Soil Moisture Monitoring in Banjarnegara Regency Using SMAP imagery

Abstract

One of the places in Indonesia where landslides occur relatively frequently, is Banjarnegara Regency. Landslides with significant losses are observed in the study area almost annually. The preceding soil wetness is one of the elements that trigger landslides. In this study, we determine high and low soil wetness by classifying soil moisture and observing how it relates between soil moisture and the occurrence of landslides. Temporary and spatial processing was done on historical soil moisture imaging data from the Soil Moisture Active Passive (SMAP) satellite. The soil moisture variability in each of the 20 grids in the study area was compared. The highest and lowest soil moisture distribution is noticeable using the high-frequency approach. The findings demonstrate that the historical soil water content trend often follows a similar pattern. When divided by the number of samples (n), the Very High-Frequency method has a minimum value of 0 and a maximum value of 25.4mm. In this value range, there are five different classes of soil moisture: very low (0–5mm), low (5.1–10mm), medium (10.1–15mm), high (15.1–20mm), and very high (20.1-25.4mm). Despite not being the highest value from very high-frequency computations, the Banjarnegara Regency is in the high class, ranging from 16.12mm to 20.03mm. The elements causing the frequent landslides in Banjarnegara Regency are excessive and antecedent soil moisture. From 894 historical data records, entire grids with very-high and high classes cumulatively have between 51% and 85% incidences of soil moisture value.