No abstract

Excessive groundwater exploitation may lead to groundwater depletion, causing groundwater level at the inland lower than sea level and result in seawater intrusion (SWI) in a coastal aquifer. To control the occurrence of SWI, an alternative solution is to increase the replenishment of groundwater using a recharge reservoir. If a recharge reservoir is built in a region with soil hydraulic conductivity below 10-5 cm/s (semi impermeable), then a sand column is usually proposed, put on the bottom of the recharge basin and directly connected to the aquifer layer. The purpose of this study is to analyze the effectiveness of the sand column’s application in the recharge reservoir to control SWI. This research is an experimental study that combines physical and numerical modeling of the recharge basin with sand columns under a laboratory scale. The results of this research are beneficial for field applications because the process that occurs in the recharge reservoir can be determined prior to the real construction in the field. The results of the research are also useful to investigate whether the recharge reservoir is effective or not as a buffer of SWI in coastal aquifers. The expected result is that by using sand columns in the recharge basin, seawater intrusion can be controlled. It is hypothesized that the higher the number of sand column density and water level on the reservoir, the farther the freshwater saltwater interface is pushed toward the sea.

The purpose of the research is the determinationof Irrigation water requirement based on primer datas collectingand analysis factors of land preparation, plant growth,determination of water loss due to percolation. Irrigation waterrequirement depends from various factors in the preparation ofthe land, plant growth, determination of water loss due topercolation, the determination of the replacement of water andrain layer effectively. The availability of irrigation water iscalculated based on discharge data retrieval on the TaroangSecondary channel. which then processed to obtain the finalresult of the availability of water in the channel. Results of thestudy shown that needs water to irrigate an area of secondarychannels Taroang covering an area of 2,140 Ha as much 39.11m3/s. While the availability of water that goes into the secondarychannel taroang where discharge a minimum of 0.12 m3/s and themaximum discharge of 0.31 m3/s.

Kota Sengkang terletak pada wilayah yang strategis sebagai pusat kota, sehingga menuntut perhatian khusus terhadap penatan teknis terutama pada drainase perkotaan yang tidak berfungsi secara efektif dengan menggunakan suatu Sistem Informasi Geografis yang berbasis database. Tujuan dari penelitian ini adalah untuk mengetahui kondisi serta peta drainase  yang ada di kota Sengkang dengan cara mengumpulkan data spasial dan data atribut yang diperoleh langsung dari lapangan, kemudian mengolahnya dalam beberapa software diantaranya Map Source, Map Info, Sengkang GIS Drainase Perkotaan v.1.0.2013, dan Google Erth yang selanjutnya akan menjadi suatu program Sistem Informasi Geografis yang dapat diakses oleh seluruh masyarakat.Hasil penelitian menunjukkan bagaimana kondisi drainase perkotaan yang ditampilkan melalui foto, video, dan data GPS,  dimana untuk drainase primer kondisinya masih memprihatinkan dan perlu perbaikan sedangkan untuk drainase sekunder sudah cukup efektif namun ada beberapa titik tertentu yang masih perlu peningkatan. Penelitian ini juga menginformasikan cara mengakses/ menampilkan  peta drainase perkotaan melalui sistem web yang dapat dilihat di seluruh dunia melalui software Google Erth. Dari penelitian ini dapat diperoleh suatu system informasi berupa database yang terupdate ( terbaru ) sehingga dapat dijadikan sebagai acuan untuk proses pengoperasian dan pemeliharaan drainase perkotan kedepannya oleh pihak- pihak yang bersangkutan.Kata Kunci: GIS, Drainase Perkotaan, Software Google Earth

The purpose of this research was to determine the surface runoff and the puddle in the of flood risk area in Manggala village. Modified Rational Method had been applied to determine runoff discharge. It is a recent transformation of the Rational Method that can be used to not only compute peak runoff rates, but also to estimate runoff volumes and hydrographs. While, flood risk areas were based on the map from National Disaster Management (BPBD Kota Makassar, 2014). Rainfall data of Manggala village wascollected from 2009 to 2018 from three stations, they areBiringRomang, Panakukkang, and TamangapaKassi. Therefore, a Thiessen method had been applied to determine the rainfall area.Research results shown that runoff discharge for return period 5 years was3.16 m3/s, with height around 0,50 to 2,00 m.