A Geographical Analysis of Land Use/Land Cover Dynamics in Lolab Watershed of Kashmir Valley, Western Himalayas Using Remote Sensing and GIS

Land is an important natural resource available to man and is the interface for most human activity which is greatly impacted by humans [1]. Land is the basic natural resource of mankind. Humans have always played with their environment in one way or the other and particularly the land. However today, the intensity and rate of change threatens to exceed the present adaptive capacities of many individual societies, particularly in the fragile and finite areas like high altitude zones. Human-induced activities stand out as a large force for causing land use/land cover changes [1]. Intensification of food production is a key activity in the development of modern society.


Introduction
Land is an important natural resource available to man and is the interface for most human activity which is greatly impacted by humans [1]. Land is the basic natural resource of mankind. Humans have always played with their environment in one way or the other and particularly the land. However today, the intensity and rate of change threatens to exceed the present adaptive capacities of many individual societies, particularly in the fragile and finite areas like high altitude zones. Human-induced activities stand out as a large force for causing land use/land cover changes [1]. Intensification of food production is a key activity in the development of modern society.
Land cover refers to the physical characteristics of earth's surface, captured in the distribution of vegetation, water, soil and other physical features of the land, including those created solely by human activities e.g., settlements [2]. The term land cover referred to the kind and state of vegetation, such as forests and grass cover and includes other things such as human structures, soil type, biodiversity, surface and ground water [3]. Changes in land cover do not necessarily imply degradation of land. However, many shifting land use patterns driven by a variety of social causes, result in land cover change that affect biodiversity, water and radiation budgets, trace gas emissions and other processes that come together to affect climate and biosphere [4].
Land-use refers to the way in which land has been used by humans and their habitat, usually with accent on the functional role of land for economic activities [2]. Land use has been defined by natural scientists in terms of syndromes of human activities such as agriculture, forestry and the built up spaces that alter land surface processes including biogeochemistry, hydrology and biodiversity [5]. Observations of changes in land use are best studied by combination of natural and human methods to decipher the impacts of change on environment. As a result, scientific investigation of the causes and consequences of Land Use (LU) and Land Cover (LC) are two fundamentals describing the terrestrial environment in connection with both natural processes and anthropogenic activities [6][7][8]. The integrated term Land Use Land Cover (LULC) includes both categories of LU and LC and analysis of changes is of prime importance to understand many social, economical and environmental problems [9]. In recent years, LULC change analysis has emerged as an important research question, because LULC change has been identified as a key factor which stands responsible for environmental modification worldwide [10]. Though it is possible to monitor LULC changes by involving traditional surveys and inventories, but Satellite Remote Sensing (SRS) apart from being advantageous in terms of cost and time saving for regional scale also provides large scale data on LULC changes with information about their geographic distribution [11]. Geographic Information Systems (GIS) and Remote Sensing (RS) have proved to be useful tools for assessing the spatiotemporal dynamics of LULC [12][13][14][15]. Information about change is necessary for updating LULC maps and the management of natural resources. It is very important to have continual, historical and precise information on LULC changes of the earth's surface for any of Ecology, Environment and Remote Sensing, Soil Conservation Department etc.
The study incorporates a two tier methodology. First, a base map on 1:50000 scale was prepared with mapping units from AIS and LUS prioritization map of the year 1974-75, generated from Aerial Photographs on the same scale. Different mapping units for each land use/land cover category were delineated. Secondly, digital interpretation of IRS-1C LISS III (FCC) of the year 2014 was carried out. A legend compatible with the 1974-75 data was prepared. This was followed by selection of sample strips with observation points for ground truthing. All the mapping units were given due representation during the selection process. The field exercise was carried out and the legend was finalized, which was followed by final plotting of the mapping units. The maps served as inputs to GIS and subsequent analysis for change detection, which was performed in GIS environment.

Land use/land cover status of 2002 and 2014 in Lolab watershed
The analysis of land use/land cover of the study area for the year 2002 and 2014 were done in order to detect the changes that had taken place in the various categories.
In 2002 (Figure 2), the total area under Agriculture which is the most fundamental form of human activity in Kashmir valley was 9865.14 hectares which accounts for about 35.03 percent of the total area of the Lolab watershed in 2002. Horticulture are the lands that are kind of sustainable development program in which LULC serves as one of the major input criteria [16,17].
Over the past two hundred years human have been dominant drivers of landscape transformations [18]. During the past 50 years, humans have changed these landscapes to meet the growing demand for food, fodder, timber, fiber and fuel more rapidly and extensively than any comparable period of time (Millennium Ecosystem Assessment, 2005). Changes in land use/land cover have occurred to such an extent that it has significantly affected the functioning of biosphere, being one of the most important cause of biodiversity loss as well as climatic change.
Land use/land cover change in mountainous areas has wider ramifications. The ecosystem is fragile and it is more susceptible to the negative impacts of this change. Deforestation, bad agricultural practices, unplanned growth of settlements and developmental activities have wide ranging effects in mountainous regions. Kashmir valley is known for its beauty throughout the world. This valley has snow clad mountains, mesmerizing landscapes, cascading rivers and streams etc., but this vale has been experiencing environmental deterioration since last several decades. The lush green forests which dotted the landscapes have started dwindling because of the unprecedented anthropogenic impact. The land use/land cover pattern has changed over the period of time. The forest cover has decreased not only in extent but also in terms of density [19][20][21]. This land has been brought under agriculture, settlement and horticulture uses. Globally, remote sensing and GIS technologies are being applied to carry out change detection studies for land use/land cover analysis especially in mountainous regions, where there are other constraints besides accessibility [22][23][24][25].
Objectives (1) To analyze the Spatio-temporal change in the land use/land cover of Lolab watershed from 2002-2014.
(2) To examine the factors responsible for this change.

Study Area
The Lolab watershed of the Kashmir valley with an area of about 28,162 hectares has been taken up as the study area. The watershed lies between 34°41' to 34°24' N Latitude and 74°09' to 74°23' E Longitude. It has been divided into 43 micro-watersheds in accordance to the guidelines of the Watershed Atlas of India (WAI) (Figure 1).
The watershed can be divided into three distinct physiographic units i.e., the Mountains, the Karewas and the Flood plains. The Lolab Valley is the most fascinating and picturesque of the Himalayan Valleys in Kashmir. The Lolab river has its source in the Nandmarg, the Kimsar and the Bagalsar heights, north of the Wular Lake. The main stream of the Lolab has a length of about 30 km and flows in a westerly direction. One of its lateral tributaries is the Kalaruch nala which originates below the peak of Nalgat 3645 meters and joins the Lolab below Khumarial. A little before its junction with the Kahmil, the Lolab kol receives the Haheom kol which flows from the north [26,27].

Materials and Methods
The methodology adopted for this study is based upon interpretation of IRS-1C LISS III (FCC) having a resolution of 23.5 mts using standard visual/digital interpretation techniques. The data were Georefrenced and as such matched to a standard SOI toposheet of 1:50000 scale. The source material was collected from published and unpublished records of various state government departments, especially Directorate of Economics and Statistics, J & K Forest Department, Directorate   Land use/land cover status of year 2014 ( Figure 2) reveals that there has been a discernible change in some of the categories. As far as agriculture is concerned, it recorded total area of 9573.5 hectares (33.99 percent) which means a small decrease in this category. Horticulture has shown a gradual increase of around 2 percent during the study period with an area of 2791.03 hectares (9.91 percent). The total area under forests has decreased to 12680.02 (45.02 percent) and the same applies to its sub categories except moderate category forests which have shown a slight increase of 0.76 percent in its area ( Figure 3). The respective area under dense forests, moderate forests and sparse forests during 2014 is 2693.27 hectares (9.56 percent), 2490.94 hectares (8.84 percent) and 7495.81 hectares (26.6 percent). Both the snow covered and water bodies have shrinked during the study period as Snow covered area has decreased to 1008.64 ha (3.58 percent) and water bodies have decreased to 2108.78 ha (7.48 percent) ( Table 2).

Change detection analysis
The perusal of table reveals that there has been a considerable change in the land use/land cover status of Lolab watershed from 2002 to 2014. The area which has been lost under one land use/land cover category has converted to other land use/land cover category thereby showing an increase in the respective category (  Figures 4 and 5).

Factors responsible for land use/land cover change in Lolab watershed
The land use/land cover alteration are generally caused by

S. No Class
Year 2002 (Ha) Percentage   mismanagement of agricultural, urban and forest land which leads to severe environmental problems. It has been a combination of climatic and economic factors in the study area (Lolab watershed) which has been responsible for the land use land cover change to take place. y y Overall, the scenario presented by the study reveals that the land use/land cover change is quite visible throughout the study area. The area decreased under one land use/land cover category has increased under other land use/land cover category (Figures 6-9).

Conclusion
To sum up, the land use/land cover of Lolab watershed has undergone drastic change during 2002-2014 as a consequence of natural increase in population and demand for settlements. The productive agricultural land is being transformed in settlement area due to increasing demand of population. The area under forest is decreasing mainly due to demand of wood for housing and furniture. The study suggested that the settlement area should not be allowed to increase at the expense of prime agricultural land and land use policy

S. No Class
Year (      should be strictly followed. Remote sensing and GIS can be potential tools for monitoring the further degradation of natural resources of the watershed and for aiding land use policy options. However, nothing can be achieved unless and until we check the population growth.