MANAGEMENT OF WATER EXTREMES: A SOUTH AFRICAN PERSPECTIVE ON GUIDELINES FOR POLICY AND STRATEGY DEVELOPMENT

Utilising insights gained from a literature study about the social, economic and political impacts of irrigation droughts, research done on the impacts and management of floods and water restrictions in South Africa as well as analysing the disaster management policy process in South Africa since 1994, this presentation endeavours to present some guidelines for policy and strategy development with regard to the effective management of floods and droughts. In compiling this contribution extensive use has been made from a paper presented at a workshop of the ICID Working Group on Irrigation under Drought and Water Scarcity, Tehran, by G.R. Backeberg and M.F. Viljoen.Resource /Energy Economics and Policy,

South African Agricultural Policy 1994 to 2004: Some reflections

Time constraints limits this paper to giving a brief overview of a selection of only the most important events on the policy front. The aim is to set the stage for the conference by giving a synoptic overview of South African agricultural policy between 1994 and 2004. To put the policy development in historical and developmental perspective, relevant pre-1994 realities will be mentioned first. After outlining the policy development between 1994 and 2004, the presentation concludes with some 2004 realities and a perspective on the relevance of agricultural economics as a discipline.Agricultural and Food Policy,

Bridging the economic divide in South African agriculture by improving access to natural resources

The paper focuses on improvement in access to the natural resources land and water to bridge the economic divide in South African agriculture. The relevance of the approach to bridging the economic divide, progress made since 1994 in land and water reform and problems experienced and strategies to overcome them are discussed. Challenges imposed by climate change and biodiversity on the effective utilization of land and water resources are also highlighted. Given the broadness of the subject, an overview of some important issues can only be attempted within the allocated time. The presentation starts with background information to place the discussion in context within the national framework and to define certain concepts. Conceptual issues regarding access to natural resources are then presented to serve as an analytical framework for the subsequent discussions on access to land and water, climate change and biodiversity. The presentation concludes by integrating the foregoing discussions and highlighting some challenges for agricultural economists.Land Economics/Use, Resource /Energy Economics and Policy,

Towards Quantifying The Economic Effects Of Poor And Fluctuating Water Quality On Irrigation Agriculture: A Case Study Of The Lower Vaal And Riet Rivers

Irrigation farmers in the lower reaches of the Vaal and Riet Rivers are experiencing substantial yield reductions in certain crops and more profitable crops have been withdrawn from production, hypothesised, as a result of generally poor but especially fluctuating water quality. In this paper secondary data is used in a linear programming model to test this hypothesis by calculating the potential loss in farm level optimal returns. The model is static with a time frame of two production seasons. Linear crop-water quality production functions (Ayers & Westcot, 1983; adapted from Maas & Hoffmann, 1977) are used to calculate net returns for the eight most common crops grown. Results show optimal enterprise composition under various water quality situations. Leaching is justified financially and there is a strong motivation for a change in the current water pricing system. SALMOD (Salinity and Leaching Model for Optimal irrigation Development) is the Excel Solver model used to derive the preliminary results, but is currently being developed further in GAMS (General Algebraic Modelling System). Useful results have already been obtained on which this paper is based. The ultimate aim for SALMOD is a mathematical model using dynamic optimisation, simulation and risk modelling techniques to aid in whole farm and system level management decisions to ensure sustainable irrigation agriculture under stochastic river water quality conditions.Crop Production/Industries, Resource /Energy Economics and Policy,

SALMOD, a Salinity Management Tool for Irrigated Agriculture

This paper presents an irrigation farm management tool, SALMOD (Salinity And Leaching Model for Optimal irrigation Development), that calculates the profit maximizing crop enterprise composition and irrigation management options for farm specific soil type, drainage status and irrigation system composition subject to various regional control measures and expected irrigation water salinities. After stating the water quality problem, and particularly salinisation in Southern Africa, the input data requirements and the results of SALMOD and their usefulness at farm level, are discussed. The impact of various possible regional or policy regulations are then discussed. SALMOD was developed for irrigators in the lower Vaal and Riet Rivers in South Africa. These farmers have been experiencing rapidly fluctuating salinity levels in their irrigation water, resulting in soil salinisation, yield loss and subsequent financial instability. SALMOD calculates the profit maximizing crop choice and distribution over the farm, matching the crop choice with soil type, drainage status and irrigation system, indicating the optimal leaching vs. yield reduction seasonal management options as well as calculate long term management options such as underground drainage installation, a change in irrigation system or the construction of on farm storage dams. Leaching is necessary to maintain an acceptable salt balance in the root-zone of irrigated crops. This however contributes to point and non-point source water pollution externalities if not managed correctly. Results show valuable policy information regarding the interactions between artificial drainage subsidisation, return flow restrictions and on-farm storage.Irrigation, water quality, return flows, salinisation, leaching, non-point source pollution, on-farm storage, SALMOD, linear programming, GAMS, Farm Management, Land Economics/Use,

Application of Stochastic Dynamic Programming (SDP) for the optimal allocation of irrigation water under capacity sharing arrangements

This study attempts to arrive at an optimal allocation of irrigation water using capacity sharing (CS) as an institutional arrangement, and stochastic dynamic programming (SDP) as an optimisation model. It determines the value of an additional unit of water under a crop enterprise mix of lucerne-maize-wheat (LMW). SDP is an improvement on linear programming (LP) under stochastic conditions. The SIM-DY-SIM Model was used to simulate optimal returns, decision and policy variables under varying conditions of capacity share. LP results show that wheat has the highest MVP of R0.39/m3, with maize exhibiting the lowest value of R0.09/m3. The MVPs generated with SDP range between R0.06/m3 and R0.35/m3 on the whole farm basis, with revenue to the farmer increasing with an increase in CS content and increased percentage water release. However, the MVP of water decreased with the increased supply of the resource – a phenomenon that follows the general rule of decreasing marginal utility of a resource as more of it is used.Resource /Energy Economics and Policy,

CREATING AGRIBUSINESS OPPORTUNITIES FOR SMALL SCALE FARMERS IN THABA NCHU BY INTRODUCING WATER HARVESTING TECHNIQUES: A PROFITABILITY AND RISK ANALYSIS

Thaba Nchu is a semi-arid area with low and erratic annual rainfall not exceeding 600mm. Various dryland crops are produced with relatively low yields and high risk of failure. Lack of appropriate technology and other constraints has led to most of the arable land being unused thus restricting agribusiness opportunities in an area where unemployment and food insecurity are thriving. Rainwater harvesting has a huge potential to increase crop yields in Thaba Nchu and reduce the risk of losses, and thus improve food security and enhance sustainability. Different in-field rainwater harvesting (IRWH) techniques have been tested and applied at Glen and Thaba Nchu. This paper gives comparative results for three crops produced with regard to relative profitability and risk of failure. This is done by integrating crop enterprise budgets with crop yield simulations models to calculate per hectare profits over an 81-year period and developing and analyzing cumulative probability functions.Land Economics/Use, Resource /Energy Economics and Policy, Risk and Uncertainty,

International Trade Performance of the South African Fish Industry

In an effort to gain a better understanding of the trade in fish products by South Africa a starting point is examining South Africa's current trade in fish products. Useful tools in this regard, the Gini-coefficient, used to examine the degree of concentration for fish exports, and the intra-industrial trade coefficient (IIT), and used to examine the balance of international fish trade by South Africa. The Gini-coefficient for fish exports shows that fish export by South Africa is highly concentrated. The trend in concentration appears to have remained constant, and therefore the South African fisheries industry may boast a competitive advantage. However, cognisance should be taken of the fact that such a high level of concentration may render the South African fisheries industry vulnerable to exogenous changes. The IIT analysis shows that, after 1985, the fisheries industry underwent substantial changes in that it has increased exportable surpluses, probably as a result of increased specialization and competitiveness. The analysis conducted does not pertinently explain the factors that sustain the levels of concentration, nor does it highlight specific factors that may underpin the competitiveness of the industry, and hence further analysis in this regard is necessary.International Relations/Trade,

Resource Use Efficiency of Millet/Cowpea Intercropping in Niger State, Nigeria

The study examined the profitability and resources-use efficiency of millet/cowpea mixed farmers production in Niger state Nigeria. The primary data for the study was obtained using structured questionnaire administered to 80 randomly sampled farmers in Kotangora Local Government Area of Niger State. Farm budgeting technique and exponential production function were used to analyze the data. The results showed that the estimated gross margin, net farm income, gross ratio, operating ratio and returns on investment are N57,542.42 per hectare, N54,240.40 per hectare, 0.37, 0.31 and 2.15. The regression result shows that seed and family labour were statistically significant at 1% level of probability, while farm size and hired labour were statistically significant at 5% level of probability. The allocative efficiency results show that seeds, family labour and agrochemicals were under-utilized. Farm size and hired labour were over-utilized. Efficiency and productivity could be improved if the farmers use more seed, family labour, agrochemicals, less of hired labour and land.Crop Production/Industries,

Enhancing food and livelihood security in the context of the food and financial crisis: challenges and opportunities for small scale rainwater harvesting and conservation

The world recently experienced the food and financial crisis. The food crisis was an indicator of the challenges towards sufficiently feeding an increasing world population. Food production through rainfed and irrigated agriculture account for the bulk of the freshwater used globally but the water is still sufficient to meet the MDG goal on hunger reduction. Agricultural water management is thus an important challenge for feeding humanity; creates the need to find sustainable methods of managing water that will include all water users. Some of these methods include rainwater harvesting which has great potential in increasing food production as compared to irrigation. This paper aims to identify challenges and opportunities for small scale rainwater harvesting in enhancing food and livelihoods security. Given the large array of practices that are classified as rainwater harvesting, infield rainwater harvesting (IRWH) developed and mainly practised in the Free State Province, South Africa is used. The technique has been in use in villages around Thaba Nchu for a couple of years. Previous studies have shown that the technique increased yield significantly, reduced risk and thus improved household food security. The paper traces the evolution of the technique based of previous studies and recent data, to identify the potential and challenges faced by adopting households. It is concluded that IRWH has great potential to improve household food security as well as contribute to sustainable rural livelihoods mainly as it can reduce dependence on market sourced food supplies.food security, livelihoods, rainwater harvesting, household, yield, Food Security and Poverty, Resource /Energy Economics and Policy,