.(3) Based on the multi-period Landsat series of image data, the spatial distributioninformation of windbreak in different age groups was extracted. The quality coefficient ofwindbreaks was calculated by the normalized vegetation index of the windbreaks.Windbreak evaluation system was established to analyze the effect of different protectionlevels on cotton yield according to the tree height and the maximum protection distance ofdifferent age groups. The results showed that the cotton yield was in a stable state when theprotection level of Manas County and Shawan County was 70%. Compared with theprotection level of 0%, the cotton yield increased by 136 kg/ha and 175 kg/ha. When theprotection level of Regimental Farm is 90%, the cotton yield is in a basically stable state.Compared with the protection level of 0%, the cotton yield increased by 214kg/ha.Compared to Manas County and Shawan County landscape pattern, the Regimental Farmcoverage and continuity is poor, showing that the construction of the windbreak in theRegimental Farm needs to be further strengthened and improved
