Reduce Flood Losses Of Kali Tanggul Using Spatial Based Technical Approaches

Flood disasters frequently occurred in Jember Regency, East Java. It is usually caused by the overflow of the Tanggul River in the rainy season, especially in the downstream area. Flood control could be done by building dams, embankments, shortcuts, and other technical flood protections. Meanwhile, mitigation efforts such as developing thematic maps of flood inundation need to be done to minimize losses caused by the flood. This study aims to design a flood mitigation strategy technically. The flood control structure was proposed by designing a shortcut in Kali Tanggul. Its performance was analyzed to reduce flood inundation in the Tanggul watershed. The flood inundation modeling was carried out using spatial analysis using ArcGIS 10.1 and hydraulic analysis using HECRAS 5.0.3. Flood inundation results were compared with the Tanggul watershed flood map developed by UPT PUSDA Lumajang. Based on modeling results, flood control using shortcuts is considered an effective strategy for flood mitigation. It was indicated by the reduction of flood inundation distributions, flood inundation height, and flood-affected areas. The results show that the flood height decrease 0.47 up to 0.56 m

Retention Pool As Alternative For Flood Control Case Study Of Bapertarum Housing, Sumenep Regency

Indonesia is a water country with thousands of rivers and hundreds of deep seas. This causes Indonesia to become a country that is very prone to flooding. But basically, there are several factors that cause this to happen, namely: natural events, drainage damage and environmental degradation caused by human activity itself. Geographically, Bapetarum Housing is an area located in a rainwater catchment area so that it is prone to flood events. High rainfall intensity can cause flood inundation as high as 30 cm. The purpose of this study is to calculate the adequacy of the retention pond to cope with flooding. The procedure for collecting research data begins with analyzing the flood, namely primary and secondary data. Meanwhile, the data analysis techniques used are planning rain analysis, rainfall intensity, flood discharge analysis, retention pond capacity. The retention pond capacity is sufficient because the dimensions of the retention pond are larger than the volume of the retention pond capacity when the flood is 6750m3>6447m3. The retention pond is planned in the downstream area of the residential river with a pool area of 50 x 40 meters and a depth of 4.5 m. The bottom condition of the pond is saturated because it is always inundated with water, the infiltration rate is constant (fc). The constant infiltration for clayey soil type is 0.5 m/day, the infiltration volume rate that occurs at the bottom of the pond is 179 m3/hour, the volume is below the threshold 8283.21 m3, infiltration time is 46 hours.

Potential Study of Liquefaction in the Downstream Area of Jono Oge-Paneki River, Central Sulawesi

Liquefaction during an earthquake is likely to occur in the quaternary geological layer of sediment. Based on the geological process, the mainland of Central Sulawesi was initially a sea lifted upward to become land Palu-Koro fault. Therefore, the land is basically of basic alluvium soil formation, sand deposits, and loose rock. The earthquake in Central Sulawesi in September 2018 was the cause of liquefaction, one of which was in the Jono Oge area, where most of the flow entered the Paneki river. This paper analyzed the potential for recurrent liquefaction by considering the soil structure and water level conditions. The authors focused on the downstream areas of the Paneki River, which passes through Langaleso and Kabobona Village. The data used is N-SPT data, followed by examining post-liquefaction settlement and lateral displacement. This study uses several variations of the earthquake magnitude and potential earthquakes that may occur. The results of observations indicate that the soil conditions of the study area are cohesionless soil. The liquefaction analysis shows that most of the research areas have liquefaction, land subsidence, and lateral displacement potential.

The Catastrophe of the Niedów Dam—The Causes of the Dam’s Breach, Its Development, and Consequences

Due to extreme rainfall in 2010 in the Lusatian Neisse River catchment area (in Poland), a flood event with a return period of over 100 years occurred, leading to the failure of the Niedów dam. The earth-type dam constructed for cooling the Turów power plant was washed away, resulting in the rapid release of nearly 8.5 million m3 of water and the flooding of the downstream area with substantial material losses. Here we analyze the conditions and causes of the dam’s failure, with special attention given to the mechanism and dynamics of the compound breaching process, in which the dam’s upstream slope reinforcement played a specific and remarkable role. The paper also describes a numerical approach for simulating a combined flood event downstream from the dam with the use of a two-dimensional hydrodynamic model (MIKE21). Considering the specific local conditions, i.e., wide floodplain, meandering character of the main channel, embankment overtopping, and available data set, an iterative solution of the unsteady state problem is proposed. This approach enables realistic flood propagation estimates to be delivered, the dam breach outflow to be reconstructed, and several important answers concerning the consequences of the dam’s failure to be provided. Finally, the paper presents the reconstruction of the dam that is more resilient to extreme hydrological conditions under changing climate.

The Physical Modeling Analysis of Fate and Transport of Silver Nanoparticles Dispersed by Water Flow

The release of silver nanoparticles (AgNPs) from consumer products into an environment has become a central issue for many countries. Despite that the fate and behaviors of AgNPs incorporated into a wastewater have been investigated by building a model of wastewater treatment process, the transport and retention behaviors of AgNPs influenced by the water flow in a river must be understood. The physical model of simulated river to mimic a natural flow of river was proposed to investigate the behaviors of AgNP transport in the river. The results showed that the large amount of AgNPs deposited on the riverbed as Ag sediment with only 1.26% of AgNPs remained in the water flow. The elemental content of Ag freely dispersed across the riverbed increases from the upstream to downstream area of the simulated river. Verification of the spatial distribution of Ag dispersed along the water flow may contribute to a better understanding of the fate and transport of AgNPs in the aquatic environment.

Water ecosystem services of Merawu Watershed, Banjarnegara, Central Java, Indonesia

Merawu watershed is one of the upstream areas of Serayu Watershed that serves as catchment area and protect the downstream area. In addition, the condition of natural landscape development which is accompanied by population growth potentially affects spring water ecosystem services. This study aims to determine the potential condition of spring as one of water providers in Merawu, then also to analyze the status of spring. Water balance analysis and Pollution Index (IP) analysis ecosystem services management were used. In this study, 12 springs were discovered with Kasimpar spring having the highest discharge (5.01 liters/second). The overall condition of the spring ecosystem services is one of surplus water / carrying capacity has not been exceedee (Dda ratio > 1), and the condition appropriate with water quality standards (IP <1). In conclusion, this study plays an important thing to figure it out about the existence of water ecosystem services in this area, as well as being a pioneer study on Payment for Ecosystem Services (PES) model in Banjarnegara Regency with an integrated upstream-downstrean concept and based on the principle of sustainability

Dam Safety Emergency Action Plan: A Current Practice for Hydropower Dam in Malaysia

There are currently 104 dams constructed in Malaysia. The dams were built for various purposes; 16 of them were built for hydropower. The dam's reservoir often presents significant risks to downstream areas if a massive downfall release occurs. The enormous downfall could be due to a dam break event, overtopping, and emergency operational release. An incident may occur due to massive flows over a spillway with high-speed discharge or unexpected peak discharge. The obvious impact of the incident is direct to the community in the downstream area. Although there is no dam failure recorded case in Malaysia since the 1900s, the possibility of dam failure occurring is still there. Therefore, the dams must have an emergency action plan (EAP) to prepare the likelihood of the emergency occurrences. This paper aims to explore the EAP practices for dam incident over the region and review the EAP practices of a hydropower dam in Malaysia. Implementing EAP in the emergency response system would minimise the public and environment's impact due to dam failures. The benefit of establishing an EAP is to create better communication and effective responses system among agencies during dam emergency occurrences. This paper revolves around the EAP practices by dam owners in mitigating the risk of dam failure occurrences.

Evaluasi Kesesuaian Peruntukan Lahan di Sempadan Sungai Krueng Lamnyong, Provinsi Aceh

Abstrak. Sempadan sungai merupakan kawasan penyangga antara ekosistem perairan (sungai) dan daratan. Sungai Krueng Lamnyong terletak di Kota Banda Aceh dan Kabupaten Aceh Besar yang merupakan daerah hilir dari sungai Krueng Aceh. Sempadan sungai Krueng Lamnyong telah dimanfaatkan oleh berbagai pihak untuk berbagai peruntukan. Penelitian ini bertujuan untuk mengevaluasi kesesuaian peruntukan lahan sempadan sungai Krueng Lamnyong berdasarkan peraturan perundang-undangan. Identifikasi serta evaluasi peruntukan lahan di sempadan sungai Krueng Lamnyong menggunakan perangkat lunak Sistem Informasi Geografis (SIG). Hasil penelitian menunjukkan bahwa penggunaan sempadan sungai Krueng Lamnyong diperoleh 10 jenis penggunaan lahan. Penggunaan sempadan sungai Krueng Lamnyong yang teridentifikasi sesuai dengan peruntukan yaitu sebesar 110,91 Ha atau 68,13% yang terdiri dari irigasi, jalan, sawah, rerumputan, tanaman palawija dan tanah kosong. Penggunaan yang tidak sesuai peruntukan sebesar 51,88 Ha atau 31,87% yang terdiri dari ruang terbangun, kebun, vegetasi mangrove dan kanopi pohon.Evaluation of Land Use Suitability in Aceh Province's Krueng Lamnyong River BorderAbstract. The river border is a buffer area between aquatic ecosystems (rivers) and land. The Krueng Lamnyong River is located in Banda Aceh City and Aceh Besar District which is the downstream area of the Krueng Aceh river. The Krueng Lamnyong river border has been used by various parties for various purposes. This study aims to evaluate the suitability of the land use of the Krueng Lamnyong river border based on the legislation. Identification and evaluation of land use in the Krueng Lamnyong river border using Geographic Information System (GIS) software. The results showed that the use of the Krueng Lamnyong river border obtain 10 types of land use. The use of the Krueng Lamnyong river border identified according to its designation is 110.91 Ha or 68.13% consisting of irrigation, roads, rice fields, grass, crops, and vacant land. The use that is not in accordance with the designation is 51.88 Ha or 31.87% consisting of build space, gardens, mangrove vegetation, and tree canopies.