Land use change is one of the factors affecting urban development including urban energy needs. This study analysis the effect of land use and surface temperature on energy system development of Gorontalo city. Gorontalo has a very high solar energy potential but has not been utilized optimally. Land Surface Temperature (LST) mapping is the first step to identify the potential of solar anergy for energy system development in Gorontalo City. Remote sensing technology and geographic information systems are helpful in mapping the spatial distribution of each parameter used. In this research the data used is Landsat 8 for mapping land cover/land use, green area and LST. The results showed that in the dry season the highest surface temperature was in the building area, and the lowest temperature was in the vegetation area. Land use in city of Gorontalo is dominated by high density vegetation (VKT) of 36% of the total area, while built-up area has 26% of the total area. LST was dominant in the wet season of 30-40 °C i.e 50.51% of the area while in dry season wasdominant at 40-50 °C covering 42%. The highest temperature in the city of Gorontalo in both dry and wet season is distributed in Pulubala, Limba U1, and Biawao. These three regions can be a recommendation for the development and utilization of solar energy as an alternative energy source. This research provides insight into land surface temperature and become a recommendation in urban planning and energy policy.

Aplikasi Penginderaan Jauh dan GIS dapat digunakan untuk mendapatkan informasi spasial produksi lahan sawah. Produktivitas sawah, yang biasanya disajikan dalam data tabular, dapat dipetakan menjadi informasi spasial dengan menggunakan respon vegetasi dari citra penginderaan jauh resolusi menengah. Tujuan dari penelitian ini adalah untuk menilai rata-rata produksi sawah di Magelang menggunakan Sentinel 2A. Citra melalui tahapan pemrosesan, yaitu koreksi atmosfer serta klasifikasi multispektral untuk mendapatkan batas sawah. Survei lapangan dan analisis regresi antara survei produktivitas aktual dan indeks vegetasi dilakukan untuk mendapatkan model terbaik. Ada 8 model indeks vegetasi yang digunakan dalam penelitian ini. Indeks Vegetasi memberikan kisaran nilai koefisien korelasi 0,62 hingga 0,74. Kisaran ini dikategorikan sebagai hubungan korelasi sedang dan kuat. Nilai koefisien korelasi tertinggi ditunjukkan oleh indeks RVI sebesar 0,74, yang berarti bahwa 74% dari model dapat mewakili sampel. Produksi beras dominan di daerah penelitian adalah di kisaran 47-52 kg / 100 m2. Nilai ini di bawah rata-rata produksi di Magelang

Abstract. Coastal tourism is a leading sector substantially contributing to the regional income of Gunungkidul Regency, Indonesia. However, with more tourists visiting the beach, more lives are threatened by coastal hazards. Rip currents are a channel of powerful, narrow, fast-moving water that can carry floating objects away from the shore, presenting one of the most common coastal hazards to swimmers. Unfortunately, most tourists are unaware of rip currents and their threats and how to avoid them. This study was designed to identify the types and dimensions of rip current in one of the regency’s tourist attractions, Drini Beach. For this purpose, an environmentally friendly fluorescent dye, Uranine, was injected from the shoreline, then the velocity and direction of its movements were observed from aerial video footage captured with a drone. Results showed stationary rip currents with a narrow channel, called a channel rip, with the mean dimensions: 250 m from the shoreline to the head and 10.25 m in width. A break in the reef flat can mostly generate rip currents at Drini Beach. It creates an area that is deeper than the surrounding reef flats through which water and the transported coastal sediments can flow easily offshore. Rip currents identified in this research provide the basis for disaster mitigation measures to reduce fatality.

Erosion is an indication of watershed degradation. In a watershed management, it is necessary to prioritize the handling that takes into account the characteristics of the watershed, one of which is morphometric character. This study aims to determine the priority location of erosion management in Oyo Watershed based on morphometric data using Fuzzy AHP modeling. Morphometric parameters that affect erosion are Rbm (bifurcation ratio), Rc (circulatory ratio), Dd (drainage density), T (texture), Su (Gradient) and Rn (Rugness Number). The highest value of the output shows the priority location that should be controlled. The high priority levels are found in 21 sub-watersheds with an area of 3,82 ha, medium levels are in 35 sub-watersheds with an area of 17,780.21 ha, low levels are in 106 sub-sub Watersheds with an area of 48,974.46 ha. The priority order for erosion management at the sub-watershed level is very important to prepare a watershed management plan in order to control soil erosion that is appropriate to protect the soil from further erosion.

Flood is one of the most frequently occurring natural disasters in Indonesia. At the end of 2017, Tropical Cyclones Cempaka and Dahlia formed over the Indian Ocean, inducing extreme rains and floods in some parts of Java Island. The Special Region of Yogyakarta was among the most affected areas, especially along the Oyo River section in Imogiri District. This research was designed to identify and map the flood-prone areas in the district as part of flood mitigation measures. For this purpose, The Unmanned Aerial Vehicle (UAV) technology was used to not only provide a detailed and up-to-date description but also produce aerial photographs (orthoimages) and Digital Elevation Model (DEM). These two products were inputted to the inundation modeling developed with a geomorphic approach and simulated in a Geographic Information System (GIS). In terms of accuracy, the resulting models were quite reliable for mapping on a detailed scale and only slightly deviated from the traced inundation in the field. Also, five areas (sub-village) were found with the highest vulnerability to floods, namely, Trukan, Butuh, Dogongan, Siluk Satu, and Kedung Miri.