Productivity analysis of the Río Bravo irrigation districts using performance indicators

Análisis productivo de los distritos de riego del Río Bravo usando indicadores de desempeño

In Mexico, irrigation districts (IDs), consisting of a delimited irrigation area, are irrigation projects established by the Federal Government through presidential decrees, since 1926, the year in which the Comisión Nacional de Irrigación was founded. IDs were created to promote national agricultural production and to ensure commercial production in times of limited or scarce rainfall.

IDs have been managed, operated and maintained by the Federal Government since creation. At the beginning of 1992, the centralized federal administration, through the Comisión Nacional del Agua (CONAGUA), transferred the administration of minor distribution network and the users irrigation service through Water Users Associations (ACUs, for its acronym in Spanish), and issued the water concession rights, as well as the use of hydraulic infrastructure works. Currently, the organization of an ID is mixed, because it involves the CONAGUA, the ACUs and a Federation of ACUs known as Limited Responsibility Society (S. de R. L., for its acronym in Spanish). The ACUs are responsible for the operation, conservation, and management of the infrastructure under concession to provide the irrigation service to the users. The water delivery responsibility from the source to the farm intake are as follow: from the CONAGUA to the S. de R. L., from the S. de R. L to the ACUs and from the ACUs to the users (Palacios-Vélez, 2000).

Irrigated agriculture requires various techniques for the farm irrigation application once water service is delivered to the ID users. This type of agriculture demands large capital investments and frequent maintenance of hydraulic infrastructure: dams, canals, and conduction, distribution and protection structures (CONAGUA, 1994).

The analysis of performance indicators for irrigation areas requires statistical tools. Infante-Gil and Zárate-de Lara (2012) show elements of descriptive statistics and statistical inference that can be used to generate and analyze performance indicators. The productivity of an irrigated area may indirectly indicate the capacity of the irrigation infrastructure to generate the planned products and the level at which the available resources or inputs are used. The better the productivity, the higher the profitability of the ID. In this way, optimal resource management seeks to ensure that every organization manages to improve productivity with the available infrastructure and resources.

The analysis of performance indicators through benchmarking applied to irrigation areas has been documented by Burt and Styles (2004) and Malano, Burton, and Makin (2004). This technique has been used to compare the water management performance of ACUs in various countries around the world (Alexander & Potter, 2004; Cakmak, Beyribey, Yildirim, & Kodal, 2004; Ruiz-Carmona, Ojeda-Bustamante, & Contijoch, 2006). Altamirano-Aguilar et al. (2017) classified and evaluated Mexico's IDs based on performance indicators, for which they grouped IDs into clusters by climate group. In this study they classified the IDs located in the Río Bravo basin, which are contemplated in the dry group in the "Water Treaty" of 1944 between Mexico and the United States of America (Mexico-USA). In the case of Bajo Río Bravo ID 025 and Bajo Río San Juan ID 026, which are located in the Bajo Bravo sub-region, Altamirano-Aguilar et al. (2017) mentioned that they belong to another climate group and, in general, the irrigation performance of all the conglomerates was reported as low.

Olmedo-Vázquez, Camacho-Poyato, Rodríguez-Díaz, Minjares-Lugo, and Hernández-Hernández (2017) analyzed irrigation water use management in ACUs of ID 041, Río Yaqui, Mexico, based on eleven yield indicators and eight productivity efficiency indicators. These authors reported that most of the ACUs were inefficient (66%) in the four agricultural years analyzed, from 2010 to 2014.

According to the dictionary of the Royal Spanish Academy (RAE in Spanish), productivity is a concept that describes the capacity or level of production per unit of input. In economics, productivity is understood as the link between what has been produced and the means used to achieve it (labor, materials, energy, among others), and is usually associated with efficiency and time: the less time invested in achieving the expected result, the greater the production character or performance of the system (Blanchard, 2017).

Since water is a scarce resource, water use efficiency is a concept of productivity at the biological level to describe the amount of biomass accumulated (yield) as a function of the volume of water supplied (Bos, Burton, & Molden, 2005). If this term is applied to irrigated agriculture, it can be expressed in terms of yield (kg·m^-3) or in economic terms regarding the unit of volume of water applied ($·m^-3).

The overall conduction efficiency of an ID (m³·m^-3) is given by the total volume of water delivered (m³) to users at farm intake level among the total volume of water withdrawn (m³) from supply sources (surface + groundwater). Intrinsically included in this relationship of volumes is the method of water distribution, infrastructure and regulation systems (Íñiguez-Covarrubias, de León-Mojarro, Prado-Hernández, & Rendón-Pimentel, 2007). On the other hand, the total volume of water extracted from the source of supply by irrigated area (m³·ha^-1) integrates the crop water needs, farm efficiency and global conduction efficiency, being an important parameter in the water resources management of an ID.

The Secretaría de Recursos Hidráulicos (SRH, 1973), in the recommendations of the “Project Manual of Irrigation Areas”, defined the global efficiency of an ID (E_dist) as the product of conduction efficiency (E_cond) and farm efficiency (E_parc), for which a conduction efficiency is determined according to the type of canal lining: soil (E_cond=0.7), masonry (E_cond=0.75) or concrete (E_cond=0.85). On the other hand, the term productivity is related to yield, since it requires good management of resources in order to achieve results that make the work carried out within the association efficient, both in the provision of the service and in the methods used and the internal relationship of the organization.

The concepts and variables associated with the main indicators for evaluating the management, planning, operation and conservation behavior of large irrigation areas are found in the study of Bos et al. (2005) By conducting an analysis of production indicators, it is possible to lay the groundwork for subsequent studies, this in order to update the indicators so that they can quantify changes in the performance of IDs in response to policies, programs, climate patterns or management of an irrigation area. In this sense, the objective of this study is to quantify and analyze the behavior of productive performance indicators of 11 IDs located in the Río Bravo basin, México.

Figure 1 shows the study region, which is the production area of the IDs located in the transboundary Río Bravo basin, Mexico, bordering the USA.

Figure 1
Location of the irrigation districts (IDs) in the Río Bravo basin, to the north of Mexico.

Table 1 shows the general data of the IDs studied. This information was extracted from the agricultural and hydrometric statistics compiled and published annually by CONAGUA (2017a). The supply main source is surface water; only IDs 005 and 009 report extractions from groundwater sources.

Table 1
General data of the agricultural year 2015-2016 of 11 irrigation districts in the Río Bravo basin, Mexico.

S_f = physical irrigable area (ha); S_r = irrigated area (ha); V_bs = gross distributed volume of surface water (hm³); V_bss = gross distributed volume of groundwater (hm³); V_b = sum of the gross distributed volumes (hm³) at the supply source level (V_b = V_bs + V_bss).

The estimation of IDs performance was obtained using the seven indicators shown in Table 2. Those performance indicators reported by Bos et al. (2005) that can be estimated with data available from official sources were chosen to evaluate IDs.

Table 2
Estimated production performance indicators for the irrigation districts (IDs) studied.

VP = economic value of total agricultural production of the IDs at current prices ($); Prod = total production (t); S_r = irrigated area (ha); V_b = sum of gross volumes extracted at source level (m³); V_n = net volume of water delivered to users at farm intake level (m³).

The rural average price (RAP) refers to the price paid to the producer for the first-hand sale of his farm, land or production area, and does not include the economic incentive granted by the federal and state government, nor the costs of transportation and sorting when the farmer brings his product to the sales center. In other words, RAP is the current price at the time the producer makes the first sale at the plot or farm.

To estimate the indicators, agricultural and hydrometric data were obtained for 15 years (2001-2002 to 2015-2016), from the agricultural statistics of the IDs reported by the CONAGUA for V_b, S_r, V_n, VP and Prod, and the financial statements of the IDs from 2012 to 2014 were used (CONAGUA, 2017b). Geospatial information on soil degradation was accessed by superimposing ID and degradation maps. This was carried out with the help of the ArcGIS v10.3 program and the data available in the Sistema Nacional de Información del Agua (SINA) of CONAGUA (2017c).

For the presentation of results, "Box-Plot", also known as box-bigot diagrams were made, used to visualize the distribution of a set of data: minimum and maximum values, quartiles (Q1, Q2 or median and Q3), existence of outliers and symmetry of the distribution. To do this, it is necessary to find the median and then the two remaining quartiles. The characteristics of this type of graph are:

1. - The symbol * is the average of the data.

2. - The horizontal line across the box is the median (Q2).

3. - The lower side of the rectangle represents the first quartile (Q1, median of the lower half of the data or 25 % of the data), and the upper side represents the third quartile (Q3, median of the upper half of the data or 75 % of the data). Therefore, the height of the box represents the interquartile range (the difference between Q3 and Q1).

4. - Vertical lines (whiskers or axes) protruding from the box extend to the minimum and maximum of the data set, as long as these values do not differ from the average by more than 1.5 times the interquartile range. The ends of the whiskers are marked by two short horizontal lines.

5. - The values, indicated by +, below and above the whiskers, lower and upper, are considered outliers.

Graphs showing the variation of the indicators in each ID studied were created. The districts were separated into two large groups, and in order to identify them in the graphs, a symbol was assigned to each ID according to Table 3.

Table 3
Symbology used for the irrigation districts (IDs) of the Río Bravo basin, Mexico.

The most common indicators for evaluating the performance of an ID in Mexico are yield and global conduction efficiency. However, as the results indicate, no single performance indicator can be used, but several complementary indicators are required to characterize IDs, integrally. Inter-district comparison of indicator values is complicated due to district variation in cropping cycles and patterns, resulting in an overestimation of the production of perennial forage and horticultural crops over grains.

The values of conduction efficiency of hydraulic infrastructure of IDs are below those contemplated in the original design of IDs. This indicates a degradation of the irrigation infrastructure, possibly due to limited conservation or operation of the IDs studied.

The productive performance of IDs is low due to a series of structural and non-structural factors that limit development at the irrigation area level. Some of the factors are low efficiency of conduction network (from the supply source to the farm), high inter-annual variability of available volumes at the source level, low irrigation fee, low technological level and increase in production costs, among others.

It is recommended to carry out the performance analysis per irrigation module and, to be not only productive, but also operational and administrative. This is the responsibility of the ACUs, because they are responsible for delivering the irrigation service to the users and for conserving the hydro-agricultural infrastructure under concession.

To dispose of unused water, one way is to improve planning, distribution and conservation of the distribution network. In addition, it is necessary to conduct a more detailed analysis of the irrigation service offered by the ACUs based on performance indicators at the ACU level, and not integrally as shown in this study.

The indicators used and results obtained can be used to evaluate the production behavior of IDs, as well as to analyze the investment policies to improve the hydro-agricultural infrastructure (both of the distribution network and of the farm technification), and agricultural policies of subsidies through guarantee prices and support to the agricultural areas under irrigation. This should be reflected in a change in performance indicators, since the value of irrigation water should be maximized for the benefit of producers and society.