A. K. Gosain

Forest and Water Policies. The need to reconcile public and science perceptions

This paper compares and contrasts some of the science and public perceptions of the role of forests in relation to the water environment. It is suggested that the disparity between the two perceptions needs to be addressed before we are in a position to devise and develop land and water policies (whether market or non-market based) which are aimed at either improving the water environment, and by doing so improving the livelihoods of poor people by greater access to water, or conserving and protecting forests. Examples are given of three research projects in South Africa, India and Costa Rica where, through the involvement of stakeholder groups, often with representatives comprising both the science and public perceptions, interactive research programmes were designed not only to derive new research findings with regard to the biophysical processes but also to achieve better “ownership” and acceptance of research findings by the stakeholders. It is concluded that to move towards a reconciliation of the different perceptions and to put in place better policies and management systems, where policy is better connected with science, will require further efforts: a) To understand how the “belief” systems underlying the science and public perceptions have evolved, and how these are affecting land and water policy processes; b) To develop management support tools, ranging from simple dissemination tools, which can demonstrate the impacts of land use decisions on the water environment to institutions and local people, to detailed robust and defensible hydrological models which are needed to help implement the new land and water policies, such as those now being implemented in RSA; and c) To understand better how land and water related policies impact on the poorest in society. It is argued that many present policies may not be significantly benefiting the poor and may even, in some situations, be resulting in perverse outcomes.

An operational model for estimating Regional Evapotranspiration through Surface Energy Partitioning (RESEP)

Considerable work has been done on estimating surface energy fluxes and thus evapotranspiration at regional scale using remote sensing technique. Approaches currently used for estimating regional evapotranspiration are either based on empirical models or utilize a surface energy balance approach. The operationalization of these models has not been successful, because of the complexities involved in the procedure, strong dependence of heat transfer coefficient on a number of local meteorological parameters and accuracy at regional scale. This paper presents a remote sensing based simplified operational procedure to estimate sensible heat flux incorporating the local meteorological conditions. The model utilizes the surface reflectance in visible, infrared and thermal bands to generate surface albedo, surface temperature and leaf area index and thus surface energy fluxes to determine regional evapotranspiration. The developed model (Regional Evapotranspiration through Surface Energy Partitioning--RESEP) is applied to a part of the Western Yamuna Canal command in the State of Haryana, India to illustrate the methodology. The proposed procedure is computationally simple with reasonable accuracy of results. For a well-watered crop, average evapotranspiration by the proposed model is estimated as 2.1 mm day -1, whereas using Penman-Monteith equation it is calculated as 1.9 mm day -1 . The error involved in estimating evapotranspiration by the proposed model is calculated to be about 10%, which is acceptable for most cases.

Evaluation of regional groundwater quality using PCA and geostatistics in the urban coastal aquifer, East Coast of India

A systematic groundwater quality-monitoring program was conducted, and a total of 201 groundwater samples were collected. Multivariate and geostatistical techniques were employed to investigate major contamination types and its spatial characteristics in the study area. Principal Component Analysis (PCA) reveals that salinity (Factor 1) and nutrient (Factor 2) are very predominant contaminants in the shallow coastal aquifer. The factor (F1 and F2) scores of each well during three seasons were indicated a spatial correlation of salinity factor (F1) up to 10 km and no spatial correlation were found for nutrient factor (F2).

What Constitutes a Fair and Equitable Water Apportionment

Water has been a source of conflict since time immemorial. Numerous mechanisms have been proposed for solving such conflicts but multiplicity of water uses and users along with self-serving definition of equitable, makes dispute resolution challenging. Doctrines advocating water appropriation based on the notion of equity and fairness are intuitively appealing. However, subjectivity of this concept impedes their translation to universal principles for water allocation as fairness quotient of any mechanism is determined unitedly by gamut of diverse factors. Thus, the present study critically reviews the connotations of equity and equality to arrive at a procedurally and distributionally just apportionment policy for real-world water conflicts. It seeks an equal opportunity paradigm for deservedness-based resource distribution that could be unanimously amenable to all stakeholders. The study is very apposite as there is a lurking fear of heightened water conflicts that could have bitter socio-political ramifications.

Impact of Anthropogenic Interventions on the Vembanad Lake System

Estuarine and coastal zone processes have always been topic of research due to their being prime centers of rich resources like diverse habitat and natural beauty. Other than ecological reasons these aquatic bodies act as important economic centers, tourist places, serve in navigational purposes, and fishing. One of the India’s most valued natural sites is the Vembanad Lake and estuarine system that lies on the western coast in the state of Kerala. This natural system, which comprises the lake, the Kuttanad wetland region and the Cochin estuary, is included in the Ramsar list of important wetland sites. Six major rivers, namely, Periyar, Muvattupuzha, Pamba, Manimala, Meenachil, and Achenkovil contribute to the system. The whole system has been vastly modified throughout the last couple of centuries owing to sedimentation and human-driven factors. On the other hand, there has been constant reclamation of the low-lying areas on the periphery of the lake and the wetlands, leading to reduction in the spread area. The special characteristics of these lands that lie to the east of the lake is that the ground level is lower than the lake water level. Therefore, the lake water easily serves for irrigational purpose in these adjacent lands. According to tentative proposals in the recent years it was intended to make further developments in the catchment areas for various purposes. The present paper takes a modeling approach to find out what would be the possible impact on the lake water profile as well as salinity/solute concentration if these proposals are implemented. The study has been carried out using the two-dimensional hydrodynamic modeling software MIKE 21 with HD and AD modules. The results from the hydrodynamic model of the lake, although not fully representative, show that the lake water levels and salinity might face quantitatively relevant changes which can pose a threat to the natural environment.

Prediction of land use changes based on Land Change Modeler and attribution of changes in the water balance of Ganga basin to land use change using the SWAT model

Conflicts between increasing irrigated agricultural area, commercial crops, shifting cultivation and ever increasing domestic and industrial demand has already been a cause of tension in the society over water in the Ganga River Basin, India. For the development of sustainable water resource strategies, it is essential to establish interaction between landuse changes and local hydrology through proper assessment. Precisely, seeing how change in each LULC affects hydrologic regimes, or conversely evaluating which LULC shall be appropriate for the local hydrological regime can help decision makers to incorporate in the policy instruments. In this study, hydrologic regimes of the Ganga River basin have been assessed with landuse change. Catchment hydrologic responses were simulated using Soil and Water Assessment Tool (SWAT). Meteorological data from IMD of 0.25° × 0.25° spatial resolution were taken as the climate inputs. Simulated stream flow was compared at different gauge stations distributed across the Gang River and its tributaries. Urbanization has been the topmost contributor to the increase in surface runoff and water yield. While increased irrigation demands were the dominant contributor to the water consumption and also added to the increased evapotranspiration. This study can be important tool in quantifying the changes in hydrological components in response to changes made in landuse in especially basins undergoing rapid commercialization. This shall provide substantive information to the decision makers required to develop ameliorative strategies.

A simple procedure for estimating distributed daily evapotranspiration using landsat-TM data

A procedure to estimate distributed daily evapotranspiration (ET) using remotely sensed data is presented. Landsat-TM data for a part of the Western Yamuna Canal command (Haryana) has been used for model application. The model utilizes the surface reflectance in visible, infrared and thermal bands to generate surface albedo, surface temperature and leaf area index and thus surface energy fluxes to determine distributed daily ET. Result reveals a reasonable estimate of distributed daily ET. For well-watered crop, average ET by the proposed model is estimated as 1.8 mm/d, whereas using Penmen-Monteith equation it is calculated as 1.9 mm/d. The error involved in estimating ET by the proposed model is calculated about 5%, which is quite acceptable for most applications. The proposed procedure is also found computationally simple and can also be applied on current Landsat ETM+ data.