[1] It has long been thought that tropical rainfall retrievals from satellites have large errors. Here we show, using a new daily 1 degree gridded rainfall data set based on about 1800 gauges from the India Meteorology Department (IMD), that modern satellite estimates are reasonably close to observed rainfall over the Indian monsoon region. Daily satellite rainfalls from the Global Precipitation Climatology Project (GPCP 1DD) and the Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis (TMPA) are available since 1998. The high summer monsoon (June-September) rain over the Western Ghats and Himalayan foothills is captured in TMPA data. Away from hilly regions, the seasonal mean and intraseasonal variability of rainfall (averaged over regions of a few hundred kilometers linear dimension) from both satellite products are about 15% of observations. Satellite data generally underestimate both the mean and variability of rain, but the phase of intraseasonal variations is accurate. On synoptic timescales, TMPA gives reasonable depiction of the pattern and intensity of torrential rain from individual monsoon low-pressure systems and depressions. A pronounced biennial oscillation of seasonal total central India rain is seen in all three data sets, with GPCP 1DD being closest to IMD observations. The new satellite data are a promising resource for the study of tropical rainfall variability.

Increasingly available and a virtually uninterrupted supply of satellite-estimated rainfall data is gradually becoming a cost-effective source of input for flood prediction under a variety of circumstances. However, most real-time and quasi-global satellite rainfall products are currently available at spatial scales ranging from 0.25° to 0.50° and hence, are considered somewhat coarse for dynamic hydrologic modeling of basin-scale flood events. This study assesses the question: what are the hydrologic implications of uncertainty of satellite rainfall data at the coarse scale? We investigated this question on the 970 km2 Upper Cumberland river basin of Kentucky. The satellite rainfall product assessed was NASA's Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA) product called 3B41RT that is available in pseudo real time with a latency of 6-10 hours. We observed that bias adjustment of satellite rainfall data can improve application in flood prediction to some extent with the trade-off of more false alarms in peak flow. However, a more rational and regime-based adjustment procedure needs to be identified before the use of satellite data can be institutionalized among flood modelers.

In order to meet the ever increasing demand of drinking water, Dhaka Water Supply Authority (DWASA) of Bangladesh has installed a number of deep tube wells that tap the upper aquifers. However, in most parts of the city, the current groundwater abstraction exceeds the recharge rate, causing the groundwater to be mined systematically and be depleted of its reserve. Thus, there is an urgent need to alleviate the demand on the upper aquifers and explore more sustainable sources to augment the present water supply. This implies a conjunctive use of groundwater and surface water in order to maintain the balance between anthropogenic demand and water's natural availability. However, the surface water along these peripheral rivers is known to be highly polluted due to municipal and industrial untreated wastewaters that are discharged. This study analyzes the present water quality scenario along the surrounding rivers of Dhaka City pertaining to a 2-day field survey during the dry season of 2005. It uses a Geographic Information System (GIS) as a tool to arrive at a solution for relocation of the current intake point for surface water withdrawal. Derivation of water quality profiles (as a function of distance) along the downstream and upstream reaches of the current intake location indicated that a new location 12 km upstream of the present intake point could potentially be ideal for withdrawing surface water during the monsoon season. Such a proposed location was considered optimal due to the anticipated moderate construction costs of the transmission system that would be necessary to draw water to the current treatment plant. The study lays

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