Dampak Skala Urbanisasi terhadap Kondisi Ekologis dan Pola Panas Permukaan: Studi Komparatif Jakarta - Kota Semarang

Abstract

Pulau Bahang Perkotaan (UHI) adalah masalah lingkungan utama di area perkotaan padat. Banyak studi mengkaji tutupan lahan dan suhu dengan UHI, namun sedikit yang membandingkan tingkat keparahan dampaknya. Penelitian ini membandingkan pengaruh kerapatan bangunan dan vegetasi terhadap kondisi ekologis di tingkat urbanisasi berbeda, serta menganalisis pola distribusi panas dan neraca energi untuk merumuskan strategi mitigasi termal yang kontekstual. Landsat 9 digunakan untuk estimasi LST-UTFVI dan perhitungan NDVI-NDBI, untuk menilai kondisi ekologis, vegetasi dan lahan terbangun. Klasifikasi terbimbing menggunakan algoritma Random Forest; perhitungan neraca energi menggunakan metode Surface Energy Balance Algorithm for Land (SEBAL). Regresi linier sederhana dan berganda mengkaji analisis hubungan UTFVI-NDVI-NDBI; uji Mann-Whitney mengidentifikasi perbedaan variabel antar-kelompok. Hasil menunjukkan bahwa Jakarta memiliki NDBI lebih tinggi dan NDVI lebih rendah dibanding Kota Semarang (p < 0,07), dengan kontribusi NDBI terhadap UTFVI lebih dominan (R² = 0,552;0,569) dibanding NDVI (R² = 0,301;0,345). Hasil regresi berganda menunjukkan koefisien NDBI yang lebih tinggi di Jakarta (0,0225), sementara NDVI lebih kuat menurunkan UTFVI di Kota Semarang (–0,0020). Secara komparatif, Jakarta memiliki suhu rata-rata 28,7?°C dan hanya 17,95% wilayahnya dalam kategori kondisi ekologis “sangat baik”; Kota Semarang mencatat suhu rata-rata 26,2?°C dengan 74,68% wilayahnya tergolong “sangat baik”. Jakarta didominasi oleh fluks H (141,41 W/m²), sementara Kota Semarang memiliki dominasi fluks LE (142,91?W/m²). Rekomendasi mitigasi mencakup solusi vertikal dan reflektif di Jakarta, serta konservasi vegetasi dan pemanfaatan fitur hijau–biru di Semarang sesuai karakter wilayah masing-masing.

Urban Heat Island (UHI) is a major environmental issue in densely urbanized areas. While many studies have examined land cover and temperature in relation to UHI, few have compared the severity of its impact. This study compares the influence of building density and urban vegetation on ecological conditions at varying levels of urbanization, and analyzes surface heat distribution and energy balance components to formulate contextual thermal mitigation strategies. Landsat 9 facilitated LST-UTFVI estimation and NDVI-NDBI calculation for assessing ecological condition, vegetation and built-up conditions. Supervised classification utilized a Random Forest algorithm; Surface Energy Balance Algorithm for Land (SEBAL) derived surface energy balance. Relationships UTFVI-NDVI-NDBI were analyzed using simple and multiple linear regression; Mann-Whitney tests identified significant inter-group differences. Results show, Jakarta has higher NDBI and lower NDVI values than Semarang City (p < 0,07), with NDBI contributing more significantly to UTFVI (R² = 0,552; 0,569) than NDVI (R² = 0,301; 0,345). Multiple regression indicated a higher NDBI coefficient in Jakarta (0,0225), while NDVI had a stronger negative effect in Semarang City (–0,0020). Jakarta recorded a higher average temperature (28,7?°C) and only 17,95% of its area in the “very good” ecological category, whereas Semarang City had a lower average temperature (26,2?°C) and 74,68% of its area classified as “very good”. Jakarta was dominated by sensible heat flux (H = 141,41?W/m²), while Semarang City was dominated by latent heat flux (LE = 142,91?W/m²). Recommended mitigation strategies include vertical and reflective solutions in Jakarta, and vegetation conservation with integrated green–blue infrastructure in Semarang City, tailored to the spatial characteristics of each city.