Geospatial Tools for Assessing Land Degradation in Budgam District, Kashmir Himalaya, India
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Geospatial tools for assessing land degradation in Budgam district, Kashmir Himalaya, India Mehnaz Rashid1,∗, Mahjoor Ahmad Lone1 and Shakil Ahmad Romshoo2 1National Geophysical Research Institute, Hyderabad 500 606, India. 2Department of Geology and Geophysics, University of Kashmir, Srinagar 190 006, India. ∗e-mail: [email protected] Land degradation reduces the ability of the land to perform many biophysical and chemical functions. The main aim of this study was to determine the status of land degradation in the Budgam area of Kashmir Himalaya using remote sensing and geographic information system. The satellite data together with other geospatial datasets were used to quantify different categories of land degradation. The results were validated in the field and an accuracy of 85% was observed. Land use/land cover of the study area was determined in order to know the effect of land use on the rate of land degradation. Normalized differential vegetation index (NDVI) and slope of the area were determined using LANDSAT-enhanced thematic mapper plus (ETM+) data, advanced space-borne thermal emission and reflection radiometer, and digital elevation model along with other secondary data were analysed to create various thematic maps, viz., land use/land cover, geology, NDVI and slopes used in modelling land degradation in the Kashmir Himalayan region. The vegetation condition, elevation and land use/land cover information of the area were integrated to assess the land degradation scenario in the area using the ArcGIS ‘Spatial Analyst Module’. The results reveal that about 13.19% of the study area has undergone moderate to high degradation, whereas about 44.12% of the area has undergone slight degradation. 1. Introduction humanity. The livelihoods of more than 900 mil- lion people in some 100 countries are now directly Land degradation is defined as long-term loss of and adversely affected by land degradation (United plant and animal productivity and diversity use- Nations 1994). Land degradation is observed in all ful to human beings (Milton et al 1994). The Food agro-climatic regions on all continents. The coun- and Agriculture Organization (FAO 1980) defines tries of the developing world, particularly, those in the concept of land degradation as the deteriora- the arid and semi-arid zones, are the most seri- tion or total loss of the productive capacity of the ously affected (UNEP 1986). The global assessment soils for present and future use. Globally, an esti- of soil degradation estimated that about 13% (850 mated 954.8 million hectares of land is affected million hectares) of the land in Asia and the Pacific by salinity (Szabolcs 1992). Also about 1.9 billion region is degraded. hectares of land worldwide (an area approximately Desertification, land and resource degradation the size of Canada and the USA) are affected by have been identified as high probability and land degradation (United Nations 1997). These fig- high impact problems which could result in ures will have serious implications on the future of human or environmental disasters (UNEP 1998). Keywords. Remote sensing; geographic information system (GIS); Budgam; Kashmir Himalaya; land degradation; normalized differential vegetation index (NDVI). J. Earth Syst. Sci. 120, No. 3, June 2011, pp. 423–433 c Indian Academy of Sciences 423 424 Mehnaz Rashid et al Overexploitation of environmental resources by (2004); Chikhaoui et al (2005); Wang et al (2006) humans and by grazing animals, non-scientific and Kiage et al (2007) have developed various political decisions or economic policies, etc., add techniques for mapping, monitoring and assessing external impetus to land degradation (Ning 1997). degraded lands. About 4131,527 hectares of land Salt-affected soils are reported to cover an esti- in Jammu and Kashmir is under different cate- mated 7.0 million hectares (Abrol and Bhumbla gories of soil erosion, out of which Budgam district 1971). Water logging, closely associated with salini- accounts for 115,044 hectares of soil erosion and zation and alkalinization, continues to be a threat 4466 hectares under stream bank erosion (ENVIS to sustained irrigated agriculture, affecting an esti- 2003). Based on these environmental reports that mated 6 million hectares of fertile land in India are ultimately linked to land degradation, the sta- (National Commission on Agriculture 1976). tus of land degradation was investigated using The most significant landscape function affected remote sensing and GIS. This will lead to proper by land degradation is the hydrologic balance of monitoring of environmental changes and develop- catchments. Unfavourable soil-surface characteris- ment of a sustainable land-use management plan tics of degraded lands and a lack of adequate plant for the study area. It was in this backdrop that the cover lead to reduced surface retention and infil- objective to study indicators such as vegetation, tration, and to higher surface runoff. This results slope and land use/ land cover were undertaken not only in reduced soil moisture content in the (Symeonakis and Drake 2004). soil profile, but also increased rates of soil ero- sion (Lal 1990). Particularly in dry areas, reduced available soil moisture in turn negatively affects plant growth and thus further reduces biomass 2. Study area production and protective soil cover. A large num- ber of studies have been carried out using different Budgam of Jammu and Kashmir (figure 1), located methods of remote sensing and geographic infor- in the northern part of India between 34◦42– mation system (GIS) to determine the extent of 34◦50Nand74◦24–74◦54E, covers an area of land degradation. Mitchell (1981); Stephen et al 1291 km2. About 6% of the state’s population (1981); Karale et al (1983); Pickup and Nelson resides in Budgam. The area supports a varied (1984); Pickup and Chewings (1988); Sharma and topography exhibiting altitudinal extremes of 1550 Bhargava (1988); Dwivedi (1992); Dwivedi et al to 4700 m above mean sea level. From southwest (1997); Dwivedi and Sreenivas (1998); Pickup et al to northeast, the area consists of the lofty Pir- (1998); Zhang et al (2003); Symeonakis and Drake Panjal, and flat-topped karewas as foothills and Jammu&Kashmir Srinagar Baramulla Srinagar River Jhelum Budgam Srinagar Airport India Gulmarg Doudhganga Sukhnag Meadows Yousmarg Dense forest Pulwama Legend Roads Pir Panjal Range Drainage 0 5 10 Km Figure 1. Location map of the study area. Geospatial tools for assessing land degradation 425 plains. The Pir-Panjal mountain range covers the Almost all remaining permanent vegetation repre- Kashmir valley on the south and southwest, sepa- sents forests mostly at higher altitude and various rating it from the Chenab valley and the Jammu types of trees in low-lying areas. Human interfe- region. The karewa formation is a unique physio- rence in the area has resulted in deterioration of graphic feature of the area. These are lacustrine wetland that is habitat to thousands of migratory deposits of the Pleistocene age composed of clays, birds. Deforestation is a great threat to the rich sands, and silts. The soils in the area are gener- biodiversity of the area. ally of three types, viz., loamy soil, karewa soil The geology of the area is quite diverse rang- and poorly developed mountain soil (Raza et al ing from Archean to Recent; Pir-Panjal represents 1978). Climate of the area is temperate type with rocks of a wide range in age. The commonest of the warm summers and cold winters. The mean annual rocks present in the area are Panjal traps, karewa temperature is 20.2◦C. The precipitation and tem- and alluvium. Although karewa overlays most of perature values for 2008 as well as long-term clima- the low-lying areas, the areas near river Jhelum are tological details are given in figure 2(a, b). Average covered with recent alluvium. Principal component annual rainfall in the area is 669.1 mm and maxi- analysis (PCA) with principal components (PC1 mum precipitation occurs during March to April to PC6) was generated. PC3 and PC4 were very when westerly winds strike the northern face of useful in distinguishing various geological forma- the Pir-Panjal Mountains. The long-term rainfall tions. The integrated use of PCA images, ground intensity is shown in figure 2(c). These climatic survey and existing geological map (Wadia 1975) conditions exert a strong influence on types of were used to distinguish various geological units of vegetation cover, and control land-use/land-cover the area (figure 3a). types which are divided into agricultural land with Drainage of the area is quite significant with various types of crops and trees, forests, kare- most of the drainage flowing into river Jhelum. was, meadows and wetlands. The natural vegeta- Dudhganga and Shaliganga are the important trib- tion of this region has been substantially modified utaries of river Jhelum. Dudhganga flows from through several thousand years of human activities. Ludurmarg and rises in the central Pir-Panjal near 30 110 100 15 1000 25 90 900 20 80 14.5 800 70 700 15 60 14 600 10 50 500 40 13.5 400 Rainfall (mm) Temperature ( C) Rainfall (mm) Temperature ( C) 5 30 300 20 13 200 0 10 100 -5 0 12.5 0 (a)Jan Feb Mar AprMay Jun Jul Aug Sep Oct Nov Dec (b) 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 Rainfall 08 Max Temp 08 Min Temp 08 Avg Temp 08 Year Rainfall Temp 1000 100 10 1 Rainfall (mm/month) 0.1 (c) Jul-80 Jul-82 Jul-83 Jul-84 Jul-85 Jul-86 Jul-87 Jul-88 Jul-89 Jul-90 Jul-91 Jul-92 Jul-93 Jul-81 Jul-94 Jul-95 Jul-96 Jul-97 Jul-98 Jul-99 Jul-00 Jul-01 Jul-02 Jul-03 Jul-04 Jul-05 Jul-06 Jul-07 Jul-08 Jan-80 Jan-82 Jan-83 Jan-84 Jan-85 Jan-86 Jan-87 Jan-88 Jan-89 Jan-90 Jan-91 Jan-92 Jan-93 Jan-94 Jan-81 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 Jan-05 Jan-06 Jan-07 Jan-08 Jan-09 Year ◦ ◦ Figure 2.