Development and application of crop stalk burning monitoring system in Northeast China based on Android client

Abstract: Stalk burning can produce a large amount of toxic and harmful substances, leading to serious pollution of the atmospheric environment, even fires. Once the stalk is gradually transformed into agricultural waste, the open burning of the stalk is ever increasing with the change in rural production and lifestyle. Therefore, it is a high demand for the fast, efficient, and low-cost monitoring of stalk burning. Remote sensing can be used to monitor the stalk burning for higher efficiency and time-saving, according to the characteristics of large-scale and rapid acquisition of ground data. At the same time, the open source and free features of the Android system can greatly contribute to agricultural informatization. In this research, a stalk-burning fire points monitoring system was proposed with the separated front and back ends using the Android operating system. A Client/Server (C/S) architecture was also built to combine the MODIS remote sensing data, the Python language, ArcGIS Server, and MySQL. The real-time data was automatically captured for the map service and the data service back-end server, ranging from the detection, process, and release of the data of fire points. Four interfaces were designed for the client, including the main, map, statistics, and upload interface. There were some functions of the map display, buffer query, partition statistics, and fire points uploading. At the same time, the Android mobile devices were used to synchronize the information to the user terminal or upload to the database, in order to realize the rapid query, positioning, and data visualization of stalk burning fire. The extraction of fire points was verified using the high-resolution image of Google Earth. The stalk burning area was identified to superimpose with the fire points data. Most of the fire points were located in the burning area in the autumn remote sensing images. The sample identification accuracy was about 75%. The case analysis of the system showed that the burning points of the stalk in Northeast China were mainly distributed in the Sanjiang and Songnen plains, and also scattered in the Liaohe plain and northwestern Inner Mongolia. Specifically, in Songnen plain, where black soil is most concentrated, the stalk burning intensity increased year by year and reached its peak in 2017. After that, the stalk burning intensity decreased significantly under the intervention of policy in 2018, but it rebounded in 2019. The concentrated stalk burning in Northeast China shifted from autumn to spring, and then gradually formed a seasonal pattern of concentrated burning in spring - farming in summer - sporadic burning in autumn - mulching in winter from 2010 to 2020. The fire points of the stalk were mainly concentrated in the Sanjiang plain and the Songnen plain, and the center of gravity was at the junction of Harbin and Suihua. The standard deviation was utilized to evaluate the inter-annual variation in the number of stalk-burning fire points. It was found that the areas with the strong stalk burning fluctuations were located in the main Sanjiang plain and the Songnen plain, which were the main grain-producing areas in Northeast China. Consequently, there was questionable for the normalized management and the sustainability of measures. In summary, the proposed system can be expected to quickly monitor, inquire, edit, report, and update data using ArcGIS services and thematic mapping. The finding can provide fast and convenient technical means for stalk burning monitoring, thereby facilitating the coordination of agricultural and environmental management. Furthermore, conservation tillage and agricultural environmental protection can be further promoted in Northeast China.