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51 CHAPTER 2 NATURAL SETTING OF THE STUDY AREA

2.1. THE STUDY AREA

The study area lies within the basin of the Tapi River, and is located close to Yawal town in the Jalgaon District of Maharashtra. The area of interest extends from 75 031’E to 75 045’E and from 21 01’N to 21 09’N, covering an area of approximately 348 km 2. Fig. 2.1 shows the study area.

The banks along this stretch of the Tapi River are subject to the processes of gullying and ravination, which have transformed a major part of the landscape into badland terrain. The location of this place being very close to the tehsil headquarter town of Yawal or Yaval, the region is also known as the Yawal Ravines. This particular stretch of the badlands shows certain distinct characteristics. Since about the year 2000, large patches of the badlands have been reclaimed for the purpose of cultivation. Yet, at the same time, certain parts of this gullied topography lie totally undisturbed and in their natural state without any human interference whatsoever. A Google Earth image provided in Fig. 2.2 demonstrates this. The area thus, is a classic example of the invasion of agriculture into a hostile terrain. For this purpose this region has been selected for the present research. In the following paragraphs the area has been described in greater detail. Fig. 2.3 and 2.4 show some of the uncultivated badlands from the study area while Fig. 2.5 and 2.6 show agriculture being practiced right on the badlands.

2.2. THE TAPI RIVER BASIN

Tapi is the second largest west flowing river of Peninsular India. It has its source near Multai Reserve Forest in Betul District, Madhya Pradesh, at an elevation of 752 m ASL in the Satpura Range. The Tapi River flows for a length of 724 km from its origin to the outfall and drains an area of 65145 km 2 before emptying into the Gulf of Khambat near Surat, Gujarat. Of

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Tapi River 53

Waghur River

Fig. 2.1.The Study Area

Badlands along Tapi 54

Deeply disturbed and cultivated Fairly undisturbed patches of badlands badlands

Fig. 2.2. Google Earth Image of the Study Area 55

Fig. 2.3. Uncultivated Badlands Fig 2.4. Uncultivated and Undisturbed Badlands 56 57

Fig. 2.5. Agriculture on Badlands Fig. 2.6. Cultivated Badlands 58 the total catchment area of the river, nearly 80% lies in the state of Maharashtra. The basin area of Tapi is nearly 2% of the total geographical area of the country. The river basin is bound by the Satpura Range in the north, the Mahadeo Hills in the west, the Ajanta and Satmala Ranges in the south, and the Arabian Sea in the west (CWC, 2015).

The Tapi River has as many as fourteen major tributaries. However, as far as the Jalgaon District is concerned the major right bank tributaries are Bhokar, Suki, Mora, Harki, Manki, Gulli and Aner while the major left bank tributaries include Purna, Bhogavati, Waghur, Girna, Bori and Panjhara. The Purna and the Girna rivers are considered as two most important left bank tributaries as they together account for nearly 45% of the total catchment area of the Tapi. The Purna originates in Betul District in the Gawilgar Hills of the Satpura Range and drains three districts of the Vidharbha region, viz. Amravati, Akola and Buldhana. The Girna has its source in the Western Ghats and drains Nasik and Jalgaon Districts (CWC, 2015).

2.3. PHYSIOGRAPHY

Jalgaon exhibits a wide variety of topographical features including, hills, ridges, pediments, plains, valleys, badlands etc. Three well-marked physiographic divisions can be identified, running almost parallel to the Tapi River. These include: the high hills of the north, the Tapi valley at the centre, and the ridges and valleys of the south and southwest (Rane et al., 2008). The following subsections contain a brief account of each of these physiographic divisions.

2.3.1. The Hills of the North

This mainly includes the Satpura Range. It stretches almost like a wall bordering the flank of the Tapi Valley. The central crest of the Satpura has an elevation of 609 m ASL. The peaks of Pancha Pandu in the east and Mondhiamal overlooking Yawal have elevations over 900 m ASL (Rane et al., 2008).

2.3.2. The Tapi Valley

The Tapi is undoubtedly the major river of the district. The river flows through a flat and well-tilted valley. The banks rise high and are bare except where they are joined by tributaries. 59

Though the valley consists of a vast alluvial plain, gully erosion and ravination are the most striking features of the landscape. About 18 m above the river bed each bank has a double terrace. The lower one comprising yellow earth is much ravinated while the upper one coincides with the level of the country ground. It is believed that presently the Tapi River has entered into Jalgaon through a new channel. Its former channel is further north along a deep gully that joined the present channel near the village of Ainpur, east of Bhusawal (Maharastra State Gazetteers, 1962).

2.3.3. The Hills, Ridges and Valleys of the South

The topography of the south is far more varied than elsewhere, comprising the valleys of rivers Purna, Waghur and Girna from east to west, as well as the Hatti and Ajanta Hills.

The Hatti hills bounding the Purna valley on the east, run north-west and south-east, and pass through the south-east corner of Jalgaon. Rising gradually from the Tapi valley, they are initially low. Further east, they rise to over 1200 m ASL and finally merge with the Nagpur hills (Rane et al., 2008).

The Ajanta Range, also known as Chandor or Satmala Hills, borders the entire southern part of the district. The hills show a series of basalt pinnacles and ridges. They act as a sort of boundary between Jalgaon and the Deccan tableland. The ranges are mostly bare with some scattered vegetation (Rane et al., 2008).

2.3.4. DEM and Slope Map of the Study Area A DEM of the precise study area appears in Fig. 2.7. The DEM of the study area was created by Joshi (2015) using Cartosat-1 stereo pairs (2.5 m resolution, 8 scenes) using dGPS and Leica Photogrammetry Suite 9.2. The author is grateful to the aforementioned for allowing her to use the DEM. It has a resolution of 10 m. The DEM clearly shows that within the area of interest the elevation varies between 131- 254 m ASL. The average elevation of the area is 182 m ASL. The northeastern corner of this portion of the Tapi Basin shows higher elevations than the southern part. The Tapi River flows southeast to northwest right across the centre of the study area. The valley of the Tapi River can be clearly seen in the DEM.

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Fig. 2.7. DEM of the Study Area 62

Fig. 2.8. Slope Map of the Study Area The slope map of the area (Fig. 2.8), extracted from the DEM, reveals an interesting pattern. While maximum percentage of the area of interest has slope below 10 0, some of the steeper slopes ranging 10 0-20 0, and at times exceeding 25 0 occur in patches along the banks of the Tapi River. This is because of the presence of deeply gullied badlands along the banks where the slopes become steep.

2.4. GEOLOGY

Most of the area is underlain by the Deccan Trap, which has been formed from the outpouring of massive amounts of lava over the greater part of Peninsular India during the Mesozoic Era. The lava is often known as ‘plateau basalt’ because of the vast basaltic plateau that it formed. Because of the stepped or terrace-like appearance of hill slopes, they are also known as ‘trap’. The volcanic trap rocks range in thickness between 30 and 300 m. The traps are compact and hard and exhibit vertical prismatic and columnar jointing. The colour varies from dark to greenish to brownish grey. The amygdaloidal variety forms the valley floors and is comparatively softer, showing greenish to purplish colour. The main minerals dominating the trap rocks include labradorite and enstatite-augite. Since the traps have cavities in them, these are filled with secondary minerals like quartz, chalcedony, agate, jasper, rock crystal, zeolites and calcite. Porphyritic basalt is also occasionally observed, showing phenocrysts of feldspars and glassy substance. Magnetite and olivine too may be seen. The basin is full of cuts and valleys in this part. In the right hand side of the basin, on the southern slopes of the Satpura Range the black soils are thick and deep. In the left part the slopes of the Sahyadris consist of dykes, red murrum soil and bare rocky outcrops (Ghatak and Ghatak, 2011).

2.5. SOIL

The soils of the region are essentially a product of weathering of the underlying Deccan Trap basalt. Four broad types of soil are found in Jalgaon. They are: Deep black soils, Medium black soils, Loamy and sandy soils, and Forest soils. Deep black soils cover the talukas of Amalner, Erandol, Jalgaon, Bhusawal and Muktainagar (Edlabad). The soil has a high content of montmorillonite clay. They are neutral to alkaline. Medium black soils cover the central Tapi

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valley and the hills of the south. They are rich in lime, fair in phosphates, poor in organic matter and nitrogen, and are alkaline. The Tapi valley itself is covered by black alluvial clay or loamy soil overlying a layer of yellowish clay. Along the river banks where gullying is observed, the soil is mixed with lime nodules. Loamy soils occur in the southernmost parts of Amalner, Erandol, Jalgaon and Bhusawal. Sandy soils cover the foothills of the north and south, while forest soils are restricted to the forested hill slopes of the Satpura Range (Jain et al., 2007; Rane et al., 2008 and Vijesh, 2013). According to the soil map published by the National Bureau of Soil Survey and Land Utilization Planning (NBSS LUP, Nagpur), titled “Maharashtra Soils”, the area has three categories of soil - slightly deep, moderately well-drained fine soils; very deep moderately well-drained fine soils; and very shallow excessively drained clayey soils.

2.6. CLIMATE

The study area is located in the rain shadow region of the Sahyadris. Rainfall in the area is extremely seasonal in character, with maximum concentration of rainfall occurring in the monsoon season from June to September. Based on the analysis of daily rainfall data collected for 15 stations of Jalgaon District for the period 1998-2012, from the Indian Meteorological Department (IMD), Pune (Fig. 2.9), it was observed that Amalner receives minimum average annual rainfall of about 630 mm and Erandol receives maximum rainfall of 750 mm (Fig. 2.10). The average annual rainfall in the district was found to be about 700 mm approximately.

Temperature likewise shows a wide variation with December being the coldest month when the mean minimum temperatures drop to around 10 0C. Temperature gradually soars from March to May. During the hottest month temperatures rise to as high as 48 0C. The air remains extremely dry except in the monsoon season.

Climate appears to exert a dominant influence on weathering and erosional processes in the study area, especially in terms of rainfall. The seasonal character of rainfall plays a significant role in soil erosion in the region. Prior to the arrival of the monsoons the soils are parched. The first rains therefore succeed in not just eroding the soils but also wet them eventually. This cycle of alternate wetting and drying controls the course of gully erosion, soil creep, landslides etc. High intensity seasonal rainfall promotes gully erosion, hill slope retreat 64

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Rainfall (mm) Fig. 2.9. Fig. 2.9. District Jalgaon Annual Rainfall of (1998 Years

–

2012)

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Mean Annual Rainfall (mm) Mean

Stations

Fig. 2.10. Station-wise Mean Annual Rainfall of Jalgaon District and accumulation of slope material at the base of the slopes. Indeed, the manifestation of these processes is seen in the deep gullies extending from the foot of the mountains to the banks of the Tapi River (Patil, 1993).

2.7. NATURAL VEGETATION

The region has its own very distinct type of natural vegetation. Broadly, the vegetation of Jalgaon can be grouped into two categories: Dry Deciduous Forests and Scrub Forests. The former are the forests of the Satpura Ranges and are quite inaccessible. The common tree species include Tectona grandis, Acacia catechu, Anogeissus latifolia, Mimosa hamata, Adina cordifolia, Mitragyna parviflora, Dalbergia latifolia, Terminalia tomentosa, Terminalia arjuna, Boswellia serrata, and Butea monosperma . The comparatively higher annual rainfall of 760- 1000 mm is the dominant control factor for this deciduous vegetation (Rane et al., 2008)

South of the Tapi River where rainfall is considerably reduced to about 380-630 mm annually and where the temperatures are nearly 50 0C scrub forests dominate. The important tree species are khair ( Acacia catechu), babul (Acacia arabica), dhavda (Anogeissus latifolia,) salai (Boswellia serrata), anjan (Hardwickia binata), bor (Zizipus jujube) etc. (Rane et al., 2008).

In other words, where rainfall and soils are favourable, as in the case of the forested hill slopes of the north; teak (Tectona grandis) is the dominant tree type, and yields timber. The lower elevations of the hills of the north and south are covered by teak pole forests. The major species are teak (Tectona grandis), khair ( Acacia catechu), dhavda (Anogeissus latifolia,) salai (Boswellia serrata) etc. Anjan (Hardwickia binata) is seen all over the forests of Raver Taluka, whereas babul (Acacia arabica) is found along the Sur River in Jamner Taluka and in Muktainagar (Edlabad). Scrublands occur everywhere just south of the Tapi River (Maharastra State Gazetteers, 1962).

2.8. LAND USE and LAND COVER

The land use/land cover map of the area of research appears in Fig. 2.11. It has been prepared using two scenes of (IRS P6 LISS-4) Resourcesat-1 (5.8 m resolution) in ERDAS

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Imagine 9.2 software (path 96, row 57 C, taken on 11 Feb 2013 and path 96, row 57 D, taken on 18 Jan 2013). Information related to different land use practices and types of crops grown in the fields were obtained during a detailed field work conducted prior to the classification exercise. Several training samples were obtained for each land use class. Land use/land cover map of the region was prepared by employing supervised classification using maximum likelihood algorithm.

The map distinctly shows the location of badlands along the channel of the Tapi River. The encroachment of cultivated areas right into the heart of the badlands is also equally evident in the map. Agriculture is the dominant land use of the area. There are few and small settlements in the region. The amount of fallow land appears to be more just south of the river than in the north. Expectedly, the concentration of agriculture is seen to increase away from the badland region. The following table (Table 2.1) shows the percentage of land area under each category of land use/land cover:

Table 2.1. Percentage Area under Different Land Use/Land Cover Categories

Land Use/Land Cover Category Land Area (%)

Agriculture 37.85

Badlands 24.30

Fallow land 33.15

Settlements 1.39

Water body 3.32

In the following chapter, the soil loss from the disturbed areas within the badlands has been estimated using the USLE.

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Fig. 2.11. Land Use/Land Cover Map of the Study Area