Analisis Kekritisan Lingkungan berdasarkan Environmental Criticality Index dan Fenomena Urban Heat Island di Kota Bima
Abstract
Konversi lahan vegetasi menjadi lahan terbangun yang terjadi di Kota Bima
mendorong terjadinya urban heat island (UHI) dan penurunan kualitas lingkungan
yang dapat mempengaruhi kualitas hidup masyarakat dan pembangunan
berkelanjutan di Kota Bima. Kekritisan lingkungan dapat diduga menggunakan
Environmental Crticality Index (ECI) yang merupakan nilai rasio Normalized
Difference Vegetation Index (NDVI) dan suhu permukaan tanah. Pada penelitian
ini, ECI dikembangkan menjadi persamaan suhu udara dan Built-up Area Index
(BU). Penelitian ini bertujuan mengetahui tingkat kekritisan lingkungan di Kota
Bima berdasarkan nilai ECI dan mengetahui hubungan antara UHI dengan ECI di
Kota Bima. Analisis dilakukan dengan menggunakan citra satelit Landsat 8 dan
pengukuran lapangan. Hasil dari penelitian ini, Kota Bima memiliki kisaran nilai
NDVI -0.16 - 0.61 dengan nilai NDVI di perkotaan lebih rendah dibandingkan di
pinggiran kota. Kisaran nilai BU -1 - 0.2 dengan BU di wilayah perkotaan lebih
tinggi dibandingkan di pinggiran kota. Nilai UHI di Kota Bima tinggi pada tahun
2021. Nilai ECI menunjukan bahwa dari tahun 2015 hingga 2021 lingkungan
semakin kritis di wilayah perkotaan. Wilayah pesisir Kota Bima memiliki nilai ECI
yang tinggi artinya kondisi lingkungannya telah memasuki kondisi kritis dan juga
diidentifikasi terjadi fenomena UHI. Korelasi (r) ECI dengan UHI di Kota Bima
cukup kuat (0.36 – 0.55), namun korelasi ECI dengan NDVI dan ECI dengan BU
sangat kuat (0.95 – 0.96) dan (0.943 – 0.975). The conversion of vegetated land into built-up land that occurs in the City of
Bima encourages the occurrence of urban heat islands (UHI) and a decrease in
environmental quality that can affect the community's quality of life and sustainable
development in the City of Bima. Environmental criticality can be estimated using
the Environmental Criticality Index (ECI), which is the ratio value of the
Normalized Difference Vegetation Index (NDVI) and soil surface temperature. In
this study, ECI was developed into an equation of air temperature and Built-up Area
Index (BU). This study aims to determine the level of environmental criticality in
Bima City based on the ECI value and determine the relationship between UHI and
ECI in Bima City. The analysis was carried out using Landsat 8 satellite imagery
and field measurements. In this study, Bima City has an NDVI value range of -0.16
- 0.61, with a lower NDVI value in urban areas than in the suburbs. The range of
BU values is -1 - 0.2, with BU in urban areas being higher than in the suburbs. The
UHI value in Bima City is increased in 2021. The ECI value shows that from 2015
to 2021, the environment is increasingly critical in urban areas. The coastal area of
Bima City has a high ECI value, meaning that the environmental conditions have
entered a critical condition, and the UHI phenomenon has also been identified. The
correlation (r) of ECI with UHI in Bima City is quite strong (0.36 – 0.55), but the
correlation of ECI with NDVI and ECI with BU is very strong (0.95 – 0.96) and
(0.943 – 0.975).