Judul: Pemetaan Indeks Kekeringan dan Pola Tanam Menggunakan Metode Palmer (Studi Kasus: Jawa Barat)
Abstrak: Drought is closely related to rainfall decrease could affect the decline in rice production in one of rice production centers: West Java. This research aims to determine the drought level, drought index distribution map, and cropping pattern in West Java. Monthly rainfall, monthly average temperature, soil type, and land use data is processed by Palmer method. The highest value index is 22 and the lowest is -34. Area with the highest drought level is Northern area of West Java, while the central and southern part of West Java area tends to be wet. Peak of the drought occurs in August and September. On the strong El Nino years, the rainfall value becomes lower followed by drought index value. In the non-irrigated land, cropping patterns that can be applied is paddy-paddy-crop with the beginning of the season in November, while for the irrigated land rice can be planted up to three times a year. In the non-irrigated land at the north area that tends to be dryer, cropping patterns that can be applied is paddy-crop-crop with the beginning of planting season in December, if conditions are adequate irrigation of rice can be planted two or three times a year.
Keyword: Bogor Agricultural University (IPB), El Nino, Palmer index, drought, cropping pattern.

Judul: Vulnerability Level Of Agricultural Drought To Rice  Plant Productivity In The Province Of East Java
Abstrak: Kekeringan merupakan kondisi kurangnya ketersediaan air pada suatu wilayah dalam jangka waktu yang panjang dan berpengaruh terhadap intensitas kebutuhan manusia. Kajian kekeringan ini digunakan untuk memantau tingkat kekeringan yang terjadi khususnya di Jawa Timur yang merupakan sentra pertanian serta membandingkan tingkat kekeringan pada fenomena tahun El Nino kuat, tahun El Nino lemah, dan tahun normal. Penelitian ini menggunakan indeks SPI untuk menghitung kekeringan meteorologi, VHI untuk kekeringan pertanian serta NDVI untuk kerentanan kekeringan menggunakan 3 tahun yang berbeda yaitu tahun 2015 sebagai tahun El Nino kuat, tahun 2017 sebagai tahun El Nino lemah, dan tahun 2017 sebagai tahun normal untuk pembanding. Kejadian El Nino menyebabkan kekeringan yang tinggi dan waktu lebih panjang dibandingkan pada tahun normal. Terdapat perbedaan waktu terjadi kekeringan meteorologi dengan kekeringan pertanian, hal ini disebabkan oleh adanya time lag (penundaan) antara curah hujan dengan munculnya gejala kekeringan pertanian. Time lag antara kekeringan pertanian dengan kekeringan meteorologi terjadi selama tiga bulan. Kerentanan kekeringan pada tahun El Nino memiliki kerentanan yang lebih tinggi dan stabil dibanding pada tahun normal, dimana kerentanan yang terlalu tinggi kurang cocok sebagai tempat budidaya tanaman yang rentan terhadap kekeringan, seperti padi. Produktivitas padi pada tahun 2019 merupakan produktivitas terendah dibandingkan pada tahun lainnya yang mencapai 5,72 ton/ha. Penurunan ini disebabkan oleh adanya pengaruh El Nino yang terjadi pada tahun 2019 lebih kuat dibandingkan pada tahun 2015, sedangkan produktivitas padi tertinggi terjadi pada tahun 2015 mencapai rata-rata 6,11 ton/ha., Drought is a condition of lack of water availability in an area over a long period and affects the intensity of human needs. This drought study is used to monitor the level of drought that occurs, especially in East Java as an agricultural center, and compare the level of drought in the phenomenon of strong El Nino years, weak El Nino years, and normal years. This study uses the SPI index to calculate meteorological drought, VHI for agricultural drought and NDVI for drought vulnerability using 3 different years, namely 2015 as a strong El Nino year, 2017 as a weak El Nino year, and 2017 as a normal year for comparison. El Nino events cause high drought and more extended time than normal years. There is a difference in timing between meteorological drought and agricultural drought, and this is due to the time lag between rainfall and the appearance of symptoms of agricultural drought. The time lag between agricultural drought and meteorological drought is three months. Drought vulnerability in El Nino years has a higher and more stable vulnerability than in normal years, where too high vulnerability is less suitable as a place for cultivating drought-prone crops, such as rice. Rice productivity in 2019 was the lowest productivity compared to other years, reaching 5.72 tons/ha. This decrease was due to the influence of El Nino occurred in 2019, which was stronger than in 2015, while the highest rice productivity occurred in 2015, reaching an average of 6.11 tons/ha.
Keyword: Drought, El Nino, NDVI, SPI, VHI

Judul: Hydroxyapatite-Chitosan Composite Coating on Stainless Steel 316 to Improve Corrosion Resistance
Abstrak: Metals that were used in bone implantation should have good corrosion resistance that were not easily corroded when implanted into the body. Metal corrosion resistance of stainless steel 316 can be enhanced through the metal coating by hydroxyapatite-chitosan composite with composition ratio of hydroxyapatite (gram) and chitosan 3% (mL) 0.2:0, 0.2:0.1, 0.2:0.5, 0.2:1.0, and 0.2:1.5. Besides improving the corrosion resistance of metal, the presence of chitosan also maintain the position of hydroxyapatite on metal surfaces. Corrosion resistance increases with increasing amount of chitosan added and the best composition of hydroxyapatite-chitosan composite was 0.2:1.0.
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