In the town centres with a long history, the initial topography is masked mainly by a layer of cultural deposits. The sediments considerable change the initial morphology of towns including range of landforms, and surface waters (e.g. wetlands), and finally the initial morphometry of urban areas (absolute and relative heights, slopes, aspects). The subject of the study is the historic centre of Cracow (former capital of Poland) where the early-medieval relief (up to the 8^th century) became masked due to the rapid increase in cultural deposits. The aim of the investigation is the reconstruction of morphology and hydrography of this area relating to the period of mid-medieval time (9^th-12^th). On the basis of rich sources of data (e.g. geoengineering, archaeology) and historical maps of the town, a hypsometric map and digital elevation model (DEM) have been generated, which showed the reconstructed morphology and hydrography of the study area. An estimation by ordinary kriging method were carried out. The final cartographic work was prepared with the use of Surfer software. The former distribution and limit of landforms (Pleistocene terrace, Holocene floodplain, meandering Vistula river channel, secondary channels, limestone hills) in the study area before the 13^th century is presented as a proposed variant of the geomorphological and hydrographic maps prepared by the authors. The former relief and distribution of wetlands was evaluated in terms of its potential for encouraging medieval settlement.

In research on land changes in historic town centres, the focus is on assessing the spatial differentiation of the thickness of cultural deposits and ultimately on assessing changes in some parameters that write the morphometry of the study areas. The material intentionally deposited in towns with a long tradition of development (hundreds or even several thousand years) comes  mainly from demolished buildings. The second way in land changes of towns was to build up the level of streets and squares mainly with mineral material. Other changes in the topography of towns were associated with the deposition of garbage, often outside town borders. The purpose of the presentation is to reconstruct the differences between paleotopography and modern topography of the historic centre of Cracow in the last millennium. The research area (9 km²) is located in the Vistula river valley in southern Poland, in which there are limestone hills surrounded by fluvial forms. The paleotopography studied represents the situation before the 8th century without significant human impact. On the basis of rich data sources (e.g. geoengineering and archaeology), a hypsometric map and digital elevation model (DEM) were generated, which showed the reconstructed paleotopography of the researched area. DEM from aerial laser scanning (ALS DEM) shows the contemporary topography of Cracow centre. The use of selected morphometric parameters allows quantitative assessment of spatial changes in absolute height, in  local levelling, slopes and exposures. In the centre of Cracow, these changes included building up and flattening the area.

In research on land changes in historic town centres, the focus is on assessing the spatial differentiation of the thickness of cultural deposits and ultimately on assessing changes in some parameters that write the morphometry of the study areas. The material intentionally deposited in towns with a long tradition of development (hundreds or even several thousand years) comes  mainly from demolished buildings. The second way in land changes of towns was to build up the level of streets and squares mainly with mineral material. Other changes in the topography of towns were associated with the deposition of garbage, often outside town borders. The purpose of the presentation is to reconstruct the differences between paleotopography and modern topography of the historic centre of Cracow in the last millennium. The research area (9 km²) is located in the Vistula river valley in southern Poland, in which there are limestone hills surrounded by fluvial forms. The paleotopography studied represents the situation before the 8th century without significant human impact. On the basis of rich data sources (e.g. geoengineering and archaeology), a hypsometric map and digital elevation model (DEM) were generated, which showed the reconstructed paleotopography of the researched area. DEM from aerial laser scanning (ALS DEM) shows the contemporary topography of Cracow centre. The use of selected morphometric parameters allows quantitative assessment of spatial changes in absolute height, in  local levelling, slopes and exposures. In the centre of Cracow, these changes included building up and flattening the area.

The purpose of this presentation is to discuss the public domain data in Mongolia and adjacent countries. This presentation includes discussions of the geologic setting, plate tectonics, the geothermal regime, satellite imagery, seismic, gravity and magnetic data, and ancillary data; and concludes with a discussion of several productive basins in northern China. Our analysis clearly confirms that regional scale geological mapping and gravity and magnetic surveys along with plate tectonic implications, satellite imagery analysis, and ancillary data give good indications of the presence of basin areas, which appear to contain sedimentary rocks of Cretaceous, Jurassic and Paleozoic age, which are considered to be prospective for commercial hydrocarbon accumulation. Continued exploration with higher quality potential field data and seismic data, leading to drilling is recommended.

The discussion on geologic setting includes a simplified surface geology map, coal and oil resource maps, stratigraphic columns, and example seismic sections. The discussion on plate tectonics presents hypotheses for the origin of this complex area. The discussion on geothermal regime utilizes both the limited data available in Mongolia and the newly available data in Northern China to strengthen the argument that Mongolia is a valid exploration target. Satellite images confirm geologic structures noted in the literature and observed in the gravity and magnetic data. The regional gravity data has been used to characterize the basin shape and major structural elements involving the older denser strata. This is a clearly valid use of the technique as shown by seismic data in China over numerous oil fields.

Khandelwal has published more than 100 research papers in different reputed national and international journals with high impact factors and reputable conference proceedings. He is the Editor-in-chief of three reputed journals and also on the editorial board of more than twenty refereed international journals published from various continents. He is the reviewer for more than 75 international reputed journals He has received certificates of outstanding contribution in reviewing from a number of international journals.