IJSRD - International Journal for Scientific Research & Development| Vol. 9, Issue 3, 2021 | ISSN (online): 2321-0613 All rights reserved by www.ijsrd.com 52 Prediction of Runoff in Ungauged Basin using Snyder method A. D. Londhe 1 , A. T. Gavhane 2 , S. S. Nikam 3 1 Design Engineer 2 Lecturer 3 Assistant Professor 2,3 Department of Civil Engineering 1 Feedback Infra. Pvt. Ltd., Andheri (East) Mumbai, Maharashtra, India-400093 2 Sou.Venutai Chavan Polytechnic, Pune, Maharashtra, India-400041 3 RMDSSOE, Warje Pune, Maharashtra, India-400056 Abstract— Drainage basins in the most parts of world are either partially gauged or completely ungauged. Prediction in ungauged basins is a serious challenge in hydrologic sciences, and there is still abundant work required to realize strong and reliable predictions for such basins. Errors in the prediction of hydrological parameters are seen due to unavailability of sufficient discharge data. In this research work Sub-basin of Kundalika River has been taken as the study area. Firstly we created the DEM by using the ArcGIS technique. To derive SUH we are used traditional synthetic unit hydrograph like Snyder’s method. After modeling we developed the unit hydrograph of basin and we predict the discharge of basin. Keywords: Ungauged basin, IUH, SRTM DEM, Snyder’s method I. INTRODUCTION A drainage basin which has inadequate records of various hydrological observations in terms of both quantity and quality for analysis at the suitable spatial and temporal scales and up to a good level of accuracy for application in fields is known as ungauged basins. If the parameter of interest is not available for the required period of time for prediction, that basin is an ungauged basin with respect to that variable. Variables of interest can be rainfall, runoff, erosion rates etc. so every basin is ungauged in some respect. Accurate and timely predictions of high and low flow events at any ungauged watershed location can provide stakeholders the information required to make strategic, informed decisions. Whenever data is not available, hydrological models are significant to establish baseline characteristics and find out long term impacts which are hard to calculate. The aim of modeling is to reduce the uncertainty in hydrological predictions. The unit hydrograph (UH) theory is a powerful tool in watershed hydrology. The Sherman UH concept used for derives the storm hydrograph at gauged stations. This was the first tool which determines the complete shape of hydrograph instead of quantum of peak discharge only. Here the synthetic word shows the UH obtain from watershed characteristics rather than rainfall-runoff data. The SUH models were grouped in to four types 1) Traditional models. 2) Conceptual models. 3) Probabilistic models. 4) Geomorphological model. High resolution DEMs and advance in DEM processing software like ArcGIS, helps to extract geomorphological data which improves the practical application of models. Because of these the extraction of typical hydrological information like drainage basin and sub-basin delineation, drainage path, drainage network extraction etc. make easy, thus limiting the role of calibration parameters. A. Objectives of Study As mentioned above, hydrological modeling in any catchment; gauged, partially gauged or ungauged helps to understand the catchment features and its responses. The specific objectives of the present study are: 1) DEM processing by using ArcGIS 2) Extracting the geomorphological characteristics of the study area. 3) Development of SUH by Snyder’s method. II. STUDY AREA River Kundalika is a small river which originates at longitude 73024’E and latitude 18031’N near a small village Hirdewadi, Tal. Mulshi, Dis. Pune. It originates at hills of Sahyadri mountain and flows to the Arabian Sea. The length of the river is 83.97 Km. and catchment area of the river is 786.5 Km2. Maximum elevation above means sea level is 1140m. There are five rain gauge stations Bira, Sudhagad, Roha, Sulkodi, and Alibaug. Up to 90% of Kundalika river water is consumed by the industries. There for the hydrological study of the river catchment is important. Fig. 1: Location of the study area. III. METHODOLOGY The following methodology is followed for developed for Snyder’s method. By using this methodology, the discharge of the river is calculated. First we develop maps using ArcGIS. Then we calculate the geographical characteristics after this developed SUH using Snyder’s.