水文学: 現在の研究

This paper outlines a study aimed to assess the long-term association between land cover/land use change and water quality changes occurred in the Ziarat Catchment, upstream of the Gharasoo River basin, Golestan Province northeast, of Iran. To assess the significance of trends in the time series of water quality variables, non-parametric trend tests (the Mann-Kendall and the seasonal Kendall) or parametric trend tests (linear regression and ANCOVA) were performed after removing variance due to discharge. The water quality and quantity data available for the analysis in this study belong to the observed period from 1974 to 2012 in a river gauge station located at the outlet of the catchment. The analysis revealed that with the exception of pH (no trend) and sulfate (negative trend), all other water quality variables including electrical conductivity, total dissolved solids, hardness, sodium, potassium, calcium, magnesium, chloride, sodium adsorption ratio and bicarbonate demonstrate statistically significant positive trends (P-value<0.05). Using the seasonal Kendall test, the negative trends have been detected for rainfall and mean discharge time series. To determine the likely responsible factor(s) for water quality changes, an investigation has been conducted on land cover/land use changes. A series of significant land cover/land use change were identified from 1967 to 2012, within five time intervals, referring to satellite images and also aerial photographic interpretation and based on RS and GIS standard techniques. The spatial analysis shows that within four decades about 980 ha of forests in the catchment have been converted to other classes of land cover/land use (about 67% to croplands and/ or rangelands, 8.5% to residential 38 areas, 13% to bare lands, and 11.5 % to roads). The results of this research suggest that land cover/land use change is one of the key factors causing water quality changes in the study area. The findings of this research assists policy makers and catchment managers in developing catchment management plans to protect and restore water quality conditions more effectively.

This article elaborates a survey on water use events and activities in households. The survey inquires socioeconomic aspects, technology, processes and devices which may play an important role in these water use events. Processes like washing clothes and utensils, cooking refrigeration and heating are discussed. Devices like water purifiers, air-coolers, and toilets are qualitatively analyzed. Water use events such as bathing and brushing teeth are studied. The survey in online format and printed version was randomly responded by one hundred sixty people including fifty three family heads within city of Jodhpur, India. More than hundred respondents answered the online questionnaire from Mandi in north India, Delhi, the national capital territory and Jodhpur in west India. More than ninety per cent of the respondents were males. Climate of the regions mentioned above played a decisive role in water consumption. The general public was very much unaware of the policies of the government towards water conservation and management. Advertisements by vendors were found to misguide consumers providing importance to aesthetic features rather than technical specification. The implications of this study helps in becoming environmentally aware of how human actions affect the management of water and related energy use at households.

The morphometric analysis of the drainage basin and channel network play an important role in understanding the geo-hydrological behavior of drainage basin and expresses the prevailing climate, geology, geomorphology, structural antecedents of the catchment. Morphometric analysis of a drainage basin expresses fully the state of dynamic balance that has been attained due to dealings between matter and energy. In the present study, morphometric analysis has been carried out using Geographical Information System (GIS) techniques to assess the geo-hydrological characteristics of Vishav drainage basin and an attempt has been made to identify the ground water potential zones through geo-morphometric specs. The morphometric parameters are discussed about linear, areal and relief aspects. The basin is characterized by dendritic to sub-dendritic drainage pattern. The development of stream segments in the basin area is affected by rainfall, groundwater discharge and snow melt over. The analysis has revealed that the total number and length of stream segments is maximum in first order streams and decreases as the stream order increases. The bifurcation ratio (Rb) between different successive orders varies revealing the geostructural control. The shape parameters (Rc=0.52, Re=0.15 and Rf=0.22) indicate the elongated shape of the basin and in association with some areal (Dd, Dt etc.) and relief (H, Sb, etc.) parameters show that it has low discharge of runoff, generally permeable subsoil condition, moderate to high infiltration capacity and good groundwater resource and a flatter peak of flow of longer duration that is easier to manage that of the circular basins. The study reveals that morphometric analysis based on GIS technique is a competent tool for geo-hydrological studies. These studies are very useful for identifying and planning the ground water potential zones and watershed management (including the whole gamut of natural resources connected with the basin).

India is fast developing large democratic country in South East Asia with more than 1.2 billion peoples with multitude of culture, language, lifestyle and food habits. The traditional culture in urban India started degrading with respect to life style and food habits (i.e., food preparation, inclusion of new food menu with effect to the modern and foreign culture). Intake of cocktail of chemicals and pathogens by general population is anticipated to increase in India. Considering those aforesaid facts, in this paper some major issues related to Indian modern food culture with special emphasis on chemical migration and food borne illness have been reviewed and highlighted.