Bøger af Janet E Nichol

Northern Area of Pakistan consists of the mountainous region, which is rich in snow cover. The concentration of snow in this area is main hydrological resource for Pakistan. Accurate mapping of snow for this area is inevitable for the forecasting of snow-melt discharge for flood control, energy production and irrigation. MODIS snow-cover product (MOD10A1) is generated through an automated procedure which detects and masks clouds from snow surface using a global default algorithm. This distinction is challenging since snow and cloud have comparable reflectance and often comparable temperatures. The accuracy of snow map depends on the accuracy of the cloud mask, that entirely relies on thresholds which may be different in different regions. In this book, development of a regional based snow mapping algorithm is discussed for Northern Pakistan using MODIS data for the period of 2000 to 2008. The results are compared with the MODIS cloud mask in daily snow cover product (MOD10A1). The algorithm can be used for water resource management, as it improves the identification of snow by reducing the spectral overlaps between clouds and snow.