The surface of the earth is been in continuous state of erosion since form its beginning and will continue for ever. Surface as a mater fact eroded by various agents of erosion, in various way at different velocity, few examples River, Glacier, Wind, Human activities and these human activities includes various factor, such as Agricultural activity, all sorts of constructional activity, chemical and bio-anthropogenic activities, etc… all these in one or the other way contributing at different proportion for erosional activity. as there is saying all agents of erosion moto is to erode earth surface completely, this led to the present surface of earth that look as it is now. This study is concentrated about a factor that which already caused erosion and here we are identifying to what level the activity of erosion had occurred and currently it’s in which state of it, for this the Concept of Hypsometry is used and Hypsometric Integral factor which helps in understanding this with respect to base elevation and Hypsometric curve, graphical representation of same integral data gives a clear calculational way to represent the curve by scientific mathematical and graphical way to understand it.

The word Hypsometry derived from Greek ‘Hupsos’ which means "height" and ‘Metron’ represent "measure" which means the measurement of land elevation (relative to mean sea level). Concept of Hypsometry was used by Langebein in (1947) 1 to illustrate, express slope and forms of drainage basin. Hypsometry it is science of measuring the elevation and depth of features on Earth’s surface with respect to sea level by keeping it as base. In other words, it can be expressed as relationship of horizontal cross-sectional drainage basin area to the elevation, here the elevation factor may take different values which could be of negative or positive or both which is mainly depends on natural topography of the place. Different types of instruments and techniques are used to collect data to know about hypsometry such as by using hypsometers, wire sounders, other instrument like echo sounders, and satellite-based altimeters were also used to quantify the distribution of land at different elevations across a given area and the surface-area distribution of the oceans and their marginal seas with depth. this was the way to show how different features like oceans, terrestrial basins, and marginal seas and changes of these with respect to the elevation and depth of the features.

Hypsometric curve in simple terms relief graph of drainage basin. It is a graphical representation of data of Hypsometric Curve and integral value in two-dimensional plane graph. The curve of hypsometric which is having relation with the integral value of Hypsometry tells degree of disequilibrium in balance of erosive and tectonic forces 2. Same thing could be expressed as volume of soil mass in the basin and total amount of erosion that occurred in the basin against the remaining mass 3. The study mainly concentrates on finding and understanding the hypsometric stage of river and it’s in which state of erosion. HI (Hypsometric Integral) which helps in understating the erosion cycle, which are broadly categorised into three major category or stages or groups. Monadnock (old) (HI < 0.3), in which the watershed is fully stabilized; equilibrium or mature stage (HI= 0.3 to 0.6) and in equilibrium or young stage (HI> 0.6), in which the watershed is highly susceptible to erosion 4 . This research is carried out to find hypsometric integral of Kumaradhara river which is in mid of Dakshina Kannada District, where the rivers flow in the mid of western ghat region.

The river Kumaradhara originates at the height of 1480 Meter AMSL (Average mean sea level) height in Kodagu district which is called as the Scot land of India, and Kashmir of Karnataka, specifically at Kumaradhara hill range which is located at mid of western ghat region. The geographical factor clearly shows harsh topographical nature and conditions of place. Kumaradhara River watershed covers area of three major districts namely Dakshina Kannada, Hassan and Kodagu. The origin place river in its native place is very impact to nominal, as it proceeds further it start flowing river basin spread across area with catchment area of nearly 1776 sq.km. The locational extent of study area is 12°29’4” to 12°58’33” North and 72°9’58” to 75°47’48” East. The river reaches to the coast at an average mean sea level height of 33meter near in Uppina Angadi a place in Puttur taluk and from that onwards it mixes or joins with another minor river named Netravthi. Precisely river Kumaradhara is not a major river, and at later point of time it is going to join with other minor tributary called Gundai and finally it becomes water basin called Kumaradhara water basin. The region very rich in biodiversity factors, and it falls in tropical evergreen, and semi evergreen forest region. Region is mainly producing Rubber, Arecanut which are major commercial crops and in terms of agricultural crops rice is the major producer where at yield which shows record of 62 quintals per hectare. Apart from these forest products are other outcomes.

Study area region has its importance in terms of forest species also. Western ghats are typical well know place for the Critically Endangered species according to the survey there are nearly 34 global hotspot regions in biodiversity category itself, and out of those many Kumaradhara river basin and its adjacent area is also one among the list. river basin and its surrounding place is also Ecologically sensitive as per the Environment protection act of 1986 of sub - section (2) and with clause of (v), and concept called Ecotone and species which are pertaining to certain conditional development and its related aspects can be easily identifiable and also very helpful in protecting and also identifying different zonal way by different criteria-based way. Kumaradhara water shed region is also a part of ESZ. which means Ecological Sensitive Zone. This is according to the Western Ghat Ecological Expert Panel i.e. (WGEEP). Region once again has its speciality in terms of trees, it is a hotspot for plant endemis. According to the Biological Diversity act of 2002 region having Cultural and Bioecological importance and it is considers as Biodiversity Heritage site (BHS). It is found that place is home for nearly endemic plants of 70 types of Documented samples of species such as Madhuca Insignis. There is one more case study where a special and unique sample of tree which exit only in two places namely Germany and British Museum of London, the tree species is Syzygium Travabcoriumn. Only in these two places these can be noticeable and not anywhere else in this world. In terms of Endangered species, the study area region itself home for Hopea ponga and Vateria indica and Ochreinauclea missionis and Gymnacranthera canarica and so many other species Madhuca Neeriifolia and so many others are well settled in this place and surroundings. In this way study area region has its own importance.

Figure 1

Data is the main components for any types research work. Various factors are taken into account before start like Authenticated sources, authenticity, Accuracy, and trustworthiness of data, compatibility and version of data and software’s and cost effectiveness and time all these things are taken into account and further analysis work carried out. Digital elevation data (DEM) the most important sources of material that downloaded from the ALOS PALSOR - Radiometric terrain corrected (TRC) data form Alaska satellite and which give Synthetic aperture radar (SAR) satellite data is taken initially. ALSOR satellite data comes with 12.5-meter-high resolution data. Performed Geometrically auto corrected still for the sake of better result and to conformity manually once again cross checking is done. Removal of peaks and sinks are taken care.

The next important study material data is Toposheet. To access the toposheet (SOI) Survey of India website is accessed.by providing credential details toposheet of study area region, namely 48p/1, 48p/2, 48p/5 48p/6 and 48p/9 finally 48/p14 is downloaded and used them in creating a full pledged mosaiced image to extract required study area.

Later point of time geological data such as Lithology data has been taken from BHUKOSH, this data will help us to understand how the interior structure of earth is made, so that it percolation and denudational process can be understood and can help us to predict in future where erosional can cause more damages may occur and preventive measure can be taken care in advance itself. So that damages can be controlled as early as possible.

The next important resources Rainfall data. Rainfall data really helps us to understand in terms of Hypsometry curve structure to a lot extent. The amount of rain fall over period of time can easily provide data in predicting what would be the next stage of curve and level erosion and level withstanding capacity of basin and structural condition of watershed both man made and natural phenomena etc…. Al these are predictable out of rainfall data source. For this rain fall data water portal, IMD, and KSNDMC organisational data has been approached and 10-year data is downloaded and with the comparative study of availability and in terms of utilization IMD data is used for analysis and same data used for maps creation.

Soil data is another most important factor in Hypsometric analysis and not only for this study, any study area assessment requires soil data, for this once again Geological survey of India and BHUKOSH is the data sources, Geology is another important factor which will help in getting details of the surface feature of study area, helps in understanding basic topography of the place and also rock age and period which it belongs to, all these things will really matters in finding the ageing factor of drainage basin. For these details once again BUKOSH is the sources provider, maps of each factor are generated and presented.

For the finding of HI of Kumaradhara river, DEM (Digital Elevation Model) is main source which is downloaded from ALOS PALSAR website which provides Dem with the resolution of 12.5 meter with. TIF file format., and student version of ArcGIS software version 10.8.2 analysing and processing work starts. For better understating of this to make sure area ground truthing SOI toposheet maps were overlayed on DEM and confirmed. Flow chart has been clearly representing how activity is carried out to generate HI.

It is hypsometric Integral result finally identified as 0.982067. which says that, the river basin is in young stage, and the same thing is also shown by creating graph. Figure 10 which explains about various stages of Hypsometric level. According to the Strahler categorisation river is in the stage of Unstable. HIS ≥ 0.6 value is indicating that if the values come His ≥ 0.6 is considered to be as Unstable and not exactly young and in a stage of Maturity or to reach stage of Balanced Equilibrium stage.