Water Harvesting Structures Research Articles

SCS-CN and GIS-based approach for identifying potential water harvesting sites in the Kali Watershed, Mahi River Basin, India

The Kali sub-watershed is situated in the semi-arid region of Gujarat, India and forms a part of the Mahi River Watershed. This watershed receives an average annual rainfall of 900mm mainly between July and September. Due to high runoff potential, evapo-transpiration and poor infiltration, drought like situation prevails in this area from December to June almost every year. In this paper, augmentation of water resource is proposed by construction of runoff harvesting structures like check dam, percolation pond, farm pond, well and subsurface dyke. The site suitability for different water harvesting structures is determined by considering spatially varying parameters like runoff potential, slope, fracture pattern and micro-watershed area. GIS is utilised as a tool to store, analyse and integrate spatial and attribute information pertaining to runoff, slope, drainage and fracture. The runoff derived by SCS-CN method is a function of runoff potential which can be expressed in terms of runoff coefficient (ratio between the runoff and rainfall) which can be classified into three classes, viz., high (>40%), moderate (20–40%) and low (<20%). In addition to IMSD, FAO specifications for water harvesting/recharging structures, parameters such as effective storage, rock mass permeability are herein considered to augment effective storage. Using the overlay and decision tree concepts in GIS, potential water harvesting sites are identified. The derived sites are field investigated for suitability and implementation. In all, the accuracy of the site selection at implementation level varies from 80–100%.

The Effect of Water Harvesting Techniques on Runoff, Sedimentation, and Soil Properties

This study addressed the hydrological processes of runoff and sedimentation, soil moisture content, and properties under the effect of different water harvesting techniques (treatments). The study was conducted at three sites, representing environmental condition gradients, located in the southern part of the West Bank. For each treatment, the study evaluated soil chemical and physical properties, soil moisture at 30 cm depth, surface runoff and sedimentation at each site. Results showed that runoff is reduced by 65-85% and sedimentation by 58-69% in stone terraces and semi-circle bunds compared to the control at the semi-humid site. In addition, stone terraces and contour ridges significantly reduced the amount of total runoff by 80% and 73%, respectively, at the arid site. Soil moisture content was significantly increased by water harvesting techniques compared to the control in all treatments at the three study sites. In addition, the difference between the control and the water harvesting structures were higher in the arid and semi-arid areas than in the semi-humid area. Soil and water conservation, via utilization of water harvesting structures, is an effective principle for reducing the negative impact of high runoff intensity and subsequently increasing soil moisture storage from rainfall. Jessour systems in the valley and stone terraces were effective in increasing soil moisture storage, prolonging the growing season for natural vegetation, and decreasing the amount of supplemental irrigation required for growing fruit trees.

Selection of suitable sites for water harvesting structures in Soankhad watershed, Punjab using remote sensing and geographical information system (RS&amp;GIS) approach— A case study

A case study has been conducted to identify suitable sites for water harvesting structures in Soankhad watershed, Punjab using information technologies such as Remote Sensing and Geographical Information System (RS-GIS). The IRS-1C, P6 satellite imagery of the Soankhad watershed was used. The various Thematic maps such as land use map, hydrological soil group map, slope map and DEM map were prepared for selecting suitable site for construction of water harvesting structures. The suitable sites were not found for nala bunding and farm ponds due to steep slope, less soil thickness and high runoff velocity. Fourteen check dams and six percolation tanks were proposed for the construction as per Integrated Mission for Sustainable Development (IMSD) guidelines. The water balance study of the Soankhad watershed was also computed with monthly mean temperature and rainfall data using TM model. The average runoff for the wet season (July–September) 1996 was computed to be about 1543.82 mm and the total runoff volume from the Soankhad watershed was estimated to be about 143.52 Mm3.

Development and Performance Evaluation of Rainwater Harvester for Drip Irrigation of Juvenile Citrus Orchard

Water crisis is assuming a more explosive and dangerous phenomenon due to stiff competition and demand between domestic use and agricultural activities. Farmer friendly and affordable indigenous water harvesting structure was developed and evaluated for the Farming systems research citrus expansion orchard at the National Horticultural Research Institute, Ibadan. The structure, made of bamboo materials and polyethylene sheets was constructed to harvest rainstorm and stored in plastic reservoirs between September and October 2007. The aim was to apply the water for drip irrigation of young citrus seedlings during the dry months of November until the on-set of rainfall. Six thousand litres of water were harvested. Drip irrigation system was connected to the rainstorm harvester to facilitate application of water to the young citrus seedlings planted at 7m by 5m spacing. Water application at the drip rate of 2.4 l/hr was done in split-plot fitted into randomized complete block design at one, twice and thrice per week with three replications under four fertilizer sources (poultry, horse, cow manures and urea fertilizer). Base line growth data for citrus at the initial watering stage stands at 139 for number of leaves, 83.5 cm for plant height, and 12.3 mm for stem diameter. Watering thrice per week under poultry manure was found to produce the best growth parameters. Generally, the structure was discovered to be cost effective, water saving, adoptable and affordable by farmers with little or no maintenance or educational background.

Impacts of micro-basin water harvesting structures in improving vegetative cover in degraded hillslope areas of north-east Ethiopia

Water is one of the most important entry points to improve rural livelihoods in drought affected areas of the north-eastern Amhara region in Ethiopia. Various attempts have been made to overcome this problem by making use of different water harvesting structures. However, the choice of structures has been difficult because of a lack of empirical evidence on the relative effectiveness of the different structures. An experiment was conducted from 2002 to 2004 to compare and evaluate three different water harvesting structures (eye-brow basin, half-moon and trench) against the normal seedling plantation practice by farmers (normal pit) as a control. Data on root collar diameter (RCD), diameter at breast height (DBH), height and survival rate of Acacia saligna tree seedlings was collected at 3-month intervals after planting and annual grass biomass production was also measured. Trench and eye-brow basin structures produced 68, 95, 52 and 44% increases in RCD, DBH, height and survival rate, respectively, 15 months after planting compared with the normal pit. Trench structures increased grass biomass by 41.1% compared with normal pits. Eye-brow basins are recommended on hillsides where stone is available while trenchs could be used where stone is scarce. The results indicated that well designed water harvesting micro-basin structures can mitigate the effect of dry spell shocks on tree seedling performance and land cover rehabilitation. They were also very effective in increasing grass biomass production indicating the potential for improving livestock feed on the available barren hillsides.

Delineation of potential sites for water harvesting structures using remote sensing and GIS

Availability of groundwater varies spatially and temporally depending upon the terrain. The scarcity of water affects the environmental and developmental activities of an area. Construction of small water harvesting structures across streams/watersheds is gaining momentum in recent years. In the present study, potential sites for construction of rainwater harvesting structures in the Bakhar watershed of Mirzapur District, Uttar Pradesh, India have been identified by using remote sensing and GIS techniques. Various thematic maps such as Landuse/Landcover, geomorphology and lineaments, etc. were prepared using remote sensing. These layers along with geology and drainage were integrated using GIS techniques to derive suitable water harvesting sites. Each theme was assigned a weightage depending on its influence on ground water recharge (for example weightages 20,18,15,25,25 and 0 were assigned to geomorphology, landuse, geology, lineament, drainage and road and villages respectively). Each class or unit in the map was assigned a knowledge based ranking of one to four depending on its significance in storage and transmittance of groundwater, and these values were multiplied with layer weightage to form score. The average score for excellent region is greater than 200, for good 121 to 200, for moderate 81 to 121 and the other polygon having value less than 80 (excluding zero) were assigned to poor category. The final map showing different categories of suitability sites for water harvesting structures such as Check dams, Contour bunding, Recharge pits, Wells and Contour trenching have been suggested.

Remote Sensing and GIS Aided Land and Water Management Plan Preparation of Watershed - A Case Study

Remote Sensing and GIS techniques were applied for the integrated watershed planning of Bajpur watershed in Khurda sadar block of Khurda district (Orissa). IRS ID, LISS III F.c.c. satellite images and toposheet number 73H/12 together with verification were used as the data source. Thematic maps like land use/ land cover map, hydrogeomorphology map, soil map, slope map, drainage and surface water body maps were prepared by using both satellite imageries and survey ofIndia toposheet. By integrating all these maps in GIS, water and land resource management plans were developed. The water resources development plan indicates the sites for groundwater exploitation and sites for surface water development including sites for different soil and water conservation structures. Eleven action items were suggested under land resource action plan with specific sites, aerial locations and maps. Thus remote sensing technology demonstrates the usefulness for providing up-to-date, reliable and accurate information on different natural resources of the watershed which is a pre-requisite for an integrated approach to identify the suitable sites for water harvesting structures, check dams, farm ponds, percolation tanks, nala bunds etc. The GIS technique is helpful to integrate the information into a composite land unit development map to generate alternate land use system for sustainable development of the watershed.

Probability analysis of rainfall for Udhagamandalam

Daily rainfall data of 43 years (1960-2002) of Udhagamandalam were used for annual, seasonal and monthly analysis at different probability levels to obtain the rainfall distribution pattern. At 80 per cent probability level, the rainfall available in the first (May to August) and second (September to November) season are more than the water requirement of the crops which are grown in this region. In the third season (December to April) the rainfall availability is not enough to support any crop without irrigation. Annual maximum daily rainfall was estimated at different return period which will be useful for design of any water harvesting and soil conservation structures. The annual one day maximum rainfall at 50 and 100 years return period was found to be 238.8 and 293.6 mm, respectively. The depthduration-frequency relationship was developed for duration of 1 to 6 days maximum rainfall for differentfrequency.

Planning, designing and construction of series of check dams for soil and water conservation in micro-watershed

Planning, design and construction parameters of series of water harvesting structures were presented for 66.75 hectares in micro-watershed. Thematic maps were prepared for planning, design of various types of water harvesting structures in 1:5,000 scale on land use/land cover, soil with drainage status. The slope of the land varies from 0-5 per cent and slight, moderate and serve erosion classeswere observed.The total volume of water storage is 61,200 m3 at cost of 6.75/1000 liters, which also be estimated to protect 1607 m3 of productive soil from flowing out of the area. The series of check dam is found suitable for retaining productive soil and also to help in conservation of moisture for horticulture land.

Delineation of potential sites for water harvesting structures through remote sensing and GIS techniques: a case study of Kali watershed, Gujarat, India

Site suitability studies for check dams, percolation ponds, and subsurface dykes form an integral part of watershed management. This work illustrates the efficacy of remote sensing and GIS tools for identifying suitable sites for these structures. Thematic layers such as land use/land cover, lithology, soils, slope, rainfall and drainage were generated using LISS-III, PAN (IRS-1D), Landsat Thematic Mapper (TM) and collateral data. Runoff potential for different combinations of land use and hydraulic soil groups was computed and classified into three classes. A potential site suitability map for water harvesting/recharging structures was derived following an analytical hierarchy process. The analytically derived potential site suitability map was validated in the field. The accuracy of prediction was estimated on the basis of proximity between derived and field validated sites. In 75% of cases, the sites derived for check dam, percolation pond and subsurface dyke were accurate.

Incorporating Land Use Mapping and Participation in Jordan

In this study, analysis of land use and suitability maps for 2 contrasting mountainous ecosystems was used to identify areas where a change from existing to potential land use was required. A socioeconomic survey was carried out to select locations for implementing 2 land management packages with the full participation of farmers. The first package included cultivation of wheat landraces in a high-rainfall site (Ajloun), while the second included community-based rangeland rehabilitation and management, including fodder shrub plantations in water harvesting structures in the low-rainfall rangeland areas (Jiza). Results showed that the average grain and straw yield of wheat landraces was significantly higher than that of the improved cultivars, which could lead to high and diverse farm income. In the low-rainfall site, fodder shrubs increased the overall land productivity and aided in improving the cover of native vegetation. After 2 years of protection, dry matter production (620 kg/ha) in the community-protected location was significantly higher than that at an experimental station (465 kg/ha). Findings from both packages indicated the possibility of improving the suitability of both mountainous areas for rainfed cultivation while conserving agrobiodiversity. Development of the arid areas as open ranges could be enhanced by the introduction of suitable cultivation practices (contour furrows in this study), with a view to improving productivity and rehabilitating the native vegetation.

Application of Remote Sensing and GIS in Planning of Soil and Water Conservation Measures

Development programmes for optimum utilization of natural resources are now increasingly planned on watershed basis. Proper planning and management of a watershed require detailed data viz. hydrologic behaviour of watershed, slopt;, rainfall pattern, land capability classification, land use etc., which govern the amount of runoff and soil loss produced by rainfall. Remote sensing and GIS techniques can be used successfully for the integration and analysis of above properties. In the present study remote sensing data are used for land information whereas GIS has been used for the integration of various thematic maps to delineate the areas suitable for adopting soil and water conservation measures. The major soil and water conservation measures proposed in Kalora-II micro-watershed of district Udaipur (Rajasthan) were contour bund, puerto rico terrace, stone wall terrace for arable land and contour trench, staggered trench, v-ditch, silvi-pasture development for non-arable land. A water harvesting structure of capacity 8.32 ha-m was also proposed for supplementary irrigation to rabi crops.

Sustainable development of rainwater harvesting in drought-prone sub-humid region: Determinants and viable options

The present study analyses viable methods of rainwater harvesting in drought-prone Bolangir and examines different bio-physical and socio-economic factors that influence the performance and sustainability of the water harvesting structures (WHSs). The study reveals that the traditional WHSs have proved to be extremely useful not only in normal years but also in water-scarce years. Most of the factors are favourable for development of WHSs in the sub-humid region like Bolangir. Small size WHSs are advantageous over medium and large irrigation projects in Bolangir because of its uneven and hilly topography. So instead of going for big dams those have already consumed a lot of time and resources but not yet completed, efforts should be made to increase the irrigation coverage through WHSs. The government patronage and convincing stakeholders to increase their participation are urgently required for sustainability of micro level water resources.

Predicting RUSLE (Revised Universal Soil Loss Equation) Monthly Erosivity Index from Readily Available Rainfall Data in Mediterranean Area

Seasonal rainerosivity is important in the structure and dynamics of Mediterranean ecosystems. The present paper contributes to the quantitative assessment of RUSLE's monthly erosion index in a data-scarce Mediterranean region. Therefore, a regionalized relationship for estimating monthly erosion index (EI30-month) from only three rainfall parameters has been obtained. Knowledge of the seasonal and annual distribution of erosivity index, permit soil and water conservationists to make improved designs for erosion control, water harvesting or small hydraulic structures. Although a few long data sets were used in the analysis, validation with established monthly erosivity index values from other Italian locations, suggest that the model presented (r2 = 0.973) is robust. It is recommended to monthly erosivity estimates when experimental data-scarce rainfall become available.

Sustainable poverty alleviation through a forestry project in Tamilnadu State of India

The World Development Report 2000–2001 recommends action on three complementary and synergistic fronts for poverty alleviation – promoting opportunity, facilitating empowerment and enhancing security. This paper analyses the Tamilnadu Forestry Project, funded by US$100 million from the Japan Bank for International Cooperation, for community forestry. The project was launched in 1997–1998 in this southern state of India and has evolved into a comprehensive poverty alleviation programme for the forest abutting villages where the proportion of poor people is largest. It endeavours to explain how the project provides the above three elements at the local level for sustainable poverty alleviation. Regeneration of forests, improvement of basic infrastructure through integration of line departments and promotion of alternate livelihoods provide ample economic opportunities. Establishment of Village Forest Councils, and delegation of sufficient powers to these Councils, has empowered the poorest of the poor. Tree assets, promotion of alternate income generation activities and water harvesting structures have provided security by reducing vulnerability to natural vagaries, particularly drought. In this project, the restoration of biodiversity and people development go hand in hand in a synergistic way that makes the project worth replicating elsewhere in the country and other parts of the world, with suitable modifications.

Water harvesting in a ‘runoff-catchment’ agroforestry system in the dry lands of Ethiopia

A major production constraint in arid and semiarid areas of Ethiopia is a lack of water for crop growth. Run off water can be harvested by channeling it into micro- catchments (MC) where it slowly infiltrates into the soil. The increased moisture provides more plant growth in these dry lands. An experiment using MC was conducted in eastern Ethiopia to study the growth of four multipurpose tree species intercropped with grass. Trees and grass were grown in 25 m2 and 100 m2 MC. Plant height, root collar diameter, and mortality rate of trees were determined 12 months after planting. Dry matter yield of grasses and trees were measured and nutrient analysis of plant tissues was determined. In a separate experiment the biomass of trees was determined after 2.5 years of continuous growth without grass competition. Soil moisture, organic matter, texture and bulk density of the soils were also determined. Mean tree height was 10% greater in the 100 m2 than in the 25 m2 MC. Root collar diameter and survival rate showed similar increase with 13% and 7.8% respectively. Acacia saligna and Leucaena leucocephala showed better growth in both plot sizes than the indigenous Acacia seyal and Acacia tortilis. The dry matter yield of grass (Panicum maximum) was over 12 tons/ha and 8 tons/ha in the 100 m2 and 25 m2 plots respectively. Soil moisture content was greater in MC than in control plots with no water harvesting structures with 31% and 24% during the wet and dry seasons respectively. The use of water harvesting can improve fodder production and carrying capacity of the dry lands of Ethiopia.

Economic analysis of water harvesting in a mountainous watershed in India

Water management is an essential feature of any project related with overall development of agriculture. The Soan river catchment in the northwest Himalayas, is fed only by rainwater. Hence, a strategy of rainfed agriculture needs to be developed through water conservation and storage techniques. The Soan is an important river from a soil erosion and water management point of view and detailed economic analysis is needed for any proposal to be implemented in the field. The present study was undertaken to propose an economic analysis of water harvesting structures for the Soan catchment. The purpose of the investigation is to control erosion and conserve water to meet the requirements of supplemental and pre-sowing irrigation for major cereal crops in the area and to maximise agricultural productivity. Benefit/cost ratios ranging from 0.41 to 1.33 are obtained for water harvesting structures of different sizes with estimated life of 25 and 40 years respectively, by taking into account different crop return from maize and wheat.

Planning and Design of Cost-effective Water Harvesting Structures for Efficient Utilization of Scarce Water Resources in Semi-arid Regions of Rajasthan, India

Water-harvesting structures have the potential to increase the productivity of arable lands by enhancing crop yields and by reducingthe risk of crop failure in arid and semi-arid regions, where water shortages are common because of scanty rainfall and its uneven distribution. In semi-arid regions of Rajasthan, India, existing practice of harvesting rainwater is through anicut and earthen embankments. Because of higher costs and higher technical skills involved in the construction of these structures, these structures have not been accepted by the resource-poor local people. Therefore, in the present paper, the detailed design of some low-cost water-harvesting structures using locally available materials and adaptable to the socio-economic conditions of the beneficiaries is discussed. Two types of cost-effective water-harvesting structures, which include dry stone masonry and upstream-wall cement masonry of heights 1, 2, and 2.5 m for catchments of less than 10, 10 to 20, and 20 to 30 ha, respectively are proposed and designed. The analysis of costs involved in constructing dry stone masonry and upstream-wall cement masonry water-harvesting structures, emergency spillway, anicuts and earthen embankments revealed that the earthen embankments have the least cost of construction whereas the anicuts have the highest construction costs for all the selected heights. However, based on the past experiences, earthen embankments are not suitable for the semi-arid regions of Rajasthan. The economic evaluation of the proposed structures indicated that the dry stone masonry structures are very cost-effective for the region with a benefit-cost ratio of 3.5:1 and the net present worth value of Rs. 102978. Although the economic indicators ranked the upstream-wall cement masonry structures lower than the dry stone masonry structures, the former has greater stability and strength compared to the latter. In practice, both the cost-effective water-harvesting structures (i.e., dry stone masonry and upstream-wall cement masonry) are gaining wide acceptance and popularity in the region through some nongovernmental organizations, which have adopted the design presented in this paper.

An Integrated Approach for Impact Assessment of Water Harvesting Techniques in Dry Areas: The Case of Oued Oum Zessar Watershed (Tunisia)

In the arid regions of Tunisia, considerable investments are being made to maintain the old water harvesting techniques and introduce new ones to capture the scarce amount of rainwater (100 mm to 230 mm annually) for agricultural and domestic purposes. However, no detailed assessment of the multiple effects and the costs and benefits of these techniques have been made so far. This paper summarizes the results of an in depth investigation of the multiple impacts (runoff mobilization, ground water recharge, agro-socio-economic impacts) of the water harvesting works undertaken in the watershed of oued Oum Zessar (southeastern Tunisia). The importance of interdisciplinary and integrated approaches was revealed through this detailed impact assessment and economic evaluation. In fact, the profitability of the water harvesting works depends largely on the criteria chosen. However, further refinements are needed to better include all possible impacts (positive and negative) that occur as a result of the installation of the water harvesting structures.

Spatial Expert Support System in Selecting Suitable Sites for Water Harvesting Structures — A Case Study of Song Watershed, Uttaranchal, India

The aim of this paper is to make a user friendly Spatial Expert Support System (SESS) for identifying suitable sites for water harvesting structures such as check dams, farm ponds, and groundwater recharge tanks. The developed system has been used to identify potential sites for water harvesting in the Song watershed, India. Basic input layers required for this study such as a digital elevation model, landuse, soils, drainage, geology, and buffer map for utility points were generated in a geographic information system (GIS). Technical guidelines suggested by the Integrated Mission for Sustainable Development (IMSD), and the Indian National Committee on Hydrology (INCOH), have been used as decision rules in the knowledge base shell of the developed SESS. Monthly water balance has been estimated using remote sensing and GIS techniques to augment the proposed water harvesting structures. The knowledge base can suitably be modified as and when required on the basis of other expert knowledge if found more judicious in this present context.