No abstract

The Feasibility study potential of small dams in Semarang District has identified 8 (eight) urgent potential small dams. These potential dams here to be constructed within 5 (five)

The flood disaster is one of the natural phenomena that are difficult to avoid. The risk of flood losses that occur in urban areas is generally greater than that occur in the countryside, which it is more due to the differences in the level of public welfare facilities and population density factors

Pembangunan bendungan memberikan manfaat untuk masyarakat sekitar waduk, namun juga menyimpan bahaya jika mengalami keruntuhan bendungan. Salah satu syarat yang harus dipenuhi sebelum mendapatkan sertifikat ijin operasi adalah RTD (Rencana Tindak Darurat). Manfaat dari disusunnya rencana tindak darurat adalah untuk pedoman para pengelola bendungan maupun pemerintah yang berada pada daerah yang terkena resiko apabila terjadi kondisi darurat pada Bendungan. Makalah ini mencakup daerah yang terdampak jika terjadi kegagalan bendungan. Pemanfaatan Software menggunakan HEC-RAS dengan studi kasus Bendungan Gondang yang berlokasi di Kabupaten Karanganyar. Lokasi terdampak menurut hasil analisis adalah Desa Gempolan, Desa Ganten, Desa Kwadungan, Desa Kutho, Kecamatan Kerjo, Kabupaten Karanganyar, Provinsi Jawa Tengah. Bendungan ini mempunyai tampungan total 9,15 juta meter kubik dengan tinggi bendungan 71 meter.  Pemodelan keruntuhan bendungan dengan 2D pada kondisi unsteady flow, simulasi keruntuhan akibat piping tengah pada elevasi +495 m. Hasil pemodelan keruntuhan Bendungan Gondang yang akan menimbulkan dampak paling besar jika terjadi piping tengah akibat banjir PMF dengan puncak debit Qoutflow= 902,40m3/det. Kecepatan banjir akibat keruntuhan bendungan tercepat yang sampai ke pemukiman adalah 24 menit yaitu sampai di Desa Gempolan yang berjarak 0,6 km dari lokasi bendungan.AbstractThe construction of a dam provides benefits to the community around the reservoir, but also saves danger if it experiences dam collapse. One of the requirements that must be met before obtaining an operating permit certificate is the RTD (Emergency Action Plan). The benefit of formulating an emergency action plan is to guide the dam managers and the government who are in the area at risk if an emergency condition occurs at the Dam. This paper covers the area affected in the event of dam failure. Utilization of Software uses HEC-RAS with a Gondang Dam case study located in Karanganyar Regency. The affected locations, according to the results of the analysis are Gempolan Village, Ganten Village, Kwadungan Village, Kutho Village, Kerjo District, Karanganyar Regency, Central Java Province. This Dam has a total reservoir of 9.15 million cubic meters with a dam height of 71 meters. Dam failure modeling with 2D under unsteady flow conditions, simulation of collapse due to middle piping at +495 m elevation. The results of the Gondang Dam collapse modeling, which will have the most significant impact if there is middle piping due to PMF flooding with peak discharge Qoutflow = 902.40m3 / sec. The speed of flooding due to the collapse of the Dam that reached the fastest settlement was 24 minutes, namely to the village of Gempolan, which is 0.6 km from the location of the Dam.Keywords: Gondang Dam, dam break, affected area Karanganyar.

Development of the coastal area without environmental consciousness is disrupting coastline equilibrium, thus triggering erosion and accretion. This results in the obscurity of the border area due to coastline change. The objective of this study is to determine the original coastline of Semarang city and Demak district. The method used is remote sensing using Landsat satellite imagery data dating from 1984 to 2018. The results showed that the length of the coastline in Semarang and Demak border coast shows a continuous increase from 48.2, 57.9, 63.7, and 73.5 km in 1984, 1992, 2000, and 2008, respectively to 92.6 km in 2018, and the average annual change rate from 1984 to 1992, 1992 to 2000, 2000 to 2008, and 2008 to 2018 is 1.2 km per year, 0.7 km per year, 1.2 km per year, and 2.1 km per year, respectively. It was concluded that the current coastline condition of Semarang city and Demak district has had an increase of 29.8 km in length and shifted inwards by 0.5-2 km in 2000 – 2018 compared to the original coastline. This shows a deviation of 5-15% from Government Regional Spatial Plan. The study recommends a sustainable coastal management and action plan to be prepared by the government, as it is vital in preserving the coastal regions.