Remote Sensing Imagery-Based Analysis of the Relationship Between Land Cover Changes and Suspended Sediments

Abstract

Anthropogenic activities like rapid urbanisation and commercial farming are driving land cover changes. South East Asia alone has witnessed large-scale changes in our environment and biodiversity due to forest conversion into commercial palm, cocoa and rubber plantations. In West Kalimantan of Indonesian Borneo, exponential increase in commercial palm plantation acreage at the cost of depleting rainforests was witnessed in the last three decades. The spatio-temporal variability of such land cover changes are effectively studied by using remote sensing techniques. The impact of such changes on hydrological processes at watershed scales can be established through change analysis. In this chapter, Landsat TM, MSS and ETM+ data between 1992 and 2013 were used to study land cover changes and estimate suspended sediment concentration from river waters. Normalised Difference Vegetation Index (NDVI) was computed for characterising vegetation land cover which was then classified as per the Food and Agricultural Organization schema. Both statistical and spatial change analysis were performed in a Geographical Information System (GIS). The results show a strong relationship between the observed land cover changes and estimated suspended sediment concentrations in the watershed which established a strong relationship between deforestation and erosion. This case study also presents an alternative methodology to link increased erosion to deforestation, especially in regions where applicability of Soil Loss Equation (SLE) based models are not possible due to lack of field collected datasets.