RESUMO
Water scarcity problems are a national agenda that must be prioritized. Thailand is an agricultural country with agriculture consuming a large amount of water. Sustainable water management for the agricultural sector is urgently needed. This study assessed the impacts of water consumption by agricultural products using a water scarcity footprint (WSF) assessment. This study presents the use of the growing season available water remaining characterization factors (AWARE CFs) of specific crops, based on growth months of that crop, instead of the annual AWARE CFs of agricultural products to assess the value of this approach for an appropriate assessment of water resource and the planning of crop production priorities. The original marginal AWARE CF was considered for determining the growing season AWARE CFs of major rice, second rice, sugarcane, maize, and cassava in 25 Thai watersheds. The growing season AWARE CFs of the food crops were used to determine their WSFs for the 25 Thai watersheds. The growing season AWARE CFs of major rice, second rice, sugarcane, maize, and cassava for Thailand were 1.74, 11.5, 6.01, 3.28, and 7.96 m3 world-eq. per m3 consumed, respectively. There were statistical differences between the means of annual AWARE CFs and growing season AWARE CFs for all Thai food crops in almost all watersheds. The WSFs using growing season AWARE CFs of major rice, second rice, sugarcane, maize, and cassava were 0.05-3.66, 1.10-193, 0.51-7.99, 1.09-8.28, and 1.65-30.3 m3 world-eq. per kilogram, respectively. This work identified suitable watersheds for growing food crops and compiled them as databases for the use of zoning food crop cultivation by the Thai government. Regarding WSF values, the least suitable watershed for growing major rice, second rice, sugarcane, and cassava was the Petchaburi watershed. The least suitable watershed for growing maize was the Chao Phraya watershed.
RESUMO
Increasing water demand and decreasing freshwater availability in an area can cause water scarcity leading to damage to human health, ecosystem quality, and natural resources. Many countries around the world, including Thailand, have recognized the importance of this problem. The available water remaining (AWARE) characterization model provides water scarcity footprint characterization factors (WSF CFs) for assessing the WSF of products. AWARE CFs were prepared from WaterGAP model's data and are available in watershed and country levels. They were not provided for specific areas and could not accurately explain water scarcity situations in certain regions, potentially leading to inappropriate water management. This work calculates the annual and monthly local CFs from local data in the Chao Phraya watershed in Thailand. The monthly local CFs with local environmental water requirement (EWR) calculations ranged from 0.10 to 100. The mean difference between AWARE CFs and local CFs was statistically significant. The most sensitive parameters for local CFs in the dry season were water availability (WA) and agricultural water consumption and that in the wet season was WA. The weighting of AWARE CFs by each type of water consumption and an aggregate of AWARE CFs for product production has been recommended for WSF assessment. The AWARE methodology was modified to assess the individual water scarcity of each water user based on the order of priority. For the Chao Phraya watershed, the ranges of the monthly local individual CFs using local EWR calculations of domestic, environment, livestock, agriculture, and industry were 0.10-0.33, 0.10-0.37, 0.10-0.37, 0.10-100, and 0.10-100, respectively. This assessment of individual water scarcity is helpful for prioritizing the level and timing of water use to minimize their impacts on critical water scarcity.
RESUMO
Alternative methodologies for the reduction of greenhouse gas (GHG) emissions from crude palm oil (CPO) production by a wet extraction mill in Thailand were developed. The production of 1 t of CPO from mills with biogas capture (four mills) and without biogas capture (two mills) in 2010 produced GHG emissions of 935 kg carbon dioxide equivalent (CO2eq), on average. Wastewater treatment plants with and without biogas capture produced GHG emissions of 64 and 47% of total GHG emission, respectively. The rest of the emissions mostly originated from the acquisition of fresh fruit bunches. The establishment of a biogas recovery system must be the first step in the reduction of GHG emissions. It could reduce GHG emissions by 373 kgCO2eq/t of CPO. The main source of GHG emission of 163 kgCO2eq/t of CPO from the mills with biogas capture was the open pond used for cooling of wastewater before it enters the biogas recovery system. The reduction of GHG emissions could be accomplished by (i) using a wastewater-dispersed unit for cooling, (ii) using a covered pond, (iii) enhancing the performance of the biogas recovery system, and (iv) changing the stabilization pond to an aerated lagoon. By using options i-iv, reductions of GHG emissions of 216, 208, 92.2, and 87.6 kgCO2eq/t of CPO, respectively, can be achieved.
