Category Archives: water management

How (and whether) to Disseminate Climate Forecasts

One topic that I’ve been interested in for a while now, but haven’t yet had the chance to explore in any depth is the way in which we disseminate drought forecasts. In this blog post I’d like to look a little further into how we disseminate, what we disseminate, and whether it makes a difference. The short version is this: we have thought quite a bit about what we provide, but surprisingly little about whether it is effective (cost or otherwise).

Numerous studies have explored the way in which we provide information (see here and edited collections here and here). They have made some real advances in shedding some light on how farmers’ make use of climate forecasts, as well as the estimated impact (i.e. whether farmers changed their responses in the context of a workshop participation).

As it turns out, farmers’ are quite capable of understanding and acting on probabilistic information. For forecasters, this is good news. One question that I would be interested in exploring further is whether the workshops required to train farmers to use forecasts is cost effective. This question relates both to the initial cost, and to the question of information retention. When testing principles in the context of daylong participatory workshops, we are unable to address issues such as usage retention (particularly following forecasts that do not match the eventual seasonal totals).

A related question, raised by a colleague of mine here at IFPRI, is whether we should really be providing the information to individual farmers or if it is more effective to provide the information to regional met agencies. Again, the question is not whether farmers are capable of using the forecasts, but rather whether providing them directly is cost effective in the long run.

The most pressing question, however, is in many ways the most obvious: do climate forecasts improve yields? A rigorous study (read randomized control) of the real-world implications of climate yields is badly needed as a means of addressing whether climate forecasts are effective. Although I understand the desire to provide a high quality product (accurate forecast) in a reliable manner, it is past time that we begin discussing the hard evidence of cost effectiveness.

Much time has been dedicated to studying climate forecasts, but surprisingly little has been invested in understanding what role climate forecasts are likely to play in improving livelihoods. We can’t afford to silo these questions any longer.

Operational Drought Monitoring

To reduce the risk to food security posed by drought, it’s crucial that we develop systems able to disseminate accurate information in a timely manner. Although doing this may seem straightforward in an era of near-ubiquitous satellite measurements and increasingly high-powered computational models, there are challenges relating both to the analysis and dissemination of information in an operational context. I’ll explore the challenges to producing operational drought forecasts and monitors in this post and write about the challenges of disseminating those forecasts in my next post.

Broadly, most operational drought systems may be subdivided into those that monitor current conditions (and perhaps make historical readings available) and those that provide projections for future conditions. Coincidentally, while doing some research for this post I started to compile a list of available hydrological monitors and data portals, which you can find here. I focused on drought, but included a few others as well.

Drought monitoring, despite the availability of near real-time satellite data, faces great challenges of data availability. In fact, methods using satellite measurements currently perform comparably to those using only a handful of gauge stations. Satellite measurements are additionally challenged with a short climatology, and inconsistencies between products. Never-the-less, these products provide unparalleled coverage for regions with sparse in-situ measurements (as is often the case in developing countries), where drought monitoring has a crucial role to play in maintaining adequate levels of food security.

Although it is often described as a “slow onset” phenomenon, the development and evolution of drought can be remarkably difficult to predict. Part of this stems from an incomplete understanding of the oceanic forcings of drought (ENSO), and part of it stems from the inherently chaotic nature of the atmosphere. A chaotic systems sensitive to initial conditions creates an environment in which errors propagate through models and forecasts quickly diverge from one another. Shukla et al., 2013 analyzed the skill of a forecast as it relates to either (1) the initial conditions of the model or (2) the forecast skill, and found that the skill was dependent on both region and time of the year.

One means of improving both the monitoring and the forecasting of drought is to further explore the limitations to current model skill under different climate regimes. While Smith et al., explored times of the year and regions, the underlying factors of substance are the moisture-temperature-atmosphere regimes. It shouldn’t be ignored that during a drought, the region of interest (which may normally be energy-limited) will be abnormally arid (and therefore potentially moisture-limited). This shift may in fact mean that where the initial condition of soil moisture was once not a limiting factor for forecast skill, it may become one during the forecast of drought recovery. In that sense, forecasting the onset as opposed to the recovery of a drought may be two problems with distinct characteristics.

A second aspect of the drought system that warrants further exploration is the dynamics of vegetation during the evolution of multi-seasonal droughts. Previous studies have pointed towards dynamic vegetation as one source of increased interannual variability in precipitation, however, the impact of this dynamic vegetation on evapotranspiration and therefore on the atmospheric boundary layer may also play a significant role in determining how a drought develops. This is particularly true during multi-year droughts when drying of the soil occurs more deeply than during one-season droughts.

Himalayan Countries Launch Study on Climate Change

For the Himalayas, hydrologic variability poses problems that range from migrating plant species to drought to monsoon flooding. Although not all of these are necessarily driven solely by climate change, they will almost certainly be impacted by a changing climate. And while these changes will impact nearly 1/5 of the world’s population, the way in which precipitation and temperature are likely to change in the future is not well known. The complex terrain and steep climatic gradients of the Himalayas make pinpointing probable changes difficult.

The International Center for Integrated Mountain Development (ICIMOD) – a regional intergovernmental organization consisting of Afghanistan, Bangladesh, Bhutan, China, Myanmar, Nepal and Pakistan – recently announced that they are launching a three-year study on the state of the Himalayas. The proposed study is reminiscent of a regional IPCC report in that it aims to address the state of scientific knowledge on the impacts of climate change for the Himalayas, and how the mountain range may be preserved as a resource for future generations.

The announcement comes as a welcome indication of how intergovernmental bodies can provide regionally relevant scientific consultation to policy makers, even as the countries involved continue to focus on developing their resources. As I discussed in my previous post, many of the countries involved (including Bhutan) are already experiencing the impact of climate change on their water resources. The dependence of Himalayan countries on the mountain water storage and runofff puts them in a particularly vulnerable position when it comes to climate change. Any change in glacial water storage or patterns of rainfall impacts not only their water – and therefore agriculture and food security – but also their power generation.

I strongly believe that the development of national and intergovernmental organizations aimed at better understanding regional changes in climate will benefit not only the countries involved, but the wider climate science community. The most immediate impact of such organizations will be the focused scientific attention devoted to a regional issue, but I believe the impact of such science will pale in comparison to the indirect effects. Such efforts are likely to encourage an interest in the sciences from the general population and policy makers, but perhaps more importantly they will provide a national sense of pride in scientific achievement. If making decisions based on climate science becomes a priority, then these nations are likely to invest in developing technical infrastructure and training future scientists, both of which will benefit the community at large in the long run.

Resource Management in Bhutan

A view of Thimphu, Bhutan from above

A view of Thimphu, Bhutan from above

I recently visited Bhutan with a Senior Researcher from the International Food Policy Research Institute (IFPRI) to discuss our current project (a study on the benefit of sustainable land management practices in Bhutan) with policy makers and technical experts. Bhutan as an example of a country grappling with the question of how to develop services for its people while conserving its natural ecosystem. While the Bhutanese have a history of conserving their natural resources – the foremost of which being their many forests – it’s simply not possible for a country to improve the livelihoods of its people without developing its natural resources. As the Secretary of the Ministry of Agriculture and Forests told us during our visit with him, you cannot tell a farmer to preserve the forest if it means his children go hungry.

And so Bhutan is developing. But the country is looking to do so in an informed manner that preserves its natural resources. Bhutan has developed an admirable focus on research-based policy, and it contains more than its share of world-class experts focusing on some flavor of natural resource development. Admittedly, there are economic incentives as well.

The two largest contributors to Bhutan’s GDP – Hydroelectric power generation and tourism – derive from its natural resources. Hydroelectric power exports to India are the largest contributor to Bhutan’s GDP annually, and the country is looking to further supplement its four existing plants with seven planned projects as part of an agreement with India to produce 10,000 MW by 2020. The incentive to predict any degradation in quantity or quality of water flowing into these hydroelectric plants is pretty clear. Sedimentation driven by a changing climate and by clearing of land for infrastructure was a recurring concern in our conversations with technical experts.

Climate change in Bhutan is affecting the quantity of water available by reducing storage in the glaciers to the North and by altering the pattern of rainfall across the country (at least as measured by available satellite and reanalysis data). In fact, while visiting a center for research on renewable natural resources one expert on use of water in agriculture told us that the changing patterns of rainfall have made previously viable, productive lands unreliable for farming.

Meanwhile, anthropogenic changes in Bhutan have primarily affected the land cover and therefore the sediment loading in rivers. Over the last five years, following a political promise by the then majority party, Bhutan has constructed a tremendous number of farm roads. These roads are unpaved and are often improperly constructed in regards to drainage and slope. The Chief Officer of the HydroMet and the head of the Druk Green Power Corporation (responsible for operation of the hydroelectric plants) both described the deleterious effects that erosion from these roads has on river water quality.

The tools required to understand the changing Bhutanese ecosystem are available, but their implementation is not trivial. While the government of Bhutan has invested in a framework of hydrologic models, including VIC coupled to DHSVM and SWAT, conflict between departments and a prolonged calibration process has prevented the models from becoming operational. Many of the professionals we spoke with in Bhutan have an interest in learning how to model their watershed and are technically proficient but lack access to the specific expertise that is required for learning new and often complex hydrologic models.

After only a week meeting with technical professionals and policy makers I’m left with the impression that Bhutan is a country whose policy toward resource development and intellectual potential is one step ahead of its infrastructure. My experience in Bhutan has reminded me of both the promise and the challenge of using hydrologic models and in-depth research as an underpinning for development policy. The process of developing that policy is not as straight forward as interpreting the output from a series of models.

Water Markets and Resource Monitoring

CERES

 

Recently Jay Famiglietti wrote and article for the Huffpost on what he dubs the “Blue Economy” and the role of modern business in that economy. For me this immediately calls to mind two ongoing debates in the world of water resource management: hydraulic fracturing and drought. I agree with Dr. Famiglietti on the scale of the problem, the immediacy and that there needs to be a more active part played by private industry. But I believe the water-as-a-commodity approach is not by definition a road to success.

Developing national markets for water would undoubtedly catalyze investment and valuation of water, but doing so is not equivalent to encouraging conservation. T Boone Pickens’ excursion into privatizing and marketing groundwater resources in Texas is a superb example of the legal tanglewood and resource-management myopia that could characterize a private water market if we are not careful. After all, private industry already holds sizeable influence over water resource development – think back to irrigation development in the era of big dams. And while the private industry should absolutely play a larger part in water resource development, there need to be checks established. Not necessarily regulation, but at the very least sufficient informationa cause Dr. Famiglietti has often championed.

Hydraulic fracturing and the ongoing drought gripping much of the Western United States could be the poster child for the difficulty of establishing an industrial valuation on a resource that is unequivocally essential to everyday life. While the blending of water-as-a-right and water-as-a-commodity is undeniably a tricky business, the issue often fails to develop to that stage. Uncertainty inevitably complicates the matter. Uncertainty about future water demand, about how long a drought will last and about the stability of an underground aquifer used for hydraulic fracturing waste water disposal. Any serious move on a nonrenewable water resource (i.e. groundwater) needs to approach each of these questions from the perspective of long-term risk analysis. Without enough information, this is virtually impossible.

So am I outright opposed to the idea of hydraulic fracturing? No. But I am opposed to the idea of risking irreversible damage to our nonrenewable water resources because an industry wants to guard its trade secrets. (Note that companies are guarding their fracking fluid formulas from the EPA, not simply from competitors). When it comes to water resources we don’t have a lot of wiggle room. If we botch what we have, we’re going to pay for it in droves down the line.

Any new developments in the water-as-a-resource field need to be matched by advances in technologies used to characterize and monitor that resource.

 

 

 

A few more interesting articles that I couldn’t help but share:

http://newswatch.nationalgeographic.com/2013/06/27/water-issues-ripple-through-obama-climate-change-speech/

http://www.huffingtonpost.com/peter-h-gleick/the-real-story-behind-the_1_b_1719554.html

http://thinkprogress.org/climate/2013/07/14/2291931/shale-shocked-sharp-rise-us-earthquakes-linked-to-fracking-wastewater-reinjection/?mobile=nc

 

On Irrigation, Groundwater and Drought

Recently groundwater has been getting a lot of attention. Particularly, scientists have focused on characterizing our groundwater use over the last few decades, and producing estimates of future water availability. Many aquifers are being depleted at alarming rates, some projected to become depleted as early as the end of the century (Jay Famiglietti has done a lot of good work on this topic, see his articles in Nat Geo here). If we continue along the path we are currently on, the question is not if we will deplete our groundwater resources, but when.

Given this reality, it seems appropriate that we begin to model management scenarios in which groundwater plays either a substantially reduced role, or no role at all in providing water for irrigation. That is no small task when you consider that in the U.S. groundwater provides 61% of total water used for irrigation (Siebert et al., 2010). These scenarios may involve switching to more efficient irrigation technology (drip irrigation as opposed to our current water-intensive practices) or reducing the irrigated area altogether.

Irrigation has a substantial impact on regional climate, and the implications of altering our current irrigation practices need to be studied further. It has been well documented that irrigation provides a regional cooling effect, a property that alleviates heat-stress in crops during droughts and heat waves (see van der Velde, 2010). Less well understood is whether switching to drip irrigation will increase water efficiency at the expense of this regional cooling effect. It is worth exploring whether during heat waves plants are in greater need of the cooling effect or the water provided by irrigation.

An alternative management scenario – allowing portions of fields to lay fallow due to insufficient water for irrigation – may have a time-dependent component, particularly when considering the time required for transitional vegetation to take root. If multi-year droughts lead farmers to leave large percentages of their fields fallow all-at-once, the vegetative landscape is likely to look very different than if the transition is gradual. Vegetation cover has an effect on atmospheric dust loading (think dust bowl) and on the latency with which the landscape reacts to drought (see work by Ning Zeng on this subject).

So, back to the point: how do we dynamically incorporate potential management decisions into climate projections? We need to conduct analyses that provide an envelope of uncertainty around management decisions, and a few scenario analyses in which different management options are explored in detail. Part of understanding the future of the hydroclimate is understanding how we are playing a dynamic role in that system and to what degree our actions will impact our hydrologic future.

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On Irrigation and the Hydroclimate

The interface between climate modeling and water resource management has long interested me and has recently returned to the news (well, at least the science-related news) in the form of irrigation-induced precipitation. In a recent paper, Min-Hui Lo and Jay Famiglietti demonstrated that irrigation in the central valley of California may have significant second order impacts in the form of increased precipitation over the Colorado River basin. The described hydrologic feedback loop is entirely anthropogenic in that the same water originating in irrigation induced precipitation (along with much more water) is diverted from the Colorado River to Southern California (although not directly to the central valley).

(Lo and Famiglietti, 2012)

(Lo and Famiglietti, 2012)

This sort of anthropogenic, hydrologic loop may not be unique. Quite simply, it has been difficult to model such processes using existing models due to the lack of irrigation scheme in large-scale models.

Despite the number of studies investigating the impacts of irrigation on climate, irrigation is still often missing from major land surface models (LSMs). Researchers have circumvented this difficulty by manually adding irrigation to model soil moisture in a number of ways – prescribing current rates of irrigation to continue into the future, assuming saturation at all times, taking a threshold approach – and while these solutions begin to address the problem, they are still unable to capture potential nonlinearities or anthropogenic feedback cycles.

Identification of the equilibrium feedback loops (“equilibrium” being used somewhat loosely) is only the beginning of understanding how large-scale irrigation affects the hydroclimate. In fact, humans play a dynamic role in the hydroclimate that will vary both with climatic and economic changes. We provide a forcing the climate system in the form of application of soil moisture, depletion of ground water, depletion of surface water, creation of reservoirs and (as a result) land cover changes. These various components have often been investigated as independent phenomena, but in reality they are not only correlated but causal. As temperatures rise and potential evapotranspiration increases, reservoirs may become habitually depleted, surface water will become less available, ground water withdraws will become greater and, if crops cannot be sufficiently irrigated due to cost or water availability, land cover will significantly change leading to a number of feedback cycles.

As climate models become increasingly nuanced, one area that deserves adequate attention is the irrigation schemes of LSMs as they may apply both to the hydrologic cycle and to the land cover scheme in the LSM. Irrigation is particularly relevant not only because it has had demonstrated effects on regional climate, but it is an entirely anthropogenic climate forcing. The expansive nature of irrigation, which enables it to act as a sizeable climate forcing, is unlikely to change in the near future. However, the way in which irrigation is practiced may change.

There seems also to be value in reminding ourselves that we have affected our environment in such fundamental, tangible ways. While the idea that water management is a means of providing resources to a population in a hostile environment is a position oft held, I believe it is founded on a false dichotomy. Drawing the distinction between “natural” and “anthropogenic” forces acting on the hydrologic cycle is no doubt a useful one, but the tendency to treat these actors as having distinct spheres of influence to be studied in isolation is detrimental to the advancement of water management. Understanding how our constructed hydrologic environment interfaces with the natural hydroclimate is crucial to developing better informed water management policies. Climate scientists, engineers and risk managers need to continue making a concerted effort to collaborate at local, state and federal levels.