Estimated Forest Ecological Water Requirements in the Jinghe Watershed—Theory and Case Study

2006 ◽  
Vol 1 (1) ◽  
pp. 43-47 ◽  
Author(s):  
Yongtao He ◽  
Qingwen Min ◽  
Wenhua Li ◽  
Guicai Li ◽  
Liwei Jin
2021 ◽  
Vol 11 (21) ◽  
pp. 10379
Author(s):  
Mohammed El Hafyani ◽  
Ali Essahlaoui ◽  
Kimberley Fung-Loy ◽  
Jason A. Hubbart ◽  
Anton Van Rompaey

This work was undertaken to develop a low-cost but reliable assessment method for agricultural water requirements in semi-arid locations based on remote sensing data/techniques. In semi-arid locations, water resources are often limited, and long-term water consumption may exceed the natural replenishment rates of groundwater reservoirs. Sustainable land management in these locations must include tools that facilitate assessment of the impact of potential future land use changes. Agricultural practices in the Boufakrane River watershed (Morocco) were used as a case study application. Land use practices were mapped at the thematic resolution of individual crops, using a total of 13 images generated from the Sentinel-2 satellites. Using a supervised classification scheme, crop types were identified as cereals, other crops followed by cereals, vegetables, olive trees, and fruit trees. Two classifiers were used, namely Support vector machine (SVM) and Random forest (RF). A validation of the classified parcels showed a high overall accuracy of 89.76% for SVM and 84.03% for RF. Results showed that cereal is the most represented species, covering 8870.43 ha and representing 52.42% of the total area, followed by olive trees with 4323.18 ha and a coverage rate of 25%. Vegetables and other crops followed by cereals cover 1530.06 ha and 1661.45 ha, respectively, representing 9.4% and 9.8% of the total area. In the last rank, fruit trees occupy only 3.67% of the total area, with 621.06 ha. The Food and Agriculture Organization (FAO) free software was used to overlay satellite data images with those of climate for agricultural water resources management in the region. This process facilitated estimations of irrigation water requirements for all crop types, taking into account total potential evapotranspiration, effective rainfall, and irrigation water requirements. Results showed that olive trees, fruit trees, and other crops followed by cereals are the most water demanding, with irrigation requirements exceeding 500 mm. The irrigation requirements of cereals and vegetables are lower than those of other classes, with amounts of 300 mm and 150 mm, respectively.


2010 ◽  
Vol 20 (4) ◽  
pp. 318-329 ◽  
Author(s):  
Baoshan Cui ◽  
Yanyan Hua ◽  
Chongfang Wang ◽  
Xiaolin Liao ◽  
Xuejie Tan ◽  
...  

Water Policy ◽  
2005 ◽  
Vol 7 (5) ◽  
pp. 443-467 ◽  
Author(s):  
Julie A. Smith ◽  
J. Maryann Green

South Africa's past apartheid inequities create unique challenges in achieving water delivery goals. The South African government implemented the free basic water (FBW) policy in July 2001 to ensure all South Africans had access to a basic amount of safe water by 2004. The FBW policy entitles all people to a free lifeline supply of 6000 ls/6 kilolitres (kl) (1 kl = 1000 l) of water per household per month. Despite being heralded as a way of ensuring access of lifeline water services to low-income households, fundamental policy flaws exist. The FBW allocation does not meet the basic water requirements and special water requirements of the majority of low-income households. Low-income households require more than the 6 kl allocation and are thereby expected to pay the full cost for their water service. The affordability crisis has not been addressed as tariff structures and cross-subsidisation mechanisms remain inadequate. The financial sustainability of the FBW policy is reliant on the equitable share, an unconditional grant from national government and user-fees, which the extensive low-income sector cannot afford to pay. The FBW policy is analysed, via a case study, conducted in Pietermaritzburg, KwaZulu-Natal, within the Msunduzi municipal jurisdiction, which draws on low-income household experience of the policy.


2016 ◽  
Vol 16 (6) ◽  
pp. 1536-1551
Author(s):  
Saroj Acharya ◽  
Ashish Pandey ◽  
S. K. Mishra ◽  
U. C. Chaube

A geographic information system (GIS) based graphical user interface for irrigation management within an ArcGIS customization has been developed using Visual Basic for Applications for estimation of spatially distributed irrigation water requirements. It is capable of providing an appropriate framework for manipulating, visualizing and analyzing spatial data to support decision making in irrigation management. Its application is demonstrated through a case study for use in the field.


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