Bihar

The report presents waterlogged area mapping and hydrological data analysis of Mokama tal area of Bihar. The drainage problems of the agriculture land use are basically associated with the stagnation of runoff and the rise of the water table. Generally, the runoff stagnation is a result of intense rain, which produces excessive runoff for which the existing drainage capacity is not adequate or outlet conditions are not favorable. The rise of water table beyond a critical limit or surface ponding results in waterlogging conditions.

In this study, an attempt has been made to study the characteristics of short interval rainfall data of the Punpun river basin lying in Bihar-Jharkhand, which has been identified as the representative basin for the NIH- Centre for Flood Management Studies, Patna. The estimation of flood peaks for small catchments is required for water resources planning, flood forecasting, design of various drainage systems, flood control and design of hydraulic structures.

The report presents an estimation of soil erosion and sediment yield for the Karso catchment of Barakar basin in Jharkhand using ANSWERS model. Quantitative assessments of runoff and soil erosion are needed for proper management of land and water resources.

The study attempts to develop a conjunctive use model involving judicious use of surface and groundwater for the Habibpur region of Gandak command in Bihar. The area is characterized by insufficient surface water during rabi and summer seasons and excess surface water in the kharif season.

In this study, the mathematical model developed at the National Institute of Hydrology for estimation of the Clark model parameters using the geomorphological characteristics of an ungauged basin has been applied for simulation of the direct surface runoff (DSRO) hydrographs of the Ajay basin up to the Sarath gauging site of South Bihar.

The study uses GIS techniques for spatial discretization of the Karso catchment into time-area segments to be used in numerical solutions of the governing differential equations for rainfall-runoff-erosion process. Various thematic layers such as soil, land use, slope, flow direction and Digital Elevation Model (DEM) were generated for the catchment using various tools available in GIS. These thematic layers were further utilized to generate attribute information such as Manning’s n, USLE K and C parameters for use in the rainfall-runoff-soil erosion model.

The study demonstrates Geographic Information Systems (GIS) based methodology for identification of sediment source areas and prediction of storm sediment yield for small watersheds. The Nagwa watershed in Bihar was discretized in to 50m grid cells using Integrated Land and Water Information Systems (ILWIS) GIS package, and unique drainage directions were obtained using GIS analysis. Also, a threshold channel network was generated from Digital Elevation Model (DEM) of the watershed. Actual observed drainage and generated drainage networks were superimposed and were found identical.

Small and big dams and big embankments were constructed in this region, without understanding the nature of the rivers which have always changed course or overshot their banks. Assuming however, that the river will not change course, the Government adopted a skewed development program - that of building embankments to contain the river.

This presentation deals with the problem of arsenic contaminated aquifers in the Gangetic belt of Bihar and the failure of the state government in tackling the crisis and calls for the establishment of a centralized knowledge & research hub with an understanding of the regional peculiarities to mitigate the crisis.

It traces the origin of arsenic crisis to the switch from use of surface water to groundwater. The health impacts of arsenic poisoning and the factors that aggravate arsenicosis are explained. A total of sixteen districts (fifty-seven blocks) in Bihar are affected by high levels of arsenic in groundwater, in trivalent form, which is a more toxic form of arsenic.

When the foundation stone for the Kosi embankment was laid on January 14, 1955, near Nirmali in Saharsa district in Bihar, euphoric people shouted, Aadhi roti khayenge, Kosi bandh banayenge (we will eat only half a chapati but we will surely build the embankment), writes the prolific engineer and activist Dinesh Mishra in his book, “ Trapped! Between the Devil and the Deep Waters.” No one really paid any attention to the protests and the fears of the people who would live with these embankments and what would happen to their lives.