17 Irrigation and Drainage
379
agricultural census, which although more reliable, is obviously time consuming
and does not provide frequent updates. Literature provides abundant evidence on
the reliability and cost-effectiveness of estimates of cropped area based on satellite
data. In many instances this has reached the stage of operational use, as
documented by the references mentioned in the section Current Applications.
Enforcement of legislation and of administrative procedures depends on the
availability of accurate and up-to-date information on land use. Water is often
allocated on the basis of water rights conditional on actual use of land for irrigated
agriculture and water fees are assessed on the basis of irrigated area or crop
category (e.g. water requirements being negligible, moderate or high for three
broad crop categories). Moreover regular and frequent (e.g. twice yearly)
determination of irrigated area and fractional cover may help fme-tuning water
allocation, distribution and application, thereby improving water use efficiency.
17.1.2 Reviews ofremote sensing applications in irrigation and drainage
Reviews were presented by Menenti (1990), Veerlapati-Govardhan (1993) and
Vidal and Sagardoy (1995). The material given in Menenti (1990) demonstrates
the feasibility of the applications listed herebelow:
mapping of irrigated area for diverse land units (from farms to large irrigation
schemes);
integration of information on irrigated lands with GIS for assessments of
water rights;
assessment of irrigation performance;
detection and monitoring of poorly drained areas;
determination of height-storage relationship of natural depressions;
appraisal of land suitability for irrigation;
planning of irrigation development.
The more recent overview by Vidal and Sagardoy (1995) described a broader
spectrum of applications:
detection of potential groundwater-rich areas;
evaluation and planning of surface water resources;
assessment of irrigation potential and evaluation of the economic impact of
irrigation;
identification and mapping of irrigated areas;
monitoring of irrigation and drainage infrastructure;
land use and crop identification;
379
agricultural census, which although more reliable, is obviously time consuming
and does not provide frequent updates. Literature provides abundant evidence on
the reliability and cost-effectiveness of estimates of cropped area based on satellite
data. In many instances this has reached the stage of operational use, as
documented by the references mentioned in the section Current Applications.
Enforcement of legislation and of administrative procedures depends on the
availability of accurate and up-to-date information on land use. Water is often
allocated on the basis of water rights conditional on actual use of land for irrigated
agriculture and water fees are assessed on the basis of irrigated area or crop
category (e.g. water requirements being negligible, moderate or high for three
broad crop categories). Moreover regular and frequent (e.g. twice yearly)
determination of irrigated area and fractional cover may help fme-tuning water
allocation, distribution and application, thereby improving water use efficiency.
17.1.2 Reviews ofremote sensing applications in irrigation and drainage
Reviews were presented by Menenti (1990), Veerlapati-Govardhan (1993) and
Vidal and Sagardoy (1995). The material given in Menenti (1990) demonstrates
the feasibility of the applications listed herebelow:
mapping of irrigated area for diverse land units (from farms to large irrigation
schemes);
integration of information on irrigated lands with GIS for assessments of
water rights;
assessment of irrigation performance;
detection and monitoring of poorly drained areas;
determination of height-storage relationship of natural depressions;
appraisal of land suitability for irrigation;
planning of irrigation development.
The more recent overview by Vidal and Sagardoy (1995) described a broader
spectrum of applications:
detection of potential groundwater-rich areas;
evaluation and planning of surface water resources;
assessment of irrigation potential and evaluation of the economic impact of
irrigation;
identification and mapping of irrigated areas;
monitoring of irrigation and drainage infrastructure;
land use and crop identification;