No abstract

Pada danau bekas tambang feldspar dipenuhi oleh air limpasan yangberpotensi mencemari lingkungan. Selama masa pascatambangdiperlukan pengelolaan kualitas air. Salah satu cara pengelolaan kualitasair yaitu remediasi pasif dengan menggunakan sistem wetland. Salahsatu aspek yang penting dalam desain wetland adalah aspek hidrologi.Air pada permukaan pada tambang terbuka bersumber dari air hujan.Wetland merupakan suatu fasilitas pengelolaan air buatan yang dangkaldengan menggunakan tanaman air. Prinsip wetland ialah menghilangkanpolutan dengan mempertimbangkan kondisi hidrologi setempat.Penelitian ini bertujuan untuk mengetahui besarnya debit air limpasanyang menuju desain wetland, serta untuk mengetahui luasan minimumkompartemen dari rencana desain wetland. Dalam penelitian inimenggunakan metode pengumpulan data, kemudian peneliti melakukananalisis intensitas curah hujan, luas daerah tangkapan hujan, kondisidanau bekas tambang, arah aliran air limpasan, analisis debit airlimpasan, dan analisis dimensi danau bekas tambang. Hasil penelitianmenunjukkan bahwa debit air limpasan hasil perhitungan sebesar 0,35m³/detik dan luas minimum kompartemen desain wetland hasilperhitungan yaitu sebesar 137 m2tiap kompartemen.

Jambakan is a hamlet in Bayat District, Central Java Province, Indonesia, which commonly has brackish groundwater. Its unique geological profile leads to variation in groundwater quality that is even found between adjacent wells. This study was designed to identify the quality and hydrochemical type of groundwater and the distribution of brackish groundwater in Jambakan. It employed a quantitative method to analyzethe data collected in the field survey and groundwater quality data (major ions). Meanwhile, the hydrochemical facies of groundwater was interpreted from the plots of major ions on trilinear and quadrilateral Piper diagrams. The results showed that some of the groundwater quality parameters in six wells, namely A6, A34, A38, A65, A67, and A73, had exceeded the standard thresholds. The parameters in question were TDS, EC, salinity, sodium, calcium, chloride, sulfate, magnesium, and hardness. Compared with the six wells, A40 and A45 had better quality. The distribution of brackish groundwater could not be modeled horizontally because salinity highly depends on rock layers where the observed wells are located. Based on the trilinear Piper plots, the groundwater consisted of four hydrochemical facies, namely magnesium bicarbonate, a mixed type, calcium chloride, and sodium chloride. Meanwhile, the quadrilateral Piper diagrams showed the presence of Type I (bicarbonate water), Type II (semi-bicarbonate water), Type III (evaporite water), and Type IVb-IVc (sulfate water) in the groundwater of Jambakan Hamlet.

Heavy metal contaminants in the soil will have a direct effect on human life. The spatial distribution of naturally occurring heavy metals is highly heterogeneous and significantly increased concentrations may be present in the soil at certain locations. Heavy metals in areas of high concentration can be distributed to other areas by surface runoff, groundwater flow, weathering and atmospheric cycles (eg wind, sea salt spray, volcanic eruptions, deposition by rivers). More and more people are now using a combination of geographic information science (GIS) with geostatistical statistical analysis techniques to examine the spatial distribution of heavy metals in soils on a regional scale. The most widely used geostatistical methods are the Inverse Distance Weighted, Kriging, and Spatial Autocorrelation methods as well as other methods. This review paper will explain clearly the source of the presence of heavy metals in soil, geostatistical methods that are often used, as well as case studies on the use of geostatistics for the distribution of heavy metals. The use of geostatistical models allows us to accurately assess the relationship between the spatial distribution of heavy metals and other parameters in a map.

Mining can cause changes in the shape of landmasses and lead to erosion. Erosion results from the interaction of climate, soil, topography, vegetation and human activity on natural resources. The purpose of this study is to analyze the level of soil erosion and provide direction for land conservation priorities. The analytical method using the Universal Soil Loss Equation (USLE) method. USLE has five parameters is rainfall erosivity factor, Soil erodibility factor, terrain factors: the slope length and slope steepness, land cover and management factor, Conservation practices factor. The soil erosion rate is composed of five classes; very low, low, moderate, heavy and very heavy. The final results of this study based on the danger level of soil erosion with analysis overlay the map could indicate that erosion very heavy consists of 30%, heavy 5%, moderate 25%, low 10% and very low 30%. Priority for land conservation is based on the land conservation index table which is from very heavy erosion to very low erosion. To minimize current erosion rates by adopting a vegetative method.