[EBOOK] REMOTE SENSING APPLICATIONS TO GROUNDWATER, A.M.J. Meijerink, Published by the United Nations Educational, Scientific and Cultural Organization

All attempt is made to be comprehensive, which implies that some subjects arc introduced in brief terms only, particularly those which arc of indirect use for studies of a practical nature and those which require socialist knowledge in processing of remotely sensed data.

Most of the text is devoted to qualitative approaches, particularly image interpretation of diverse geologic terrains from an Earth science perspective. The synoptic view offered by images allows for the study of surface features related to the interaction of surface and groundwater. In hard rock terrain success rates can often be increased by drilling close to lineaments identified bv visual interpretation: relative recharge patterns can be mapped bv interpretation and can he quantified in a second stage.

Interpretation must be based on hydrogeological knowledge; for example, groundwater intake areas on higher and permeable ground arc accompanied by discharge areas in adjoining lower terrain, and with that knowledge one looks for features on images that place a groundwater flow system in a spatial context. A number of examples arc given in this book.

Simple (cross-sectional) modelling may also help in understanding features seen on images, while image data can provide input in setting up tile model. Examples arc also discussed here.

Although exploration of groundwater remains important, particularly considering the lack of good drinking water in many regions, over the last decades attention has shifted to groundwater management. Remote sensing provides much of the spatial data needed to understand the interactions between surface water and groundwater.

A numerical groundwater model is an important instrument in making decisions about wise management of groundwater, and it is fortunate that more studies arc becoming available on the use of remotely sensed information as inputs in such models. A chapter is devoted to the subject, where the various geophysical techniques that can provide inputs for modelling arc discussed.

Furthermore, site selection for managed aquifer recharge (artificial recharge) schemes is included because such schemes arc badly needed to mitigate further depletion of groundwater, especially in aquifers used for irrigation.

Attention is also given to the relationship between groundwater and the environment. Remote sensing data provides information on spatial patterns of groundwater dependent vegetation or salinization and is often the only source to study the history of change.

Concerning general image interpretation, an important aspect is that such interpretations do not require specialist software or socialist services to handle complex remote sensing processing (c.g. measurement of changes in land surface). Hydrogcologic image intcqrrctation and evaluation of results do require a background in Earth science or knowledge of the interaction between surface water and groundwater. It is emphasized that hvdrogcological image interpretation should be confirmed through follow-up fieldwork and needs consultation of existing hvdrogcologic data, because interpretation is often a matter of inference.

Tribute should be paid to the stair of many local offices and consultant services in groundwater exploration and development, who undertook much of the practical application of remote sensing. Their objectives were to find suitable sites, develop wells and lav down the results in departmental reports, rather than publish their tuediods in scientific-journals. In fact, plotting information obtained from local drillers about successful and dry wells on images is a good start in hydrogeological image interpretation for the development of groundwater.

[EBOOK] REMOTE SENSING APPLICATIONS TO GROUNDWATER, A.M.J. Meijerink, Published by the United Nations Educational, Scientific and Cultural Organization

CLICK HERE TO DOWNLOAD THIS EBOOK

Keyword: ebook, giáo trình, REMOTE SENSING APPLICATIONS TO GROUNDWATER, REMOTE SENSING APPLICATION, công nghệ viễn thám, ứng dụng công nghệ viễn thám vào thăm dò nước ngầm