Analisis Spasiotemporal Hubungan Penggunaan Lahan dan Kualitas Air di DAS Ciliwung

Abstract

DAS Ciliwung menghadapi tekanan lingkungan akibat urbanisasi dan perubahan penggunaan lahan yang berpotensi menurunkan kualitas air sungai. Penelitian ini bertujuan menganalisis kondisi kualitas air DAS Ciliwung secara spasiotemporal serta mengevaluasi hubungannya dengan perubahan penggunaan lahan. Data kualitas air tahun 2007, 2011, 2014, 2017, 2019, dan 2024 dianalisis menggunakan parameter dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), dan Total Coliform, kemudian dinilai dengan metode CCME-WQI. Perubahan penggunaan lahan dianalisis melalui klasifikasi citra, sedangkan hubungan keduanya diuji menggunakan korelasi Pearson. Hasil menunjukkan kualitas air DAS Ciliwung secara umum berada dalam kategori buruk (poor). Nilai CCME-WQI menurun dari 32,85 (2007) menjadi 21,93 (2011) dan 15,16 (2014), kemudian meningkat menjadi 27,76 (2017), 26,83 (2019), dan 30,02 (2024). Pencemar dominan adalah BOD dan Total Coliform yang masih melampaui baku mutu, meskipun DO, COD, dan TSS menunjukkan perbaikan pada 2024. Lahan terbangun meningkat dari 43,07% (2007) menjadi 75,38% (2024), disertai penurunan hutan, lahan terbuka, dan pertanian lahan kering. Area terbangun berkorelasi positif dengan TSS dan COD serta negatif dengan DO, sedangkan badan air berkorelasi positif signifikan dengan CCME-WQI. Degradasi ini berkaitan dengan ekspansi kawasan terbangun, tekanan pencemaran domestik, dan berkurangnya tutupan lahan alami, sehingga pengendalian tata ruang, perbaikan sanitasi, serta pengelolaan limbah domestik perlu diprioritaskan. Kata kunci: CCME-WQI, DAS Ciliwung, kualitas air, penggunaan lahan.

The Ciliwung Watershed faces environmental pressure from urbanization and land use change that potentially degrades river water quality. This study aimed to analyze the spatiotemporal condition of water quality in the Ciliwung Watershed and evaluate its relationship with land use change. Water quality data from 2007, 2011, 2014, 2017, 2019, and 2024 were analyzed using dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), and Total Coliform, then assessed using the Canadian Council of Ministers of the Environment Water Quality Index (CCME-WQI). Land use change was analyzed through image classification, while their relationship was examined using Pearson correlation. The results show that water quality generally remained in the poor category. CCME-WQI values declined from 32.85 (2007) to 21.93 (2011) and 15.16 (2014), then increased to 27.76 (2017), 26.83 (2019), and 30.02 (2024). BOD and Total Coliform were the dominant pollutants, still exceeding water quality standards, although DO, COD, and TSS improved in 2024. Built-up land expanded from 43.07% (2007) to 75.38% (2024), accompanied by declines in forest, open land, and dryland agriculture. Built-up areas correlated positively with TSS and COD and negatively with DO, while water bodies correlated significantly and positively with CCME-WQI. This degradation is linked to built-up expansion, domestic pollution pressure, and reduced natural land cover, making spatial planning control, sanitation improvement, and domestic waste management priorities. Keywords: Built-up land, CCME-WQI, Ciliwung Watershed, land use change, water quality.