Transdisciplinary research in support of land and water management in China and Southeast Asia : evaluation of four research projects

Unidad de excelencia María de Maeztu MdM-2015-0552Transdisciplinary research (TDR) aims at identifying implementable solutions to difficult sustainability problems and at fostering social learning. It requires a wellmanaged collaboration among multidisciplinary scientists and multisectoral stakeholders. Performing TDR is challenging, particularly for foreign researchers working in countries with different institutional and socio-cultural conditions. There is a need to synthesize and share experience among researchers as well as practitioners regarding how TDR can be conducted under specific contexts. In this paper, we aim to evaluate and synthesize our unique experience in conducting TDR projects in Asia. We applied guiding principles of TDR to conduct a formative evaluation of four consortium projects on sustainable land and water management in China, the Philippines, and Vietnam. In all projects, local political conditions restricted the set of stakeholders that could be involved in the research processes. The set of involved stakeholders was also affected by the fact that stakeholders in most cases only participate if they belong to the personal network of the project leaders. Language barriers hampered effective communication between foreign researchers and stakeholders in all projects and thus knowledge integration. The TDR approach and its specific methods were adapted to respond to the specific cultural, social, and political conditions in the research areas, also with the aim to promote trust and interest of the stakeholders throughout the project. Additionally, various measures were implemented to promote collaboration among disciplinary scientists. Based on lessons learned, we provide specific recommendations for the design and implementation of TDR projects in particular in Asia

Conceptual modelling to assess the influence of hydro-climatic variability on runoff processes in data scarce semi-arid Andean catchments

Using hydro-meteorological time series of 50years and in situ measurements, the dominant runoff processes in perennial Andean headwater catchments in Chile were determined using the hydrological model HBV light. First, cluster analysis was used to identify dry, wet and intermediate years. From these, sub-periods were identified with contrasting seasonal climatic influences on streamflow. By calibrating the model across different periods, impacts on model performance, parameter sensitivity and identifiability were investigated, providing insights into differences in hydrological processes. The modelling approach suggested that, independently of a dry or wet period of calibration, the streamflow response is mostly consistent with flux from groundwater storage, while only a small fraction comes from direct routing of snowmelt. The variation of model parameters, such as the groundwater rate coefficient, was found to be consistent with differing recharge in wet and dry years. The resulting snowmelt-groundwater model is a realistic hypothesis of the hydrological operation of such complex, data scarce and semi-arid Andean catchments. This model may also be a useful tool for predictions of seasonal water availability and a basis for further field studies

Assessment of climate change impact on river flow regimes in The Red River Delta, Vietnam – A case study of the Nhue-Day River Basin

Global warming has caused dramatic changes in regional climate variability, particularly regarding fluctuations in temperature and rainfall. Thus, it is predicted that river flow regimes will be altered accordingly. The purpose of this paper is to present the results of modeling such changes by simulating discharge using the HEC-HMS model. The precipitation was projected using super-high resolution multiple climate models (20 km resolution) with newly updated emission scenarios as the input for the HEC-HMS model for flow analysis at the Red River Basin in the northern area of Vietnam. The findings showed that climate change impact on the river flow regimes tend towards a decrease in the dry season and a longer duration of flood flow. A slight runoff reduction is simulated for November while a considerable runoff increase is modeled for July and August amounting to 30% and 25%, respectively. The discharge scenarios serve as a basis for water managers to develop suitable adaptation methods and responses on the river basin scale

Modelling water resources for planning irrigation development in drought-prone southern Chile

To foster poverty reduction in drought-prone Araucania, the Chilean Irrigation Commission is planning an important expansion of irrigated areas. Scenarios incorporating climate change (2030-2059) were simulated for a pilot basin using the WEAP water allocation model, showing that larger irrigated areas, coupled with higher temperatures and less precipitation, are likely to cause severe seasonal water scarcity. As decision support for the planning of effective measures to increase drought resilience, we modelled the construction of two upstream reservoirs combined with higher irrigation efficiency. We find that unmet water demand can be reduced by up to 97.7% by these measures

ASSESSING THE PERFORMANCE OF IRRIGATION SYSTEM IN THE DOMINANT PADDY RICE REGION OF THE VU GIA THU BON DELTA

Assessing irrigation performance plays an important role in improving irrigation efficiency and water resource management in the low land of Vu Gia – Thu Bon river basin where traditional irrigation practices are applied to a predominantly paddy rice cultivation. Relative Water Supply (RWS) and Relative Irrigation Supply (RIS) were selected as relevant indicators to assess the relationship between water supply and water demand of the irrigation system. About 120 primary and secondary pumping stations were visited during field trips. 13 large primary pumping stations were chosen to validate the actual irrigation supply. Annually there are two crops Winter-Spring and Summer-Autumn being cultivated in this region. Monthly RWS and RIS were calculated for 13 irrigation management schemes during the two crops in the years 2004 - 2005. The obtained results differ from scheme to scheme and were analysed individually. The result presents an under - irrigation supply at six irrigation management schemes including Tu Phu, Tu Cau, Xuyen Dong, Bich Bac, An Trach, Ai Nghia in both crop seasons Winter – Spring and Summer – Autumn, especially from February to July. Both RWS and RIS are high in December and August implying that there is considerable potential to save and use water more effectively during this period. At Ai Nghia and Chau Son irrigation management schemes, RIS values are zero while RWS is relatively high in May demonstrating that rainfall variability plays an important role in changing RWS and RIS. Reducing the irrigation supply should be considered for those periods, so that effective irrigation management can be achieved

Assessing the temporal and spatial performance of satellite-based rainfall estimates across the complex topographical and climatic gradients of Chile

Accurate representation of the real spatio-temporal variability of catchment rainfall inputs is currently severely limited. Moreover, spatially interpolated catchment precipitation is subject to large uncertainties, particularly in developing countries and regions which are difficult to access. Recently, satellite-based rainfall estimates (SRE) provide an unprecedented opportunity for a wide range of hydrological applications, from water resources modelling to monitoring of extreme events such as droughts and floods. This study attempts to exhaustively evaluate -for the first time- the suitability of seven state-of-the-art SRE products (TMPA 3B42v7, CHIRPSv2, CMORPH, PERSIANN-CDR, PERSIAN-CCS-adj, MSWEPv1.1 and PGFv3) over the complex topography and diverse climatic gradients of Chile. Different temporal scales (daily, monthly, seasonal, annual) are used in a point-to-pixel comparison between precipitation time series measured at 366 stations (from sea level to 4600 m a.s.l. in the Andean Plateau) and the corresponding grid cell of each SRE (rescaled to a 0.25 ◦ grid if necessary). The modified Kling-Gupta efficiency was used to identify possible sources of systematic errors in each SRE. In addition, five categorical indices (PC, POD, FAR, ETS, fBIAS) were used to assess the ability of each SRE to correctly identify different precipitation intensities. Results revealed that most SRE products performed better for the humid South (36.4-43.7 ◦ S) and Central Chile (32.18-36.4 ◦ S), in particular at low- and mid-elevation zones (0-1000 m a.s.l.) compared to the arid northern regions and the Far South. Seasonally, all products performed best during the wet seasons autumn and winter (MAM-JJA) compared to summer (DJF) and spring (SON). In addition, all SREs were able to correctly identify the occurrence of no rain events, but they presented a low skill in classifying precipitation intensities during rainy days. Overall, PGFv3 exhibited the best performance everywhere and for all time scales, which can be clearly attributed to its bias-correction procedure using 217 stations from Chile. Good results were also obtained by the research products CHIRPSv2, TMPA 3B42v7 and MSWEPv1.1, while CMORPH, PERSIANN-CDR and the real-time PERSIANN-CCS-adj were less skillful in representing observed rainfall. While PGFv3 (currently available up to 2010) might be used in Chile for historical analyses and calibration of hydrological models, the high spatial resolution, low latency and long data records of CHIRPS and TMPA 3B42v7 (in transition to IMERG) show promising potential to be used in meteorological studies and water resources assessments. We finally conclude that despite improvements of most SRE products, a site-specific assessment is still needed before any use in catchment-scale hydrological studies

Drought impacts on water quality and potential implications for agricultural production in the Maipo River Basin, Central Chile

Droughts can have serious negative impacts on the water quality needed for irrigated agriculture. The Metropolitan region of Chile is a relevant producer of high-value crops and is prone to droughts. Standardized Drought Indices were used to characterize meteorological and hydrological droughts for the period from 1985 to 2015. To understand the relationship between droughts and water quality, we evaluated the correlations between daily discharge and surface water quality observations. The threshold level method was used to compare physicochemical parameters during hydrological drought periods with the Chilean water quality thresholds for agricultural uses. A significant (p < 0.05) negative relationship between discharge and electrical conductivity and major ions was found in most of the basin. Hydrological stations located in irrigation districts exceeded the official thresholds for these parameters during hydrological drought periods seriously threatening irrigated agriculture of the region

Guiding the data collection for integrated Water-Energy-Food-Environment systems using a pilot smallholder farm in Costa Rica

Smart integration of water, energy, agriculture, and environmental systems can create synergies, increase socio-economic benefits, and minimize environmental impact. However, effective planning of integrated water-energy-food-environment systems (iWEFEs) requires high resolution temporal and spatial data on various environmental and socioeconomic variables. Insufficient data availability and accessibility hampers the implementation of iWEFEs, particularly in remote areas of low- and middle-income countries. Addressing this gap, first, essential variables for the planning of iWEFEs are identified. Next, remote datasets are evaluated and selected regarding their suitability to serve for the planning of iWEFEs using a multi-criteria-analysis considering data accessibility, spatial coverage, spatial resolution, temporal resolution, and temporal coverage. Remote and in-situ data collection for the identified WEFE variables are implemented using a pilot case study of a smallholder farm in the data-scarce tropics of Costa Rica. The remote data collection is automated via APIs to open servers, data analysis and data visualization scripts, and complemented by an online survey. In-situ measurements are recommended to address data gaps in remote sensing, which are especially prevalent in the water domain. The research shall lay the foundation for free, open and automated data collection enabling the planning of iWEFEs worldwide

OWEFE—open modeling framework for integrated water, energy, food, and environment systems

The integrated approach to managing the fundamental resources for human life, namely, water, energy, food, and the environment as their irreplaceable foundation, presents a profound opportunity for sustainable development. However, despite their huge potential, integrated water, energy, food, and environment systems (iWEFEs) are rarely put into practice because of, among others, complexity and a lack of uniform and openly available models to describe, configure and simulate such systems. To fill this gap, we present the open modeling framework for integrated water, energy, food, and environment systems (OWEFEs) based on the open energy modeling framework. OWEFE follows an open, cross-sectoral, and modular design approach to address crucial challenges for the project development of iWEFEs. In this study, we apply OWEFE for the first time to model a wastewater biogas system and an agrivoltaics system. The results of the OWEFE-based models are in the range of a conventional approach respectively of on-site measurements indicating the framework’s capability to model diverse iWEFEs. The wide application of the framework can improve the assessment, planning, and configuration of iWEFEs for sustainable and integrated infrastructure development