The Sierra Nevada de Santa Marta, a UNESCO-declared Biosphere Reserve, is an isolated mountain complex encompassing approximately 17,000 km², set apart from the Andes chain that runs through Colombia. The Sierra Nevada has the world’s highest coastal peak (5,775 m above sea level) just 42 kilometres from the Caribbean coast. The Sierra Nevada is the source of 36 basins, making it the major regional ‘water factory’ supplying 1.5 million inhabitants as well as vast farming areas in the surrounding plains used mainly for the cultivation of banana and oil palm. The main problems to be solved in these basins are: i) Declining availability of water for irrigation, ii) Declining availability and quality of water for human consumption, iii) Increasing salinization of ground water and soils, iv) Increasing incidence of floods.

This is a feasibility study on the adoption of more efficient irrigation techniques by oil palm farmers in the Sevilla basin (713 km²), one of the key basins in the Sierra Nevada. The general objective is to identify the local environment at basin scale, the limiting factors and suitable field interventions in oil palm areas to improve the water use. A preparation and implementation phase was developed including an initial baseline assessment of the basin on climate, water availability, drought hazard, soil characteristics, land use, and topography. The agronomy (e.g. cultivars) and current field practices (e.g. nutrient management and irrigation practices) of the oil palm areas were characterized, and the crop water requirements determined. In addition, costs and benefits associated to the implementation of efficient irrigation technologies such as fertigation and water harvesting were assessed. Potential locations, risks and opportunities for water harvesting were evaluated with the idea to store water in the wet season to be able to use the resource in an efficient way in the dry season. A range of GIS and satellite-based datasets (e.g. CHIRPS, MODIS-ET, MODIS-NDVI, HiHydroSoil) were used to evaluate the environmental conditions, and local data and information was provided by local partners Cenipalma and Solidaridad to generate a comprehensive assessment at basin and field scale. The expectation is that fertigation and water harvesting techniques can be adopted in the Sevilla basin, but also in other basins in the Sierra Nevada de Santa Marta to reduce the environmental impact of oil palm production.

The Asian Development Bank supports Tajikistan in achieving increased climate resilience and food security through investments in modernization of Irrigation and Drainage (I&D) projects. A Technical Assistance is preparing modernization projects for two I&D systems in the Lower Vaksh river basin in Tajikistan. In line with this, the TA will prepare a holistic feasibility study and project design for the system (38,000 ha), as well as advanced designs and bidding documents for selected works.

FutureWater is part of the team of international experts, working together with the local consultant on the climate risk and adaptation assessment that accompanies the feasibility projects. For this purpose, past climate trends will be analyzed, climate model projections processed, and a climate impact model will be used to assess how the project performs under a wide range of future conditions, to assess the robustness of the proposed I&D investments, and identify possible climate adaptation measures.

In Angola, more and better-quality data is required to improve crop suitability assessments over large extensions of arable land to ensure sustainable food and income security. For example, environmental data on soil texture, soil water storage capacity, vegetation growth, terrain slopes, rainfall and air temperature are key to develop reliable crop suitability assessments. These datasets are available from state-of-the-art satellite-based products and machine learning observations (de Boer, 2016; Funk et al., 2015; Hengl et al., 2014, 2017). The benefit of these data products is that data can be obtained for any province, municipality, or farm in Angola. On top of that, data can be shown in maps to easily visualize spatial variation and identify the most suitable location and area to grow desired crops. Land-crop suitability maps are obtained by calculating a weighted average of the environmental variables that influence crop growth (e.g. rainfall, air temperature, soil water storage capacity), providing an integrated and complete assessment on where to plant. Also, potential crop yields are determined for desired cropping seasons using the FAO AquaCrop model to provide more information about potential income.

Irrigated agriculture in Angola has been developed in commercial farms using mainly central pivot and drip irrigation systems. The installation of new irrigation systems is foreseen in large extensions of land over 5000 hectares. Irrigated agriculture results in higher crop yields and allows higher incomes to farmers. However, commercial farms must invest in high energy supply to operate irrigation systems with water pumping stations. The challenge for irrigation system operators is to know exactly when and how much to irrigate during the cropping season. If better information about irrigation volumes and intervals are provided a significal reduction in energy costs could be achieved. The objective is to predict irrigation demand volumes during the cropping season and provide a user-friendly decision tool to irrigation operators. To achieve this, weather forecasts, remote sensing, and the SPHY model will be used.

The project should increase agricultural water use productivity in the selected agricultural districts in Uzbekistan through a threefold approach: (i) climate resilient and modernized I&D infrastructure to improve measurement, control and conveyance within existing systems; (ii) enhanced and reliable onfarm water management including capacity building of water consumers’ associations (WCAs), physical improvements for land and water management at the farm level and application of high level technologies for increased water productivity; and (iii) policy and institutional strengthening for sustainable water resources management. This will include strategic support to the Ministry of Water Resources (MWR) and its provincial, basin and district agencies.

The project supports the Strategy of Actions on Further Development of Uzbekistan (2017), which includes: (i) introduction of water saving technologies and measures to mitigate the negative impact of climate change and drying of the Aral Sea; (ii) further improvement of irrigated lands and reclamation and irrigation facilities; and (iii) modernization of agriculture by educating areas of cotton and cereal crops to expand horticulture production.

FutureWater focuses on the climate risk and adaptation assessment that accompanies the feasibility projects, and will analyze climate trends, climate model projections, climate impacts on the projects and assess adaptation options.

Watch the video below to learn more about the management of Climate Adaptive Water Resources in the Aral Sea Basin in Uzbekistan (source: ADB)

Cambodia is currently improving in economic standing, however the benefits of this are largely contained to urban areas. As a major contributor to GDP, ensuring the sustainability of Cambodia’s agricultural sector is highly important, especially when coupled with the increasing awareness of the dangers of climate change. Access to water for agriculture, fisheries and domestic supply is an issue, with many rural communities competing for resources. Coupled with the effects of flood and drought activity in recent years, the need for adequate and reliable water resource management in rural, agricultural areas is prominent. This project focuses on the North- Western Cambodian provinces of Oddar Meanchey (OMC) and Banteay Meanchey (BMC) and the neighbouring North-Eastern Thai provinces of Surin and Sisaket.

In order to protect rural livelihoods and maintain agricultural production, communities must be supplied with permanent and regulated water year-round. Analysis of recent flood and drought histories and their effects in the provinces are first necessary to determine the most vulnerable areas both in terms of agriculture and households. In addition, water resource assessments of supplies and demand will identify the most crucial areas to ensure supplies are increased and sustained both for crops and domestic use. Socio-economic studies will also ensure ‘cross- cutting’ issues are considered in WR planning, such as: gender, economic vulnerability and cultural factors related to WRM. Furthermore, meetings with stakeholders at multiple levels can address issues in water infrastructure, alongside assessment of the capacities of those managing monitoring systems for example. From this, future recommendations for improvements in infrastructure can be made with an awareness of the necessary knowledge capacities to ensure proper maintenance and sustainability.

Initially, an analysis of the current water resource situation in the study area will be conducted through collection of available data on water resources, flood and drought histories and socioeconomic issues in the area. Following this, areas for more detailed analysis will be established and strategies to improve WRM supporting agricultural livelihoods can be developed. FutureWater is involved in the implementation of the WEAP model, for evaluation of various water resources management strategies in the catchments under baseline and projected future conditions.

The scope of the project work is as follows:

  • Train selected NCBA Clusa PROMAC staff on drone operation, imagery processing software, and crop monitoring;
  • Provide technical assistance to trained NCBA Clusa staff on drone operation, imagery processing, and interpretation of crop monitoring data;
  • Present technical reports on crop development and land productivity (i.e. crop yield) at the end of the rainy and dry season

The trainings and technical assistance for the NCBA Clusa staff are provided in collaboration with project partners HiView (The Netherlands) and ThirdEye Limitada (Central Mozambique). Technical staff of the NCBA Clusa are trained in using the Flying Sensors (drones) in making flights, processing and interpreting the vegetation status camera images. This camera makes use of the Near-Infrared wavelength to detect stressed conditions in the vegetation. Maps of the vegetation status are used in the field (with an app) to determine the causes of the stressed conditions: water shortage, nutrient shortage, pests or diseases, etc. This information provides the NCBA Clusa technical staff and extension workers with relevant spatial information to assist their work in providing tailored information to local farmers.

At the end of the growing season the flying sensor images are compiled to report on the crop development. The imagery in combination with a crop growth simulation model is used to calculate the crop yield and determine the magnitude of impact the conservation agriculture interventions have in contrast with traditional agricultural practices.

The detection of on-site farm reservoirs and ponds in large areas is a complex task that can be addressed through the combination of visual inspection of orthophotos and the application of automatic pixel classification algorithms.

This analysis applied a general workflow to detect and quantify the area and density of on-farm reservoirs and water bodies in three representative Mediterranean irrigated oases in Sicily-Italy, Northern of Morocco, and Israel. For each area of analysis, the most recent orthophotos available were collected from Google Earth, and the ilastik algorithms were implemented for the pixel classification (Random Forest -RF-) and semantic-segmentation. The RF classifier, which is previously applied to a set of filtered imagery and iteratively trained, provides probability maps of different classes that are finally used for quantitative analysis, or the retrieval of a segmentation-categorical (water vs non-water) maps.

In irrigated agriculture options to save water tend to focus on improved irrigation techniques such as drip and sprinkler irrigation. These irrigation techniques are promoted as legitimate means of increasing water efficiency and “saving water” for other uses (such as domestic use and the environment). However, a growing body of evidence, including a key report by FAO (Perry and Steduto, 2017) shows that in most cases, water “savings” at field scale translate into an increase in water consumption at system and basin scale. Yet despite the growing and irrefutable body of evidence, false “water savings” technologies continue to be promoted, subsidized and implemented as a solution to water scarcity in agriculture.

The goal is to stop false “water savings” technologies to be promoted, subsidized and implemented. To achieve this, it is important to quantify the hydrologic impacts of any new investment or policy in the water sector. Normally, irrigation engineers and planners are trained to look at field scale efficiencies or irrigation system efficiencies at the most. Also, many of the tools used by irrigation engineers are field scale oriented (e.g. FAO AquaCrop model). The serious consequences of these actions are to worsen water scarcity, increase vulnerability to drought, and threaten food security.

There is an urgent need to develop simple and pragmatic tools that can evaluate the impact of field scale crop-water interventions at larger scales (e.g. irrigation systems and basins). Although basin scale hydrological models exist, many of these are either overly complex and unable to be used by practitioners, or not specifically designed for the upscaling from field interventions to basin scale impacts. Moreover, achieving results from the widely-used FAO models such as AquaCrop into a basin-wide impact model is time-consuming, complex and expensive. Therefore, FutureWater is developing a simple but robust tool to enhance usability and reach, transparency, transferability in data input and output. The tool is based on proven concepts of water productivity, water accounting and the appropriate water terminology, as promoted by FAO globally (FAO, 2013). Hence, the water use is separated in consumptive use, non-consumptive use, and change in storage (see Figure).

Separation of water use according to the FAO terminology.

A complete training package is developed which includes a training manual and an inventory of possible field level interventions. The training manual includes the following aspects: 1) introduce and present the real water savings tool, 2) Describe the theory underlying the tool and demonstrating some typical applications, 3) Learn how-to prepare the data required for the tool for your own area of interest, 4) Learn when real water savings occur at system and basin scale with field interventions.

Asian Development Bank (ADB) Technical Assistance (TA) 7610-CAM supports the preparation of MOWRAM’s Roadmap and Investment Program for Irrigation and Water Resources Management, 2019-2033. This investment program provides a comprehensive and strategic framework for the country’s investment in the water resources and irrigation sector.

The current project under TA 7610-CAM concerns (i) rapid water resources assessment of the Tonle Sap and the Mekong Delta river basin groups (24 basins); (ii) ecological assessment of these two river basin groups to identify areas for development and conservation; (iii) detailed surface water resources assessment for five river basins within these groups.

The overall project objective is to support MOWRAM to make more informed, evidence-based water resources management and irrigation investment decisions through better understanding of water resources and ecosystems of two river basin groups: the Tonle Sap and the Mekong Delta and at least five selected river basins within these groups. These river basins are to be selected based on their current and projected level of water stress. The health of high-priority ecosystems and their water demands are assessed in relation to basin hydrological characteristics and foreseen development of water resources.

Outputs of the project are:

  • A comprehensive knowledge base on water resources and eco-hydrology in 24 river basins
  • Hydrological characterization of 24 river basins
  • Quantification of environmental flow requirements for 24 basins
  • Selection of the five most water-stressed basins
  • Recommended options for efficient and equitable water allocation
  • Targeted investment options in the irrigation sector
  • Coupled set of calibrated hydrological / water allocation models
  • Geospatial data on (eco-)hydrology compatible with the national Water Resources Information System (WRIS) currently under development

FutureWater is the lead firm in the assignment and executes the water resources modelling components of the project.

Methodology

  • Development of adaptation benefit-cost framework: The framework was developed in a manner to make it possible to isolate development- and climate-related benefits and costs of individual projects and to assess the sensitivity of adaptation benefits and costs to the uncertainty inherent in regional climate change scenarios.
  • Development of analytical tools and procedures: The project developed general procedures and specific analytical tools for consistently measuring the costs and benefits of adaptation projects in the agriculture sector in Africa. These procedures and tools allow multi- and by-lateral development institutions to evaluate the benefits and costs specifically related to climate adaptation “add-ons” to sustainable development projects.
  • Application of analytical tools and procedures: The project applied these procedures and analytical tools to estimate the benefits and costs of a well-defined adaptation project in the agricultural sector, particularly on the predominant crop in The Gambia: millet.
  • Water-crop model:
    A detailed water-crop model has been setup and applied for a reference period and for future projected climates. Adaptation strategies have been defined and explored with the model developed and an economic analysis have been applied on the results.

Overview of The Gambia. Landsat composite from 1990.

The major steps taken were:

  • collection of base data and information
  • extraction of IPCC projections for The Gambia
  • downscaling of these projections to the local conditions for The Gambia
  • setup of a crop-water model
  • evaluation of the impact of climate change on yields
  • definition of adaptation strategies
  • evaluation of the impact of these adaptation strategies
  • evaluation of the economics of these adaptation strategies

Result and conclusions

For the development and application of the adaptation benefit-cost framework data from two GCMs were used while concentrating on the most common grain crop in The Gambia: millet. The most relevant adaptation strategies were selected: crop variety improvements, fertilizer applications and irrigation. However, the modeling framework as it is setup can be easily applied to other GCMs, SRES scenarios, crops, soils, or adaptation strategies.

From the analysis it is clear that the impact of climate change on millet yields depends highly on the GCM selected. The HADCM3 projections indicate a much drier future, while the ECHAM4 ones indicate somewhat more rainfall in the future. Considering the “no-regret” principle, we decided to explore the adaptation strategies for the HADCM3 projections only.

Model mean anomaly for A2 Maximum Temperature °C.

Emphasize was put on the annual variation, and more specifically on the successive years of low yields. Introduction of irrigation appears to be the most successful adaptation strategy, yields will increase and, moreover, year-to-year variation decreases substantially.

Variation in annual precipitation over the entire country (Based on: CRU dataset).

A rough estimate of the benefits in terms of gross return was carried out by multiplying the yield by the price of millet (about $ 0.15 kg-1). For the irrigation adaptation strategy this means that the gross return per hectare will increase from $170 to $235. As mentioned before, the reduction in year-to-year variation by the adaptation strategies will be even more important and should be analyzed in detail.

Finally, the most promising adaptations has to be implemented and successive studies should look into whether these adaptation strategies can be adopted through market forces, whether the government should impose these by subsidizes or tax regulations, or whether bi-lateral aid should focus on this in an effort to minimize risks of food shortages.