Role of Geospatial Technologies in Solid Waste Management
Rapid urbanization and industrialization in India have heightened solid waste generation giving tough time to urban local bodies in keeping cities clean. Waste generated from households and industries are mostly disposed in open space leading to serious environmental problems. The practice leads to serious health risk like burning eyes, respiratory diseases, skin problem, malaria, dengue, leptospirosis, typhoid, etc.
India is the largest producer of waste in the world. India’s financial capital Mumbai and national capital Delhi are the largest producers of solid waste with 30.6 billion tonnes and 24.9 billion tonnes respectively. They are followed by Chennai which produces 18.3 billion tonnes, Greater Hyderabad 16.4 billion tonnes and Bengaluru 12.8 billion tonnes. The problem is more severe as the garbage disposal facilities are not keeping pace with the amount of waste generated here. And, in times to come the problem will only increase as A report by the World Bank estimate that the country produces 2.01 billion tonnes of municipal waste every year and this is projected to increase by 70% making it to 3.4 billion tonnes by 2050.
Thus, the need of the hour is to manage waste properly; including collection, transportation and disposal for a clean and hygienic environment. It is crucial for decision-makers to opt for more innovative approaches where geospatial technology in amalgamation with new age technologies like Internet of Things and Sensors can make the process easy. Let us have a look how these technologies can help in proper Solid Waste Management.
Role of Technologies in Stages of Solid Waste Management
Waste management solution starts when a material or product becomes waste and is of no use. The first stage in the lifecycle of solid waste management is collection and transportation of waste. In this stage collection agents are employed who go to every doorstep, street, road and collect unsegregated waste. However, this method of collection is prone to error and many times it is seen that collection agents miss some of the bins. As collection and transportation of solid waste account for approximately 80% to 95% of Municipal Solid Waste, it is important that the total budget is planned and managed effectively, leaving no room for error. In such a scenario, all the household in the city from where the Garbage is to be collected are mapped on GIS using property survey method. Houses can be connected with control room via RFID or via Mobile Apps and the status of Waste collection may be updated accordingly.
Secondary Waste Collection Points
Secondary Waste Collection Points are places where wastes are disposed either directly or by agents in the Secondary Collection Points in garbage bins. Here GIS along with IoT and sensors also helps to develop an optimal routing system for better collection of waste. GIS data helps to pinpoint the location of bins. These bins are sensor enabled and when they are full, transmit information to the Command & Control centres of the city. Once the information from a bin is received, the garbage collection truck which is nearby the bin is directed to it for collection. This complete process reduces distance and time for the collection vehicle fleet. GIS also helps in reallocation of waste bins and complete redesign of the collection sectors.
Waste Segregation is practiced in a few municipalities. Segregation is done either at Secondary Waste Points or from Landfills by Agencies. In this case the fill sensors can be put on separately for Wet garbage and for dry garbage to ease the segregation process.
Once the waste is collected it is then transported where appointed agencies collect the waste from every household and secondary disposal points to Landfill sites. In this stage, GIS supports in defining the route of the vehicle based on capacity of vehicles, the frequency of filling of community bins/secondary waste disposal sites and the time taken for waste transportation. GIS supports in optimizing the routes. The vehicles are attached with GPS to track the real time location of the waste carrying vehicles and generate reports on stoppages of vehicle and time taken by the vehicle. The weighbridge reports may also be integrated with GIS to understand the utilization of the Vehicle capacity and transportation.
Landfill is the most common and oldest method of waste disposal. This is a method for disposal of solid and hazardous waste on land and is the most economical method as well as it does not require, any infrastructure or equipment. In this process waste is poured into the soil by weight in a uniform manner. After this, the debris is covered with a layer of soil each day. The allocation of a landfill is a difficult task as it requires the integration of various environmental and socioeconomic data and involves decisions based on complicated technical and legal parameters. The challenge is to make an environmentally friendly and financially sound selection.
Geospatial technology helps to identify suitable landfill sites. GIS map layers are created for criteria that will be used to make decisions to reach the final goal of selecting MSW disposal sites. Layers could include topography, settlements, roads, highway, slope, geology, land use, floodplains, aquifers, and surface water to enable their analysis separately and together to find acceptable areas. These are then evaluated and used for preparing MSW disposal plans. Thematic maps of the chosen criteria is developed within the concept of standard GIS software. All the data layers are obtained and prepared from the related maps by scanning, georeferencing, georectifying and digitizing the relevant information. After this, the collected information is than compiled and is used to establish the buffer zones for each layer. After creating the classes for each layer by using buffer zones, each layer is converted into individual raster maps. After the preparation of all input layers, the AHP method is often used to analyze the data for landfill site selection and the output map is prepared. This map then becomes the reference for city managers to use.
The last stage is waste utilization. With technological advancement it is now possible to generate energy from Municipal Waste. These wastes can be used to generate Vermicomposting, biogas, fuel, electricity generation and can also be used as Raw Material for industries. Here, GIS based monitoring or Logistic management may be undertaken for the Waste Utilization also.