ABSTRACT:One of the regencies in Gorontalo Province, Indonesia, Bone Bolango is an area in which landslides occur frequently. This study was at identifying the mechanism and characteristics of landslides in Bone Bolango Regency. This study is important to minimize hazards caused by this disaster. Data were obtained from the results of site survey, surface geological survey and geotechnical investigation. Cohesion during the dry season ranged between 0-15kPa, and the angle of internal friction ranged between 30 o -44 o . The topography of this area indicates a steep slope (>40°), with weathered rock and discontinuity. These internal factors made the slopes prone to landslide. Meanwhile, external factors that trigger landslides are high precipitation (>100mm), the absence of vegetation covering the slopes, as well as land use on the slopes. In general, the types of the landslide in the study area were debris flows, rotational slides, and rock falls. At the period of high precipitation, the rate of infiltration of rainwater into the soil was slower than the rate of the increase in the volume of rainwater deposited and flowing into the slope surface, resulting in the debris flow. Slope-forming material became soft due to the rise of groundwater levels. This caused a decrease in shear strength and pore water pressure that turned into positive. In the rock slope, rainwater filled the crack of slope discontinuity area so that rock got loose and fell freely. Therefore, a further research is necessary to conduct in order to determine the most accurate and efficient method for slope stability.

ABSTRAKBanjir adalah suatu bencana yang sering terjadi pada musim penghujan. Kerusakan yang ditimbulkan oleh bencana ini tidak hanya berupa kerusakan materi seperti kerusakan rumah penduduk, fasilitas umum, dan rusaknya lahan pertanian, tetapi juga menimbulkan wabah penyakit di sekitar lokasi bencana. Salah satu solusi untuk mengurangi limpasan air hujan, perlu dibuatkan model sumur resapan yang mudah dan praktis dengan memanfaatkan material lokal.Tujuan dari penelitian ini adalah pemodelan sumur resapan dan drainase untuk pencegahan dan penanggulangan bahaya banjir agar tercapai suatu kondisi lingkungan yang sehat, aman, dan nyaman. Lokasi penelitian adalah Desa Lauwonu, Kecamatan Tilango, Kabupaten Gorontalo. Bahan konstruksi untuk pembuatan model adalah material lokal yang berada di sekitar lokasi. Sumur resapan yang dibuat berukuran (2x1x1) m 3 dan (2x1,5x1) m 3 . Apabila setiap rumah tangga memiliki 1 buah sumur resapan dengan minimal volume 2 m 3 , maka akan mengurangi limpasan air hujan, sehingga bencana banjir dapat dihindari. Kata kunci: sumur resapan, drainase, banjir, material lokal ABSTRACTFlooding is a disaster that often occurs in the rainy season. The damage caused by this failure is not only material damage such as damage to houses, public facilities, and destruction of agricultural land, but also create disease outbreaks around the disaster site. One solution to reduce rainwater runoff needs to be made easy and practical recharge well model by utilizing local materials. The purpose of this research is the modeling of absorbing wells and drainage for prevention and control of flood hazard to achieve a healthy, safe, and comfortable. The research location is Lauwonu Village, Tilango District, Gorontalo Regency. Construction materials for modeling are local materials located around the site. The recharge wells are sized (2x1x1) m 3 and (2x1,5x1) m 3 . If every household has a recharge well with a minimum volume of 2 m 3 , it will reduce rainfall runoff so that that flood disaster can be avoided.

Alo watershed is the sub-watershed within the system of Limboto watershed which directly disembogues to Limboto Lake. Land degradation happened in the Alo watershed is caused by the agricultural system that does not apply land conservation techniques such as terracing and mounds and it triggers erosion and landslide. The method used in this research is geoelectric method with Wenner Alpha configuration; while the data analysis utilizes resistivity imaging method which produces two-dimensional cross-sectional images. In total, there are seven trajectories with a length of 170-180 meters each. The result of the research presents the slip surfaces of 7 locations are located in 3-17 meters depth with the inclination of 11o -79o trending dominantly northwest and one location trending southeast.

Konsumsi bahan plastik semakin hari semakin banyak sehingga akibat yang ditimbulkan semakin buruk. Karena barang berbahan plastik merupakan bahan polimer sintetis sehingga sulit terdegradasi di alam. Hasil observasi yang dilakukan mahasiswa kemudian dilanjutkan dengan rapat perencanaan program kerja yang akan ditawarkan untuk warga masyarakat dan karang taruna. Rapat tersebut menghasilkan keputusan bahwa program yang akan dilaksanakan salah satunya adalah pemanfaatn botol plastik bekas dan sampah plastik sebagai bahan konstruksi pembatas dusun dan tempat sampah. Pembuatan ecobrick memakan waktu yang cukup lama, oleh karena itu dapat dilakukan disela-sela waktu luang sehingga suatu saat bila sudah terkumpul dalam jumlah banyak bisa digunakan sekaligus. Apabila waktu yang tersedia cukup singkat isian botol dapat digantikan dengan pasir kering ataupun kerikil. Penggunaan botol dan sampah plastik sebagai batu bata ramah lingkungan tanpa disadari merupakan suatu langkah kecil yang lama kelamaan menimbulkan efek yang sangat besar bagi kelestarian lingkungan.