| Desert shrub is an important component of the fragile ecosystem in arid and semi-arid regions.The biomass is an important indicator for the study of the structure and function of desert ecosystem.However,the traditional methods of measurement are mostly artificial plots or quadrat surveys,which are mainly destructive measurement.The advantage is that the measurement method is simple and direct.The disadvantage is that it is difficult to obtain the tree related factors of shrub biomass.At the same time,it must harvest the whole shrub,which can't carry out continuous observation of the same shrub.It also has a certain destructive effect on the fragile desert shrub ecosystem.Therefore,the traditional measurement method has become one of the main constraints of shrub biomass modeling,especially in the large spatial and temporal scale to monitor the shrub biomass.It needs to carry out a large number of Wild Shrubs.The limitations of traditional methods are more significant.In order to realize the real-time,non-destructive and rapid estimation of the aboveground biomass of desert shrubs,the experimental samples were constructed that was based on the traditional biomass modeling method.By means of the image of shrubs in the study area by smart phone shooting method,combining image processing and analysis and according to the characteristics of shrub,a new variable of shrub image area(S)was introduced to build biomass model.By using the technology of mechanical design and manufacture,a field measuring device for the aboveground biomass of desert shrubs was manufactured.Integrated application of digital image processing algorithm and based on the Android platform,the non-destructive and rapid estimation software for the aboveground biomass of desert shrubs was developed.The research shows that it is flexible and effective to estimate the biomass of desert shrubs which based on the image analysis of smart phones.The results are as follows:(1)The feasibility of estimating the shrub biomass by the side area of the image is verified.The optimal biomass model is B = 0.081 S.which based on the area of side view area(S)of Haloxylon ammodendron.The coefficient of determination is the maximum value.The relative error is from 10.178 to 44.98%,and the relative average error is: 13.26%.The correlation coefficient between the estimated value and the measured value is about 0.9028.This method can effectively estimate the biomass of small desert Haloxylon ammodendron.(2)It is found that using the vertical view area of the image to estimate the shrub biomass is better than that using the side area of the image,which can make up for the lack of the shooting method of the larger shrubs.The optimal biomass model is B = 15.215 + 369.44S-42.03 S + 1.668 S which based on the area of vertical view of Tamarix ramosissima.The coefficient of determination is the maximum value.Compared with the actual measurement results,the average absolute error of the system is 79.12 g,the average system error is 1.73%,the mean absolute percentage error is about 18.59%,and the correlation coefficient between the estimated value and the measured value is about 0.9391.This method can estimate the biomass of Tamarix ramosissima successfully,which can improve the work efficiency of non-destructive and rapid estimation of aboveground biomass.(3)A field measurement device for shrub biomass based on mobile phone image analysis is designed.It includes the design of hardware,and the design of Bluetooth wireless control module.This paper develops software for the rapid estimation of the aboveground biomass of desert shrubs based on the Android platform,and constructs software and hardware integrated measurement device.Compared with the traditional method,the method has the advantages of nondestructive,rapid,flexible and convenient.At the same time,it has important significance to protect and develop the shrub resources and promote the improvement of ecological environment. |
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