Spatial prioritisation of revegetation sites for dryland salinity management: an analytical framework using GIS

[Abstract]: To address the lack of analytical and modelling techniques in prioritising revegetation sites for dryland salinity management, a case study of the Hodgson Creek catchment in Queensland, Australia, was conducted. An analytical framework was developed, incorporating the use of spatial datasets (Landsat 7 image, DEM, soil map, and salinity map) which were processed using image processing techniques and a geographic information system (GIS). Revegetation sites were mapped and their priority determined based on recharge area, land use/cover and sub-catchment salinity. The analytical framework presented here enhances the systematic use of land information, widens the scope for scenario testing, and improves the testing of alternative revegetation options. The spatial patterns of revegetation sites could provide an additional set of information relevant in the design of revegetation strategies

Pesticide pollution: mitigating the negative impacts

Water pollution, Pesticide residues, Irrigation canals, Salinity, Groundwater, Sri Lanka

Water Figures: quarterly newsletter of the International Water Management Institute (IWMI).

Agricultural research, Research projects, Research policy, Research institutes, Impact assessment, Water management, Wetlands, Dams, Reservoirs

Land Use Changes and Their Perception in the Hinterland of Barranquilla, Colombian Caribbean

The coastal strip of the western peri-urban area of Barranquilla in the Atlántico Department (Colombia) is experiencing changes in human-environment interactions through infrastructure, residential, and tourism projects in a vulnerable landscape. In the hilly area, fragments of biodiverse tropical dry forest still exist in various states of conservation and degradation. To understand the interrelated social, economic, and ecological transformations in the area, we analyzed land use change on the local scale including the local community’s perception, because the local community is a key actor for sustainable land use. For the analysis of the interrelated social, economic, and ecological processes, we combined visual interpretation of high-resolution satellite imagery, on-site field land use mapping, and a spatial statistical analysis of the distribution of land use classes with in-depth interviews and a participatory GIS workshop, thus benefitting from the complementary methodological strengths of these approaches. The case study is the rural community of El Morro, which exhibits the typical social, economic, and ecological changes of the coastal strip of the western peri-urban area of Barranquilla. The local community perceives a continuous loss of forest area, but observations from on-site field mapping cannot confirm this linear trend. We observed a gradual replacement of traditional land uses such as smallholder agriculture, charcoal production, and cattle breeding by services for tourism, gated community projects for urban dwellers, and infrastructure projects; these spatial developments have several characteristics of rural gentrification. We conclude that the drivers of environmental degradation have changed and the degradation increased. The development projects of external companies have been rejected by the local community and have induced environmental consciousness among community members. Thus, the local community has become an advocate for sustainable land use in the study area

Assessing water availability under pastoral livestock systems in drought-prone Isiolo District, Kenya

Water availability / Water demand / Surface water / Groundwater / Wells / Salinity / Livestock / Grazing / Land use / Water supply / Drainage / GIS / Databases / Cost recovery

The development of an integrated modelling system to support decisions on organic farms

This paper was presented at the UK Organic Research 2002 Conference of the Colloquium of Organic Researchers (COR). An Integrated Decision Support System (IDSS) is developed which synthesises current understanding of organic farming by means of a multiple objective framework incorporating GIS, biophysical models and socio-economic models of the farming goals. The IDSS uses a multitiered concept of a farming system as a collection of micro-enterprises at the field level, with individual resource endowments, objectives and activities. Farm-level decision drivers trickle down to affect the micro-level field enterprise selection. Biophysical models describe typical forage, cereal, root and legume output and a user-friendly interfaces permits easy access and output display via a GIS. A prototype of the IDSS framework, being developed as a part of the SAC organic research programme is presented

Simulation of site-specific irrigation control strategies with sparse input data

Crop and irrigation water use efficiencies may be improved by managing irrigation application timing and volumes using physical and agronomic principles. However, the crop water requirement may be spatially variable due to different soil properties and genetic variations in the crop across the field. Adaptive control strategies can be used to locally control water applications in response to in-field temporal and spatial variability with the aim of maximising both crop development and water use efficiency. A simulation framework ‘VARIwise’ has been created to aid the development, evaluation and management of spatially and temporally varied adaptive irrigation control strategies (McCarthy et al., 2010). VARIwise enables alternative control strategies to be simulated with different crop and environmental conditions and at a range of spatial resolutions. An iterative learning controller and model predictive controller have been implemented in VARIwise to improve the irrigation of cotton. The iterative learning control strategy involves using the soil moisture response to the previous irrigation volume to adjust the applied irrigation volume applied at the next irrigation event. For field implementation this controller has low data requirements as only soil moisture data is required after each irrigation event. In contrast, a model predictive controller has high data requirements as measured soil and plant data are required at a high spatial resolution in a field implementation. Model predictive control involves using a calibrated model to determine the irrigation application and/or timing which results in the highest predicted yield or water use efficiency. The implementation of these strategies is described and a case study is presented to demonstrate the operation of the strategies with various levels of data availability. It is concluded that in situations of sparse data, the iterative learning controller performs significantly better than a model predictive controller

Air pollution and livestock production

The air in a livestock farming environment contains high concentrations of dust particles and gaseous pollutants. The total inhalable dust can enter the nose and mouth during normal breathing and the thoracic dust can reach into the lungs. However, it is the respirable dust particles that can penetrate further into the gas-exchange region, making it the most hazardous dust component. Prolonged exposure to high concentrations of dust particles can lead to respiratory health issues for both livestock and farming staff. Ammonia, an example of a gaseous pollutant, is derived from the decomposition of nitrous compounds. Increased exposure to ammonia may also have an effect on the health of humans and livestock. There are a number of technologies available to ensure exposure to these pollutants is minimised. Through proactive means, (the optimal design and management of livestock buildings) air quality can be improved to reduce the likelihood of risks associated with sub-optimal air quality. Once air problems have taken hold, other reduction methods need to be applied utilising a more reactive approach. A key requirement for the control of concentration and exposure of airborne pollutants to an acceptable level is to be able to conduct real-time measurements of these pollutants. This paper provides a review of airborne pollution including methods to both measure and control the concentration of pollutants in livestock buildings

Multi-Sectoral Uses of Water & Approaches to DSS in Water Management in the NOSTRUM Partner Countries of the Mediterranean

Agriculture contributes an average of about 10% to the GDP of the partner countries of the Mediterranean involved in the project NOSTRUM. On the other hand, industry contributes an average of about 30% in these countries. It is to remark that in almost all countries the weight of industry accounts between 20% and 30% of the national economy, with the exception of Algeria, where this weight is at about 60%, mainly imputable to the great development of oil extraction and energy sector. In the majority of participating countries, agriculture sector is the greatest consumer of water (more than 65% of total water consumption). Although the case from France where agriculture water use is only about 10% of total water consumption and Italy with around 45%, but this may be due to the fact that most countries reporting for their agricultural water consumption do not include the amount of rain-fed to cultivated lands as a part of their agriculture water use. Most agriculture water use is limited to irrigation water from streams/rivers and groundwater. Rain-fed cultivated-lands in France is almost 90% of its total cultivated area. For Croatia, data given in National Report indicate a 0% of water use for agriculture. The average of water use for agriculture for all the basin is of 62.3% but with a great scatter expressed by a high standard deviation (26.8%) that reflects a wide variation range of water use for agriculture among different countries. The average of water use for agriculture is weakly less on northern countries (52.7%) than on southern countries (75.2) but the twice values are still on the range of the average of the all basin and cannot be taken as indication of difference between north and south. Integrated Water Resources Management (IWRM) plans are currently developed and implemented by various countries to organize the multi-sectoral water uses. On the other hand, the need for Decision Support System (DSS) as a tool in developing and implementing Integrated Water Resources Management (IWRM) is in growing demand. In spite of the great potential for the research and the development of DSS, the utilization of DSS in water management is not widely spread in the partner countries. In some countries, DSS was planned and developed at the scale of territorial integrated water management. Integration of DSS application to the existing IWRM systems at the partner countries would assist in satisfying the water related Millennium Development Goals (MDGs).Integrated Water Resources Management, Decision Support Systems, Mediterranean Basin

The changing face of irrigation in Kenya: opportunities for anticipating changes in Eastern and Southern Africa

Small scale systems / Environmental effects / Government managed irrigation systems / Farmer managed irrigation systems / Health / Waterborne diseases / River basins / Pest control / Social impact / Water policy / Water law / Institutional development / Water allocation / Drip irrigation / Pumps / Technology / GIS / Databases / Irrigation programs / Drainage / Water resource management / Economic aspects / Social aspects / Water scarcity / Conflict / Case studies / Land management / Sedimentation / Flood control / Wetlands / Water quality / Erosion / Grassland management / Livestock / Rain / Drought / Participatory management / Design / Credit / Horticulture / Farmers’ associations / Farmers’ attitudes / Gender / Rice / Legislation / Land tenure / Cooperatives / Income / Southern Africa / Eastern Africa / Kenya / Upper Ewaso Ng’iro North Basin / Lake Victoria Basin / Tana River Basin / Mwea Irrigation Scheme