Satellite based coping mechanisms for drought prone Raichur
Drought is a normal and recurrent condition of climate that occurs when the available soil moisture becomes insufficient to support plant growth. Droughts adversely affect the agricultural sector especially when they are prevailing for a longer duration. Agricultural droughts should be identified well before it’s occurrence to reduce its impact on the crop.
Normalized Difference Vegetation Index (NDVI) or rainfall information is most widely used to detect the agricultural drought. However, NDVI only detects the agricultural drought when crops are already affected by it. Rainfall monitoring using rain gauge stations won’t represent spatial variations in the field. The unavailability of near real-time data is a limitation in drought detection and management.
After precipitation, a certain amount of water is retained in the soil which dissipates due to evaporation or transpiration with the passage of time. The top 2 inches of the soil hold an infinitesimal fraction of the planet’s water1. Although the amount of water is small, because of its position at the interface between land and atmosphere it forms a crucial part of the global water cycle. Monitoring soil moisture over time can help to tackle adverse climatic changes and hence can help to reduce its effect on crop yield. It can also predict the condition of agricultural drought well in advance and thus provides a possibility of preparedness without compromising on the yield.
Based on the 2010-11 census, a majority of farmers holds below 1 ha land in India. Hence, the identification of drought should be done at this scale. However, currently available satellites which are sensitive to soil moisture either have a high temporal (daily revisit) or higher spatial (less than 1 ha) resolution. Satyukt analytics Pvt Ltd has developed proprietary algorithms to retrieve soil moisture and other indicators of agricultural drought at a higher spatiotemporal (less than 1 ha at the daily frequency). Satyukt analytics Pvt Ltd is capable of tracking the drought conditions across India during the Kharif season.
The average soil moisture map of April over Raichur, Karnataka is shown in the figure. The map clearly shows the effects of drought in the district. Residents of the Raichur district have been leaving the district due to recurrent severe drought conditions. Proper management of existing water resources can solve this problem to a great extent.
