Methods, systems, and computer program products for detection of an arbitrarily-shaped source of an abnormal event via use of a hierarchical reconstruction method are provided herein. A computer-implemented method includes detecting an abnormal event based on analysis of sensor data, wherein said analysis of the sensor data comprises comparing the sensor data to a user-defined threshold; generating a query based on the detected abnormal event; processing the query against one or more given data repositories; executing an inverse model using an output generated in relation to said processing to identify a source of the detected abnormal event, wherein the source to comprises an arbitrary shape; and outputting the identified source of the detected abnormal event.
Please help me write a proper abstract based on the patent claims. CLAIM: 1. A computer-implemented method, comprising: detecting an abnormal event based on analysis of sensor data, wherein said analysis of the sensor data comprises comparing the sensor data to a user-defined threshold; generating a query based on the detected abnormal event; processing the query against one or more data repositories; executing an inverse model using an output generated in relation to said processing to identify a source of the detected abnormal event, wherein the source comprises an arbitrary shape; and outputting the identified source of the detected abnormal event; wherein the steps are carried out by at least one computing device. 2. The computer-implemented method of claim 1, further comprising: applying one or more regularized optimizations to the identified source of the detected abnormal event. 3. The computer-implemented method of claim 1, wherein the abnormal event comprises an abnormal air pollution event. 4. The computer-implemented method of claim 1, wherein the sensor data comprises a one-time observation. 5. The computer-implemented method of claim 1, wherein said sensor data comprises real-time air quality data. 6. The computer-implemented method of claim 1, wherein the inverse model comprises a dispersion model. 7. The computer-implemented method of claim 1, wherein the source of the detected abnormal event comprises a single item. 8. The computer-implemented method of claim 1, wherein the source of the detected abnormal event comprises a distribution across multiple items. 9. The computer-implemented method of claim 8, wherein the distribution across multiple items comprises an arbitrary distribution shape. 10. The computer-implemented method of claim 8, wherein the distribution across multiple items comprises a distribution across multiple disjoint items. 11. The computer-implemented method of claim 1, wherein the source of the detected abnormal event comprises a single geographic area. 12. The computer-implemented method of claim 1, wherein the source of the detected abnormal event comprises a distribution across multiple geographic areas. 13. The computer-implemented method of claim 12, wherein the distribution across multiple geographic areas comprises an arbitrary distribution shape. 14. The computer-implemented method of claim 12, wherein the distribution across multiple geographic areas comprises a distribution across multiple disjoint geographic areas. 15. The computer-implemented method of claim 1, wherein said executing the inverse model comprises implementing a hierarchical reconstruction technique. 16. The computer-implemented method of claim 1, wherein an uncertainty factor associated with the inverse model is modeled by one or more uniform random variables. 17. The computer-implemented method of claim 1, wherein said outputting comprises uploading the identified source of the detected abnormal event to a server. 18. A computer program product, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a device to cause the device to: detect an abnormal event based on analysis of sensor data, wherein said analysis of the sensor data comprises comparing the sensor data to a user-defined threshold; generate a query based on the detected abnormal event; process the query against one or more given data repositories; execute an inverse model using an output generated in relation to said processing to identify a source of the detected abnormal event, wherein the source comprises an arbitrary shape; and output the identified source of the detected abnormal event. 19. The computer program product of claim 18, wherein the program instructions executable by a device further cause the device to: apply one or more regularized optimizations to the identified source of the detected abnormal event. 20. A system comprising: a memory; and at least one processor coupled to the memory and configured for: detecting an abnormal event based on analysis of sensor data, wherein said analysis of the sensor data comprises comparing the sensor data to a user-defined threshold; generating a query based on the detected abnormal event; processing the query against one or more given data repositories; executing an inverse model using an output generated in relation to said processing to identify a source of the detected abnormal event, wherein the source comprises an arbitrary shape; and outputting the identified source of the detected abnormal event.