Geoinformatic Studies of Morna Watershed
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International Journal of Scientific & Engineering Research, Volume 5, Issue 12, December-2014 5 ISSN 2229-5518 Geoinformatic studies of Morna watershed Dr. A.J.Shirke Dept. of Civil Engineering. P.D.V.V.P. College of Engineering, Ahemdnagar, E-mail [email protected] A.R.Take Dept. of Civil Engineering. P.D.V.V.P. College of Engineering, Ahemdnagar, Abstract geomorphometry denotes the measurement of the form of the earth’s surface. Sustainable developments and management Geomorphometry supplies the quantitative of the watershed is influenced by topography values of geomorphology and hydrology. of the area and the geomorphologic features. Geomorphometry supplies the quantitative The Geographical Information System (GIS) values to geomorphology and hydrology. The has been adopted for the geomorphometric RS &GIS has been adopted for analysis of the study area. GIS is the data geomorphometric analysis of the study area. handling and analysis system based on sets of The software ILWIS (developed by ITC, data distributed spatially in two dimensions Netherlands) has been used for inputting (Borrough, 1998). Geographic data has three managing, analyzing, interpreting and major components: geographic position. presenting the data. The generated Properties (attributes) and time. The GIS geoinfromatics can be readily used for software (ILWIS) allows inputting, managing, decision-making. The attempt has been made analyzing and presenting geographic data by to study some geomorphometric parameters of which information can be generated. Morna River, which is right tributary of Koyana in Patan tahsil of Western Maharashtra. The Spatial map data (Vector/raster) and attribute manual estimation of geomorphic parameters data get combined as they are referenced in is tedious and cumbersome process. However relative terms to a specific location on the through this attempt,IJSER it has been found that earth’s surface. Application of GIS makes the integration of RS & GIS allows reliable, computation of geomorphometic parameters accurate and most updated data base tool for easy, less time consuming and more accurate. handling spatial data, very useful in deriving geomorphometric parameters which are Integration of Remote Sensing (Floyd; Lillisand essential for planning future infrastructural, and Kiefer, 2000) GIS techniques provide sustainable water resources planning of the reliable, accurate and update database on study area. land and water resources, which is a prerequisite for an integrated approach in Introduction identifying runoff potential zones and suitable sites for water harvesting structures (Meijerink Watershed is a smaller unit of the river basin et al. 1994) which contributes runoff to a common point and lies within 4000 to 40,000 hectare area. It Study Area: is a natural geographic convenient basic unit for development and planning. It is physical The Morna river is flowing through Patan system in terms of input of precipitation and Tahsil of Satara District of Maharashtra state. solar radiation and output of discharge and The study area is lying between the latitudes evapotranspiration. Assessing, managing and 17º15’N to 17º21’N and longitude 73º45’ E to planning of water resources for sustainable 73º57’E. The whole area can be obtained in a use becomes an important issue in human life, single toposheet Nos. 47G/15, covering the especially in water scarcity regions. area of 104.458 sq.km, acquired from Survey Topography of an area along with geological of India. The area is approachable through structures and lithology play an important role the road link, Sangwad bridge and 25km. for watershed development. Thus, the away from Karad. IJSER © 2014 http://www.ijser.org International Journal of Scientific & Engineering Research, Volume 5, Issue 12, December-2014 6 ISSN 2229-5518 (Strahler, 1964). In other words morphometry The Morna watershed encircled the village of may be defined as the measurement and Gureghar, Ambrag, Nayakwadi, mathematical analysis of the configuration of Chougulewadi, Dhangarwadi, Kokisre, the earth’s surface and of the shape and Natoshi. Other villages within the watershed dimensions of its landforms (Dury, 1970). are Kordewadi, Kotawade, Kusrud, Kadamwadi, Kalkewadi. The geomorphological and climatic characteristics of a basin govern its The mouthward side of the basin is dominated hydrological response to a considerable by the settlements within the agricultural fields. extent. The geomorphological characteristics At the altitude of 760 m the dense mixed of a basin represents its attribute, which may reserved forest occupies the basin. Villages be employed in synthesizing its hydrological and the agricultural fields along with the forest, response. The importance of geomorphic cover the upper reaches of the basin at the factors like basin shape, relief etc., cannot be altitude of 680 m to 720 m. The Morna overlooked in accurate prediction of runoff. watershed is lying between the Koyna Basin characteristics when measured and watershed(North) & Warna watershed(South). expressed in quantified geomorphic parameters can be studied for their influence General Geology Of the Area: on runoff. Hence, linking of the geomorphologic parameters with the Geologically, Morna basin belongs to the part hydrologic characteristics of the basin can lead of Deccan Volcanic Province constituted to a simple and useful procedure to simulate mainly of basaltic lava flows of the late the hydrologic behavior of various basins, cretaceous of Eocene. The flat-topped hills particularly the engaged ones. Interpretation and step-like terraces characterize the terrain. and quantitative analysis of various drainage This topography is a result of the variation in parameters enables qualitative evaluation of hardness of different flows. The include surface runoff, infiltration and susceptibility to varieties of basalts alternating with each other. erosion within the basin. The compact basalts, amygdaloidal basalts, vesicular basalts etc are common. The rock is The geomorphometric analysis of dendritic volcanic, basic, find grained, aphanitic and drainage of Morna river basin deals with the melanocratic containing the mafic minerals like computation of stream order, length ration, pyroxenes, ca-plagiodase, olivine, ilmanite etc. relief aspects, drainage density, slope and volcanic breccias, volcanic ash and tachylite form factor etc. beds are also found. IJSERComputation of Morphometric Alluvium deposits formed during Pleistocene Parameters : to recent are common in the lower regions providing a good agricultural and land Various important morphometric parameters alongside of Morna and marked by alternate of the watershed (as in the table) criss-cross concave-convex slopes. Along the are analyzed as follows : tributaries they form very good gently sloping soil cover called ‘Lavans’. The basalts near Stream Order (u) : the surface and just below these deposits are On the basis of the principles of Strahler’s highly weathered. Spheriodal weathering is method of steam ordering five order of steams common in the area. Morna River is in are identified, where the 5th order stream form youthful stage and basalts are exposed as a the main stream. bed rock. Cascades, water falls potholes, are common in the upper parts. From civil Stream Number (Nu) : engineering point of view the rock provides It is the number of stream segment of various good foundation conditions for any civil Engg. orders. Horton’s law of stream numbers states Structure. that the number of stream segments of each order is in inverse geometric sequence with Geomorphometry order number. There are 423 streams within the basin. Geomorphometry is essential quantitative, involving numerical variables whose values Stream Length (Lu) : may be recovered from topographic maps. It is the length of each stream segment. Morphometry is the precise measurement of Adding length of each stream for a given the shape or geometry of any natural form order, the total stream length of each order (L) IJSER © 2014 http://www.ijser.org International Journal of Scientific & Engineering Research, Volume 5, Issue 12, December-2014 7 ISSN 2229-5518 is computed. The total stream length divided the next higher order. Bifurcation ratio is by the number of stream segments (N) of that found to be one of the important order gives the mean stream length for that geomorphologic characteristics. It has been order. very widely used in the derivation of geomorphologic instantaneous unit Length Ratio (R) : hydrographs for various basins. It is the radio of mean stream lengths of any order and that of next lower order. Stream Frequency (Sf) : It is the number of streams per unit area within Relief Ratio (Rh) : the basin. It mainly depends on the lithology It is the total watershed relief of the basin and reflects the texture of the divided by the maximum length of the drainage network. There are six streams an watershed. It represents the overall steepness average per square kilometer of the of drainage basin and is an indicator of the watershed. potential energy of the system to drain off. Large Rh values give rise to quick depletion of Drainage Density (D) : water from the basin and hence result in large It is the average length of stream per unit area peaks and steep limbs of hydrographs. within the basin. Drainage gives an idea about the physical properties of the underlying rocks. Relative Relief (Rr) : Low drainage density occurs in the regions of It is the ratio of the maximum watershed relief highly resistant