Blue and Grey Water Footprints of Dairy Farms in Kuwait

In Kuwait, dairy farming faces challenges due to its significant water demands. The current study assessed seasonal patterns of water use to estimate the blue water footprint (WF) and grey WF per kg of fat protein corrected milk (FPCM) for confined dairy farming systems in Kuwait. Blue and grey WFs were evaluated using data from three operational farms. The average blue WF (L·kg-1 FPCM) was estimated to be 54.5 ± 4.0 L·kg-1 in summer and 19.2 ± 0.8 L·kg-1 in winter. The average grey WF (generated from milk house wastewater) was assessed on bimonthly basis and determined based on its phosphate (PO4) concentration (82.2 ± 14.3 mg·L-1) which is the most limiting factor to be 23.0 ± 9.0 L·kg-1 FPCM d-1. The outcomes indicate that enhancing the performance of dairy cows and adopting alternative water management strategies can play a role in minimizing the impacts of confined dairy farming systems in Kuwait on water quality and quantity.

Environmental sustainability of grey water footprints in Peshawar Basin:Current and future reduced flow scenarios for Kabul River

Assessing water pollution at basin level is a challenging task.In this study,the environmental sustainability of grey water footprints(WFgrey)of Peshawar Basin in Pakistan was analysed.The release of nitrogen(N)and phosphorus(P)from point and non-point sources during the period 1986 to 2015 were studied.Water pollution level(WPL)for normal and 10%-50%future reduced runoff in Kabul River as a result of construction of dams was considered.Methodologies described in Water Footprint Assessment Manual and Grey Water Footprint Accounting Guidelines were followed.Results showed that 30-year annual average of N and P discharges were 24.5×10^(3)t/a and 10.9×10^(4)t/a respectively.The discharge of N and P from non-point sources contribute 97%and 99%respectively.N related WFgrey was 50×10^(8)m^(3)/a and 50×10^(9)m^(3)/a for P.WPL of N was within the sustainable limit for all reduced runoff scenarios while P-related WPL for normal runoff exceeded sustainable limits and was worse in each reduced runoff scenario.This study confirms the deteriorated water quality of Kabul River and the findings may be helpful for future planning and water resource management of the basin.

The Analysis of Water Footprint of Production and Water Stress in China

Water footprint of production can be used to identify pressure on national or regional water resources generated by production activities. Water stress is defined as the ratio of water use （the difference between a re- gional water footprint of production and a green water footprint） to renewable water resources available in a country or region. Water stress can be used to identify pressure on national or regional water resources generated by production activities. This paper estimates the water footprint of production and the water stress in China during the years 1985-2009. The result shows that China＇s water footprint of production increased from 781.58×109 m^3 in 1985 to 1109.76 × 10^9 m^3 in 2009. Mega-cities and regions with less agriculture production due to local climatic conditions （Tibet and Qinghai） had lower water footprint of production, while the provinces （Henan, Shandong） with higher agriculture production had higher footprint. Provinces with severe water stress increased from 6 in 1985 to 9 in 2009. High to severe water stress exists mainly in mega-cities and agricultural areas located in the downstream areas of the Yellow River and the Yangtze River in North and Central China. The outlook for water resources pressure in China is not optimistic, with areas of stress expanding from northern to southern of China.

Analysis of Agricultural Eco-Efficiency and Influencing Factors in Henan Province

In order to improve the agricultural eco-efficiency and promote the sustainable development of agriculture in Henan Province, China, based on the footprint theory, the super-efficiency SBM model is used to scientifically calculate and analyze the agricultural eco-efficiency in Henan Province. On this basis, the influencing factors of agricultural eco-efficiency in Henan Province are quantitatively analyzed by using the grey incidence analysis model. The results show that unilaterally considering one of grey water footprints and carbon footprints will overestimate or underestimate the agricultural eco-efficiency of Henan Province in different degrees in different time periods, and the agricultural eco-efficiency obtained by comprehensively considering grey water footprint and carbon footprint (GWCAEE) is more in line with the reality of agricultural development in Henan Province. In 2000-2004, GWCAEE in Henan Province was better. During 2005-2014, GWCAEE in Henan Province showed a fluctuating decline and continued to be in an inefficient state. From 2015 to 2019, GWCAEE of Henan Province gradually increased, and it became effective in 2019. In recent years, GWCAEE has developed well. Through the grey incidence analysis between 12 influencing factors including endogenous factors and exogenous factors and GWCAEE, it is found that the six leading factors of GWCAEE in Henan Province are agricultural structure, financial input for agriculture, number of agricultural employees, crop sown area, consumption of chemical pesticide, consumption of agricultural diesel oil. According to the above research conclusions, suggestions for improving agricultural eco-efficiency in Henan Province are put forward.