RISIKO BANJIR PADA LAHAN SAWAH DI SEMARANG DAN SEKITARNYA - Hartini, Sri; Hadi, M. Pramono; Sudibyakto, Sudibyakto; Poniman, Aris (MAJALAH ILMIAH GLOBE, 2015)
Lahan sawah di wilayah Semarang dan sekitarnya berada pada dataran rendah pesisir yang rawan banjir, baik yang disebabkan oleh curah hujan yang tinggi maupun rob. Analisis risiko banjir diperlukan karena banjir merupakan ancaman bagi lahan sawah. Banjir dapat menyebabkan berkurangnya produktivitas lahan sawah, bahkan lahan sawah akan rusak dan tidak dapat ditanami padi jika tergenang banjir secara permanen. Penelitian ini bertujuan untuk menganalisis risiko banjir genangan pada lahan sawah berdasarkan kondisi bahaya dan kerentanannya. Lingkup penelitian mencakup analisis bahaya, kerentanan, dan risiko banjir genangan pada lahan sawah. Data yang digunakan dalam penelitian ini terdiri dari peta Rupa Bumi Indonesia (RBI), peta Sistem Lahan, citra penginderaan jauh resolusi tinggi, data curah hujan, debit sungai, tinggi pasang air laut, data statistik Potensi Desa (PODES), data statistik pertanian dan laporan banjir. Analisis kerawanan banjir merupakan gabungan antara kerawanan banjir genangan yang disebabkan oleh hujan dan rob. Analisis kerentanan banjir menggunakan data statistik PODES 2008 dan laporan kejadian banjir. Hasil penelitian menunjukkan bahwa banjir genangan rob merupakan ancaman dan berisiko pada pengurangan lahan sawah di wilayah ini. Selama periode 1994 â 2009 lahan sawah telah berkurang seluas 8.508,50 ha. Sebagian lahan sawah yang tergenang rob secara permanen telah dialihfungsikan ke penggunaan lain.Kata kunci: banjir genangan, rob, sawah, risikoABSTRACTPaddy field in Semarang and its surrounding areas are situated in low-lying flood-prone coastal area, whether caused by heavy rainfall and high tide. Flood risk analysis is required because flooding in this area is considered as a threat to the paddy field. Floods can lead to reduction of the paddy fieldsâ productivity, even damaging and cannot be planted with rice if flooded occurred permanently. This study aimed to analyze the risk of flood inundation in paddy fields based on hazard and vulnerability factors. The scope of the research includes analysis of hazards, vulnerabilities, and risks of flood inundation in the paddy fields. The data used in this study consisted of topographic and land systems maps, high-resolution satellite remote sensed imageries, rainfall data, river discharge, tides, and statistical data of Village Potential (PODES), statistical data of agriculture and flood reports data. The analysis of flood vulnerability is a combination of flood vulnerability caused by high rainfall and tides. The flood vulnerability analysis conducted by using PODES 2008 statistical data and flood incidencereports. The results showed that the tidal flood inundation is the main threat and provide risk on the reduction of the paddy fields in this area. During the period of 1994 â 2009, the paddy field has been reduced by 8,508.50 hectares. Some of the paddy fields that have been flooded permanently due to tides have been converted to other uses.Keywords: flood inundation, tidal flood, paddy field, risk