Mohammd Rafiq

Estimating Land Surface Temperature and its Lapse Rate over Kashmir Valley Using MODIS Data

The study of the Land Surface Temperature (LST) is very important for its applications in many fields of natural sciences and is oftenused as input data in climate, agro-meteorological or hydrological models for forecasting ecosystem responses. Due to sparse and irregular distribution of meteorological station over Kashmir Himalayas, climate forecasting using interpolation of metrological air temperature data (Tair) is not scientifically robust option. Remotely-sensed LST is, therefore, a good option to supplement the scanty network of the ground-based temperature observations for understanding and modelling a variety of environmental and ecological processes and phenomena. In the present study, an attempt was made to estimate LST and its lapse rate over Kashmir Himalayas using MODIS data and relate it with air temperature (Tair) from Indian Metrological Department. Comparison between LST and Tair shows a very close agreement with MAE of ±20C. The calculated correlation coefficient between Tair and LST is above 0.9. Using ASTER DEM, LST was used to estimate the Lapse rate along various transects across the Kashmir Himalaya, which showed variations in space and time (from 0.30C to 1.20C per 100m change in the altitude). The information and knowledge generated from this research are going to improve the understanding and quantifications of various processes related to climate, hydrology and ecosystem where the use of temperature and lapse rate is an important and critical driving force.

Spatio-temporal variation of land surface temperature and temperature lapse rate over mountainous Kashmir Himalaya

In this study, Land Surface Temperature (LST) and its lapse rate over the mountainous Kashmir Himalaya was estimated using MODIS data and correlated with the observed in-situ air temperature (Tair) data. Comparison between the MODIS LST and Tair showed a close agreement with the maximum error of the estimate ±1°C and the correlation coefficient >0.90. Analysis of the LST data from 2002-2012 showed an increasing trend at all the selected locations except at a site located in the southeastern part of Kashmir valley. Using the GTOPO30 DEM, MODIS LST data was used to estimate the actual temperature lapse rate (ATLR) along various transects across Kashmir Himalaya, which showed significant variations in space and time ranging from 0.3°C to 1.2°C per 100 m altitude change. This observation is at variance with the standard temperature lapse rate (STLR) of 0.65°C used universally in most of the hydrological and other land surface models. Snowmelt Runoff Model (SRM) was used to determine the efficacy of using the ATLR for simulating the stream flows in one of the glaciated and snow-covered watersheds in Kashmir. The use of ATLR in the SRM model improved the R2 between the observed and predicted streamflows from 0.92 to 0.97. It is hoped that the operational use of satellite-derived LST and ATLR shall improve the understanding and quantification of various processes related to climate, hydrology and ecosystem in the mountainous and data-scarce Himalaya where the use of temperature and ATLR are critical parameters for understanding various land surface and climate processes.

Monitoring Convective Clouds Over India and Nearby Regions Using Multi-spectral Satellite Observations

Convective clouds are the sources of severe weather and extreme precipitation events which often produce flooding, landslides and other disasters. The physical characteristics of convective clouds influence the distribution of radiative heating/cooling in the troposphere. They play a crucial role in atmospheric circulation and the hydrological cycle. Present study deals with the detection of convective clouds using multispectral observations at split window channels (near 11 and 12 µm) and water vapour absorption channels (near 6.7 µm) from EUMETSAT (Meteosat 7) data. Results are compared with the observations (reflectivity-based threshold) from Precipitation Radar (PR) on-board Tropical Rainfall Measuring Mission (TRMM). The Results have also been validated against convective clouds derived from rain gauge based precipitation product from the IMD data. Validation results show a correlation coefficient (cc) of 0.79 and Root Mean Square Error (RMSE) of 2.61 (%) against rain gauge based observations of convective clouds.

On land-use and land-cover changes over Lidder Valley in changing environment

ABSTRACT We have examined the land surface changes in the Lidder Valley of Kashmir in the context of socio-economy, climate and environmental aspect using geoscience technology. It was found that there are large-scale changes in agriculture, horticulture and built-up in the subject area. Records for horticulture, agriculture and built-up were generated from satellite data. A geodatabase of socio-economic data is examined and corelated with the land system changes. Furthermore, environmental driving factors like precipitation, temperature, snowfall and black carbon (BC) data were used to relate with the changes in LU/LC over the study area. This study reports decrease in agricultural area from 189.73 km2 in 1979 to 77.18 km2 in 2011 while the horticulture is increasing by 3 km2 annually from last three decades. With the increase of about 95% in horticulture, the concentration of BC has also increased. BC is showing a significant decadal increase of 10.5 mg/m2 which is mainly attributed to the biomass burning from horticulture waste. Rainfall, as well as snowfall over the study area, is decreasing by an amount of 2.95 and 15 mm per decade, respectively, and also their pattern is changing. These variations over the study area result in water scarcity forcing people to implement horticulture.