Electronic Theses and Dissertation

Wilayah pesisir Kota Banda Aceh masih mengalami dampak salinisasi tanah pascatsunami tahun 2004 yang memengaruhi kualitas lahan dan berpotensi menurunkan kualitas air tanah. Variabilitas salinitas tanah dipengaruhi oleh kondisi topografi, curah hujan, dan jenis tanah. Penelitian ini bertujuan menganalisis hubungan Topographic Wetness Index (TWI), curah hujan, dan jenis tanah terhadap variabilitas salinitas tanah melalui pendekatan spasial. Data yang digunakan meliputi hasil pengukuran salinitas tanah menggunakan Electrical Conductivity (EC) Meter, Digital Terrain Model (DTM) dari JICA, data curah hujan CHIRPS periode 2006–2025, dan data jenis tanah. Analisis dilakukan menggunakan Sistem Informasi Geografis (SIG), analisis spasial, dan Korelasi Pearson. Hasil penelitian menunjukkan bahwa salinitas tanah cenderung lebih tinggi pada wilayah bertekstur halus, sedangkan nilai TWI tinggi umumnya berada pada daerah dataran rendah atau cekungan yang berpotensi mengakumulasi air. Distribusi curah hujan menunjukkan variasi spasial, namun tidak memiliki hubungan yang signifikan terhadap salinitas tanah. Secara statistik, TWI memiliki hubungan positif lemah terhadap salinitas tanah (r = 0,219; p = 0,181), sedangkan curah hujan memiliki hubungan sangat lemah (r = −0,047; p = 0,774). Namun, pada tanah lempung ditemukan hubungan yang sangat kuat antara TWI dan salinitas tanah (r = −0,940; p = 0,030). Hasil penelitian menunjukkan bahwa jenis tanah memengaruhi hubungan antara topografi dan salinitas tanah, sehingga perlu dipertimbangkan dalam pengelolaan wilayah pesisir pascatsunami.

Kata kunci: salinitas tanah, Topographic Wetness Index, curah hujan, SIG, pascatsunami, Banda Aceh

The coastal area of Banda Aceh continues to experience soil salinization as a long-term impact of the 2004 tsunami, affecting land quality and potentially reducing groundwater quality. Soil salinity variability is influenced by topographic conditions, rainfall, and soil type. This study aims to analyze the relationship between the Topographic Wetness Index (TWI), rainfall, and soil type and soil salinity variability using a spatial approach. The data used consisted of soil salinity measurements obtained using an Electrical Conductivity (EC) Meter, a Digital Terrain Model (DTM) provided by JICA, CHIRPS rainfall data for the 2006–2025 period, and a soil type map. The analysis was conducted using a Geographic Information System (GIS), spatial analysis, and Pearson correlation analysis. The results indicate that soil salinity tends to be higher in areas with fine-textured soils, while high TWI values are generally found in low-lying or depression areas with greater potential for water accumulation. Rainfall distribution exhibits spatial variation but does not show a significant relationship with soil salinity. Statistically, TWI shows a weak positive correlation with soil salinity (r = 0.219; p = 0.181), whereas rainfall exhibits a very weak correlation (r = −0.047; p = 0.774). However, in clay soils, a very strong and significant negative correlation was found between TWI and soil salinity (r = −0.940; p = 0.030). These findings indicate that soil type influences the relationship between topographic conditions and soil salinity, and therefore should be considered in the management of tsunami-affected coastal areas. Keywords: soil salinity, Topographic Wetness Index, rainfall, GIS, post-tsunami, Banda Aceh