Penilaian Rain Garden di Kampus IPB Dramaga, Kabupaten Bogor, Provinsi Jawa Barat

Abstract

Perubahan tutupan lahan akibat urbanisasi meningkatkan limpasan permukaan dan menurunkan kemampuan infiltrasi tanah sehingga diperlukan pendekatan pengelolaan air hujan yang berkelanjutan. Salah satu pendekatan yang berkembang adalah rain garden, yaitu sistem bioretensi yang berfungsi mengelola limpasan sekaligus memberikan manfaat ekologis dan sosial. Penelitian ini bertujuan menilai Rain Garden IKA Faperta IPB berdasarkan aspek hidrologis, biodiversitas, dan sosial, serta mengkaji keterkaitan ketiga aspek tersebut dalam satu sistem lanskap multifungsi. Penelitian dilakukan menggunakan pendekatan studi kasus di kampus IPB Dramaga, Kabupaten Bogor. Kajian hidrologis dilakukan melalui analisis neraca air yang meliputi curah hujan, infiltrasi, evaporasi, dan transpirasi. Pengamatan hidrologis dilakukan pada 30 kejadian hujan aktual. Kajian biodiversitas dilakukan melalui inventarisasi flora dan fauna, sedangkan kajian sosial dilakukan melalui survei terhadap pengunjung Rain Garden menggunakan kuesioner. Selain itu, dilakukan analisis Multifunctionality Index (MI) menggunakan pendekatan Multi-Criteria Decision Analysis (MCDA) untuk mengevaluasi kinerja Rain Garden secara terintegrasi. Hasil penelitian menunjukkan bahwa Rain Garden memiliki performa hidrologis yang baik dalam mengelola limpasan hujan. Rain Garden mampu mereduksi limpasan sebesar 67% dengan kontribusi infiltrasi mencapai 66% dari total input air hujan. Pada aspek biodiversitas, Rain Garden mendukung terbentuknya habitat yang mampu menunjang keberadaan berbagai jenis flora dan fauna dengan nilai indeks keragaman fauna (H’) sebesar 3,923 dan total 194 spesies fauna yang menunjukkan bahwa komunitas relatif stabil. Pada aspek sosial, Rain Garden dinilai positif oleh pengunjung dan lebih disukai (84%) dibandingkan taman konvensional. Hasil sintesis menunjukkan bahwa fungsi hidrologis, biodiversitas, dan sosial pada Rain Garden saling berkaitan dan membentuk satu kesatuan sistem lanskap. Proses infiltrasi dan pengelolaan air hujan menciptakan kondisi yang mendukung perkembangan flora dan kehadiran fauna, yang selanjutnya meningkatkan kualitas ruang bagi pengguna. Evaluasi menggunakan MCDA menunjukkan bahwa Rain Garden memiliki MI sebesar 71,1 yang termasuk kategori tinggi. Dengan demikian, Rain Garden IKA Faperta IPB tidak hanya berfungsi sebagai infrastruktur pengelolaan limpasan air hujan, tetapi juga sebagai sistem lanskap yang adaptif, hidup, dan multifungsi melalui integrasi fungsi hidrologis, biodiversitas, dan sosial secara simultan. Temuan ini menegaskan potensi rain garden sebagai bentuk Nature-Based Solution (NBS) yang mendukung pengembangan lanskap kampus yang berkelanjutan.

Land cover changes due to urbanization have increased surface runoff and reduced soil infiltration capacity, creating the need for sustainable stormwater management approaches. One of the approaches that has gained considerable attention is the Rain Garden, a bioretention system designed to manage stormwater runoff while providing ecological and social benefits. This study aimed to assess the Rain Garden IKA Faperta at IPB Dramaga Campus from hydrological, biodiversity, and social perspectives, and to examine the interrelationships among these aspects within a landscape system. This research employed a case study approach at IPB Dramaga Campus, Bogor Regency, West Java. The hydrological assessment was conducted using a water balance analysis, including rainfall, infiltration, evaporation, and transpiration components. Hydrological observations were carried out during 30 rainfall events. Biodiversity assessment was conducted through flora and fauna inventories, while the social assessment was performed using visitor surveys and questionnaires. In addition, a Multifunctionality Index (MI) was calculated using a Multi-Criteria Decision Analysis (MCDA) approach to evaluate the integrated performance of the Rain Garden. Ther result demonstrated that the Rain Garden exhibited good hydrological performance in managing stormwater runoff. The system reduced runoff by 67%, with infiltration contributing 66% of the total water input. From the biodiversity perspective, the Rain Garden supported habitat formation for various plant and animal species, with a fauna diversity index (H’) of 3.923, indicating a relatively stable ecological community. From the social perspective, the Rain Garden was positively perceived by visitors and was preferred by 84% of respondents compared to a conventional garden. The synthesis of finding revealed that hydrological, biodiversity, and social functions were interconnected and formed an integrated landscape system. Stormwater management created environmental conditions that supported vegetation growth and fauna occurrence, which subsequently enhanced spatial quality and user experience. The MCDA evaluation showed that the Rain Garden achieved a MI of 71.1, categorized as high. Therefore, the Rain Garden IKA Faperta IPB functions not only as stormwater management infrastructure but also as an adaptive, living, and multifunctional landscape through the simultaneous integration of hydrological, biodiversity, and social functions. These findings highlight the potential of rain gardens as a Nature-Based Solution (NBS) for supporting sustainable campus landscape development.