Soil Moisture Sensor-Based Landslide Monitoring: A Laboratory-Based Approach for Guwahati City MADHUSHREE SHARMA, SHAKUNTALA LASKAR Electrical and Electronics Engineering Department Assam Don Bosco University Azara, Guwahati, Assam INDIA Abstract: - Various techniques for landslide mapping, monitoring and modelling are being employed in a variety of studies to keep people safe from landslides. Guwahati, a city in Assam (India) is surrounded by hills, with varied slope angles, become prone to landslide during monsoon season. Relative increase in the moisture content of soil is a major parameter for determining the occurrence of landslides that are induced by rainfall. An experimental model with varying slope angles is demonstrated to witness some proportionality behaviour of soil moisture value for the collected soil sample from landslide prone areas. The soil moisture sensor value increases with increase in slope angle. The toe position of moisture value also shows a significant display of data during landslide. This early warning module can be incorporated with the help of Blynk Application to send messages to the residents of landslide prone areas. This study would be a cost effective alternative for landslide early warning hazard monitoring and fast emergency response process and the model may be considered as a miniature version of real-life slope conditions for the hills of Guwahati city, Assam, India. Key-Words: - Breakdown, Slope Angle, Toe of Slope Area, Top of Slope Area, Display, Early Warning Received: January 19, 2023. Revised: November 12, 2023. Accepted: December 15, 2023. Published: February 13, 2024. 1 Introduction Natural catastrophes (landslide, flood, erosion etc.) cannot be prevented, but we can prepare ourselves by learning how to either mitigate them or set up an effective early warning system. Landslide is one such natural hazard that affects a small region ([1], [2], [3]). Landslide mitigation techniques involve mainly two methods- firstly, some advanced techniques like installing of abutment and anchor piles. However, the second option of installing a suitable alarm and warning system is a more economical option. The unplanned construction due to rapid urbanization has pushed the city of Guwahati to the brink by destroying the natural balance of the city [4]. Along with gravity, heavy rainfall, earthquake and a slope that was cut, may also induce and trigger landslide like conditions. As per report, during June 14-June 21, 2022, around 72 landslides took place across the hills of Guwahati owing to the rain and as many as 266 families residing in locations vulnerable to mud slips have been asked by the District Administration to shift to the safer places. Hence an urgent need for landslide early warning process for the city of Guwahati is the objective of the study. The early warning system of landslide has 3 steps viz. landslide mapping, monitoring and modeling ([5], [6], [7]). There are mainly two causes of rainfall induced landslides- reduction in soil’s shearing resistance due to an increase in soil moisture content and increase in unit weight of the soil [8]. Landslides are further caused by changes in the slope angle, surface erosion, and an increase in pore water pressure in faults and joints [9]. Therefore, a rise in soil moisture content brought on by precipitation infiltration plays a crucial role in causing slope failure. Additionally, slope collapses are usually caused by a specific area at the slope's toe where the soil moisture content nearly reached full saturation, even when other areas of the sliding mass were still International Journal of Environmental Engineering and Development DOI: 10.37394/232033.2024.2.3 Madhushree Sharma, Shakuntala Laskar E-ISSN: 2945-1159 27 Volume 2, 2024