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Drought was yearly disaster which often happen at region of Indonesia. In this reseaech, we observe in Wonogiri especially Alang Watershed, located at southwest of Wonogiri dam and between Plumbon and Serenan district. The purpose of this research is to find the value of drought index using Normalized Difference Vegetation Index (NDVI). The drought is detected by using the debit. So, then created the relations of drought index and debit. Next, mapping the drought area in Alang watershed using software ArcGIS. Collecting data is the first step of this research., then analyze the data and doing validation test using RAPS method. Calculating the rain area using polygon thiessen. NDVI value is obtained from processing the Landsat 7 and 8 image with Arcgis. Classifying NDVI value based on Peraturan Menteri Kehutanan RI nomor P.12/Menhut-II/2012. Calculating debit using NRECA. Then, creat the relation chart between drought index and debit. Mapping the drought area from the month which had lowest NDVI value and had lowest debit. Also mapping the drouht from 2008-2017. knowing the drought area in Alang watershed and knowing the realtion chart between drought index and debit are the purpose of this research. The result showed that the relation chart of drouht index and debit aren't good to detecting the debit. The distribution of drought area is obtained from processing the Landsat 8 image with variative distribution and more accurate result.

<p>Dam is a reservoir that is needed to save water so that it can be used at the time needed both for irrigation, hydropower, and tourism. One of the Functional Dam in Indonesia is the Sangiran Dam. Sangiran Dam is located in Sumber Bening Village, Bringin District, Ngawi Regency, East Java Province. The Sangiran Dam is equipped with an overflow ogee crest type overflow building with side channels. Sangiran Dam gate type is slide gate with automatic operation using electric generator. The reservoir, which was operated starting in 2000, is designed to meet the needs of a plantation area of 1535 ha. However, in the operation that is needed in meeting the needs of irrigation air needs to be done in research the current operating patterns of the operating patterns that have been designed at the time of the reservoir design to compile an operating pattern that can meet water needs, at this time, looking for a relation between the elevation of reservoir water levels with an outflow discharge coming out of the reservoir. Based on the results of the analysis conducted on the current operating patterns are not in accordance with the pattern of initial design operations with an average deviation of 51.78% per year. This research is being carried out to analyze the optimal operating patterns of the Sangiran Dam and / or possible operating patterns in meeting water needs in the following years.</p>

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