International Journal of Civil, Structural, Environmental and Infrastructure Engineering Research and Development (IJCSEIERD) ISSN 2249-6866 Vol. 3, Issue 3, Aug 2013, 21-28 © TJPRC Pvt. Ltd. GEOMORPHOLOGICAL STUDIES OF YERRIGEDDA CATCHMENT AREA, VISAKHAPATNAM, ANDHRAPRADESH- USING REMOTE SENSING AND GIS TECHNIQUES K. HARIKRISHNA, V. VENKATESWARA RAO, E. AMMINEDU & G. JAISANKAR Department of Geo-Engineering, College of Engineering, Andhra University, Visakhapatnam, Andhra Pradesh, India ABSTRACT Geomorphological map is an essential tool for various types of planning and developmental activities in a catchment area such as land use planning, agriculture, forestry, civil-engineering, exploration and utilization of mineral resources, groundwater development, terrain evaluation etc. The geogmorphological mapping for Yerrigedda catchment area was carried out with the help of IRS-P6, LISS III imagery on 1:50,000 scale by visual interpretation techniques. The method was found suitable for identifying and delineating different categories of geomorphic units. The terrain features which are difficult to be mapped in the field by conventional methods could very well be delineated with the help of Remote Sensing techniques. Based on the existing landforms, drainage characteristics, nature of relief, structure, slope on the imagery, following geomorphic units have been identified in Yerrigedda catchment area, viz. These are Structural hills, Denudation hills, Piedmont slope, Pedi plain moderate and Pedi plain shallow. Remote Sensing sources ranging from satellite imagery to aerial photographs are most useful to get the primary data about the terrain features. KEYWORDS: Geomorphology, Remote Sensing, Lineament, Geology, Drainage and Slope INTRODUCTION The very recent studies by the International Institute of Environment and Development, a service organization of England reveals that the Visakhapatnam city is one of the fastest developing city in the world. The Visakhapatnam city consists of highly undulating terrain and the storm water generated in elevated places reach the plains and low-lying areas immediately and causing floods. Since last 15 to 20 years every year some of the areas like Gnanapuram, kancharapalem, and some margin areas all along the streams in the Yerrigedda catchment area get inundated after a high intensity rainfall. This is predominant where catchments area of a drain covered with more than 60-70% urbanization/ concretion. The present study is an attempt to analyze the Geomorphologic studies of Yerrigedda Catchment Area. Numbers of research papers were published relating to Geomorphology, Geology, and drainage net work analysis. Borse R.J and Patil Y.V, (2006) has analyzed a study of Hydro geomorphic Feature in Jalgaon District. Hydrological Characteristics and Fluvial Morphology in the Bhagirathi-Jalangi Floodplains of the east central West Bengal by Prasad Nageshwar and Mukherje Indrani (2010). Srinivasulu,G. et al. (2009) has analysed the Geomorphological studies to assess the imapct of watershed development Practices in Kondurg Mandal, Mahabubnagar District of Andhra Pradesh. The study of Identifying Geomorphological Characteristics of Roha, Raigada district Using Remote Sensing Technique, Maharastra state by Swaminathan and Chanedrasekharam (2006). Vaidyanathan (2010) have discussed Some Aspects of Applied Geomorphology. Physiographically, the study area is highly variable terrains like hill range, up lands, undulating plains, low lying areas and marshy swamps. Kailasa hill range runs for about 10km in the east-west direction starting from the sea coast to Simhachalam in which 4 km stretch is a part of the study area. Maximum altitude of the hill range in the study area is 22 K. Harikrishna, V. Venkateswara Rao, E. Amminedu & G. Jaisankar +484m (figure 2). An elevated hill mound/ ridge exist along the east boarder of the catchment and the area covered by the mound is Rajendranagar, CBM Compound and Asilmetta. The highly intensified urban agglomeration in the study area consists of Dwarakanagar, Seethampeta, Srinagar, Akkayyapalem, Madhuranagar, Lalithanagar, Dondaparthi, Railway new colony, railway quarters area etc., situated on undulating plains and are in between +10m and +30m contour lines. Area below 10m contour is railway grounds, Gnanapuram, Sebastian colony and FCI godowns area. Some part of the area below +10m contour is marshy land consists of clays and marine clays and prone to frequent flooding. STUDY AREA The study area is covered in 65 O/5, 65 O/6, 65 O/1 and 65 O/2&3 Survey of India topo sheets on 1:50,000 scale bounded between north latitudes 170 32’ and 170 52’ and east longitudes 830 04’and 830 24’. The GVMC area comes under the Visakhapatnam District of Andhra Pradesh. Location of the study area is shown in Figure 1. Figure 1 OBJECTIVES Analysis of Geomorphologicial features of the study area. To study the natural drainage network of entire Yerrigedda catchment area and divide into sub-catchments areas. DATABASE AND METHODOLOGY The present work is carried out with two important sources. Firstly, the topographical information like contours, spot heights, and drainage was gathered from Survey of India, toposheets. The identification of different geomorphic units and lineaments was carried out with the help of interpretation of the satellite imagery - IRS-P6, LISS IV (Feb., 2005) based on the photo elements like slope, geology, drainage pattern etc. which supported by number of field visits. The National Remote Sensing Centre classification of geomorphic units was used for this study. Digital data was analyzed through image processing software (ERDAS imagine 9.1) and Arc GIS 9.1 software. The various geomorphic features were delineated in online digitization. GEOMORPHOLOGICAL STUDIES Geomorphology is the science of landforms. In this study an attempt has been made to discern different geomorphological landforms in relation to understand fluviatile activity in the area. In this study, 5 no.s of different landforms have been delineated by standard visual interpretation techniques. These are Structural hills, Denudation hills, Piedmont slope, Pedi plain moderate and Pedi plain shallow and are shown in figure 2&3. Brief descriptions of these landforms are given below. Geomorphological Studies of Yerrigedda Catchment Area, Visakhapatnam, 23 Andhrapradesh- Using Remote Sensing and GIS Techniques Structural Hills: The northern part of the study area consists of kailasa hill range belong to khondalite rock with east-west strike. Denudational Hill: Isolated hills are observed on the western part belong to khondalite as well in the eastern part belong to leptinite/ charnockite rock. Khondalite rock has better groundwater nature than the leptinite/ charnockite rock. Piedmont Slope (PS): This zone is normally located in the hilly area. Disappearance of drainage is one of the characters of this landform. This geomorphic unit is disturbed greatly by various anthropogenic activities like construction of buildings, excavations and various developmental activities. Part of Seetammadhara, port quarters, Narasimhanagar, CBM compound, Asilmetta places covered in this zone. Pediplain Shallow (PPS): The culmination of pediments in the formation of multi concave topographic surface is called Pediplain. The shallow Pediplain regions are having close proximity to the hilly terrain. In this geomorphic unit the weathering takes place through in-situ process and by transportation. The soil cover is less than 5 meters thickness and slightly sloppy. This geomorphic unit is completely disturbed by settlements and various developmental activities in order to meet the population requirements. Some of the places covered in this geomorphic unit are Lalithanagar, Dwarakanagar seetampeta, Dondaparthi and Tatichtlapaem. Figure 2 Figure 3 24 K. Harikrishna, V. Venkateswara Rao, E. Amminedu & G. Jaisankar Pediplain Moderate (PPM): The evolution of this landform is totally controlled by in-situ process. This zone is confined over the plains, which are suitable for sediment deposition. Pediplain moderate has 5-10 meters soil cover. The areas covered under this category are Railway new colony, railway yards, FCI godowns and Gnanapuram. LINEAMENT STUDIES Different Scientists with variety of meanings defined the term lineaments in various ways. Leary defined lineaments as map able, simple or composite linear features of a surface, whose parts are aligned in a rectilinear or slightly curvilinear relationship, which differs distinctly from the patterns of adjacent features and presumably reflect a subsurface phenomenon. The advent of remote sensing technology has provided aerial photographs and satellite imageries, which are being used for structural analysis, especially in the lineament mapping. Lineaments are seen as linear tonal discontinuities in an image. Lineaments play an important role in the development of groundwater regime. They create the secondary porosity and the weak zones which help the precipitations to percolate down wards to create the secondary porosity and the weak zones which help the precipitations to percolate downwards to create an aquifer. In hard rock terrain these lineaments create the opening, which increases the permeability of the rock, which forms a trap for groundwater to form an aquifer. Therefore in any study related to groundwater or surface water delineation of lineaments are very important and are shown in Figure 4. Figure 4 The major lineaments direction is NS-SW and NW-SE, these are classified