Grape Distribution Extraction And Ecological Environment Quality Evaluation At The Eastern Foot Of Helan Mountain Based On RS

Human activities will lead to changes in land use and cover,and have a series of impacts on the regional ecological environment through the components and structures of the ecosystem.The ecological evaluation is helpful to comprehensively and scientifically evaluate the ecological benefits of human activities,and to grasp the changes of the macro-structure,ecological quality and ecological services of the ecosystem.This is not only the hot spot of subject research,but also the demand of regional science and technology.The largest grapevine belt has been built at the eastern foot of Helan Mountain in Ningxia.Through the surface monitoring method combined with "3S" technology,can grasp the grapes regional distribution the status quo,Lin implementation grape Lin the rapid,effective extraction and monitoring of ecological information.And on this basis,the forest cultivation of grapes in ecological environment impact assessment,in order to comprehensively and accurately know the grapes forest ecological status and influence.This paper takes grape forest land in Helan,Yongning and Qingtongxia regions as the typical sample land.Through field survey of ground feature types and measured ground temperature data of the sample land,combined with multi-source remote sensing data for analysis,the following research results are obtained:(1)By using the decision tree method of time series spectrum and using the GF-1/WFV time series data set,the optimal time phase and threshold values for grape forest extraction were determined on the remote sensing images of different phases,and the spatial information of grape forest was extracted.Among them,the development mode of grape forest in Helan planting area is scattered planting in wasteland,Yongning planting area is centralized planting in oasis,and qingtongxia planting area is centralized development and planting in transition area of wasteland and oasis.(2)MODIS-NDVI remote sensing data product was used to obtain key time nodes,and Landsat data was used to obtain the monitoring indexes of green degree(NDVI),WET degree(WET),heat degree(LST)and dry degree(NDSI)in three grape growing areas of Helan,Yongning and Qingtongxia in 2003,2010 and 2017.The results showed that from 2003 to 2017,the mean values of NDVI,WET and LST in all planting areas increased gradually,and the mean values of NDSI decreased gradually.This is related to the geographical background and landscape pattern of grape forest distribution in different regions.(3)Four ecological indexes,including NDVI,WET,LST and NDSI,were transformed into principal components and calculated by RSEI.The results showed that RSEI values in all planting areas showed a steady upward trend from 2003 to 2017.From 2003 to 2010,Helan planting area had the highest ecological environment quality increase,with the RSEI value rising from 0.246 to 0.393,followed by qingtongxia planting area and yongning planting area.From 2010 to 2017,the planting area of Qingtongxia saw the highest increase in ecological environment quality,with the RSEI value rising from 0.406 to 0.480,followed by Helan planting area and yongning planting area.(4)The RSEI value is divided into five grades:"excellent","good","medium","inferior" and"poor".The results showed that from 2003 to 2017,the ecological environment quality of Helan planting area was mostly in the "poor" and "good" grades.The ecological environment quality of Yongning planting area is mostly in the "good" and "excellent" level.Most of the ecological environment quality in the planting area of Qingtongxia is in the "poor" and "excellent" grades,and the main change is that wasteland area with "poor" ecological environment status is transformed into the grape forest planting area with "medium" ecological status.(5)According to the analysis of the overall change trend of RSEI,the overall ecological environment quality of each grape-growing area at the eastern foot of Helan Mountain showed a better trend from 2003 to 2017.Through the model prediction,it is found that planting grape in the wasteland is an important factor to improve the ecological environment quality in the eastern foot of Helan Mountain.