Informasi prakiraan awal musim yang dikeluarkan BMKG sangat penting khususnya bagi komoditas pertanian. Parameter cuaca yang digunakan BMKG dalam penentuan awal musim selama ini hanya dengan jumlah curah hujan dasarian tanpa melihat frekuensinya (banyaknya hari hujan). Oleh karena itu kajian ini bertujuan untuk melihat bagaimana frekuensi hari hujan dalam penentuan awal musim dengan wilayah kajian Jawa Timur. Data yang digunakan adalah data curah hujan (CH) dan hari hujan (HH) dasarian dari 82 titik pos hujan di wilayah Jawa Timur, dimana jumlah hari hujan yang digunakan 5 skenario kajian. Dengan metode analisa subjektif deskriptif dengan melibatkan analisa grafik dan analisa spasial maka didapatlah kriteria awal musim alternatif di wilayah Jawa Timur yaitu dengan menambahkan parameter 3 HH. Dengan penjelasan CH ≥50 mm dan HH ≥3 hari per dasarian untuk awal musim hujan (AMH) sementara itu untuk awal musim kemarau (AMK) diperoleh ketika CH per dasarian < 50 mm dan HH < 3 hari per dasarian.

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ABSTRAKDampak terhadap pemanasan global adalah terjadinya perubahan iklim yang berpengaruh terhadap kondisi ekosistem Daerah Aliran Sungai (DAS). Kondisi ini menyebabkan penurunan tingkat kesejahteraan masyarakat dan meningkatkan tingkat kerentanan masyarakat. Penelitian ini bertujuan melakukan analisis tingkat kerentanan masyarakat terhadap perubahan iklim di Sub DAS Garang Hulu. Penelitian ini merupakan penelitian deskriptif-eksploratif dengan menggunakan pendekatan metode kombinasi kualititatif dan kuantitatif (mixed method). Data sekunder dikumpulkan melalui kegiatan studi literatur dan desk study. Data primer berupa persepsi masyarakat dengan wawancara mendalam dengan metode purposive sampling. Penilaian kerentanan masyarakat terhadap perubahan iklim menggunakan fungsi dari tiga komponen, yaitu paparan, kepekaan, dan kemampuan adaptasi. Hasil analisis kerentanan masyarakat ditampilkan dalam bentuk peta-peta dengan bantuan Sistem Informasi Geografi (SIG). Hasil kajian menunjukkan bahwa tingkat kerentanan masyarakat terhadap perubahan iklim didominasi dalam kategori rendah sampai dengan sedang dengan persentase 73.83%. Daerah yang memiliki kerentanan tinggi adalah daerah Kecamatan Ungaran Timur dan kelurahan Sukorejo di Kota Semarang.Kata Kunci : DAS, Kerentanan, Paparan, Kepekaan, Kemampuan Adaptasi ABSTRACTThe impact of global warming is climate change affecting the condition of Watershed Ecosystem. This condition causes the decreasing in the level of social welfare and the increasing level of vulnerability of living community. This study was aimed to analyze the level of vulnerability of living communities due to climate change in Garang Hulu sub-watersheds . This research was a descriptive-explorative approach by using a combination of qualititative and quantitative methods (mixed method). Secondary data were collected through the study of literature and desk study. Primary data were taken in the form of public perception along with indepth interviews. Respondents were chosen through purposive sampling method. Assessment of the social vulnerability to climate change was using a function of three components, namely the exposure, sensitivity, and adaptability. The results of the vulnerability analysis were presented in the form of maps using the GIS. The study results showed that the level of vulnerability of communities to climate change was dominated by low category to moderate with the percentage of 73.83%. Areas that had a high vulnerability were East Ungaran local district and Sukorejo village in Semarang.

Indonesia is one of the countries that is most vulnerable to climate change. As a small Indonesian island, Bali is likely to also be affected by climate change impacts, including rising sea levels, drought, and flooding, which will also impact on its paddy production. This paper shows how the focus area of vulnerability assessments in Bali has been identified, based on multiple assessments including literature reviews, statistical assessment, stakeholder and policy assessment, and interviews with farmers. A project team applied a six-step process to identify issues linked to climate change, the purpose and system of vulnerability assessment, potential risk/harm in context, and potential variables for a further assessment. The team identified paddy production as a significant issue, and the purpose and system was the Presidential Decree No.5 on paddy production. Significant concerns linked to paddy production included droughts, land use change, and potential variables for vulnerability assessment such as water level and the price of rice. This paper suggests how adaptive measures should be implemented to handle paddy production in a changing climate. The results of this paper were used by a vulnerability assessment on rice paddy and climate change [Takama, T., Setyani, P., & Aldrian, E. (2014). Climate change vulnerability to rice paddy production in Bali, Indonesia. In W. Leal Filho (Ed.), Handbook of climate change adaptation (pp. 1-23). Berlin: Springer]. IntroductionThe devastating impact of climate change is already evident in Indonesia. The combination of high population density and a high level of biodiversity, together with its more than 15,000 islands and a coastline that has (a staggering total of) tens of thousands of kilometres, make Indonesia one of the most vulnerable countries to the impact of climate change. As a small island of Indonesia, Bali is likely to be affected by climate change, impacting various aspects such as rising sea level, drought, flood, as well as paddy production.The purpose of this paper is to show how a project team identified the focus area of vulnerability assessment in Bali based on multiple assessments, including literature reviews, statistical assessment, stakeholder/policy assessment, and interviews with farmers. The focus areas have to be applicable not only to Bali Island, but also to the rest of Indonesia in order to make this study scalable in the future. Through a six-step process, the project team identified issues concerned with climate change, the purpose and system of vulnerability assessment, potential risk/harm in context, and potential variables for a further assessment.According to Harvey, there are 10 steps to complete a vulnerability assessment to create vulnerability indicators (Harvey et al., 2009). This paper applies the first six steps, namely identifying a range of issues to the potential variables ( Figure 1). Reviews on the existing reports identified a range of issues. The purpose and system of vulnerability assessment and potential harms were ident...

Coastal areas are very vulnerable to disasters. One of the disasters that needs serious attention in coastal areas, including the coast of Jakarta, is coastal inundation. However, there is no integrated coastal inundation prediction system implemented in this area. This study aimed to build a model of coastal inundation by combining various factors, namely hydrodynamic model, wave model, and river model. The model used in this research is the integration of the Delft3D model, the WaveWatch III-SWAN model, and the SOBEK model. The results show that the simulation of the water level was in accordance with the observed data, from 30 November to 8 December 2017 during the supermoon period with a correlation accuracy of 0.9 and RMSE of 5.9 cm. However, the results of the simulation and astronomical tide prediction have a correlation of 0.81 and an RMSE is 13.6 cm. Therefore, it can be seen that the model is better than the astronomical tide prediction. The hydrodynamic model shows that Jakarta Bay has a water level range of 0.66 to 0.68 m during the supermoon period. The mapping of flood inundation areas show that the water level in the Tanjung Priok and Marunda in North Jakarta has a maximum inundation level of 50 to 100 cm with an inundation area of 272.17312 and 456.03653 m 2 . Meanwhile, our analysis for the Ancol and Kalibaru shows an inundation level of 0 to 30 cm with an inundation area of 388.04358 and 169.17656 m 2 . Our model provides better accuracy because it takes into account several important variables for modeling coastal inundation. Our early warning system proved to be accurate in providing coastal inundation prediction information for the North Jakarta area.