Karakteristik Fisik Tanah di Sekitar Ruas Jalan Sentul-Semplak dan Kaitannya dengan Potensi Aliran Permukaan (Runoff)

Abstract

Keberadaan jalan dapat mengubah kondisi lahan di sekitarnya dan memengaruhi karakteristik fisik tanah yang berpotensi meningkatkan aliran permukaan (runoff). Penelitian bertujuan mengukur sifat fisik tanah dan kandungan C-organik di sekitar ruas Jalan Sentul-Semplak, mengetahui hubungan antara karakteristik fisik tanah dengan permeabilitas tanah, dan kaitannya dengan potensi aliran permukaan (runoff). Sampel tanah diambil pada kedalaman 0–20 cm dari lima jenis penggunaan lahan: ruang terbuka hijau, lahan tegalan, kebun pisang, sempadan jalan, dan taman universitas. Analisis laboratorium meliputi tekstur tanah, bobot isi tanah, pori drainase (sangat cepat, cepat, dan lambat), indeks stabilitas agregat tanah, kandungan C-organik tanah, dan permeabilitas tanah. Hasil penelitian menunjukkan bahwa taman universitas memiliki bobot isi tertinggi; kebun pisang memiliki ruang pori total, volume pori drainase (sangat cepat dan cepat), serta permeabilitas tanah tertinggi; ruang terbuka hijau memiliki nilai indeks stabilitas agregat dan kandungan C-organik tertinggi; sedangkan lahan tegalan memiliki volume pori drainase lambat tertinggi. Permeabilitas tanah berkorelasi negatif dengan bobot isi dan berkorelasi positif dengan ruang pori total, volume pori drainase, serta stabilitas agregat. Secara keseluruhan, kawasan penelitian tergolong memiliki permeabilitas sedang hingga lambat, yang mengindikasikan potensi limpasan permukaan yang tinggi.

Road construction can significantly alter surrounding land conditions and impact soil physical properties, potentially increasing surface runoff. This study investigates the physical characteristics and organic carbon content of soils adjacent to the Sentul–Semplak road section, aiming to assess the relationship between these properties and soil permeability, and their implications for runoff potential. Soil samples were collected from a depth of 0–20 cm across five land-use types: green open space, dry farmland, banana plantation, road boundary, and university park. Laboratory analyses included measurements of soil texture, bulk density, drainage pore classes (very fast, fast, and slow), aggregate stability index, organic carbon content, and permeability. Results indicated that the university park exhibited the highest bulk density; the banana plantation had the greatest total pore space, drainage pore volumes (very fast and fast), and soil permeability; green open space showed the highest aggregate stability and organic carbon content; and dry farmland had the highest proportion of slow drainage pores. Soil permeability was negatively correlated with bulk density and positively correlated with total pore space, drainage pore volumes, and aggregate stability. Overall, the area was predominantly classified as having moderate to slow permeability, suggesting a high potential for surface runoff.